Summary:
Previously, the `MemPurge` sampling function was assessing whether a random entry from a memtable was garbage or not by simply querying the given memtable (see https://github.com/facebook/rocksdb/issues/8628 for more details).
In this diff, I am updating the sampling function by querying not only the memtable the entry was drawn from, but also all subsequent memtables that have a greater memtable ID.
I also added the size of the value for KV entries in the payload/useful payload estimates (which was also one of the reasons why sampling was not as good as mempurging all the time in terms of L0 SST files reduction).
Once these changes were made, I was able to clean obsolete objects and functions from the `MemtableList` struct, and did a bit of cleanup everywhere.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8656
Reviewed By: pdillinger
Differential Revision: D30288583
Pulled By: bjlemaire
fbshipit-source-id: 7646a545ec56f4715949daa59ab5eee74540feb3
Summary:
- Remove extra `;` in trace_record.h
- Remove some unnecessary `assert` in trace_record_handler.cc
- Initialize `env_` after` exec_handler_` in `ReplayerImpl` to let db be asserted in creating the handler before getting `db->GetEnv()`.
- Update history to include the new `TraceReader::Reset()`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8652
Reviewed By: ajkr
Differential Revision: D30276872
Pulled By: autopear
fbshipit-source-id: 476ee162e0f241490c6209307448343a5b326b37
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
Summary:
Current internal regression tests pass in an old option flag `experimental_allow_mempurge` to a more recently built db.
This flag was retired and removed in a recent PR (https://github.com/facebook/rocksdb/issues/8628), and therefore, the following error comes up : `Failed: Invalid argument: Could not find option: : experimental_allow_mempurge`.
In this PR, I reintroduce the two flags retired in https://github.com/facebook/rocksdb/issues/8628, `experimental_allow_mempurge` and `experimental_mempurge_policy` in `db_options.cc` and mark them both as `kDeprecated`.
This is a temporary fix to save us time to find a long term solution, which hopefully will consist in ignoring options prefixed with `experimental_` that are no longer recognized.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8650
Reviewed By: pdillinger
Differential Revision: D30257307
Pulled By: bjlemaire
fbshipit-source-id: 35303655fd2dd9789fd9e3c450e9d8009f3c1f54
Summary:
The last few releases overlooked adding to this test. This
change fixes that.
This change also fixes the problem of older branches not understanding
ROCKSDB_NO_FBCODE and referencing compilers no longer supported.
During the test, build_detect_platform is patched to force no FBCODE
compiler usage. (We should not need to update old branches perpetually.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8651
Test Plan: local run reproduces regression described in https://github.com/facebook/rocksdb/issues/8650
Reviewed By: jay-zhuang, zhichao-cao
Differential Revision: D30261872
Pulled By: pdillinger
fbshipit-source-id: 02b447d224d7e0eb8613c63185437ded146713bc
Summary:
Add comment for `options.allow_fallocate` that btrfs
preallocated space are not freed and a suggestion to disable
preallocation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8646
Test Plan: No code change
Reviewed By: ajkr
Differential Revision: D30240050
Pulled By: jay-zhuang
fbshipit-source-id: 75b7190bc8276ce8d8ac2d0cb9064b386cbf4768
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
Summary:
The patch attempts to deflake `DBTestXactLogIterator.TransactionLogIteratorCorruptedLog`
by disabling file deletions while retrieving the list of WAL files and truncating the first WAL file.
This is to prevent the `PurgeObsoleteFiles` call triggered by `GetSortedWalFiles` from
invalidating the result of `GetSortedWalFiles`. The patch also cleans up the test case a bit
and changes it to using `test::TruncateFile` instead of calling the `truncate` syscall directly.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8627
Test Plan: `make check`
Reviewed By: akankshamahajan15
Differential Revision: D30147002
Pulled By: ltamasi
fbshipit-source-id: db11072a4ad8900a2f859cb5294e22b1888c23f6
Summary:
`GenericRateLimiter` slow path handles requests that cannot be satisfied
immediately. Such requests enter a queue, and their thread stays in `Request()`
until they are granted or the rate limiter is stopped. These threads are
responsible for unblocking themselves. The work to do so is split into two main
duties.
(1) Waiting for the next refill time.
(2) Refilling the bytes and granting requests.
Prior to this PR, the slow path logic involved a leader election algorithm to
pick one thread to perform (1) followed by (2). It elected the thread whose
request was at the front of the highest priority non-empty queue since that
request was most likely to be granted. This algorithm was efficient in terms of
reducing intermediate wakeups, which is a thread waking up only to resume
waiting after finding its request is not granted. However, the conceptual
complexity of this algorithm was too high. It took me a long time to draw a
timeline to understand how it works for just one edge case yet there were so
many.
This PR drops the leader election to reduce conceptual complexity. Now, the two
duties can be performed by whichever thread acquires the lock first. The risk
of this change is increasing the number of intermediate wakeups, however, we
took steps to mitigate that.
- `wait_until_refill_pending_` flag ensures only one thread performs (1). This\
prevents the thundering herd problem at the next refill time. The remaining\
threads wait on their condition variable with an unbounded duration -- thus we\
must remember to notify them to ensure forward progress.
- (1) is typically done by a thread at the front of a queue. This is trivial\
when the queues are initially empty as the first choice that arrives must be\
the only entry in its queue. When queues are initially non-empty, we achieve\
this by having (2) notify a thread at the front of a queue (preferring higher\
priority) to perform the next duty.
- We do not require any additional wakeup for (2). Typically it will just be\
done by the thread that finished (1).
Combined, the second and third bullet points above suggest the refill/granting
will typically be done by a request at the front of its queue. This is
important because one wakeup is saved when a granted request happens to be in an
already running thread.
Note there are a few cases that still lead to intermediate wakeup, however. The
first two are existing issues that also apply to the old algorithm, however, the
third (including both subpoints) is new.
- No request may be granted (only possible when rate limit dynamically\
decreases).
- Requests from a different queue may be granted.
- (2) may be run by a non-front request thread causing it to not be granted even\
if some requests in that same queue are granted. It can happen for a couple\
(unlikely) reasons.
- A new request may sneak in and grab the lock at the refill time, before the\
thread finishing (1) can wake up and grab it.
- A new request may sneak in and grab the lock and execute (1) before (2)'s\
chosen candidate can wake up and grab the lock. Then that non-front request\
thread performing (1) can carry over to perform (2).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8602
Test Plan:
- Use existing tests. The edge cases listed in the comment are all performance\
related; I could not really think of any related to correctness. The logic\
looks the same whether a thread wakes up/finishes its work early/on-time/late,\
or whether the thread is chosen vs. "steals" the work.
- Verified write throughput and CPU overhead are basically the same with and\
without this change, even in a rate limiter heavy workload:
Test command:
```
$ rm -rf /dev/shm/dbbench/ && TEST_TMPDIR=/dev/shm /usr/bin/time ./db_bench -benchmarks=fillrandom -num_multi_db=64 -num_low_pri_threads=64 -num_high_pri_threads=64 -write_buffer_size=262144 -target_file_size_base=262144 -max_bytes_for_level_base=1048576 -rate_limiter_bytes_per_sec=16777216 -key_size=24 -value_size=1000 -num=10000 -compression_type=none -rate_limiter_refill_period_us=1000
```
Results before this PR:
```
fillrandom : 108.463 micros/op 9219 ops/sec; 9.0 MB/s
7.40user 8.84system 1:26.20elapsed 18%CPU (0avgtext+0avgdata 256140maxresident)k
```
Results after this PR:
```
fillrandom : 108.108 micros/op 9250 ops/sec; 9.0 MB/s
7.45user 8.23system 1:26.68elapsed 18%CPU (0avgtext+0avgdata 255688maxresident)k
```
Reviewed By: hx235
Differential Revision: D30048013
Pulled By: ajkr
fbshipit-source-id: 6741bba9d9dfbccab359806d725105817fef818b
Summary: UBSAN revealed a pointer underflow when `LZ4HC_init_internal` is called with a null `start`.
Reviewed By: ajkr
Differential Revision: D30181874
fbshipit-source-id: ca9bbac1a85c58782871d7f153af733b000cc66c
Summary:
Some FIFO users want to keep the data for longer, but the old data is rarely accessed. This feature allows users to configure FIFO compaction so that data older than a threshold is moved to a warm storage tier.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8310
Test Plan: Add several unit tests.
Reviewed By: ajkr
Differential Revision: D28493792
fbshipit-source-id: c14824ea634814dee5278b449ab5c98b6e0b5501
Summary:
FaultInjectionTestFS injects error in Rename operation. Because
of injected error, info.log fails to be created if rename returns error and info_log is set to nullptr which leads to this assertion
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8632
Test Plan: run the db_stress job locally
Reviewed By: ajkr
Differential Revision: D30167387
Pulled By: akankshamahajan15
fbshipit-source-id: 8d08c4c33e8f0cabd368bbb498d21b9de0660067
Summary:
This draining mechanism should not be run during `JoinThreads()` because it can detach threads that will be joined. Joining detached threads would throw an exception.
With this PR, we skip draining when `JoinThreads()` has already decided what threads to `join()`, so the threads will exit naturally once the work queue empties.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8635
Test Plan: verified it unblocked using `WaitForJobsAndJoinAllThreads()` in https://github.com/facebook/rocksdb/issues/8611.
Reviewed By: riversand963
Differential Revision: D30174587
Pulled By: ajkr
fbshipit-source-id: 144966398a607987e0763c7152a0f653fdbf3c8b
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
Summary:
Guarantees that if a restore is interrupted, DB::Open will fail. This works by
restoring CURRENT first to CURRENT.tmp then as a final step renaming to CURRENT.
Also makes restore respect BackupEngineOptions::sync (default true). When set,
the restore is guaranteed persisted by the time it returns OK. Also makes the above
atomicity guarantee work in case the interruption is power loss or OS crash (not just
process interruption or crash).
Fixes https://github.com/facebook/rocksdb/issues/8500
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8568
Test Plan:
added to backup mini-stress unit test. Passes with
gtest_repeat=100 (whereas fails 7 times without the CURRENT.tmp)
Reviewed By: akankshamahajan15
Differential Revision: D29812605
Pulled By: pdillinger
fbshipit-source-id: 24e9a993b305b1835ca95558fa7a7152e54cda8e
Summary:
By default, the low priority pool is not the flush pool, so calling `Env#setBackgroundThreads` without providing a priority will not do what the caller expected.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8576
Reviewed By: ajkr
Differential Revision: D29925154
Pulled By: mrambacher
fbshipit-source-id: cd7211fc374e7d9929a9b88ea0a5ba8134b76099
Summary:
- Changed MergeOperator, CompactionFilter, and CompactionFilterFactory into Customizable classes.
- Added Options/Configurable/Object Registration for TTL and Cassandra variants
- Changed the StringAppend MergeOperators to accept a string delimiter rather than a simple char. Made the delimiter into a configurable option
- Added tests for new functionality
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8481
Reviewed By: zhichao-cao
Differential Revision: D30136050
Pulled By: mrambacher
fbshipit-source-id: 271d1772835935b6773abaf018ee71e42f9491af
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
Summary:
Previously we attempted to rename "LOG" to "LOG.old.*" without checking
its existence first. "LOG" had no reason to exist in a new DB.
Errors in renaming a non-existent "LOG" were swallowed via
`PermitUncheckedError()` so things worked. However the storage service's
error monitoring was detecting all these benign rename failures. So it
is better to fix it. Also with this PR we can now distinguish rename failure
for other reasons and return them.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8622
Test Plan: new unit test
Reviewed By: akankshamahajan15
Differential Revision: D30115189
Pulled By: ajkr
fbshipit-source-id: e2f337ffb2bd171be0203172abc8e16e7809b170
Summary:
```FaultInjectionTestFS``` injects various types of read errors in ```FileSystem``` APIs. One type of error is corruption errors, where data is intentionally corrupted or truncated. There is corresponding validation in db_stress to verify that an injected error results in a user visible Get/MultiGet error. However, for corruption errors, its hard to know when a corruption is supposed to be detected by the user request, due to prefetching and, in case of direct IO, padding. This results in false positives. So remove that functionality.
Block checksum validation for Get/MultiGet is confined to ```BlockFetcher```, so we don't lose a lot by disabling this since its a small surface area to test.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8616
Reviewed By: zhichao-cao
Differential Revision: D30074422
Pulled By: anand1976
fbshipit-source-id: 6a61fac18f95514c15364b75013799ddf83294df
Summary:
Context:
As need for new feature of resource management using RocksDB's rate limiter like [https://github.com/facebook/rocksdb/issues/8595](https://github.com/facebook/rocksdb/pull/8595) arises, it is about time to re-learn our rate limiter and make this learning process easier for others by improving its readability. The comment/assertion/one extra else-branch are added based on my best understanding toward the rate_limiter.cc and rate_limiter_test.cc up to date after giving it a hard read.
- Add code comments/assertion/one extra else-branch (that is not affecting existing behavior, see PR comment) to describe how leader-election works under multi-thread settings in GenericRateLimiter::Request()
- Add code comments to describe a non-obvious trick during clean-up of rate limiter destructor
- Add code comments to explain more about the starvation being fixed in GenericRateLimiter::Refill() through partial byte-granting
- Add code comments to the rate limiter's setup in a complicated unit test in rate_limiter_test
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8596
Test Plan: - passed existing rate_limiter_test.cc
Reviewed By: ajkr
Differential Revision: D29982590
Pulled By: hx235
fbshipit-source-id: c3592986bb5b0c90d8229fe44f425251ec7e8a0a
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
Summary:
Insert warm blocks (data, uncompressed dict, index and filter blocks) during flush in Block cache which is enabled under option BlockBasedTableOptions.prepopulate_block_cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8561
Test Plan: Added unit test
Reviewed By: anand1976
Differential Revision: D29773411
Pulled By: akankshamahajan15
fbshipit-source-id: 6631123c10134340ef0bd7e90baafaa6deba0e66
Summary:
The db_stress crash was caused by a call to `IsFlushPending()` made by a stats function which triggered an `assert([false])`, which I didn't plan when I created the `trigger_flush` bool. It turns out that this bool variable is not useful: I created it because I thought the `imm_flush_needed` atomic bool would actually trigger a flush.
It turns out that this bool is only checked in `IsFlushPending` - this is its only use - and a flush is triggered by either a background thread checking on the imm array, or by an explicit call to `SchedulePendingFlush` which creates a flush request, that is then added to a flush request queue.
In this PR, I reverted the MemtableList::Add function to what it was before my changes.
I tested the fix by running the exact command line that deterministically triggered the assert error (see below), which confirmed that this is where the error was coming from.
I also run `db_crashtest.py whitebox` and `blackbox` for a couple hours locally before committing this PR.
Experiment run:
```./db_stress --acquire_snapshot_one_in=0 --allow_concurrent_memtable_write=1 --avoid_flush_during_recovery=0 --avoid_unnecessary_blocking_io=1 --backup_max_size=104857600 --backup_one_in=100000 --batch_protection_bytes_per_key=0 --block_size=16384 --bloom_bits=76.90653425292307 --bottommost_compression_type=disable --cache_index_and_filter_blocks=1 --cache_size=1048576 --checkpoint_one_in=1000000 --checksum_type=kCRC32c --clear_column_family_one_in=0 --column_families=1 --compact_files_one_in=1000000 --compact_range_one_in=0 --compaction_ttl=2 --compression_max_dict_buffer_bytes=0 --compression_max_dict_bytes=0 --compression_parallel_threads=1 --compression_type=zstd --compression_zstd_max_train_bytes=0 --continuous_verification_interval=0 --db=/dev/shm/rocksdb/rocksdb_crashtest_blackbox --db_write_buffer_size=0 --delpercent=4 --delrangepercent=1 --destroy_db_initially=0 --enable_compaction_filter=1 --enable_pipelined_write=0 --expected_values_path=/dev/shm/rocksdb/rocksdb_crashtest_expected --experimental_allow_mempurge=1 --experimental_mempurge_policy=kAlternate --fail_if_options_file_error=1 --file_checksum_impl=none --flush_one_in=1000000 --format_version=2 --get_current_wal_file_one_in=0 --get_live_files_one_in=1000000 --get_property_one_in=1000000 --get_sorted_wal_files_one_in=0 --index_block_restart_interval=14 --index_type=0 --iterpercent=0 --key_len_percent_dist=1,30,69 --level_compaction_dynamic_level_bytes=False --long_running_snapshots=1 --mark_for_compaction_one_file_in=10 --max_background_compactions=1 --max_bytes_for_level_base=67108864 --max_key=100000000 --max_key_len=3 --max_manifest_file_size=1073741824 --max_write_batch_group_size_bytes=64 --max_write_buffer_number=3 --max_write_buffer_size_to_maintain=0 --memtablerep=skip_list --mmap_read=0 --mock_direct_io=True --nooverwritepercent=1 --open_files=-1 --open_metadata_write_fault_one_in=8 --open_read_fault_one_in=32 --open_write_fault_one_in=16 --ops_per_thread=100000000 --optimize_filters_for_memory=1 --paranoid_file_checks=0 --partition_filters=0 --partition_pinning=0 --pause_background_one_in=1000000 --periodic_compaction_seconds=1000 --prefix_size=-1 --prefixpercent=0 --progress_reports=0 --read_fault_one_in=0 --readpercent=60 --recycle_log_file_num=1 --reopen=20 --set_options_one_in=0 --snapshot_hold_ops=100000 --sst_file_manager_bytes_per_sec=104857600 --sst_file_manager_bytes_per_truncate=0 --subcompactions=3 --sync=1 --sync_fault_injection=False --target_file_size_base=16777216 --target_file_size_multiplier=1 --test_batches_snapshots=0 --top_level_index_pinning=1 --unpartitioned_pinning=3 --use_clock_cache=0 --use_direct_io_for_flush_and_compaction=1 --use_direct_reads=0 --use_full_merge_v1=1 --use_merge=0 --use_multiget=0 --use_ribbon_filter=1 --user_timestamp_size=0 --verify_checksum=1 --verify_checksum_one_in=1000000 --verify_db_one_in=100000 --write_buffer_size=33554432 --write_dbid_to_manifest=1 --writepercent=35```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8604
Reviewed By: pdillinger
Differential Revision: D30047295
Pulled By: bjlemaire
fbshipit-source-id: b9e379bfa3d6b9bd2b275725fb0bca4bd81a3dbe
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
Summary:
An arbitrary string can be used as a delimiter in StringAppend merge operator
flavor. In particular, it allows using an empty string, combining binary values for
the same key byte-to-byte one next to another.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8536
Reviewed By: mrambacher
Differential Revision: D29962120
Pulled By: zhichao-cao
fbshipit-source-id: 4ef5d846a47835cf428a11200409e30e2dbffc4f
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
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
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
Summary:
Introduction of a new `fillanddeleteuniquerandom` benchmark (`db_bench`) with 5 new option flags to simulate a benchmark where the following sequence is repeated multiple times:
"A set of keys S1 is inserted ('`disposable entries`'), then after some delay another set of keys S2 is inserted ('`persistent entries`') and the first set of keys S1 is deleted. S2 artificially represents the insertion of hypothetical results from some undefined computation done on the first set of keys S1. The next sequence can start as soon as the last disposable entry in the set S1 of this sequence is inserted, if the `delay` is non negligible."
New flags:
- `disposable_entries_delete_delay`: minimum delay in microseconds between insertion of the last `disposable` entry, and the start of the insertion of the first `persistent` entry.
- `disposable_entries_batch_size`: number of `disposable` entries inserted at the beginning of each sequence.
- `disposable_entries_value_size`: size of the random `value` string for the `disposable` entries.
- `persistent_entries_batch_size`: number of `persistent` entries inserted at the end of each sequence, right before the deletion of the `disposable` entries starts.
- `persistent_entries_value_size`: size of the random value string for the `persistent` entries.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8593
Reviewed By: pdillinger
Differential Revision: D29974436
Pulled By: bjlemaire
fbshipit-source-id: f578033e5b45e8268ba6fa6f38f4770c2e6e801d
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
Summary:
* Basic handling of SST file with just range tombstones rather than
failing assertion about smallest_seqno <= largest_seqno
* Adds --verbose option so that there exists a way to see the INFO
output from Repairer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8544
Test Plan: unit test added, manual testing for --verbose
Reviewed By: ajkr
Differential Revision: D29954805
Pulled By: pdillinger
fbshipit-source-id: 696af25805fc36cc178b04ba6045922a22625fd9
Summary:
Internal task T96186510.
Created new inline member functions in `CompactionIterator`,
`DefinitelyInSnapshot`, `DefinitelyNotInSnapshot`, and
`InEarliestSnapshot` to replace the macros at the top of
`compaction_iterator.cc`.
Placed the definitions in `compaction_iterator.h` in accordance with
Google's style guide for inline functions. Separated the declarations
and definitions, and only placed the `inline` keyword on the
definitions, in line with ISO CPP recommendations.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8592
Test Plan: Ran `make check`. Successful build and all tests appeared to pass.
Reviewed By: riversand963
Differential Revision: D29966782
Pulled By: jimmycFB
fbshipit-source-id: 3584290bbbabf862e9ab58852281f46d37f58be6
Summary:
Add `experimental_mempurge_policy` flag to `db_stress` and `db_crashtest.py`.
This flag is only read if the `experimental_allow_mempurge` flag is set to `true`. This flag can take the following values: `kAlways`, and `kAlternate` (default).
- `kAlways`: a flush is always redirected to a mempurge. If the mempurge aborts, the a regular flush proceeds.
- `kAlternate`: if one or more of the flush input memtables is an mempurge output memtable, then a flush is performed, else a mempurge is carried out. Similar to kAlways, if a mempurge aborts, the FlushJob proceeds to a regular flush to storage.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8588
Reviewed By: pdillinger
Differential Revision: D29934251
Pulled By: bjlemaire
fbshipit-source-id: 90c1debed2029b9915d066914556547507c33dae
