Commit Graph

423 Commits

Author SHA1 Message Date
Andrew Kryczka
aa2b3bf675 Added TraceOptions::preserve_write_order (#9334)
Summary:
This option causes trace records to be written in the serialized write thread. That way, the write records in the trace must follow the same order as writes that are logged to WAL and writes that are applied to the DB.

By default I left it disabled to match existing behavior. I enabled it in `db_stress`, though, as that use case requires order of write records in trace matches the order in WAL.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9334

Test Plan:
- See if below unsynced data loss crash test can run  for 24h straight. It used to crash after a few hours when reaching an unlucky trace ordering.

```
DEBUG_LEVEL=0 TEST_TMPDIR=/dev/shm /usr/local/bin/python3 -u tools/db_crashtest.py blackbox --interval=10 --max_key=100000 --write_buffer_size=524288 --target_file_size_base=524288 --max_bytes_for_level_base=2097152 --value_size_mult=33 --sync_fault_injection=1 --test_batches_snapshots=0 --duration=86400
```

Reviewed By: zhichao-cao

Differential Revision: D33301990

Pulled By: ajkr

fbshipit-source-id: 82d97559727adb4462a7af69758449c8725b22d3
2021-12-28 15:04:26 -08:00
slk
2e5f764294 Make IncreaseFullHistoryTsLow to a public API (#9221)
Summary:
As (https://github.com/facebook/rocksdb/issues/9210) discussed, the **full_history_ts_low** is a member of CompactRangeOptions currently, which means a CF's fullHistoryTsLow is advanced only when users submit a CompactRange request.
However, users may want to advance the fllHistoryTsLow without an immediate compact.
This merge make IncreaseFullHistoryTsLow to a public API so users can advance each CF's fullHistoryTsLow seperately.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9221

Reviewed By: akankshamahajan15

Differential Revision: D33201106

Pulled By: riversand963

fbshipit-source-id: 9cb1d013ba93260f72e16353e693ffee167b47ee
2021-12-23 11:03:51 -08:00
Andrew Kryczka
538d2365e9 Fix race condition in BackupEngineTest.ChangeManifestDuringBackupCreation (#9327)
Summary:
The failure looked like this:

```
utilities/backupable/backupable_db_test.cc:3161: Failure
Value of: db_chroot_env_->FileExists(prev_manifest_path).IsNotFound()
  Actual: false
Expected: true
```

The failure could be coerced consistently with the following patch:

```
 diff --git a/db/db_impl/db_impl_compaction_flush.cc b/db/db_impl/db_impl_compaction_flush.cc
index 80410f671..637636791 100644
 --- a/db/db_impl/db_impl_compaction_flush.cc
+++ b/db/db_impl/db_impl_compaction_flush.cc
@@ -2772,6 +2772,8 @@ void DBImpl::BackgroundCallFlush(Env::Priority thread_pri) {
     if (job_context.HaveSomethingToClean() ||
         job_context.HaveSomethingToDelete() || !log_buffer.IsEmpty()) {
       mutex_.Unlock();
+      bg_cv_.SignalAll();
+      sleep(1);
       TEST_SYNC_POINT("DBImpl::BackgroundCallFlush:FilesFound");
       // Have to flush the info logs before bg_flush_scheduled_--
       // because if bg_flush_scheduled_ becomes 0 and the lock is
```

The cause was a familiar problem, which is manual flush/compaction may
return before files they obsoleted are removed. The solution is just to
wait for "scheduled" work to complete, which includes all phases
including cleanup.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9327

Test Plan:
after this PR, even the above patch to coerce the bug cannot
cause the test to fail.

Reviewed By: riversand963

Differential Revision: D33252208

Pulled By: ajkr

fbshipit-source-id: 720a7eaca58c7247d221911fffe3d5e1dbf581e9
2021-12-22 21:59:53 -08:00
mrambacher
423538a816 Make MemoryAllocator into a Customizable class (#8980)
Summary:
- Make MemoryAllocator and its implementations into a Customizable class.
- Added a "DefaultMemoryAllocator" which uses new and delete
- Added a "CountedMemoryAllocator" that counts the number of allocs and free
- Updated the existing tests to use these new allocators
- Changed the memkind allocator test into a generic test that can test the various allocators.
- Added tests for creating all of the allocators
- Added tests to verify/create the JemallocNodumpAllocator using its options.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8980

Reviewed By: zhichao-cao

Differential Revision: D32990403

Pulled By: mrambacher

fbshipit-source-id: 6fdfe8218c10dd8dfef34344a08201be1fa95c76
2021-12-17 04:20:47 -08:00
Peter Dillinger
0050a73a4f New stable, fixed-length cache keys (#9126)
Summary:
This change standardizes on a new 16-byte cache key format for
block cache (incl compressed and secondary) and persistent cache (but
not table cache and row cache).

The goal is a really fast cache key with practically ideal stability and
uniqueness properties without external dependencies (e.g. from FileSystem).
A fixed key size of 16 bytes should enable future optimizations to the
concurrent hash table for block cache, which is a heavy CPU user /
bottleneck, but there appears to be measurable performance improvement
even with no changes to LRUCache.

This change replaces a lot of disjointed and ugly code handling cache
keys with calls to a simple, clean new internal API (cache_key.h).
(Preserving the old cache key logic under an option would be very ugly
and likely negate the performance gain of the new approach. Complete
replacement carries some inherent risk, but I think that's acceptable
with sufficient analysis and testing.)

The scheme for encoding new cache keys is complicated but explained
in cache_key.cc.

Also: EndianSwapValue is moved to math.h to be next to other bit
operations. (Explains some new include "math.h".) ReverseBits operation
added and unit tests added to hash_test for both.

Fixes https://github.com/facebook/rocksdb/issues/7405 (presuming a root cause)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9126

Test Plan:
### Basic correctness
Several tests needed updates to work with the new functionality, mostly
because we are no longer relying on filesystem for stable cache keys
so table builders & readers need more context info to agree on cache
keys. This functionality is so core, a huge number of existing tests
exercise the cache key functionality.

### Performance
Create db with
`TEST_TMPDIR=/dev/shm ./db_bench -bloom_bits=10 -benchmarks=fillrandom -num=3000000 -partition_index_and_filters`
And test performance with
`TEST_TMPDIR=/dev/shm ./db_bench -readonly -use_existing_db -bloom_bits=10 -benchmarks=readrandom -num=3000000 -duration=30 -cache_index_and_filter_blocks -cache_size=250000 -threads=4`
using DEBUG_LEVEL=0 and simultaneous before & after runs.
Before ops/sec, avg over 100 runs: 121924
After ops/sec, avg over 100 runs: 125385 (+2.8%)

### Collision probability
I have built a tool, ./cache_bench -stress_cache_key to broadly simulate host-wide cache activity
over many months, by making some pessimistic simplifying assumptions:
* Every generated file has a cache entry for every byte offset in the file (contiguous range of cache keys)
* All of every file is cached for its entire lifetime

We use a simple table with skewed address assignment and replacement on address collision
to simulate files coming & going, with quite a variance (super-Poisson) in ages. Some output
with `./cache_bench -stress_cache_key -sck_keep_bits=40`:

```
Total cache or DBs size: 32TiB  Writing 925.926 MiB/s or 76.2939TiB/day
Multiply by 9.22337e+18 to correct for simulation losses (but still assume whole file cached)
```

These come from default settings of 2.5M files per day of 32 MB each, and
`-sck_keep_bits=40` means that to represent a single file, we are only keeping 40 bits of
the 128-bit cache key.  With file size of 2\*\*25 contiguous keys (pessimistic), our simulation
is about 2\*\*(128-40-25) or about 9 billion billion times more prone to collision than reality.

More default assumptions, relatively pessimistic:
* 100 DBs in same process (doesn't matter much)
* Re-open DB in same process (new session ID related to old session ID) on average
every 100 files generated
* Restart process (all new session IDs unrelated to old) 24 times per day

After enough data, we get a result at the end:

```
(keep 40 bits)  17 collisions after 2 x 90 days, est 10.5882 days between (9.76592e+19 corrected)
```

If we believe the (pessimistic) simulation and the mathematical generalization, we would need to run a billion machines all for 97 billion days to expect a cache key collision. To help verify that our generalization ("corrected") is robust, we can make our simulation more precise with `-sck_keep_bits=41` and `42`, which takes more running time to get enough data:

```
(keep 41 bits)  16 collisions after 4 x 90 days, est 22.5 days between (1.03763e+20 corrected)
(keep 42 bits)  19 collisions after 10 x 90 days, est 47.3684 days between (1.09224e+20 corrected)
```

The generalized prediction still holds. With the `-sck_randomize` option, we can see that we are beating "random" cache keys (except offsets still non-randomized) by a modest amount (roughly 20x less collision prone than random), which should make us reasonably comfortable even in "degenerate" cases:

```
197 collisions after 1 x 90 days, est 0.456853 days between (4.21372e+18 corrected)
```

I've run other tests to validate other conditions behave as expected, never behaving "worse than random" unless we start chopping off structured data.

Reviewed By: zhichao-cao

Differential Revision: D33171746

Pulled By: pdillinger

fbshipit-source-id: f16a57e369ed37be5e7e33525ace848d0537c88f
2021-12-16 17:15:13 -08:00
Yanqin Jin
bd513fd075 Add commit marker with timestamp (#9266)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9266

This diff adds a new tag `CommitWithTimestamp`. Currently, there is no API to trigger writing
this tag to WAL, thus it is unavailable to users.
This is an ongoing effort to add user-defined timestamp support to write-committed transactions.
This diff also indicates all column families that may potentially participate in the same
transaction must either disable timestamp or have the same timestamp format, since
`CommitWithTimestamp` tag is followed by a single byte-array denoting the commit
timestamp of the transaction. We will enforce this checking in a future diff. We keep this
diff small.

Reviewed By: ltamasi

Differential Revision: D31721350

fbshipit-source-id: e1450811443647feb6ca01adec4c8aaae270ffc6
2021-12-10 11:05:35 -08:00
Si Ke
79f4a04ee3 Get DBTest passing Assert Status Checked (#7737)
Summary:
Closes https://github.com/facebook/rocksdb/pull/7737

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9231

Reviewed By: hx235

Differential Revision: D32978332

Pulled By: pdillinger

fbshipit-source-id: b28900b685d60c668529a90dbaa8e1b357b28f76
2021-12-09 11:00:17 -08:00
sdong
88875df821 File temperature information should be preserved when restart the DB (#9242)
Summary:
Fix a bug that causes file temperature not preserved after DB is restarted, or options.max_manifest_file_size is hit.
Also, pass temperature information to NewRandomAccessFile() to allow users to hack a solution where they don't preserve tiering information.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9242

Test Plan: Add a unit test that would fail without the fix.

Reviewed By: jay-zhuang

Differential Revision: D32818150

fbshipit-source-id: 36aa3f148c60107f7b8e9d65b63b039f9e1a1eec
2021-12-03 14:43:14 -08:00
lgqss
77c7085594 MemTableList::TrimHistory now use allocated bytes (#9020)
Summary:
Fix a bug when both max_write_buffer_size_to_maintain and max_write_buffer_number_to_maintain are 0.
The bug was introduced in 6.5.0 and  https://github.com/facebook/rocksdb/issues/5022.
Fix https://github.com/facebook/rocksdb/issues/8371

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9020

Reviewed By: pdillinger

Differential Revision: D32767084

Pulled By: ajkr

fbshipit-source-id: c401ee6e2557230e892d0fe8abb4966cbd18e85f
2021-12-02 11:45:39 -08:00
Peter Dillinger
2a67d475f1 Fix bug affecting GetSortedWalFiles, Backups, Checkpoint (#9208)
Summary:
Saw error like this:
`Backup failed -- IO error: No such file or directory: While opening a
file for sequentially reading:
/dev/shm/rocksdb/rocksdb_crashtest_blackbox/004426.log: No such file or
directory`

Unfortunately, GetSortedWalFiles (used by Backups, Checkpoint, etc.)
relies on no file deletions happening while its operating, which
means not only disabling (more) deletions, but ensuring any pending
deletions are completed. Two fixes related to this:

* There was a gap in several places between decrementing
pending_purge_obsolete_files_ and incrementing bg_purge_scheduled_ where
the db mutex would be released and GetSortedWalFiles (and others) could
get false information that no deletions are pending.

* The fix to https://github.com/facebook/rocksdb/issues/8591 (disabling deletions in GetSortedWalFiles) seems
incomplete because it doesn't prevent pending deletions from occuring
during the operation (if deletions not already disabled, the case that
was to be fixed by the change).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9208

Test Plan:
existing tests (it's hard to write a test for interleavings
that are now excluded - this is what stress test is for)

Reviewed By: ajkr

Differential Revision: D32630675

Pulled By: pdillinger

fbshipit-source-id: a121e3da648de130cd24d44c524232f4eb22f178
2021-11-24 14:52:00 -08:00
Jay Zhuang
6cde8d2190 Deprecating iter_start_seqnum and preserve_deletes (#9091)
Summary:
`ReadOptions::iter_start_seqnum` and `DBOptions::preserve_deletes` are
deprecated, please try using user defined timestamp feature instead.
The feature is used to support differential snapshots, but not well
maintained (https://github.com/facebook/rocksdb/issues/6837, https://github.com/facebook/rocksdb/issues/8472) and the interface is not user friendly which
returns an internal key from the iterator. The user defined timestamp
feature is a more flexible feature to support similar usecase, please
switch to that if you have such usecase.
The deprecated feature will be removed in a future release.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9091

Test Plan:
check LOG

Fix https://github.com/facebook/rocksdb/issues/9090

Reviewed By: ajkr

Differential Revision: D32071750

Pulled By: jay-zhuang

fbshipit-source-id: b882c4668dd1bf26ce03c4c192f1bba584bf6104
2021-11-19 16:55:45 -08:00
Yanqin Jin
1e8322c0f5 Fix a bug in FlushJob picking more memtables beyond synced WALs (#9142)
Summary:
After RocksDB 6.19 and before this PR, RocksDB FlushJob may pick more memtables to flush beyond synced WALs.
This can be problematic if there are multiple column families, since it can prematurely advance the flushed column
family's log_number. Should subsequent attempts fail to sync the latest WALs and the database goes
through a recovery, it may detect corrupted WAL number below the flushed column family's log number
and complain about column family inconsistency.
To fix, we record the maximum memtable ID of the column family being flushed. Then we call SyncClosedLogs()
so that all closed WALs at the time when memtable ID is recorded will be synced.
I also disabled a unit test temporarily due to reasons described in https://github.com/facebook/rocksdb/issues/9151

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9142

Test Plan: make check

Reviewed By: ajkr

Differential Revision: D32299956

Pulled By: riversand963

fbshipit-source-id: 0da75888177d91905cf8c9d00605b73afb5970a7
2021-11-19 09:56:00 -08:00
Andrew Kryczka
8cf4294e25 Adhere to per-DB concurrency limit when bottom-pri compactions exist (#9179)
Summary:
- Fixed bug where bottom-pri manual compactions were counting towards `bg_compaction_scheduled_` instead of `bg_bottom_compaction_scheduled_`. It seems to have no negative effect.
- Fixed bug where automatic compaction scheduling did not consider `bg_bottom_compaction_scheduled_`. Now automatic compactions cannot be scheduled that exceed the per-DB compaction concurrency limit (`max_compactions`) when some existing compactions are bottommost.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9179

Test Plan: new unit test for manual/automatic. Also verified the existing automatic/automatic test ("ConcurrentBottomPriLowPriCompactions") hanged until changing it to explicitly enable concurrency.

Reviewed By: riversand963

Differential Revision: D32488048

Pulled By: ajkr

fbshipit-source-id: 20c4c0693678e81e43f85ed3cc3402fcf26e3310
2021-11-18 17:31:50 -08:00
Yanqin Jin
2035798834 Update TransactionUtil::CheckKeyForConflict to also use timestamps (#9162)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9162

Existing TransactionUtil::CheckKeyForConflict() performs only seq-based
conflict checking. If user-defined timestamp is enabled, it should perform
conflict checking based on timestamps too.

Update TransactionUtil::CheckKey-related methods to verify the timestamp of the
latest version of a key is smaller than the read timestamp. Note that
CheckKeysForConflict() is not updated since it's used only by optimistic
transaction, and we do not plan to update it in this upcoming batch of diffs.

Existing GetLatestSequenceForKey() returns the sequence of the latest
version of a specific user key. Since we support user-defined timestamp, we
need to update this method to also return the timestamp (if enabled) of the
latest version of the key. This will be needed for snapshot validation.

Reviewed By: ltamasi

Differential Revision: D31567960

fbshipit-source-id: 2e4a14aed267435a9aa91bc632d2411c01946d44
2021-11-15 12:52:18 -08:00
slk
937fbcbddc Track per-SST user-defined timestamp information in MANIFEST (#9092)
Summary:
Track per-SST user-defined timestamp information in MANIFEST https://github.com/facebook/rocksdb/issues/8957

Rockdb has supported user-defined timestamp feature. Application can specify a timestamp
when writing each k-v pair. When data flush from memory to disk file called SST files, file
creation activity will commit to MANIFEST. This commit is for tracking timestamp info in the
MANIFEST for each file. The changes involved are as follows:
1) Track max/min timestamp in FileMetaData, and fix invoved codes.
2) Add NewFileCustomTag::kMinTimestamp and NewFileCustomTag::kMinTimestamp in
    NewFileCustomTag ( in the kNewFile4 part ), and support invoved codes such as
    VersionEdit Encode and Decode etc.
3) Add unit test code for VersionEdit EncodeDecodeNewFile4, and fix invoved test codes.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9092

Reviewed By: ajkr, akankshamahajan15

Differential Revision: D32252323

Pulled By: riversand963

fbshipit-source-id: d2642898d6e3ad1fef0eb866b98045408bd4e162
2021-11-10 10:49:04 -08:00
Jay Zhuang
29102641dd Skip directory fsync for filesystem btrfs (#8903)
Summary:
Directory fsync might be expensive on btrfs and it may not be needed.
Here are 4 directory fsync cases:
1. creating a new file: dir-fsync is not needed on btrfs, as long as the
   new file itself is synced.
2. renaming a file: dir-fsync is not needed if the renamed file is
   synced. So an API `FsyncAfterFileRename(filename, ...)` is provided
   to sync the file on btrfs. By default, it just calls dir-fsync.
3. deleting files: dir-fsync is forced by set
   `IOOptions.force_dir_fsync = true`
4. renaming multiple files (like backup and checkpoint): dir-fsync is
   forced, the same as above.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8903

Test Plan: run tests on btrfs and non btrfs

Reviewed By: ajkr

Differential Revision: D30885059

Pulled By: jay-zhuang

fbshipit-source-id: dd2730b31580b0bcaedffc318a762d7dbf25de4a
2021-11-03 12:21:27 -07:00
leipeng
230c98f3ce fix histogram NUM_FILES_IN_SINGLE_COMPACTION (#9026)
Summary:
currently histogram `NUM_FILES_IN_SINGLE_COMPACTION` just counted files in first level of compaction input, this fix counts files in all levels of compaction input.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9026

Reviewed By: ajkr

Differential Revision: D31668241

Pulled By: jay-zhuang

fbshipit-source-id: c02f6c4a5df9fbf0b7510036594811152e8738af
2021-11-01 12:57:27 -07:00
leipeng
2b70224f82 remove bad extra RecordTick(stats_, WRITE_WITH_WAL) (#9064)
Summary:
This PR fix wrong ticker `WRITE_WITH_WAL`.

`RecordTick(WRITE_WITH_WAL)` will be called later in `WriteToWAL` and `ConcurrentWriteToWAL`.

Fixes:
1. Delete these two extra `RecordTick(WRITE_WITH_WAL)`
2. Fix corresponding test case

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9064

Reviewed By: ajkr

Differential Revision: D31944459

Pulled By: riversand963

fbshipit-source-id: f1aa8d2a4320456bc357bc5b0902032f7dcad086
2021-11-01 11:43:14 -07:00
Andrew Kryczka
f24c39ab3d Prevent corruption with parallel manual compactions and change_level == true (#9077)
Summary:
The bug can impact the following scenario. There must be two `CompactRange()`s, call them A and B. Compaction A must have `change_level=true`. Compactions A and B must run in parallel, and new data must be added while they run as well.

Now, on to the details of the race condition. Compaction A must reach the refitting phase while B's next step is to trivial move new data (i.e., data that has been inserted behind A) down to the same level that A's refit targets (`CompactRangeOptions::target_level`). B must be unregistered  (i.e., has not yet called `AddManualCompaction()` for the current `RunManualCompaction()`) while A invokes `DisableManualCompaction()`s to prepare for refitting. In the old code, B could still proceed to register a manual compaction, while A had disabled manual compaction.

The next part of the race condition is B picks and schedules a trivial move while A has released the lock in refitting phase in order to persist the LSM state change (i.e., the log phase of `LogAndApply()`). That way, B does not see the refitted data when picking a trivial-move compaction. So it is susceptible to picking one that overlaps.

Finally, B executes the picked trivial-move compaction. Trivial-move compactions are special in that they never check whether manual compaction is disabled. So the picked compaction causing overlap ends up being applied, leading to LSM corruption if `force_consistency_checks=false`, or entering read-only mode with `Status::Corruption` if `force_consistency_checks=true` (the default).

The fix is just to prevent B from registering itself in `RunManualCompaction()` while manual compactions are disabled, consequently preventing any trivial move or other compaction from being picked/scheduled.

Thanks to siying for finding the bug.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9077

Test Plan: The test does not go all the way in exposing the bug because it requires a compaction to be picked/scheduled while logging LSM state change for RefitLevel(). But the fix is to make such a compaction not picked/scheduled in the first place, so any repro of that scenario would end up hanging RefitLevel() logging. So instead I just verified no such compaction is registered in the scenario where `RefitLevel()` disables manual compactions.

Reviewed By: siying

Differential Revision: D31921908

Pulled By: ajkr

fbshipit-source-id: 9bb5d0e847ad428211227f40830c685c209fbecb
2021-10-27 23:08:56 -07:00
Yanqin Jin
f72fd58565 Fix atomic flush waiting forever for MANIFEST write (#9034)
Summary:
In atomic flush, concurrent background flush threads will commit to the MANIFEST
one by one, in the order of the IDs of their picked memtables for all included column
families. Each time, a background flush thread decides whether to wait based on two
criteria:
- Is db stopped? If so, don't wait.
- Am I the one to commit the currently earliest memtable? If so, don't wait and ready to go.

When atomic flush was implemented, error writing to or syncing the MANIFEST would
cause the db to be stopped. Therefore, this background thread does not have to check
for the background error while waiting. If there has been such an error, `DBStopped()`
would have been true, and this thread will **not** wait forever.

After we improved error handling, RocksDB may map an IOError while writing to MANIFEST
to a soft error, if there is no WAL. This requires the background threads to check for
background error while waiting. Otherwise, a background flush thread may wait forever.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9034

Test Plan: make check

Reviewed By: zhichao-cao

Differential Revision: D31639225

Pulled By: riversand963

fbshipit-source-id: e9ab07c4d8f2eade238adeefe3e42dd9a5a3ebbd
2021-10-20 21:34:47 -07:00
leipeng
0a73ada7b5 remove unused local obj and simpilify comple code (#9052)
Summary:
This PR does not change code sematics, it just changes for:

1. local obj `nonmem_w` and `lfile` are unused
2. null check for `delete ptr` is unnecessary
3. use `unique_ptr::reset` instead of `release` + `delete`

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9052

Reviewed By: zhichao-cao

Differential Revision: D31801661

Pulled By: anand1976

fbshipit-source-id: 16a77d45da8c8833bf5bf3bce546bb3711b335df
2021-10-20 14:08:05 -07:00
leipeng
0c53b41856 db_impl_write.cc: use stats_ instead of immutable_db_options_.stats (#9053)
Summary:
This PR has no semantic changes, just to make code shorter.

`stats_` has value same with `immutable_db_options_.stats`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9053

Reviewed By: zhichao-cao

Differential Revision: D31801603

Pulled By: anand1976

fbshipit-source-id: cbd8fe478d3e90ae078ace49b4f2eb9bb028ccf6
2021-10-20 14:04:59 -07:00
Peter Dillinger
ad5325a736 Experimental support for SST unique IDs (#8990)
Summary:
* New public header unique_id.h and function GetUniqueIdFromTableProperties
which computes a universally unique identifier based on table properties
of table files from recent RocksDB versions.
* Generation of DB session IDs is refactored so that they are
guaranteed unique in the lifetime of a process running RocksDB.
(SemiStructuredUniqueIdGen, new test included.) Along with file numbers,
this enables SST unique IDs to be guaranteed unique among SSTs generated
in a single process, and "better than random" between processes.
See https://github.com/pdillinger/unique_id
* In addition to public API producing 'external' unique IDs, there is a function
for producing 'internal' unique IDs, with functions for converting between the
two. In short, the external ID is "safe" for things people might do with it, and
the internal ID enables more "power user" features for the future. Specifically,
the external ID goes through a hashing layer so that any subset of bits in the
external ID can be used as a hash of the full ID, while also preserving
uniqueness guarantees in the first 128 bits (bijective both on first 128 bits
and on full 192 bits).

Intended follow-up:
* Use the internal unique IDs in cache keys. (Avoid conflicts with https://github.com/facebook/rocksdb/issues/8912) (The file offset can be XORed into
the third 64-bit value of the unique ID.)
* Publish the external unique IDs in FileStorageInfo (https://github.com/facebook/rocksdb/issues/8968)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8990

Test Plan:
Unit tests added, and checking of unique ids in stress test.
NOTE in stress test we do not generate nearly enough files to thoroughly
stress uniqueness, but the test trims off pieces of the ID to check for
uniqueness so that we can infer (with some assumptions) stronger
properties in the aggregate.

Reviewed By: zhichao-cao, mrambacher

Differential Revision: D31582865

Pulled By: pdillinger

fbshipit-source-id: 1f620c4c86af9abe2a8d177b9ccf2ad2b9f48243
2021-10-18 23:32:01 -07:00
Jay Zhuang
314de7e7de Make DB::Close() thread-safe (#8970)
Summary:
If `DB::Close()` is called in multi-thread env, the resource
could be double released, which causes exception or assert.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8970

Test Plan:
Test with multi-thread benchmark, with each thread try to
close the DB at the end.

Reviewed By: pdillinger

Differential Revision: D31242042

Pulled By: jay-zhuang

fbshipit-source-id: a61276b1b61e07732e375554106946aea86a23eb
2021-10-18 20:32:35 -07:00
Peter Dillinger
3ffb3baa0b Add (Live)FileStorageInfo API (#8968)
Summary:
New classes FileStorageInfo and LiveFileStorageInfo and
'experimental' function DB::GetLiveFilesStorageInfo, which is intended
to largely replace several fragmented DB functions needed to create
checkpoints and backups.

This function is now used to create checkpoints and backups, because
it fixes many (probably not all) of the prior complexities of checkpoint
not having atomic access to DB metadata. This also ensures strong
functional test coverage of the new API. Specifically, much of the old
CheckpointImpl::CreateCustomCheckpoint has been migrated to and
updated in DBImpl::GetLiveFilesStorageInfo, with the former now
calling the latter.

Also, the class FileStorageInfo in metadata.h compatibly replaces
BackupFileInfo and serves as a new base class for SstFileMetaData.
Some old fields of SstFileMetaData are still provided (for now) but
deprecated.

Although FileStorageInfo::directory is accurate when using db_paths
and/or cf_paths, these have never been supported by Checkpoint
nor BackupEngine and still are not. This change does now detect
these cases and return NotSupported when appropriate. (More work
needed for support.)

Somehow this change broke ProgressCallbackDuringBackup, but
the progress_callback logic was dubious to begin with because it
would call the callback based on copy buffer size, not size actually
copied. Logic and test updated to track size actually copied
per-thread.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8968

Test Plan:
tests updated.
DB::GetLiveFilesStorageInfo mostly tested by use in CheckpointImpl.
DBTest.SnapshotFiles updated to also test GetLiveFilesStorageInfo,
including reading the data after DB close.
Added CheckpointTest.CheckpointWithDbPath (NotSupported).

Reviewed By: siying

Differential Revision: D31242045

Pulled By: pdillinger

fbshipit-source-id: b183d1ce9799e220daaefd6b3b5365d98de676c0
2021-10-16 10:04:32 -07:00
Giuseppe Ottaviano
4bfd415e34 Fix sequence number bump logic in multi-CF SST ingestion (#9005)
Summary:
The code in `IngestExternalFiles()` that bumps the DB's sequence number
depending on what seqnos were assigned to the files has 3 bugs:

1) There is an assertion that the sequence number is increased in all the
affected column families, but this is unnecessary, it is fine if some files can
stick to a lower sequence number. It is very easy to hit the assertion: it is
sufficient to insert 2 files in 2 CFs, one which overlaps the CF and one that
doesn't (for example the CF is empty). The line added in the
`IngestFilesIntoMultipleColumnFamilies_Success` test makes the assertion fail.

2) SetLastSequence() is called with the sum of all the bumps across CFs, but we
should take the maximum instead, as all CFs start with the current seqno and bump
it independently.

3) The code above is accidentally under a `#ifndef NDEBUG`, so it doesn't run in
optimized builds, so some files may be assigned seqnos from the future.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9005

Test Plan:
Added line in `IngestFilesIntoMultipleColumnFamilies_Success` that
triggers the assertion, verified that the test (and all the others) pass after
the fix.

Reviewed By: ajkr

Differential Revision: D31597892

Pulled By: ot

fbshipit-source-id: c2d3237f90290df1178736ace8653a9623f5a770
2021-10-12 20:39:52 -07:00
Giuseppe Ottaviano
22d4dc5066 Fix race in WriteBufferManager (#9009)
Summary:
EndWriteStall has a data race: `queue_.empty()` is checked outside of the
mutex, so once we enter the critical section another thread may already have
cleared the list, and accessing the `front()` is undefined behavior (and causes
interesting crashes under high concurrency).

This PR fixes the bug, and also rewrites the logic to make it easier to reason
about it. It also fixes another subtle bug: if some writers are stalled and
`SetBufferSize(0)` is called, which disables the WBM, the writer are not
unblocked because of an early `enabled()` check in `EndWriteStall()`.

It doesn't significantly change the locking behavior, as before writers won't
lock unless entering a stall condition, and `FreeMem` almost always locks if
stalling is allowed, but that is inevitable with the current design. Liveness is
guaranteed by the fact that if some writes are blocked, eventually all writes
will be blocked due to `stall_active_`, and eventually all memory is freed.

While at it, do a couple of optimizations:

- In `WBMStallInterface::Signal()` signal the CV only after releasing the
  lock. Signaling under the lock is a common pitfall, as it causes the woken-up
  thread to immediately go back to sleep because the mutex is still locked by
  the awaker.

- Move all allocations and deallocations outside of the lock.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9009

Test Plan:
```
USE_CLANG=1 make -j64 all check
```

Reviewed By: akankshamahajan15

Differential Revision: D31550668

Pulled By: ot

fbshipit-source-id: 5125387c3dc7ecaaa2b8bbc736e58c4156698580
2021-10-12 00:16:21 -07:00
Zhichao Cao
bcd049cd2d Ingest external SST files with Temperature hints (#8949)
Summary:
Add the file temperature to `IngestExternalFileArg` such that when SST files are ingested, user is able to assign the temperature to each SST file. If the temperature vector is empty or its size does not match the file name vector size, all ingested SST files will be assigned with `Temperature::unKnown`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8949

Test Plan: add the new test and make check

Reviewed By: siying

Differential Revision: D31127852

Pulled By: zhichao-cao

fbshipit-source-id: 141a81f0f7b473d88f4ab0cb2a21a114cbc6f83c
2021-10-08 10:32:24 -07:00
Andrew Kryczka
fcaa7ff638 Cancel manual compactions waiting on automatic compactions to drain (#8991)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8991

Test Plan: the new test hangs forever without this fix and passes with this fix.

Reviewed By: hx235

Differential Revision: D31456419

Pulled By: ajkr

fbshipit-source-id: a82c0e5560b6e6153089dccd8e46163c61b07bff
2021-10-07 15:23:55 -07:00
anand76
532ff334d9 Don't ignore deletion rate limit if WAL dir is different (#8967)
Summary:
If WAL dir is different from the DB dir, we should still honor the SstFileManager deletion rate limit for SST files.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8967

Test Plan: Add a new unit test in db_sst_test

Reviewed By: pdillinger

Differential Revision: D31220116

Pulled By: anand1976

fbshipit-source-id: bcde8a53a7d728e15e597fb5d07ee86c1b38bd28
2021-09-30 13:26:31 -07:00
mrambacher
13ae16c315 Cleanup includes in dbformat.h (#8930)
Summary:
This header file was including everything and the kitchen sink when it did not need to.  This resulted in many places including this header when they needed other pieces instead.

Cleaned up this header to only include what was needed and fixed up the remaining code to include what was now missing.

Hopefully, this sort of code hygiene cleanup will speed up the builds...

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8930

Reviewed By: pdillinger

Differential Revision: D31142788

Pulled By: mrambacher

fbshipit-source-id: 6b45de3f300750c79f751f6227dece9cfd44085d
2021-09-29 04:04:40 -07:00
Akanksha Mahajan
78afb4d81e Support SingleDelete for user-defined timestamps (#8921)
Summary:
Added support for SingleDelete for user-defined timestamps. Users can now Get and Iterate over keys deleted with SingleDelete. It also includes changes in CompactionIterator which  preserves the same user key with different timestamps, unless the timestamp is below a certain threshold full_history_ts_low.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8921

Test Plan: Added new unit tests

Reviewed By: riversand963

Differential Revision: D31098191

Pulled By: akankshamahajan15

fbshipit-source-id: 78a59ef4b4884ae324fcd10f56e62a27d5ee2f49
2021-09-27 11:51:07 -07:00
Yanqin Jin
b512f4bc76 Batch blob read IO for MultiGet (#8699)
Summary:
In batched `MultiGet()`, RocksDB batches blob read IO and uses `RandomAccessFileReader::MultiRead()`
to read the blobs instead of issuing multiple `Read()`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8699

Test Plan:
```
make check
```

Reviewed By: ltamasi

Differential Revision: D31030861

Pulled By: riversand963

fbshipit-source-id: a0df6060cbfd54cff9515a4eee08807b1dbcb0c8
2021-09-17 19:23:13 -07:00
Akanksha Mahajan
d6aa8c49f8 Expose blob file information through the EventListener interface (#8675)
Summary:
1. Extend FlushJobInfo and CompactionJobInfo with information about the blob files generated by flush/compaction jobs. This PR add two structures BlobFileInfo and BlobFileGarbageInfo that contains the required information of blob files.
 2. Notify the creation and deletion of blob files through OnBlobFileCreationStarted, OnBlobFileCreated, and OnBlobFileDeleted.
 3. Test OnFile*Finish operations notifications with Blob Files.
 4. Log the blob file creation/deletion events through EventLogger in Log file.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8675

Test Plan: Add new unit tests in listener_test

Reviewed By: ltamasi

Differential Revision: D30412613

Pulled By: akankshamahajan15

fbshipit-source-id: ca51b63c6e8c8d0485a38c503572bc5a82bd5d07
2021-09-16 17:23:36 -07:00
eharry
0b6be7eb68 Fix WAL log data corruption #8723 (#8746)
Summary:
Fix WAL log data corruption when using DBOptions.manual_wal_flush(true) and WriteOptions.sync(true) together (https://github.com/facebook/rocksdb/issues/8723)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8746

Reviewed By: ajkr

Differential Revision: D30758468

Pulled By: riversand963

fbshipit-source-id: 07c20899d5f2447dc77861b4845efc68a59aa4e8
2021-09-13 20:15:59 -07:00
Yanqin Jin
2a2b3e03a5 Allow WriteBatch to have keys with different timestamp sizes (#8725)
Summary:
In the past, we unnecessarily requires all keys in the same write batch
to be from column families whose timestamps' formats are the same for
simplicity. Specifically, we cannot use the same write batch to write to
two column families, one of which enables timestamp while the other
disables it.

The limitation is due to the member `timestamp_size_` that used to exist
in each `WriteBatch` object. We pass a timestamp_size to the constructor
of `WriteBatch`. Therefore, users can simply use the old
`WriteBatch::Put()`, `WriteBatch::Delete()`, etc APIs for write, while
the internal implementation of `WriteBatch` will take care of memory
allocation for timestamps.

The above is not necessary.
One the one hand, users can set up a memory buffer to store user key and
then contiguously append the timestamp to the user key. Then the user
can pass this buffer to the `WriteBatch::Put(Slice&)` API.
On the other hand, users can set up a SliceParts object which is an
array of Slices and let the last Slice to point to the memory buffer
storing timestamp. Then the user can pass the SliceParts object to the
`WriteBatch::Put(SliceParts&)` API.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8725

Test Plan: make check

Reviewed By: ltamasi

Differential Revision: D30654499

Pulled By: riversand963

fbshipit-source-id: 9d848c77ad3c9dd629aa5fc4e2bc16fb0687b4a2
2021-09-12 15:34:26 -07:00
mrambacher
beed86473a Make MemTableRepFactory into a Customizable class (#8419)
Summary:
This PR does the following:
-> Makes the MemTableRepFactory into a Customizable class and creatable/configurable via CreateFromString
-> Makes the existing implementations compatible with configurations
-> Moves the "SpecialRepFactory" test class into testutil, accessible via the ObjectRegistry or a NewSpecial API

New tests were added to validate the functionality and all existing tests pass.  db_bench and memtablerep_bench were hand-tested to verify the functionality in those tools.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8419

Reviewed By: zhichao-cao

Differential Revision: D29558961

Pulled By: mrambacher

fbshipit-source-id: 81b7229636e4e649a0c914e73ac7b0f8454c931c
2021-09-08 07:46:44 -07:00
Andrew Kryczka
941543721d Bytes read stat for VerifyChecksum() and VerifyFileChecksums() APIs (#8741)
Summary:
- Clarified some comments on compatibility for adding new ticker stats
- Added read I/O stats for `VerifyChecksum()` and `VerifyFileChecksums()` APIs

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8741

Test Plan: new unit test

Reviewed By: zhichao-cao

Differential Revision: D30708578

Pulled By: ajkr

fbshipit-source-id: d06b961f7e199ae92c266b683e39870aa8f63449
2021-09-07 13:28:29 -07:00
Peter Dillinger
4750421ece Replace most typedef with using= (#8751)
Summary:
Old typedef syntax is confusing

Most but not all changes with

    perl -pi -e 's/typedef (.*) ([a-zA-Z0-9_]+);/using $2 = $1;/g' list_of_files
    make format

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8751

Test Plan: existing

Reviewed By: zhichao-cao

Differential Revision: D30745277

Pulled By: pdillinger

fbshipit-source-id: 6f65f0631c3563382d43347896020413cc2366d9
2021-09-07 11:31:59 -07:00
Peter Dillinger
c9cd5d25a8 Remove some unneeded code (#8736)
Summary:
* FullKey and ParseFullKey appear to serve no purpose in the public API
(or anything else) so removed. Only use in one test updated.
* NumberToString serves no purpose vs. ToString so removed, numerous
calls updated
* Remove unnecessary forward declarations in metadata.h by re-arranging
class definitions.
* Remove some unneeded semicolons

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8736

Test Plan: existing tests

Reviewed By: mrambacher

Differential Revision: D30700039

Pulled By: pdillinger

fbshipit-source-id: 1e436a576f511a6ed8b4d97af7cc8216bc729af2
2021-09-01 14:28:58 -07:00
Peter Dillinger
13ded69484 Built-in support for generating unique IDs, bug fix (#8708)
Summary:
Env::GenerateUniqueId() works fine on Windows and on POSIX
where /proc/sys/kernel/random/uuid exists. Our other implementation is
flawed and easily produces collision in a new multi-threaded test.
As we rely more heavily on DB session ID uniqueness, this becomes a
serious issue.

This change combines several individually suitable entropy sources
for reliable generation of random unique IDs, with goal of uniqueness
and portability, not cryptographic strength nor maximum speed.

Specifically:
* Moves code for getting UUIDs from the OS to port::GenerateRfcUuid
rather than in Env implementation details. Callers are now told whether
the operation fails or succeeds.
* Adds an internal API GenerateRawUniqueId for generating high-quality
128-bit unique identifiers, by combining entropy from three "tracks":
  * Lots of info from default Env like time, process id, and hostname.
  * std::random_device
  * port::GenerateRfcUuid (when working)
* Built-in implementations of Env::GenerateUniqueId() will now always
produce an RFC 4122 UUID string, either from platform-specific API or
by converting the output of GenerateRawUniqueId.

DB session IDs now use GenerateRawUniqueId while DB IDs (not as
critical) try to use port::GenerateRfcUuid but fall back on
GenerateRawUniqueId with conversion to an RFC 4122 UUID.

GenerateRawUniqueId is declared and defined under env/ rather than util/
or even port/ because of the Env dependency.

Likely follow-up: enhance GenerateRawUniqueId to be faster after the
first call and to guarantee uniqueness within the lifetime of a single
process (imparting the same property onto DB session IDs).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8708

Test Plan:
A new mini-stress test in env_test checks the various public
and internal APIs for uniqueness, including each track of
GenerateRawUniqueId individually. We can't hope to verify anywhere close
to 128 bits of entropy, but it can at least detect flaws as bad as the
old code. Serial execution of the new tests takes about 350 ms on
my machine.

Reviewed By: zhichao-cao, mrambacher

Differential Revision: D30563780

Pulled By: pdillinger

fbshipit-source-id: de4c9ff4b2f581cf784fcedb5f39f16e5185c364
2021-08-30 15:20:41 -07:00
James Yin
7ddc096d7d Fix typo in the comment of log_empty_ (#8711)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8711

Reviewed By: riversand963

Differential Revision: D30566761

Pulled By: jay-zhuang

fbshipit-source-id: dd4690f5e2af2d263ed75ea1b9ed24692fe81362
2021-08-27 12:10:29 -07:00
anand76
ebaa3c8a59 Fix a race condition in DumpStats() during iteration of the ColumnFamilySet (#8714)
Summary:
DumpStats() iterates through the ColumnFamilySet. There is a potential
race condition because it does Ref the cfd, and the cfd could get
destroyed during the iteration.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8714

Test Plan: make check

Reviewed By: ltamasi

Differential Revision: D30580199

Pulled By: anand1976

fbshipit-source-id: 60a3443ad0d4f7ac6a977dec780e6d2c1b70b850
2021-08-26 15:40:26 -07:00
Yanqin Jin
229350ef48 Allow iterate refresh for secondary instance (#8700)
Summary:
Test plan
make check

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8700

Reviewed By: zhichao-cao

Differential Revision: D30523907

Pulled By: riversand963

fbshipit-source-id: 68928ab4dafb64ce80ab7bc69d83727a4713ab91
2021-08-24 15:40:56 -07:00
Akanksha Mahajan
5efec84c60 Fix blob callback in compaction and atomic flush (#8681)
Summary:
Pass BlobFileCompletionCallback  in case of atomic flush and
compaction job which is currently nullptr(default parameter).
BlobFileCompletionCallback is used in case of IntegratedBlobDB to report new blob files to
SstFileManager.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8681

Test Plan: CircleCI jobs

Reviewed By: ltamasi

Differential Revision: D30445998

Pulled By: akankshamahajan15

fbshipit-source-id: ba48093843864faec57f1f365cce7b5a569c4021
2021-08-20 11:41:14 -07:00
Baptiste Lemaire
c625b8d017 Add condition on NotifyOnFlushComplete that FlushJob was not mempurge. Add event listeners to mempurge tests. (#8672)
Summary:
Previously, when a `FlushJob` was redirected to a MemPurge, the function `DBImpl::NotifyOnFlushComplete` was called, which created a series of issues because the JobInfo was not correctly collected from the memtables.
This diff aims at correcting these two issues (`FlushJobInfo` collection in `FlushJob::MemPurge` , no call to `DBImpl::NotifyOnFlushComplete` after successful mempurge).
Event listeners were added to the unit tests to handle these situations.
Surprisingly none of the crashtests caught this issue, I will try to add event listeners to crash tests in the future.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8672

Reviewed By: akankshamahajan15

Differential Revision: D30383109

Pulled By: bjlemaire

fbshipit-source-id: 35a8d4295886923ee4049a6447f00022cb221c73
2021-08-18 17:40:01 -07:00
Peter Dillinger
b6269b078a Stable cache keys on ingested SST files (#8669)
Summary:
Extends https://github.com/facebook/rocksdb/issues/8659 to work for ingested external SST files, even
the same file ingested into different DBs sharing a block cache.

Note: These new cache keys are currently only enabled when FileSystem
does not provide GetUniqueId. For now, they are typically larger,
so slightly less efficient.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8669

Test Plan: Extended unit test

Reviewed By: zhichao-cao

Differential Revision: D30398532

Pulled By: pdillinger

fbshipit-source-id: 1f13e2af4b8bfff5741953a69466e9589fbc23c7
2021-08-18 11:33:03 -07:00
Adam Retter
5de333fd99 Add db_test2 to to ASSERT_STATUS_CHECKED (#8640)
Summary:
This is the `db_test2` parts of https://github.com/facebook/rocksdb/pull/7737 reworked on the latest HEAD.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8640

Reviewed By: akankshamahajan15

Differential Revision: D30303684

Pulled By: mrambacher

fbshipit-source-id: 263e2f82d849bde4048b60aed8b31e7deed4706a
2021-08-16 08:10:32 -07:00
Merlin Mao
f58d276764 Make TraceRecord and Replayer public (#8611)
Summary:
New public interfaces:
`TraceRecord` and `TraceRecord::Handler`, available in "rocksdb/trace_record.h".
`Replayer`, available in `rocksdb/utilities/replayer.h`.

User can use `DB::NewDefaultReplayer()` to create a Replayer to auto/manual replay a trace file.

Unit tests:
- `./db_test2 --gtest_filter="DBTest2.TraceAndReplay"`: Updated with the internal API changes.
- `./db_test2 --gtest_filter="DBTest2.TraceAndManualReplay"`: New for manual replay.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8611

Reviewed By: ajkr

Differential Revision: D30266329

Pulled By: autopear

fbshipit-source-id: 1ecb3cbbedae0f6a67c18f0cc82e002b4d81b6f8
2021-08-11 19:32:46 -07:00
Baptiste Lemaire
e3a96c4823 Memtable sampling for mempurge heuristic. (#8628)
Summary:
Changes the API of the MemPurge process: the `bool experimental_allow_mempurge` and `experimental_mempurge_policy` flags have been replaced by a `double experimental_mempurge_threshold` option.
This change of API reflects another major change introduced in this PR: the MemPurgeDecider() function now works by sampling the memtables being flushed to estimate the overall amount of useful payload (payload minus the garbage), and then compare this useful payload estimate with the `double experimental_mempurge_threshold` value.
Therefore, when the value of this flag is `0.0` (default value), mempurge is simply deactivated. On the other hand, a value of `DBL_MAX` would be equivalent to always going through a mempurge regardless of the garbage ratio estimate.
At the moment, a `double experimental_mempurge_threshold` value else than 0.0 or `DBL_MAX` is opnly supported`with the `SkipList` memtable representation.
Regarding the sampling, this PR includes the introduction of a `MemTable::UniqueRandomSample` function that collects (approximately) random entries from the memtable by using the new `SkipList::Iterator::RandomSeek()` under the hood, or by iterating through each memtable entry, depending on the target sample size and the total number of entries.
The unit tests have been readapted to support this new API.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8628

Reviewed By: pdillinger

Differential Revision: D30149315

Pulled By: bjlemaire

fbshipit-source-id: 1feef5390c95db6f4480ab4434716533d3947f27
2021-08-10 18:09:03 -07:00
Levi Tamasi
87882736ef Fix the sorting of KeyContexts for batched MultiGet (#8633)
Summary:
`CompareKeyContext::operator()` on the trunk has a bug: when comparing
column family IDs, `lhs` is used for both sides of the comparison. This
results in the `KeyContext`s getting sorted solely based on key, which
in turn means that keys with the same column family do not necessarily
form a single range in the sorted list. This violates an assumption of the
batched `MultiGet` logic, leading to the same column family
showing up multiple times in the list of `MultiGetColumnFamilyData`.
The end result is the code attempting to check out the thread-local
`SuperVersion` for the same CF multiple times, causing an
assertion violation in debug builds and memory corruption/crash in
release builds.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8633

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D30169182

Pulled By: ltamasi

fbshipit-source-id: a47710652df7e95b14b40fb710924c11a8478023
2021-08-06 16:27:42 -07:00
Levi Tamasi
9b25d26dc8 Attempt to deflake ObsoleteFilesTest.DeleteObsoleteOptionsFile (#8624)
Summary:
We've been seeing occasional crashes on CI while inserting into the
vectors in `ObsoleteFilesTest.DeleteObsoleteOptionsFile`. The crashes
don't reproduce locally (could be either a race or an object lifecycle
issue) but the good news is that the vectors in question are not really
used for anything meaningful by the test. (The assertion about the sizes
of the two vectors being equal is guaranteed to hold, since the two sync
points where they are populated are right after each other.) The patch
simply removes the vectors from the test, alongside the associated
callbacks and sync points.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8624

Test Plan: `make check`

Reviewed By: akankshamahajan15

Differential Revision: D30118485

Pulled By: ltamasi

fbshipit-source-id: 0a4c3d06584e84cd2b1dcc212d274fa1b89cb647
2021-08-05 18:36:16 -07:00
Yanqin Jin
0879c24040 Fix NotifyOnFlushCompleted() for atomic flush (#8585)
Summary:
PR https://github.com/facebook/rocksdb/issues/5908 added `flush_jobs_info_` to `FlushJob` to make sure
`OnFlushCompleted()` is called after committing flush results to
MANIFEST. However, `flush_jobs_info_` is not updated in atomic
flush, causing `NotifyOnFlushCompleted()` to skip `OnFlushCompleted()`.

This PR fixes this, in a similar way to https://github.com/facebook/rocksdb/issues/5908 that handles regular flush.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8585

Test Plan: make check

Reviewed By: jay-zhuang

Differential Revision: D29913720

Pulled By: riversand963

fbshipit-source-id: 4ff023c98372fa2c93188d4a5c8a4e9ffa0f4dda
2021-08-03 13:31:10 -07:00
Levi Tamasi
3f7e929865 Fix a race in ColumnFamilyData::UnrefAndTryDelete (#8605)
Summary:
The `ColumnFamilyData::UnrefAndTryDelete` code currently on the trunk
unlocks the DB mutex before destroying the `ThreadLocalPtr` holding
the per-thread `SuperVersion` pointers when the only remaining reference
is the back reference from `super_version_`. The idea behind this was to
break the circular dependency between `ColumnFamilyData` and `SuperVersion`:
when the penultimate reference goes away, `ColumnFamilyData` can clean up
the `SuperVersion`, which can in turn clean up `ColumnFamilyData`. (Assuming there
is a `SuperVersion` and it is not referenced by anything else.) However,
unlocking the mutex throws a wrench in this plan by making it possible for another thread
to jump in and take another reference to the `ColumnFamilyData`, keeping the
object alive in a zombie `ThreadLocalPtr`-less state. This can cause issues like
https://github.com/facebook/rocksdb/issues/8440 ,
https://github.com/facebook/rocksdb/issues/8382 ,
and might also explain the `was_last_ref` assertion failures from the `ColumnFamilySet`
destructor we sometimes observe during close in our stress tests.

Digging through the archives, this unlocking goes way back to 2014 (or earlier). The original
rationale was that `SuperVersionUnrefHandle` used to lock the mutex so it can call
`SuperVersion::Cleanup`; however, this logic turned out to be deadlock-prone.
https://github.com/facebook/rocksdb/pull/3510 fixed the deadlock but left the
unlocking in place. https://github.com/facebook/rocksdb/pull/6147 then introduced
the circular dependency and associated cleanup logic described above (in order
to enable iterators to keep the `ColumnFamilyData` for dropped column families alive),
and moved the unlocking-relocking snippet to its present location in `UnrefAndTryDelete`.
Finally, https://github.com/facebook/rocksdb/pull/7749 fixed a memory leak but
apparently exacerbated the race by (otherwise correctly) switching to `UnrefAndTryDelete`
in `SuperVersion::Cleanup`.

The patch simply eliminates the unlocking and relocking, which has been unnecessary
ever since https://github.com/facebook/rocksdb/issues/3510 made `SuperVersionUnrefHandle` lock-free.
This closes the window during which another thread could increase the reference count,
and hopefully fixes the issues above.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8605

Test Plan: Ran `make check` and stress tests locally.

Reviewed By: pdillinger

Differential Revision: D30051035

Pulled By: ltamasi

fbshipit-source-id: 8fe559e4b4ad69fc142579f8bc393ef525918528
2021-08-02 18:12:11 -07:00
mrambacher
ab7f7c9e49 Allow WAL dir to change with db dir (#8582)
Summary:
Prior to this change, the "wal_dir"  DBOption would always be set (defaults to dbname) when the DBOptions were sanitized.  Because of this setitng in the options file, it was not possible to rename/relocate a database directory after it had been created and use the existing options file.

After this change, the "wal_dir" option is only set under specific circumstances.  Methods were added to the ImmutableDBOptions class to see if it is set and if it is set to something other than the dbname.  Additionally, a method was added to retrieve the effective value of the WAL dir (either the option or the dbname/path).

Tests were added to the core and ldb to test that a database could be created and renamed without issue.  Additional tests for various permutations of wal_dir were also added.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8582

Reviewed By: pdillinger, autopear

Differential Revision: D29881122

Pulled By: mrambacher

fbshipit-source-id: 67d3d033dc8813d59917b0a3fba2550c0efd6dfb
2021-07-30 12:16:44 -07:00
Yanqin Jin
066b51126d Several simple local code clean-ups (#8565)
Summary:
This PR tries to remove some unnecessary checks as well as unreachable code blocks to
improve readability. An obvious non-public API method naming typo is also corrected.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8565

Test Plan: make check

Reviewed By: lth

Differential Revision: D29963984

Pulled By: riversand963

fbshipit-source-id: cc96e8f09890e5cfe9b20eadb63bdca5484c150a
2021-07-30 12:07:49 -07:00
Peter Dillinger
1d34cd797e Fix insecure internal API for GetImpl (#8590)
Summary:
Calling the GetImpl function could leave reference to a local
callback function in a field of a parameter struct. As this is
performance-critical code, I'm not going to attempt to sanitize this
code too much, but make the existing hack a bit cleaner by reverting
what it overwrites in the input struct.

Added SaveAndRestore utility class to make that easier.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8590

Test Plan:
added unit test for SaveAndRestore; existing tests for
GetImpl

Reviewed By: riversand963

Differential Revision: D29947983

Pulled By: pdillinger

fbshipit-source-id: 2f608853f970bc06724e834cc84dcc4b8599ddeb
2021-07-29 17:23:01 -07:00
sdong
e8f218cb68 DB::GetSortedWalFiles() to ensure file deletion is disabled (#8591)
Summary:
If DB::GetSortedWalFiles() runs without file deletion disbled, file might get deleted in the middle and error is returned to users. It makes the function hard to use. Fix it by disabling file deletion if it is not done.

Fix another minor issue of logging within DB mutex, which should not be done unless a major failure happens.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8591

Test Plan: Run all existing tests

Reviewed By: pdillinger

Differential Revision: D29969412

fbshipit-source-id: d5f42b5271608a35b9b07687ce18157d7447b0de
2021-07-29 11:51:08 -07:00
Baptiste Lemaire
c521a9ab2b Retire superfluous functions introduced in earlier mempurge PRs. (#8558)
Summary:
The main challenge to make the memtable garbage collection prototype (nicknamed `mempurge`) was to not get rid of WAL files that contain unflushed (but mempurged) data. That was successfully guaranteed by not writing the VersionEdit to the MANIFEST file after a successful mempurge.
By not writing VersionEdits to the `MANIFEST` file after a succesful mempurge operation, we do not change the earliest log file number that contains unflushed data: `cfd->GetLogNumber()` (`cfd->SetLogNumber()` is only called in `VersionSet::ProcessManifestWrites`). As a result, a number of functions introduced earlier just for the mempurge operation are not obscolete/redundant. (e.g.: `FlushJob::ExtractEarliestLogFileNumber`), and this PR aims at cleaning up all these now-unnecessary functions. In particular, we no longer need to store the earliest log file number in the `MemTable` struct itself. This PR therefore also reverts the `MemTable` struct to its original form.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8558

Test Plan: Already included in `db_flush_test.cc`.

Reviewed By: anand1976

Differential Revision: D29764351

Pulled By: bjlemaire

fbshipit-source-id: 0f43b260fa270251862512f397d3f24ee62e8437
2021-07-22 18:29:13 -07:00
Yanqin Jin
2e5388178f Return error if trying to open secondary on missing or inaccessible primary (#8200)
Summary:
If the primary's CURRENT file is missing or inaccessible, the secondary should not hang
trying repeatedly to switch to the next MANIFEST.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8200

Test Plan: make check

Reviewed By: jay-zhuang

Differential Revision: D27840627

Pulled By: riversand963

fbshipit-source-id: 071fed97cbab1bc5cdefd1dc235e5cd406c174e1
2021-07-22 15:48:58 -07:00
Peter Dillinger
84eef260de Remove TaskLimiterToken::ReleaseOnce for fix (#8567)
Summary:
Rare TSAN and valgrind failures are caused by unnecessary
reading of a field on the TaskLimiterToken::limiter_ for an assertion
after the token has been released and the limiter destroyed. To simplify
we can simply destroy the token before triggering DB shutdown
(potentially destroying the limiter). This makes the ReleaseOnce logic
unnecessary.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8567

Test Plan: watch for more failures in CI

Reviewed By: ajkr

Differential Revision: D29811795

Pulled By: pdillinger

fbshipit-source-id: 135549ebb98fe4f176d1542ed85d5bd6350a40b3
2021-07-21 17:37:53 -07:00
Jay Zhuang
42eaa45c1b Avoid updating option if there's no value updated (#8518)
Summary:
Try avoid expensive updating options operation if
`SetDBOptions()` does not change any option value.
Skip updating is not guaranteed, for example, changing `bytes_per_sync`
to `0` may still trigger updating, as the value could be sanitized.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8518

Test Plan: added unittest

Reviewed By: riversand963

Differential Revision: D29672639

Pulled By: jay-zhuang

fbshipit-source-id: b7931de62ceea6f1bdff0d1209adf1197d3ed1f4
2021-07-21 13:45:59 -07:00
sdong
9e885939a3 Change to code for trimmed memtable history is to released outside DB mutex (#8530)
Summary:
Currently, the code shows that we delete memtables immedately after it is trimmed from history. Although it should never happen as the super version still holds the memtable, which is only switched after it, it feels a good practice not to do it, but use clean it up in the standard way: put it to WriteContext and clean it after DB mutex.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8530

Test Plan: Run all existing tests.

Reviewed By: ajkr

Differential Revision: D29703410

fbshipit-source-id: 21d8068ac6377de4b6fa7a89697195742659fde4
2021-07-16 19:28:48 -07:00
Peter Dillinger
df5dc73bec Don't hold DB mutex for block cache entry stat scans (#8538)
Summary:
I previously didn't notice the DB mutex was being held during
block cache entry stat scans, probably because I primarily checked for
read performance regressions, because they require the block cache and
are traditionally latency-sensitive.

This change does some refactoring to avoid holding DB mutex and to
avoid triggering and waiting for a scan in GetProperty("rocksdb.cfstats").
Some tests have to be updated because now the stats collector is
populated in the Cache aggressively on DB startup rather than lazily.
(I hope to clean up some of this added complexity in the future.)

This change also ensures proper treatment of need_out_of_mutex for
non-int DB properties.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8538

Test Plan:
Added unit test logic that uses sync points to fail if the DB mutex
is held during a scan, covering the various ways that a scan might be
triggered.

Performance test - the known impact to holding the DB mutex is on
TransactionDB, and the easiest way to see the impact is to hack the
scan code to almost always miss and take an artificially long time
scanning. Here I've injected an unconditional 5s sleep at the call to
ApplyToAllEntries.

Before (hacked):

    $ TEST_TMPDIR=/dev/shm ./db_bench.base_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     433.219 micros/op 2308 ops/sec;    0.1 MB/s ( transactions:78999 aborts:0)
    rocksdb.db.write.micros P50 : 16.135883 P95 : 36.622503 P99 : 66.036115 P100 : 5000614.000000 COUNT : 149677 SUM : 8364856
    $ TEST_TMPDIR=/dev/shm ./db_bench.base_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     448.802 micros/op 2228 ops/sec;    0.1 MB/s ( transactions:75999 aborts:0)
    rocksdb.db.write.micros P50 : 16.629221 P95 : 37.320607 P99 : 72.144341 P100 : 5000871.000000 COUNT : 143995 SUM : 13472323

Notice the 5s P100 write time.

After (hacked):

    $ TEST_TMPDIR=/dev/shm ./db_bench.new_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     303.645 micros/op 3293 ops/sec;    0.1 MB/s ( transactions:98999 aborts:0)
    rocksdb.db.write.micros P50 : 16.061871 P95 : 33.978834 P99 : 60.018017 P100 : 616315.000000 COUNT : 187619 SUM : 4097407
    $ TEST_TMPDIR=/dev/shm ./db_bench.new_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     310.383 micros/op 3221 ops/sec;    0.1 MB/s ( transactions:96999 aborts:0)
    rocksdb.db.write.micros P50 : 16.270026 P95 : 35.786844 P99 : 64.302878 P100 : 603088.000000 COUNT : 183819 SUM : 4095918

P100 write is now ~0.6s. Not good, but it's the same even if I completely bypass all the scanning code:

    $ TEST_TMPDIR=/dev/shm ./db_bench.new_skip -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     311.365 micros/op 3211 ops/sec;    0.1 MB/s ( transactions:96999 aborts:0)
    rocksdb.db.write.micros P50 : 16.274362 P95 : 36.221184 P99 : 68.809783 P100 : 649808.000000 COUNT : 183819 SUM : 4156767
    $ TEST_TMPDIR=/dev/shm ./db_bench.new_skip -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     308.395 micros/op 3242 ops/sec;    0.1 MB/s ( transactions:97999 aborts:0)
    rocksdb.db.write.micros P50 : 16.106222 P95 : 37.202403 P99 : 67.081875 P100 : 598091.000000 COUNT : 185714 SUM : 4098832

No substantial difference.

Reviewed By: siying

Differential Revision: D29738847

Pulled By: pdillinger

fbshipit-source-id: 1c5c155f5a1b62e4fea0fd4eeb515a8b7474027b
2021-07-16 14:13:08 -07:00
Baptiste Lemaire
206845c057 Mempurge support for wal (#8528)
Summary:
In this PR, `mempurge` is made compatible with the Write Ahead Log: in case of recovery, the DB is now capable of recovering the data that was "mempurged" and kept in the `imm()` list of immutable memtables.
The twist was to add a uint64_t to the `memtable` struct to store the number of the earliest log file containing entries from the `memtable`. When a `Flush` operation is replaced with a `MemPurge`, the `VersionEdit` (which usually contains the new min log file number to pick up for recovery and the level 0 file path of the newly created SST file) is no longer appended to the manifest log, and every time the `deleteWal` method is called, a check is made on the list of immutable memtables.
This PR also includes a unit test that verifies that no data is lost upon Reopening of the database when the mempurge feature is activated. This extensive unit test includes two column families, with valid data contained in the imm() at time of "crash"/reopening (recovery).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8528

Reviewed By: pdillinger

Differential Revision: D29701097

Pulled By: bjlemaire

fbshipit-source-id: 072a900fb6ccc1edcf5eef6caf88f3060238edf9
2021-07-15 17:49:13 -07:00
longlijian
803a40d412 Delete legacy code not used any more. (#8508)
Summary:
The removed function in this PR,  just only have declared and dose not have any reference used.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8508

Reviewed By: mrambacher

Differential Revision: D29649033

Pulled By: jay-zhuang

fbshipit-source-id: df98143b73d6c184a2a60c9f7ea2548a065ee35d
2021-07-14 16:04:56 -07:00
Dmitry Vorobev
0b75b22321 Implement missing Handler methods in ColumnFamilyCollector. (#8456)
Summary:
When db is open as secondary, there are basically 2 step process:
1) Collect column families from wal log
2) Apply changes to Memtable
In case primary db is TransactionDB instance, wal log will contain some additional data, like noop, etc. ColumnFamilyCollector doesn't implement methods to handle these, so it fails to open a wal log written by TransactionDB. (Everything works fine with standard DB::Open).
Memtable recovery process knows how to handle such wal logs, so only missing piece seems to be ColumnFamilyCollector.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8456

Reviewed By: ajkr

Differential Revision: D29455945

Pulled By: mrambacher

fbshipit-source-id: 5b29560fcbc008e17e95d0dc4b07558f3d63e26f
2021-07-12 09:23:45 -07:00
anand76
d1b70b05a6 Avoid passing existing BG error to WriteStatusCheck (#8511)
Summary:
In ```DBImpl::WriteImpl()```, we call ```PreprocessWrite()``` which, among other things, checks the BG error and returns it set. This return status is later on passed to ```WriteStatusCheck()```, which calls ```SetBGError()```. This results in a spurious call, and info logs, on every user write request. We should avoid passing the ```PreprocessWrite()``` return status to ```WriteStatusCheck()```, as the former would have called ```SetBGError()``` already if it encountered any new errors, such as error when creating a new WAL file.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8511

Test Plan: Run existing tests

Reviewed By: zhichao-cao

Differential Revision: D29639917

Pulled By: anand1976

fbshipit-source-id: 19234163969e1645dbeb273712aaf5cd9ea2b182
2021-07-11 22:37:52 -07:00
Baptiste Lemaire
837705ad80 Make mempurge a background process (equivalent to in-memory compaction). (#8505)
Summary:
In https://github.com/facebook/rocksdb/issues/8454, I introduced a new process baptized `MemPurge` (memtable garbage collection). This new PR is built upon this past mempurge prototype.
In this PR, I made the `mempurge` process a background task, which provides superior performance since the mempurge process does not cling on the db_mutex anymore, and addresses severe restrictions from the past iteration (including a scenario where the past mempurge was failling, when a memtable was mempurged but was still referred to by an iterator/snapshot/...).
Now the mempurge process ressembles an in-memory compaction process: the stack of immutable memtables is filtered out, and the useful payload is used to populate an output memtable. If the output memtable is filled at more than 60% capacity (arbitrary heuristic) the mempurge process is aborted and a regular flush process takes place, else the output memtable is kept in the immutable memtable stack. Note that adding this output memtable to the `imm()` memtable stack does not trigger another flush process, so that the flush thread can go to sleep at the end of a successful mempurge.
MemPurge is activated by making the `experimental_allow_mempurge` flag `true`. When activated, the `MemPurge` process will always happen when the flush reason is `kWriteBufferFull`.
The 3 unit tests confirm that this process supports `Put`, `Get`, `Delete`, `DeleteRange` operators and is compatible with `Iterators` and `CompactionFilters`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8505

Reviewed By: pdillinger

Differential Revision: D29619283

Pulled By: bjlemaire

fbshipit-source-id: 8a99bee76b63a8211bff1a00e0ae32360aaece95
2021-07-09 17:23:59 -07:00
longlijian
ac3f3f3719 Eliminate compiler complaining, which the return type of the function… (#8498)
Summary:
… should be uint64_t.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8498

Reviewed By: jay-zhuang

Differential Revision: D29605064

Pulled By: ajkr

fbshipit-source-id: e431448ac9d8a37ae83679c4cc5732e29fe49de4
2021-07-08 10:09:05 -07:00
Baptiste Lemaire
714ce5041d Fix clang_analyzer failure (#8492)
Summary:
Previously, the following command:
```USE_CLANG=1 TEST_TMPDIR=/dev/shm/rocksdb OPT=-g make -j$(nproc) analyze```
was raising an error/warning the new_mem could potentially be a `nullptr`. This error appeared due to code changes from https://github.com/facebook/rocksdb/issues/8454, including an if-statement containing "`... && new_mem != nullptr && ...`", which made the analyzer believe that past this `if`-statement, a `new_mem==nullptr` was a possible scenario.
This code patch simply introduces `assert`s and removes this condition in the `if`-statement.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8492

Reviewed By: jay-zhuang

Differential Revision: D29571275

Pulled By: bjlemaire

fbshipit-source-id: 75d72246b70ebbbae7dea11ccb5778686d8bcbea
2021-07-06 18:48:56 -07:00
Baptiste Lemaire
9dc887ece0 Memtable "MemPurge" prototype (#8454)
Summary:
Implement an experimental feature called "MemPurge", which consists in purging "garbage" bytes out of a memtable and reuse the memtable struct instead of making it immutable and eventually flushing its content to storage.
The prototype is by default deactivated and is not intended for use. It is intended for correctness and validation testing. At the moment, the "MemPurge" feature can be switched on by using the `options.experimental_allow_mempurge` flag. For this early stage, when the allow_mempurge flag is set to `true`, all the flush operations will be rerouted to perform a MemPurge. This is a temporary design decision that will give us the time to explore meaningful heuristics to use MemPurge at the right time for relevant workloads . Moreover, the current MemPurge operation only supports `Puts`, `Deletes`, `DeleteRange` operations, and handles `Iterators` as well as `CompactionFilter`s that are invoked at flush time .
Three unit tests are added to `db_flush_test.cc` to test if MemPurge works correctly (and checks that the previously mentioned operations are fully supported thoroughly tested).
One noticeable design decision is the timing of the MemPurge operation in the memtable workflow: for this prototype, the mempurge happens when the memtable is switched (and usually made immutable). This is an inefficient process because it implies that the entirety of the MemPurge operation happens while holding the db_mutex. Future commits will make the MemPurge operation a background task (akin to the regular flush operation) and aim at drastically enhancing the performance of this operation. The MemPurge is also not fully "WAL-compatible" yet, but when the WAL is full, or when the regular MemPurge operation fails (or when the purged memtable still needs to be flushed), a regular flush operation takes place. Later commits will also correct these behaviors.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8454

Reviewed By: anand1976

Differential Revision: D29433971

Pulled By: bjlemaire

fbshipit-source-id: 6af48213554e35048a7e03816955100a80a26dc5
2021-07-02 05:23:02 -07:00
Akanksha Mahajan
c76778e2bd Call OnCompactionCompleted API in case of DisableManualCompaction (#8469)
Summary:
Call OnCompactionCompleted API in case of
DisableManualCompaction() with updated Status::Incomplete

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8469

Reviewed By: ajkr

Differential Revision: D29475517

Pulled By: akankshamahajan15

fbshipit-source-id: a1726c5e6ee18c0b5097ea04f5e6975fbe108055
2021-07-01 19:18:55 -07:00
Jay Zhuang
93a7389442 Add statistics support on CompactionService remote side (#8368)
Summary:
Add statistics option on CompactionService remote side.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8368

Test Plan: `make check`

Reviewed By: ajkr

Differential Revision: D28944427

Pulled By: jay-zhuang

fbshipit-source-id: 2a19217f4a69b6e511af87eed12391860ef00c5e
2021-06-29 11:48:14 -07:00
mrambacher
be219089ad Add BlobMetaData retrieval methods (#8273)
Summary:
Added BlobMetaData to ColumnFamilyMetaData and LiveBlobMetaData and DB API GetLiveBlobMetaData to retrieve it.

First pass at struct.  More tests and maybe fields to come...

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8273

Reviewed By: ltamasi

Differential Revision: D29102400

Pulled By: mrambacher

fbshipit-source-id: 8a2383a4446328be6b91dced9841fdd3dfc80b73
2021-06-28 08:13:29 -07:00
Zhichao Cao
a904c62d28 Using existing crc32c checksum in checksum handoff for Manifest and WAL (#8412)
Summary:
In PR https://github.com/facebook/rocksdb/issues/7523 , checksum handoff is introduced in RocksDB for WAL, Manifest, and SST files. When user enable checksum handoff for a certain type of file, before the data is written to the lower layer storage system, we calculate the checksum (crc32c) of each piece of data and pass the checksum down with the data, such that data verification can be down by the lower layer storage system if it has the capability. However, it cannot cover the whole lifetime of the data in the memory and also it potentially introduces extra checksum calculation overhead.

In this PR, we introduce a new interface in WritableFileWriter::Append, which allows the caller be able to pass the data and the checksum (crc32c) together. In this way, WritableFileWriter can directly use the pass-in checksum (crc32c) to generate the checksum of data being passed down to the storage system. It saves the calculation overhead and achieves higher protection coverage. When a new checksum is added with the data, we use Crc32cCombine https://github.com/facebook/rocksdb/issues/8305 to combine the existing checksum and the new checksum. To avoid the segmenting of data by rate-limiter before it is stored, rate-limiter is called enough times to accumulate enough credits for a certain write. This design only support Manifest and WAL which use log_writer in the current stage.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8412

Test Plan: make check, add new testing cases.

Reviewed By: anand1976

Differential Revision: D29151545

Pulled By: zhichao-cao

fbshipit-source-id: 75e2278c5126cfd58393c67b1efd18dcc7a30772
2021-06-25 00:47:17 -07:00
Jay Zhuang
54d73d6429 Fix DeleteFilesInRange may cause inconsistent compaction error (#8434)
Summary:
`DeleteFilesInRange()` marks deleting files to `being_compacted`
before deleting, which may cause ongoing compactions report corruption
exception or ASSERT for debug build.

Adding the missing `ComputeCompactionScore()` when `being_compacted` is set.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8434

Test Plan: Unittest

Reviewed By: ajkr

Differential Revision: D29276127

Pulled By: jay-zhuang

fbshipit-source-id: f5b223e3c1fc6d821e100e3f3442bc70c1d50cf7
2021-06-22 09:17:37 -07:00
Zhichao Cao
82a70e1470 Trace MultiGet Keys and CF_IDs to the trace file (#8421)
Summary:
Tracing the MultiGet information including timestamp, keys, and CF_IDs to the trace file for analyzing and replay.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8421

Test Plan: make check, add test to trace_analyzer_test

Reviewed By: anand1976

Differential Revision: D29221195

Pulled By: zhichao-cao

fbshipit-source-id: 30c677d6c39ab31ef4bbdf7e0d1fa1fd79f295ff
2021-06-18 15:04:05 -07:00
anand76
575ea26ec9 Don't log a warning if file system doesn't support ReopenWritableFile() (#8414)
Summary:
RocksDB logs a warning if WAL truncation on DB open fails. Its possible that on some file systems, truncation is not required and they would return ```Status::NotSupported()``` for ```ReopenWritableFile```. Don't log a warning in such cases.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8414

Reviewed By: akankshamahajan15

Differential Revision: D29181738

Pulled By: anand1976

fbshipit-source-id: 6e01e9117e1e4c1d67daa4dcee7fa59d06e057a7
2021-06-17 12:05:40 -07:00
mrambacher
d5bd0039b9 Rename ImmutableOptions variables (#8409)
Summary:
This is the next part of the ImmutableOptions cleanup.  After changing the use of ImmutableCFOptions to ImmutableOptions, there were places in the code that had did something like "ImmutableOptions* immutable_cf_options", where "cf" referred to the "old" type.

This change simply renames the variables to match the current type.  No new functionality is introduced.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8409

Reviewed By: pdillinger

Differential Revision: D29166248

Pulled By: mrambacher

fbshipit-source-id: 96de97f8e743f5c5160f02246e3ed8269556dc6f
2021-06-16 16:51:38 -07:00
Peter Dillinger
b3dbeadc34 Fix double-dumping CF stats to log (#8380)
Summary:
DBImpl::DumpStats is supposed to do this:
Dump DB stats to LOG
For each CF, dump CFStatsNoFileHistogram to LOG
For each CF, dump CFFileHistogram to LOG

Instead, due to a longstanding bug from 2017 (https://github.com/facebook/rocksdb/issues/2126), it would dump
CFStats, which includes both CFStatsNoFileHistogram and CFFileHistogram,
in both loops, resulting in near-duplicate output.

This fixes the bug.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8380

Test Plan: Manual inspection of LOG after db_bench

Reviewed By: jay-zhuang

Differential Revision: D29017535

Pulled By: pdillinger

fbshipit-source-id: 3010604c4a629a80347f129cd746ce9b0d0cbda6
2021-06-11 17:06:09 -07:00
Zhichao Cao
f44e69c64a Use DbSessionId as cache key prefix when secondary cache is enabled (#8360)
Summary:
Currently, we either use the file system inode or a monotonically incrementing runtime ID as the block cache key prefix. However, if we use a monotonically incrementing runtime ID (in the case that the file system does not support inode id generation), in some cases, it cannot ensure uniqueness (e.g., we have secondary cache migrated from host to host). We use DbSessionID (20 bytes) + current file number (at most 10 bytes) as the new cache block key prefix when the secondary cache is enabled. So can accommodate scenarios such as transfer of cache state across hosts.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8360

Test Plan: add the test to lru_cache_test

Reviewed By: pdillinger

Differential Revision: D29006215

Pulled By: zhichao-cao

fbshipit-source-id: 6cff686b38d83904667a2bd39923cd030df16814
2021-06-10 11:02:43 -07:00
David Devecsery
80a59a03a7 Cancel compact range (#8351)
Summary:
Added the ability to cancel an in-progress range compaction by storing to an atomic "canceled" variable pointed to within the CompactRangeOptions structure.

Tested via two tests added to db_tests2.cc.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8351

Reviewed By: ajkr

Differential Revision: D28808894

Pulled By: ddevec

fbshipit-source-id: cb321361c9e23b084b188bb203f11c375a22c2dd
2021-06-07 11:41:31 -07:00
Peter (Stig) Edwards
c75ef03e58 Do not truncate WAL if in read_only mode (#8313)
Summary:
I noticed ```openat``` system call with ```O_WRONLY``` flag and ```sync_file_range``` and ```truncate``` on WAL file when using ```rocksdb::DB::OpenForReadOnly``` by way of ```db_bench --readonly=true --benchmarks=readseq --use_existing_db=1 --num=1 ...```

Noticed in ```strace``` after seeing the last modification time of the WAL file change after each run (with ```--readonly=true```).

  I think introduced by 7d7f14480e from https://github.com/facebook/rocksdb/pull/8122

I added a test to catch the WAL file being truncated and the modification time on it changing.
I am not sure if a mock filesystem with mock clock could be used to avoid having to sleep 1.1s.
The test could also check the set of files is the same and that the sizes are also unchanged.

Before:

```
[ RUN      ] DBBasicTest.ReadOnlyReopenMtimeUnchanged
db/db_basic_test.cc:182: Failure
Expected equality of these values:
  file_mtime_after_readonly_reopen
    Which is: 1621611136
  file_mtime_before_readonly_reopen
    Which is: 1621611135
  file is: 000010.log
[  FAILED  ] DBBasicTest.ReadOnlyReopenMtimeUnchanged (1108 ms)
```

After:

```
[ RUN      ] DBBasicTest.ReadOnlyReopenMtimeUnchanged
[       OK ] DBBasicTest.ReadOnlyReopenMtimeUnchanged (1108 ms)
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8313

Reviewed By: pdillinger

Differential Revision: D28656925

Pulled By: jay-zhuang

fbshipit-source-id: ea9e215cb53e7c830e76bc5fc75c45e21f12a1d6
2021-05-27 10:27:55 -07:00
Jay Zhuang
3786181a90 Add remote compaction public API (#8300)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8300

Reviewed By: ajkr

Differential Revision: D28464726

Pulled By: jay-zhuang

fbshipit-source-id: 49e9f4fb791808a6cbf39a7b1a331373f645fc5e
2021-05-19 21:41:31 -07:00
mrambacher
8948dc8524 Make ImmutableOptions struct that inherits from ImmutableCFOptions and ImmutableDBOptions (#8262)
Summary:
The ImmutableCFOptions contained a bunch of fields that belonged to the ImmutableDBOptions.  This change cleans that up by introducing an ImmutableOptions struct.  Following the pattern of Options struct, this class inherits from the DB and CFOption structs (of the Immutable form).

Only one structural change (the ImmutableCFOptions::fs was changed to a shared_ptr from a raw one) is in this PR.  All of the other changes involve moving the member variables from the ImmutableCFOptions into the ImmutableOptions and changing member variables or function parameters as required for compilation purposes.

Follow-on PRs may do a further clean-up of the code, such as renaming variables (such as "ImmutableOptions cf_options") and potentially eliminating un-needed function parameters (there is no longer a need to pass both an ImmutableDBOptions and an ImmutableOptions to a function).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8262

Reviewed By: pdillinger

Differential Revision: D28226540

Pulled By: mrambacher

fbshipit-source-id: 18ae71eadc879dedbe38b1eb8e6f9ff5c7147dbf
2021-05-05 14:00:17 -07:00
Andrew Kryczka
c70bae1b05 Fix ConcurrentTaskLimiter token release for shutdown (#8253)
Summary:
Previously the shutdown process did not properly wait for all
`compaction_thread_limiter` tokens to be released before proceeding to
delete the DB's C++ objects. When this happened, we saw tests like
"DBCompactionTest.CompactionLimiter" flake with the following error:

```
virtual
rocksdb::ConcurrentTaskLimiterImpl::~ConcurrentTaskLimiterImpl():
Assertion `outstanding_tasks_ == 0' failed.
```

There is a case where a token can still be alive even after the shutdown
process has waited for BG work to complete. In particular, this happens
because the shutdown process only waits for flush/compaction scheduled/unscheduled counters to all
reach zero. These counters are decremented in `BackgroundCallCompaction()`
functions. However, tokens are released in `BGWork*Compaction()` functions, which
actually wrap the `BackgroundCallCompaction()` function.

A simple sleep could repro the race condition:

```
$ diff --git a/db/db_impl/db_impl_compaction_flush.cc
b/db/db_impl/db_impl_compaction_flush.cc
index 806bc548a..ba59efa89 100644
 --- a/db/db_impl/db_impl_compaction_flush.cc
+++ b/db/db_impl/db_impl_compaction_flush.cc
@@ -2442,6 +2442,7 @@ void DBImpl::BGWorkCompaction(void* arg) {
       static_cast<PrepickedCompaction*>(ca.prepicked_compaction);
   static_cast_with_check<DBImpl>(ca.db)->BackgroundCallCompaction(
       prepicked_compaction, Env::Priority::LOW);
+  sleep(1);
   delete prepicked_compaction;
 }

$ ./db_compaction_test --gtest_filter=DBCompactionTest.CompactionLimiter
db_compaction_test: util/concurrent_task_limiter_impl.cc:24: virtual rocksdb::ConcurrentTaskLimiterImpl::~ConcurrentTaskLimiterImpl(): Assertion `outstanding_tasks_ == 0' failed.
Received signal 6 (Aborted)
#0   /usr/local/fbcode/platform007/lib/libc.so.6(gsignal+0xcf) [0x7f02673c30ff] ??      ??:0
https://github.com/facebook/rocksdb/issues/1   /usr/local/fbcode/platform007/lib/libc.so.6(abort+0x134) [0x7f02673ac934] ??       ??:0
...
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8253

Test Plan: sleeps to expose race conditions

Reviewed By: akankshamahajan15

Differential Revision: D28168064

Pulled By: ajkr

fbshipit-source-id: 9e5167c74398d323e7975980c5cc00f450631160
2021-05-04 17:27:24 -07:00
Peter Dillinger
d2ca04e3ed Add more LSM info to FilterBuildingContext (#8246)
Summary:
Add `num_levels`, `is_bottommost`, and table file creation
`reason` to `FilterBuildingContext`, in anticipation of more powerful
Bloom-like filter support.

To support this, added `is_bottommost` and `reason` to
`TableBuilderOptions`, which allowed removing `reason` parameter from
`rocksdb::BuildTable`.

I attempted to remove `skip_filters` from `TableBuilderOptions`, because
filter construction decisions should arise from options, not one-off
parameters. I could not completely remove it because the public API for
SstFileWriter takes a `skip_filters` parameter, and translating this
into an option change would mean awkwardly replacing the table_factory
if it is BlockBasedTableFactory with new filter_policy=nullptr option.
I marked this public skip_filters option as deprecated because of this
oddity. (skip_filters on the read side probably makes sense.)

At least `skip_filters` is now largely hidden for users of
`TableBuilderOptions` and is no longer used for implementing the
optimize_filters_for_hits option. Bringing the logic for that option
closer to handling of FilterBuildingContext makes it more obvious that
hese two are using the same notion of "bottommost." (Planned:
configuration options for Bloom-like filters that generalize
`optimize_filters_for_hits`)

Recommended follow-up: Try to get away from "bottommost level" naming of
things, which is inaccurate (see
VersionStorageInfo::RangeMightExistAfterSortedRun), and move to
"bottommost run" or just "bottommost."

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8246

Test Plan:
extended an existing unit test to exercise and check various
filter building contexts. Also, existing tests for
optimize_filters_for_hits validate some of the "bottommost" handling,
which is now closely connected to FilterBuildingContext::is_bottommost
through TableBuilderOptions::is_bottommost

Reviewed By: mrambacher

Differential Revision: D28099346

Pulled By: pdillinger

fbshipit-source-id: 2c1072e29c24d4ac404c761a7b7663292372600a
2021-04-30 13:50:13 -07:00
Peter Dillinger
85becd94c1 Refactor: use TableBuilderOptions to reduce parameter lists (#8240)
Summary:
Greatly reduced the not-quite-copy-paste giant parameter lists
of rocksdb::NewTableBuilder, rocksdb::BuildTable,
BlockBasedTableBuilder::Rep ctor, and BlockBasedTableBuilder ctor.

Moved weird separate parameter `uint32_t column_family_id` of
TableFactory::NewTableBuilder into TableBuilderOptions.

Re-ordered parameters to TableBuilderOptions ctor, so that `uint64_t
target_file_size` is not randomly placed between uint64_t timestamps
(was easy to mix up).

Replaced a couple of fields of BlockBasedTableBuilder::Rep with a
FilterBuildingContext. The motivation for this change is making it
easier to pass along more data into new fields in FilterBuildingContext
(follow-up PR).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8240

Test Plan: ASAN make check

Reviewed By: mrambacher

Differential Revision: D28075891

Pulled By: pdillinger

fbshipit-source-id: fddb3dbb8260a0e8bdcbb51b877ebabf9a690d4f
2021-04-29 07:00:50 -07:00
mrambacher
01e460d538 Make types of Immutable/Mutable Options fields match that of the underlying Option (#8176)
Summary:
This PR is a first step at attempting to clean up some of the Mutable/Immutable Options code.  With this change, a DBOption and a ColumnFamilyOption can be reconstructed from their Mutable and Immutable equivalents, respectively.

readrandom tests do not show any performance degradation versus master (though both are slightly slower than the current 6.19 release).

There are still fields in the ImmutableCFOptions that are not CF options but DB options.  Eventually, I would like to move those into an ImmutableOptions (= ImmutableDBOptions+ImmutableCFOptions).  But that will be part of a future PR to minimize changes and disruptions.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8176

Reviewed By: pdillinger

Differential Revision: D27954339

Pulled By: mrambacher

fbshipit-source-id: ec6b805ba9afe6e094bffdbd76246c2d99aa9fad
2021-04-22 20:43:54 -07:00
Jay Zhuang
f0fca2b1d5 Add internal compaction API for Secondary instance (#8171)
Summary:
Add compaction API for secondary instance, which compact the files to a secondary DB path without installing to the LSM tree.
The API will be used to remote compaction.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8171

Test Plan: `make check`

Reviewed By: ajkr

Differential Revision: D27694545

Pulled By: jay-zhuang

fbshipit-source-id: 8ff3ec1bffdb2e1becee994918850c8902caf731
2021-04-22 13:02:28 -07:00
Zhichao Cao
09a9ec3ac0 Fix the false positive alert of CF consistency check in WAL recovery (#8207)
Summary:
In current RocksDB, in recover the information form WAL, we do the consistency check for each column family when one WAL file is corrupted and PointInTimeRecovery is set. However, it will report a false positive alert on "SST file is ahead of WALs" when one of the CF current log number is greater than the corrupted WAL number (CF contains the data beyond the corrupted WAl) due to a new column family creation during flush. In this case, a new WAL is created (it is empty) during a flush. Also, due to some reason (e.g., storage issue or crash happens before SyncCloseLog is called), the old WAL is corrupted. The new CF has no data, therefore, it does not have the consistency issue.

Fix: when checking cfd->GetLogNumber() > corrupted_wal_number also check cfd->GetLiveSstFilesSize() > 0. So the CFs with no SST file data will skip the check here.

Note potential ignored inconsistency caused due to fix: empty CF can also be caused by write+delete. In this case, after flush, there is no SST files being generated. However, this CF still have the log in the WAL. When the WAL is corrupted, the DB might be inconsistent.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8207

Test Plan: added unit test, make crash_test

Reviewed By: riversand963

Differential Revision: D27898839

Pulled By: zhichao-cao

fbshipit-source-id: 931fc2d8b92dd00b4169bf84b94e712fd688a83e
2021-04-22 10:28:37 -07:00
sdong
4985cea141 Add comment to DisableManualCompaction() (#8186)
Summary:
Add comment to DisableManualCompaction() which was missing.
Also explictly return from DBImpl::CompactRange() to avoid memtable flush when manual compaction is disabled.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8186

Test Plan: Run existing unit tests.

Reviewed By: jay-zhuang

Differential Revision: D27744517

fbshipit-source-id: 449548a48905903b888dc9612bd17480f6596a71
2021-04-21 15:23:46 -07:00
Akanksha Mahajan
596e9008e4 Stall writes in WriteBufferManager when memory_usage exceeds buffer_size (#7898)
Summary:
When WriteBufferManager is shared across DBs and column families
to maintain memory usage under a limit, OOMs have been observed when flush cannot
finish but writes continuously insert to memtables.
In order to avoid OOMs, when memory usage goes beyond buffer_limit_ and DBs tries to write,
this change will stall incoming writers until flush is completed and memory_usage
drops.

Design: Stall condition: When total memory usage exceeds WriteBufferManager::buffer_size_
(memory_usage() >= buffer_size_) WriterBufferManager::ShouldStall() returns true.

DBImpl first block incoming/future writers by calling write_thread_.BeginWriteStall()
(which adds dummy stall object to the writer's queue).
Then DB is blocked on a state State::Blocked (current write doesn't go
through). WBStallInterface object maintained by every DB instance is added to the queue of
WriteBufferManager.

If multiple DBs tries to write during this stall, they will also be
blocked when check WriteBufferManager::ShouldStall() returns true.

End Stall condition: When flush is finished and memory usage goes down, stall will end only if memory
waiting to be flushed is less than buffer_size/2. This lower limit will give time for flush
to complete and avoid continous stalling if memory usage remains close to buffer_size.

WriterBufferManager::EndWriteStall() is called,
which removes all instances from its queue and signal them to continue.
Their state is changed to State::Running and they are unblocked. DBImpl
then signal all incoming writers of that DB to continue by calling
write_thread_.EndWriteStall() (which removes dummy stall object from the
queue).

DB instance creates WBMStallInterface which is an interface to block and
signal DBs during stall.
When DB needs to be blocked or signalled by WriteBufferManager,
state_for_wbm_ state is changed accordingly (RUNNING or BLOCKED).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7898

Test Plan: Added a new test db/db_write_buffer_manager_test.cc

Reviewed By: anand1976

Differential Revision: D26093227

Pulled By: akankshamahajan15

fbshipit-source-id: 2bbd982a3fb7033f6de6153aa92a221249861aae
2021-04-21 13:54:02 -07:00
Yanqin Jin
a376c22066 Handle rename() failure in non-local FS (#8192)
Summary:
In a distributed environment, a file `rename()` operation can succeed on server (remote)
side, but the client can somehow return non-ok status to RocksDB. Possible reasons include
network partition, connection issue, etc. This happens in `rocksdb::SetCurrentFile()`, which
can be called in `LogAndApply() -> ProcessManifestWrites()` if RocksDB tries to switch to a
new MANIFEST. We currently always delete the new MANIFEST if an error occurs.

This is problematic in distributed world. If the server-side successfully updates the CURRENT
file via renaming, then a subsequent `DB::Open()` will try to look for the new MANIFEST and fail.

As a fix, we can track the execution result of IO operations on the new MANIFEST.
- If IO operations on the new MANIFEST fail, then we know the CURRENT must point to the original
  MANIFEST. Therefore, it is safe to remove the new MANIFEST.
- If IO operations on the new MANIFEST all succeed, but somehow we end up in the clean up
  code block, then we do not know whether CURRENT points to the new or old MANIFEST. (For local
  POSIX-compliant FS, it should still point to old MANIFEST, but it does not matter if we keep the
  new MANIFEST.) Therefore, we keep the new MANIFEST.
    - Any future `LogAndApply()` will switch to a new MANIFEST and update CURRENT.
    - If process reopens the db immediately after the failure, then the CURRENT file can point
      to either the new MANIFEST or the old one, both of which exist. Therefore, recovery can
      succeed and ignore the other.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8192

Test Plan: make check

Reviewed By: zhichao-cao

Differential Revision: D27804648

Pulled By: riversand963

fbshipit-source-id: 9c16f2a5ce41bc6aadf085e48449b19ede8423e4
2021-04-19 18:11:13 -07:00
Yanqin Jin
b1f62be10e Use the right level (L0) for files written during WAL recovery (#8187)
Summary:
As the name of `DBImpl::WriteLevel0TableForRecovery` suggests, the resulting table file
should be placed on L0. However, the argument `level` passed to `BuildTable()` is -1.

We need to correct this since the level information will be useful to determine file placement.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8187

Test Plan: make check

Reviewed By: ltamasi

Differential Revision: D27748570

Pulled By: riversand963

fbshipit-source-id: e1cd23128a8de31f14b1edc2ea92754c154e4f10
2021-04-14 23:40:22 -07:00
Giuseppe Ottaviano
48cd7a3aae Fix flush reason attribution (#8150)
Summary:
Current flush reason attribution is misleading or incorrect (depending on what the original intention was):

- Flush due to WAL reaching its maximum size is attributed to `kWriteBufferManager`
- Flushes due to full write buffer and write buffer manager are not distinguishable, both are attributed to `kWriteBufferFull`

This changes the first to a new flush reason `kWALFull`, and splits the second between `kWriteBufferManager` and `kWriteBufferFull`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8150

Reviewed By: zhichao-cao

Differential Revision: D27569645

Pulled By: ot

fbshipit-source-id: 7e3c8ca186a6e71976e6b8e937297eebd4b769cc
2021-04-07 23:18:37 -07:00
Peter Dillinger
a4e82a3cca Fix read-only DB writing to filesystem with write_dbid_to_manifest (#8164)
Summary:
Fixing another crash test failure in the case of
write_dbid_to_manifest=true and reading a backup as read-only DB.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8164

Test Plan:
enhanced unit test for backup as read-only DB, ran
blackbox_crash_test more with elevated backup_one_in

Reviewed By: zhichao-cao

Differential Revision: D27622237

Pulled By: pdillinger

fbshipit-source-id: 680d0f99ddb465a601737f2e3f2c80efd47384fb
2021-04-07 10:26:47 -07:00
Peter Dillinger
879357fdb0 Make backups openable as read-only DBs (#8142)
Summary:
A current limitation of backups is that you don't know the
exact database state of when the backup was taken. With this new
feature, you can at least inspect the backup's DB state without
restoring it by opening it as a read-only DB.

Rather than add something like OpenAsReadOnlyDB to the BackupEngine API,
which would inhibit opening stackable DB implementations read-only
(if/when their APIs support it), we instead provide a DB name and Env
that can be used to open as a read-only DB.

Possible follow-up work:

* Add a version of GetBackupInfo for a single backup.
* Let CreateNewBackup return the BackupID of the newly-created backup.

Implementation details:

Refactored ChrootFileSystem to split off new base class RemapFileSystem,
which allows more general remapping of files. We use this base class to
implement BackupEngineImpl::RemapSharedFileSystem.

To minimize API impact, I decided to just add these fields `name_for_open`
and `env_for_open` to those set by GetBackupInfo when
include_file_details=true. Creating the RemapSharedFileSystem adds a bit
to the memory consumption, perhaps unnecessarily in some cases, but this
has been mitigated by (a) only initialize the RemapSharedFileSystem
lazily when GetBackupInfo with include_file_details=true is called, and
(b) using the existing `shared_ptr<FileInfo>` objects to hold most of the
mapping data.

To enhance API safety, RemapSharedFileSystem is wrapped by new
ReadOnlyFileSystem which rejects any attempts to write. This uncovered a
couple of places in which DB::OpenForReadOnly would write to the
filesystem, so I fixed these. Added a release note because this affects
logging.

Additional minor refactoring in backupable_db.cc to support the new
functionality.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8142

Test Plan:
new test (run with ASAN and UBSAN), added to stress test and
ran it for a while with amplified backup_one_in

Reviewed By: ajkr

Differential Revision: D27535408

Pulled By: pdillinger

fbshipit-source-id: 04666d310aa0261ef6b2385c43ca793ce1dfd148
2021-04-06 14:37:53 -07:00
Akanksha Mahajan
689b13e639 Add request_id in IODebugContext. (#8045)
Summary:
Add request_id in IODebugContext which will be populated by
    underlying FileSystem for IOTracing purposes. Update IOTracer to trace
    request_id in the tracing records. Provided API
    IODebugContext::SetRequestId which will set the request_id and enable
    tracing for request_id. The API hides the implementation and underlying
    file system needs to call this API directly.

Update DB::StartIOTrace API and remove redundant Env* from the
    argument as its not used and DB already has Env that is passed down to
    IOTracer.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8045

Test Plan: Update unit test.

Differential Revision: D26899871

Pulled By: akankshamahajan15

fbshipit-source-id: 56adef52ee5af0fb3060b607c3af1ec01635fa2b
2021-04-01 13:14:51 -07:00