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
Summary:
The current BlobDB garbage collection logic works by relocating the valid
blobs from the oldest blob files as they are encountered during compaction,
and cleaning up blob files once they contain nothing but garbage. However,
with sufficiently skewed workloads, it is theoretically possible to end up in a
situation when few or no compactions get scheduled for the SST files that contain
references to the oldest blob files, which can lead to increased space amp due
to the lack of GC.
In order to efficiently handle such workloads, the patch adds a new BlobDB
configuration option called `blob_garbage_collection_force_threshold`,
which signals to BlobDB to schedule targeted compactions for the SST files
that keep alive the oldest batch of blob files if the overall ratio of garbage in
the given blob files meets the threshold *and* all the given blob files are
eligible for GC based on `blob_garbage_collection_age_cutoff`. (For example,
if the new option is set to 0.9, targeted compactions will get scheduled if the
sum of garbage bytes meets or exceeds 90% of the sum of total bytes in the
oldest blob files, assuming all affected blob files are below the age-based cutoff.)
The net result of these targeted compactions is that the valid blobs in the oldest
blob files are relocated and the oldest blob files themselves cleaned up (since
*all* SST files that rely on them get compacted away).
These targeted compactions are similar to periodic compactions in the sense
that they force certain SST files that otherwise would not get picked up to undergo
compaction and also in the sense that instead of merging files from multiple levels,
they target a single file. (Note: such compactions might still include neighboring files
from the same level due to the need of having a "clean cut" boundary but they never
include any files from any other level.)
This functionality is currently only supported with the leveled compaction style
and is inactive by default (since the default value is set to 1.0, i.e. 100%).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8994
Test Plan: Ran `make check` and tested using `db_bench` and the stress/crash tests.
Reviewed By: riversand963
Differential Revision: D31489850
Pulled By: ltamasi
fbshipit-source-id: 44057d511726a0e2a03c5d9313d7511b3f0c4eab
Summary:
Enable SingleDelete with user defined timestamp in db_bench,
db_stress and crash test
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8971
Test Plan:
1. For db_stress, ran the command for full duration: i) python3 -u tools/db_crashtest.py
--enable_ts whitebox --nooverwritepercent=100
ii) make crash_test_with_ts
2. For db_bench, ran: ./db_bench -benchmarks=randomreplacekeys
-user_timestamp_size=8 -use_single_deletes=true
Reviewed By: riversand963
Differential Revision: D31246558
Pulled By: akankshamahajan15
fbshipit-source-id: 29cd8740c9921341e52f09242fca3c44d75a12b7
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
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
Summary:
This is essentially resurrection and fixing of the part of
https://github.com/facebook/rocksdb/issues/8198 that was reverted in https://github.com/facebook/rocksdb/issues/8212, using data added in https://github.com/facebook/rocksdb/issues/8246. Basically,
when configuring Ribbon filter, you can specify an LSM level before which
Bloom will be used instead of Ribbon. But Bloom is only considered for
Leveled and Universal compaction styles and file going into a known LSM
level. This way, SST file writer, FIFO compaction, etc. use Ribbon filter as
you would expect with NewRibbonFilterPolicy.
So that this can be controlled with a single int value and so that flushes
can be distinguished from intra-L0, we consider flush to go to level -1 for
the purposes of this option. (Explained in API comment.)
I also expect the most common and recommended Ribbon configuration to
use Bloom during flush, to minimize slowing down writes and because according
to my estimates, Ribbon only pays off if the structure lives in memory for
more than an hour. Thus, I have changed the default for NewRibbonFilterPolicy
to be this mild hybrid configuration. I don't really want to add something like
NewHybridFilterPolicy because at least the mild hybrid configuration (Bloom for
flush, Ribbon otherwise) should be considered a natural choice.
C APIs also updated, but because they don't support overloading,
rocksdb_filterpolicy_create_ribbon is kept pure ribbon for clarity and
rocksdb_filterpolicy_create_ribbon_hybrid must be called for a hybrid
configuration. While touching C API, I changed bits per key options from
int to double.
BuiltinFilterPolicy is needed so that LevelThresholdFilterPolicy doesn't inherit
unused fields from BloomFilterPolicy.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8679
Test Plan: new + updated tests, including crash test
Reviewed By: jay-zhuang
Differential Revision: D30445797
Pulled By: pdillinger
fbshipit-source-id: 6f5aeddfd6d79f7e55493b563c2d1d2d568892e1
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:
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:
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
Summary:
https://github.com/facebook/rocksdb/pull/8548 is not complete. We should instead cover all cases writable files are buffered, not just when failures are ingested. Extend it to any case where failures are ingested in DB open.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8570
Test Plan: Run db_stress and see it doesn't break
Reviewed By: jay-zhuang
Differential Revision: D29830415
fbshipit-source-id: 94449a0468fb2f7eec17423724008c9c63b2445d
Summary:
Delete column family handlers before deleting db to avoid `last_ref`
assert.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8564
Test Plan: Inject compaction test in db_stress test
Reviewed By: pdillinger
Differential Revision: D29797375
Pulled By: jay-zhuang
fbshipit-source-id: e8baf4d279f4db5d963db95c9445454156205501
Summary:
Already has good coverage for GetProperty and GetIntProperty
but this one was missing.
This should add more confidence to https://github.com/facebook/rocksdb/issues/8538
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8551
Test Plan:
brief local run with boosted probability showed no immediate
issues
Reviewed By: siying
Differential Revision: D29746383
Pulled By: pdillinger
fbshipit-source-id: 9f9f525bc1a7607f85e563e33bda1979ef197127
Summary:
When DB Stress enables write failure in reopen, WAL files are also created with a wrapper writalbe file which buffers write until fsync. However, crash test currently expects all writes to WAL is persistent. This is at odd with the unsynced bytes dropped. To work it around temporarily, we disable WAL write failure for now.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8548
Test Plan: Run db_stress. Manual printf to make sure only WAL files are skipped.
Reviewed By: jay-zhuang
Differential Revision: D29745095
fbshipit-source-id: 1879dd2c01abad7879ca243ee94570ec47c347f3
Summary:
Add `experiemental_allow_mempurge` flag support for `db_stress` and `db_crashtest.py`, with a `false` default value.
I succesfully tested locally both `whitebox` and `blackbox` crash tests with `experiemental_allow_mempurge` flag set as true.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8545
Reviewed By: akankshamahajan15
Differential Revision: D29734513
Pulled By: bjlemaire
fbshipit-source-id: 24316c0eccf6caf409e95c035f31d822c66714ae
Summary:
… small overwritten files.
If a file is overwritten with renamed and the parent path is not synced, FaultInjectionTestFS::DeleteFilesCreatedAfterLastDirSync() will delete the file. However, RocksDB relies on file renaming to be atomic no matter whether the parent directory is synced or not, and the current behavior breaks the assumption and caused some false positive: https://github.com/facebook/rocksdb/pull/8489
Since the atomic renaming is used in CURRENT files, to fix the problem, in FaultInjectionTestFS::DeleteFilesCreatedAfterLastDirSync(), we recover the state of overwritten file if the file is small.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8501
Test Plan: Run stress test for a while and see it doesn't break.
Reviewed By: anand1976
Differential Revision: D29594384
fbshipit-source-id: 589b5c2f0a9d2aca53752d7bdb0231efa5b3ae92
Summary:
Write and metadata error injection during DB open was enabled in https://github.com/facebook/rocksdb/issues/8474. This causes crash tests to fail very frequently due to another fault injection feature that deletes files created after the last dir sync during DB open. In real life, a similar failure would happen if the FS returns error on the CURRENT file rename, but the rename actually succeeded and got partially persisted (dir entry for the old CURRENT file got removed, but the entry for the new one is not persisted). Temporarily disable the fault injection feature until we figure out the likelihood of this bug happening and the proper way to fix it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8489
Test Plan: Stress test can open the DB successfully
Reviewed By: siying
Differential Revision: D29564516
Pulled By: anand1976
fbshipit-source-id: ffd1650715ea3c5bf7131936b0ca6fcf66f4e14e
Summary:
Inject read failures in DB reopen, just as what we do for metadata writes and writes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8476
Test Plan: Some manual tests and make sure failures are triggered.
Reviewed By: anand1976
Differential Revision: D29507283
fbshipit-source-id: d04da0163973447041038bd87701686a417c4e0c
Summary:
add the injest_error_severity to control if it is a retryable IO Error or a fatal or unrecoverable error. Use a flag to indicate, if fatal error comes, the flag is set and db is stopped (but not corrupted).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8479
Test Plan: run ./db_stress --reopen=0 --read_fault_one_in=1000 --write_fault_one_in=5 --disable_wal=true --write_buffer_size=3000000 -writepercent=5 -readpercent=50 --injest_error_severity=2 --column_families=1, make check
Reviewed By: anand1976
Differential Revision: D29524271
Pulled By: zhichao-cao
fbshipit-source-id: 1aa9fb9b5655b0adba6f5ad12005ca8c074c795b
Summary:
Previously Stress can inject metadata write failures when reopening a DB. We extend it to file append too, in the same way.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8474
Test Plan: manually run crash test with various setting and make sure the failures are triggered as expected.
Reviewed By: zhichao-cao
Differential Revision: D29503116
fbshipit-source-id: e73a446e80ccbd09301a579280e56ff949381fab
Summary:
Add a ```-secondary_cache_uri``` to db_stress to allow the user to specify a custom ```SecondaryCache``` object from the object registry. Also allow db_crashtest.py to be run with an alternate db_stress location. Together, these changes will allow us to run db_stress using FB internal components.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8455
Reviewed By: zhichao-cao
Differential Revision: D29371972
Pulled By: anand1976
fbshipit-source-id: dd1b1fd80ebbedc11aa63d9246ea6ae49edb77c4
Summary:
Marked the Ribbon filter and optimize_filters_for_memory features
as production-ready, each enabling memory savings for Bloom-like filters.
Use `NewRibbonFilterPolicy` in place of `NewBloomFilterPolicy` to use
Ribbon filters instead of Bloom, or `ribbonfilter` in place of
`bloomfilter` in configuration string.
Some small refactoring in db_stress.
Removed/refactored unused code in db_bench, in part preparing for future
default possibly being different from "disabled."
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8408
Test Plan:
Lots of prior automated, ad-hoc, and "real world" testing.
Updated tests for new API names. Quick db_bench test:
bloom fillrandom
77730 ops/sec
rocksdb.block.cache.filter.bytes.insert COUNT : 89929384
ribbon fillrandom
71492 ops/sec
rocksdb.block.cache.filter.bytes.insert COUNT : 64531384
Reviewed By: mrambacher
Differential Revision: D29140805
Pulled By: pdillinger
fbshipit-source-id: d742c922722421678f95ad85eeb0aaebc9f5e49a
Summary:
When injecting in DB open, error can happen in background threads, causing DB open succeed, but DB is soon made read-only and subsequence writes will fail, which is not expected. To prevent it from happening, wait for compaction to finish before serving the traffic. If there is a failure, reopen.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8270
Test Plan: Run the test.
Reviewed By: ajkr
Differential Revision: D28230537
fbshipit-source-id: e2e97888904f9b9bb50c35ccf95b88c2319ef5c3
Summary:
Refactor kill point to one single class, rather than several extern variables. The intention was to drop unflushed data before killing to simulate some job, and I tried to a pointer to fault ingestion fs to the killing class, but it ended up with harder than I thought. Perhaps we'll need to do this in another way. But I thought the refactoring itself is good so I send it out.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8241
Test Plan: make release and run crash test for a while.
Reviewed By: anand1976
Differential Revision: D28078486
fbshipit-source-id: f9182c1455f52e6851c13f88a21bade63bcec45f
Summary:
DB Stress to add --open_metadata_write_fault_one_in which would randomly fail in some file metadata modification operations during DB Open, including file creation, close, renaming and directory sync. Some operations can fail before and after the operations take place.
If DB open fails, db_stress would retry without the failure ingestion, and DB is expected to open successfully.
This option is enabled in crash test in half of the time.
Some follow up changes would allow write failures in open time, and ingesting those failures in non-DB open cases.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8235
Test Plan: Run stress tests for a while and see failures got triggered. This can reproduce the bug fixed by https://github.com/facebook/rocksdb/pull/8192 and a similar one that fails when fsyncing parent directory.
Reviewed By: anand1976
Differential Revision: D28010944
fbshipit-source-id: 36a96da4dc3633e5f7680cef3ea0a900fcdb5558
Summary:
This partially reverts commit 10196d7edc.
The problem with this change is because of important filter use cases:
FIFO compaction and SST writer. FIFO "compaction" always uses level 0 so
would only use Ribbon filters if specifically including level 0 for the
Ribbon filter policy. SST writer sets level_at_creation=-1 to indicate
unknown level, and this would be treated the same as level 0 unless
fixed.
We are keeping the part about committing to permanent schema, which is
only changes to API comments and HISTORY.md.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8212
Test Plan: CI
Reviewed By: jay-zhuang
Differential Revision: D27896468
Pulled By: pdillinger
fbshipit-source-id: 50a775f7cba5d64fb729d9b982e355864020596e
Summary:
Since the Ribbon filter schema seems good (compatible back to
6.15.0), this change commits to long term support of the SST schema,
even though we expect the API for enabling Ribbon to change (still
called NewExperimentalRibbonFilterPolicy).
This also adds support for "hybrid" configuration in which some levels
use Bloom (higher levels, lower numbered) for speed and the rest use
Ribbon (lower levels, higher numbered) for memory space efficiency.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8198
Test Plan: unit test added, crash test support
Reviewed By: jay-zhuang
Differential Revision: D27831232
Pulled By: pdillinger
fbshipit-source-id: 90e528677689474d293ed6710b42ba89fbd5b5ab
Summary:
Enable backup/restore functionality with Integrated BlobDB in
db_stress and crash test.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8165
Test Plan:
Ran python3 -u tools/db_crashtest.py --simple whitebox along
with :
1. decreased "backup_in_one" value for backups to be more frequent and
2. manually changed code for "enable_blob_file" to be always true and
apply blobdb params 100% for testing purpose.
Reviewed By: ltamasi
Differential Revision: D27636025
Pulled By: akankshamahajan15
fbshipit-source-id: 0d0e0d1479ced163f992872dc998e79c581bfc99
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
Summary:
Add some basic test for user-defined timestamp to db_stress. Currently,
read with timestamp always tries to read using the current timestamp.
Due to the per-key timestamp-sequence ordering constraint, we only add timestamp-
related tests to the `NonBatchedOpsStressTest` since this test serializes accesses
to the same key and uses a file to cross-check data correctness.
The timestamp feature is not supported in a number of components, e.g. Merge, SingleDelete,
DeleteRange, CompactionFilter, Readonly instance, secondary instance, SST file ingestion, transaction,
etc. Therefore, db_stress should exit if user enables both timestamp and these features at the same
time. The (currently) incompatible features can be found in
`CheckAndSetOptionsForUserTimestamp`.
This PR also fixes a bug triggered when timestamp is enabled together with
`index_type=kBinarySearchWithFirstKey`. This bug fix will also be in another separate PR
with more unit tests coverage. Fixing it here because I do not want to exclude the index type
from crash test.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8061
Test Plan: make crash_test_with_ts
Reviewed By: jay-zhuang
Differential Revision: D27056282
Pulled By: riversand963
fbshipit-source-id: c3e00ad1023fdb9ebbdf9601ec18270c5e2925a9
Summary:
Since our stress/crash tests by default generate values of size 8, 16, or 24,
it does not make much sense to set `min_blob_size` to 256. The patch
updates the set of potential `min_blob_size` values in the crash test
script and in `db_stress` where it might be set dynamically using
`SetOptions`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8085
Test Plan: Ran `make check` and tried the crash test script.
Reviewed By: riversand963
Differential Revision: D27238620
Pulled By: ltamasi
fbshipit-source-id: 4a96f9944b1ed9220d3045c5ab0b34c49009aeee
Summary:
This does not add any new public APIs or published
functionality, but adds the ability to read and use (and in tests,
write) backups with a new meta file schema, based on the old schema
but not forward-compatible (before this change). The new schema enables
some capabilities not in the old:
* Explicit versioning, so that users get clean error messages the next
time we want to break forward compatibility.
* Ignoring unrecognized fields (with warning), so that new non-critical
features can be added without breaking forward compatibility.
* Rejecting future "non-ignorable" fields, so that new features critical
to some use-cases could potentially be added outside of linear schema
versions, with broken forward compatibility.
* Fields at the end of the meta file, such as for checksum of the meta
file's contents (up to that point)
* New optional 'size' field for each file, which is checked when present
* Optionally omitting 'crc32' field, so that we aren't required to have
a crc32c checksum for files to take a backup. (E.g. to support backup
via hard links and to better support file custom checksums.)
Because we do not have a JSON parser and to share code, the new schema
is simply derived from the old schema.
BackupEngine code is updated to allow missing checksums in some places,
and to make that easier, `has_checksum` and `verify_checksum_after_work`
are eliminated. Empty `checksum_hex` indicates checksum is unknown. I'm
not too afraid of regressing on data integrity, because
(a) we have pretty good test coverage of corruption detection in backups, and
(b) we are increasingly relying on the DB itself for data integrity rather than
it being an exclusive feature of backups.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8069
Test Plan:
new unit tests, added to crash test (some local run with
boosted backup probability)
Reviewed By: ajkr
Differential Revision: D27139824
Pulled By: pdillinger
fbshipit-source-id: 9e0e4decfb42bb84783d64d2d246456d97e8e8c5
Summary:
For performance purposes, the lower level routines were changed to use a SystemClock* instead of a std::shared_ptr<SystemClock>. The shared ptr has some performance degradation on certain hardware classes.
For most of the system, there is no risk of the pointer being deleted/invalid because the shared_ptr will be stored elsewhere. For example, the ImmutableDBOptions stores the Env which has a std::shared_ptr<SystemClock> in it. The SystemClock* within the ImmutableDBOptions is essentially a "short cut" to gain access to this constant resource.
There were a few classes (PeriodicWorkScheduler?) where the "short cut" property did not hold. In those cases, the shared pointer was preserved.
Using db_bench readrandom perf_level=3 on my EC2 box, this change performed as well or better than 6.17:
6.17: readrandom : 28.046 micros/op 854902 ops/sec; 61.3 MB/s (355999 of 355999 found)
6.18: readrandom : 32.615 micros/op 735306 ops/sec; 52.7 MB/s (290999 of 290999 found)
PR: readrandom : 27.500 micros/op 871909 ops/sec; 62.5 MB/s (367999 of 367999 found)
(Note that the times for 6.18 are prior to revert of the SystemClock).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8033
Reviewed By: pdillinger
Differential Revision: D27014563
Pulled By: mrambacher
fbshipit-source-id: ad0459eba03182e454391b5926bf5cdd45657b67
Summary:
New comment for share_files_with_checksum:
// Only used if share_table_files is set to true. Setting to false is
// DEPRECATED and potentially dangerous because in that case BackupEngine
// can lose data if backing up databases with distinct or divergent
// history, for example if restoring from a backup other than the latest,
// writing to the DB, and creating another backup. Setting to true (default)
// prevents these issues by ensuring that different table files (SSTs) with
// the same number are treated as distinct. See
// share_files_with_checksum_naming and ShareFilesNaming.
I have also removed interim option kFlagMatchInterimNaming, which is no
longer needed and was never needed for correct+compatible operation
(just performance).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8020
Test Plan:
tests updated. Backward+forward compatibility verified with
SHORT_TEST=1 check_format_compatible.sh. ldb uses default backup
options, and I manually verified shared_checksum in
/tmp/rocksdb_format_compatible_peterd/bak/current/ after run.
Reviewed By: ajkr
Differential Revision: D26786331
Pulled By: pdillinger
fbshipit-source-id: 36f968dfef1f5cacbd65154abe1d846151a55130
Summary:
For dictionary compression, we need to collect some representative samples of the data to be compressed, which we use to either generate or train (when `CompressionOptions::zstd_max_train_bytes > 0`) a dictionary. Previously, the strategy was to buffer all the data blocks during flush, and up to the target file size during compaction. That strategy allowed us to randomly pick samples from as wide a range as possible that'd be guaranteed to land in a single output file.
However, some users try to make huge files in memory-constrained environments, where this strategy can cause OOM. This PR introduces an option, `CompressionOptions::max_dict_buffer_bytes`, that limits how much data blocks are buffered before we switch to unbuffered mode (which means creating the per-SST dictionary, writing out the buffered data, and compressing/writing new blocks as soon as they are built). It is not strict as we currently buffer more than just data blocks -- also keys are buffered. But it does make a step towards giving users predictable memory usage.
Related changes include:
- Changed sampling for dictionary compression to select unique data blocks when there is limited availability of data blocks
- Made use of `BlockBuilder::SwapAndReset()` to save an allocation+memcpy when buffering data blocks for building a dictionary
- Changed `ParseBoolean()` to accept an input containing characters after the boolean. This is necessary since, with this PR, a value for `CompressionOptions::enabled` is no longer necessarily the final component in the `CompressionOptions` string.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7970
Test Plan:
- updated `CompressionOptions` unit tests to verify limit is respected (to the extent expected in the current implementation) in various scenarios of flush/compaction to bottommost/non-bottommost level
- looked at jemalloc heap profiles right before and after switching to unbuffered mode during flush/compaction. Verified memory usage in buffering is proportional to the limit set.
Reviewed By: pdillinger
Differential Revision: D26467994
Pulled By: ajkr
fbshipit-source-id: 3da4ef9fba59974e4ef40e40c01611002c861465
Summary:
The patch adds checkpoint support to BlobDB. Blob files are hard linked or
copied, depending on whether the checkpoint directory is on the same filesystem
or not, similarly to table files.
TODO: Add support for blob files to `ExportColumnFamily` and to the checksum
verification logic used by backup/restore.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7959
Test Plan: Ran `make check` and the crash test for a while.
Reviewed By: riversand963
Differential Revision: D26434768
Pulled By: ltamasi
fbshipit-source-id: 994be55a8dc08133028250760fca440d2c7c4dc5
Summary:
The patch adds support for the options related to the new BlobDB implementation
to `db_stress`, including support for dynamically adjusting them using `SetOptions`
when `set_options_one_in` and a new flag `allow_setting_blob_options_dynamically`
are specified. (The latter is used to prevent the options from being enabled when
incompatible features are in use.)
The patch also updates the `db_stress` help messages of the existing stacked BlobDB
related options to clarify that they pertain to the old implementation. In addition, it
adds the new BlobDB to the crash test script. In order to prevent a combinatorial explosion
of jobs and still perform whitebox/blackbox testing (including under ASAN/TSAN/UBSAN),
and to also test BlobDB in conjunction with atomic flush and transactions, the script sets
the BlobDB options in 10% of normal/`cf_consistency`/`txn` crash test runs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7900
Test Plan: Ran `make check` and `db_stress`/`db_crashtest.py` with various options.
Reviewed By: jay-zhuang
Differential Revision: D26094913
Pulled By: ltamasi
fbshipit-source-id: c2ef3391a05e43a9687f24e297df05f4a5584814
Summary:
We recently encounter two cases of txn lock timeout in stress test. It might be caused due to latencies of resource scheduling in the internal infrastructure. Hopefully increasing the timeout can make the related tests less flaky.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7823
Test Plan: watch internal stress test to pass.
Reviewed By: siying
Differential Revision: D25739233
Pulled By: cheng-chang
fbshipit-source-id: 84a5a8ae820db24dacd0cfc05928b26505fab89d
Summary:
fix memory leak in db_stress checkpoint test. If s is not ok, checkpoint is not deleted, may cause memory leak.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7813
Test Plan: make asan_check
Reviewed By: cheng-chang
Differential Revision: D25702999
Pulled By: zhichao-cao
fbshipit-source-id: 08253b0852835acb8cfd412503cdabf720afb678
Summary:
Inject the random write error to stress test, it requires set reopen=0 and disable_wal=true.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7653
Test Plan: pass db_stress and python3 db_crashtest.py blackbox
Reviewed By: ajkr
Differential Revision: D25354132
Pulled By: zhichao-cao
fbshipit-source-id: 44721104eecb416e27f65f854912c40e301dd669
Summary:
Added experimental public API for Ribbon filter:
NewExperimentalRibbonFilterPolicy(). This experimental API will
take a "Bloom equivalent" bits per key, and configure the Ribbon
filter for the same FP rate as Bloom would have but ~30% space
savings. (Note: optimize_filters_for_memory is not yet implemented
for Ribbon filter. That can be added with no effect on schema.)
Internally, the Ribbon filter is configured using a "one_in_fp_rate"
value, which is 1 over desired FP rate. For example, use 100 for 1%
FP rate. I'm expecting this will be used in the future for configuring
Bloom-like filters, as I expect people to more commonly hold constant
the filter accuracy and change the space vs. time trade-off, rather than
hold constant the space (per key) and change the accuracy vs. time
trade-off, though we might make that available.
### Benchmarking
```
$ ./filter_bench -impl=2 -quick -m_keys_total_max=200 -average_keys_per_filter=100000 -net_includes_hashing
Building...
Build avg ns/key: 34.1341
Number of filters: 1993
Total size (MB): 238.488
Reported total allocated memory (MB): 262.875
Reported internal fragmentation: 10.2255%
Bits/key stored: 10.0029
----------------------------
Mixed inside/outside queries...
Single filter net ns/op: 18.7508
Random filter net ns/op: 258.246
Average FP rate %: 0.968672
----------------------------
Done. (For more info, run with -legend or -help.)
$ ./filter_bench -impl=3 -quick -m_keys_total_max=200 -average_keys_per_filter=100000 -net_includes_hashing
Building...
Build avg ns/key: 130.851
Number of filters: 1993
Total size (MB): 168.166
Reported total allocated memory (MB): 183.211
Reported internal fragmentation: 8.94626%
Bits/key stored: 7.05341
----------------------------
Mixed inside/outside queries...
Single filter net ns/op: 58.4523
Random filter net ns/op: 363.717
Average FP rate %: 0.952978
----------------------------
Done. (For more info, run with -legend or -help.)
```
168.166 / 238.488 = 0.705 -> 29.5% space reduction
130.851 / 34.1341 = 3.83x construction time for this Ribbon filter vs. lastest Bloom filter (could make that as little as about 2.5x for less space reduction)
### Working around a hashing "flaw"
bloom_test discovered a flaw in the simple hashing applied in
StandardHasher when num_starts == 1 (num_slots == 128), showing an
excessively high FP rate. The problem is that when many entries, on the
order of number of hash bits or kCoeffBits, are associated with the same
start location, the correlation between the CoeffRow and ResultRow (for
efficiency) can lead to a solution that is "universal," or nearly so, for
entries mapping to that start location. (Normally, variance in start
location breaks the effective association between CoeffRow and
ResultRow; the same value for CoeffRow is effectively different if start
locations are different.) Without kUseSmash and with num_starts > 1 (thus
num_starts ~= num_slots), this flaw should be completely irrelevant. Even
with 10M slots, the chances of a single slot having just 16 (or more)
entries map to it--not enough to cause an FP problem, which would be local
to that slot if it happened--is 1 in millions. This spreadsheet formula
shows that: =1/(10000000*(1 - POISSON(15, 1, TRUE)))
As kUseSmash==false (the setting for Standard128RibbonBitsBuilder) is
intended for CPU efficiency of filters with many more entries/slots than
kCoeffBits, a very reasonable work-around is to disallow num_starts==1
when !kUseSmash, by making the minimum non-zero number of slots
2*kCoeffBits. This is the work-around I've applied. This also means that
the new Ribbon filter schema (Standard128RibbonBitsBuilder) is not
space-efficient for less than a few hundred entries. Because of this, I
have made it fall back on constructing a Bloom filter, under existing
schema, when that is more space efficient for small filters. (We can
change this in the future if we want.)
TODO: better unit tests for this case in ribbon_test, and probably
update StandardHasher for kUseSmash case so that it can scale nicely to
small filters.
### Other related changes
* Add Ribbon filter to stress/crash test
* Add Ribbon filter to filter_bench as -impl=3
* Add option string support, as in "filter_policy=experimental_ribbon:5.678;"
where 5.678 is the Bloom equivalent bits per key.
* Rename internal mode BloomFilterPolicy::kAuto to kAutoBloom
* Add a general BuiltinFilterBitsBuilder::CalculateNumEntry based on
binary searching CalculateSpace (inefficient), so that subclasses
(especially experimental ones) don't have to provide an efficient
implementation inverting CalculateSpace.
* Minor refactor FastLocalBloomBitsBuilder for new base class
XXH3pFilterBitsBuilder shared with new Standard128RibbonBitsBuilder,
which allows the latter to fall back on Bloom construction in some
extreme cases.
* Mostly updated bloom_test for Ribbon filter, though a test like
FullBloomTest::Schema is a next TODO to ensure schema stability
(in case this becomes production-ready schema as it is).
* Add some APIs to ribbon_impl.h for configuring Ribbon filters.
Although these are reasonably covered by bloom_test, TODO more unit
tests in ribbon_test
* Added a "tool" FindOccupancyForSuccessRate to ribbon_test to get data
for constructing the linear approximations in GetNumSlotsFor95PctSuccess.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7658
Test Plan:
Some unit tests updated but other testing is left TODO. This
is considered experimental but laying down schema compatibility as early
as possible in case it proves production-quality. Also tested in
stress/crash test.
Reviewed By: jay-zhuang
Differential Revision: D24899349
Pulled By: pdillinger
fbshipit-source-id: 9715f3e6371c959d923aea8077c9423c7a9f82b8
Summary:
After replaying the WALs, the memtables are flushed synchronously to L0 instead of being flushed in background. Currently, we only track WAL obsoletion events in the code path of background flush jobs. This PR tracks these events in RecoverLogFiles.
After this change, we can enable `track_and_verify_wal_in_manifest` in `db_stress`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7649
Test Plan: `python tools/db_crashtest.py whitebox`
Reviewed By: riversand963
Differential Revision: D24824501
Pulled By: cheng-chang
fbshipit-source-id: 207129f7b845c50b333680ce6818a68a2fad54b9
Summary:
Consider the following sequence of events:
1. Db flushed an SST with file number N, appended to MANIFEST, and tried to sync the MANIFEST.
2. Syncing MANIFEST failed and db crashed.
3. Db tried to recover with this MANIFEST. In the meantime, no entry about the newly-flushed SST was found in the MANIFEST. Therefore, RocksDB replayed WAL and tried to flush to an SST file reusing the same file number N. This failed because file system does not support overwrite. Then Db deleted this file.
4. Db crashed again.
5. Db tried to recover. When db read the MANIFEST, there was an entry referencing N.sst. This could happen probably because the append in step 1 finally reached the MANIFEST and became visible. Since N.sst had been deleted in step 3, recovery failed.
It is possible that N.sst created in step 1 is valid. Although step 3 would still fail since the MANIFEST was not synced properly in step 1 and 2, deleting N.sst would make it impossible for the db to recover even if the remaining part of MANIFEST was appended and visible after step 5.
After this PR, in step 3, immediately after recovering from MANIFEST, a new MANIFEST is created, then we find that N.sst is not referenced in the MANIFEST, so we delete it, and we'll not reuse N as file number. Then in step 5, since the new MANIFEST does not contain N.sst, the recovery failure situation in step 5 won't happen.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7621
Test Plan:
1. some tests are updated, because these tests assume that new MANIFEST is created after WAL recovery.
2. a new unit test is added in db_basic_test to simulate step 3.
Reviewed By: riversand963
Differential Revision: D24668144
Pulled By: cheng-chang
fbshipit-source-id: 90d7487fbad2bc3714f5ede46ea949895b15ae3b
Summary:
When a WAL is synced, an edit is written to MANIFEST.
After flushing memtables, the obsoleted WALs are piggybacked to MANIFEST while writing the new L0 files to MANIFEST.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7601
Test Plan:
`track_and_verify_wals_in_manifest` is enabled by default for all tests extending `DBBasicTest`, and in db_stress_test.
Unit test `wal_edit_test`, `version_edit_test`, and `version_set_test` are also updated.
Watch all tests to pass.
Reviewed By: ltamasi
Differential Revision: D24553957
Pulled By: cheng-chang
fbshipit-source-id: 66a569ff1bdced38e22900bd240b73113906e040
