Summary:
L0 score is based on size target and number of files. The size target
used is `max_bytes_for_level_base`. However, the base level's size can
dynamically expand in write burst mode. In fact, it can expand so much
that L0->Lbase becomes the highest fanout in target sizes. This doesn't
make sense from an efficiency perspective, so this PR bounds the
L0->Lbase fanout to the smoothed level multiplier. The L0 scoring based
on file count remains unchanged.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7325
Test Plan:
contrived benchmark that exhibits the problem:
```
$ TEST_TMPDIR=/data/users/andrewkr/ ./db_bench -benchmarks=filluniquerandom,readrandom -write_buffer_size=1048576 -target_file_size_base=1048576 -max_bytes_for_level_base=4194304 -level0_file_num_compaction_trigger=4 -level_compaction_dynamic_level_bytes=true -compression_type=none -max_background_jobs=12 -rate_limiter_bytes_per_sec=104857600 -benchmark_write_rate_limit=10485760 -num=100000000
```
Results:
- "Burst W-Amp" is the write-amp near the end of the fillrandom benchmark
- "Total W-Amp" is the write-amp after readrandom has run a while and all levels no longer need compaction
Branch | Burst W-Amp | Total W-Amp | fillrandom (MB/s)
-- | -- | -- | --
master | 20.2 | 21.5 | 4.7
dynamic-l0-score | 12.6 | 14.1 | 7.2
Reviewed By: siying
Differential Revision: D23412935
Pulled By: ajkr
fbshipit-source-id: f91f2067188e432dd39deab02f1c56f195057a0e
Summary:
Add a unit test case to check memory usage when
max_write_buffer_size_to_maintain is set if flushed immutable memtables are
trimmed timely or not.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7311
Test Plan: Compared the results with before bug fix.
Reviewed By: ltamasi
Differential Revision: D23321702
Pulled By: akankshamahajan15
fbshipit-source-id: da04ee21137d641a07fd499a9e2749eb036fcb1e
Summary:
A new file interface `SupportPrefetch()` is added. When the user overrides it to `false`, an internal prefetch buffer will be used for readahead. Useful for non-directIO but FS doesn't have readahead support.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7312
Reviewed By: anand1976
Differential Revision: D23329847
Pulled By: jay-zhuang
fbshipit-source-id: 71cd4ce6f4a820840294e4e6aec111ab76175527
Summary:
This is a "real" fix for the issue worked around in https://github.com/facebook/rocksdb/issues/7294.
To get DB checksum info for live files, we now read the manifest file
that will become part of the checkpoint/backup. This requires a little
extra handling in taking a custom checkpoint, including only reading the
manifest file up to the size prescribed by the checkpoint.
This moves GetFileChecksumsFromManifest from backup code to
file_checksum_helper.{h,cc} and removes apparently unnecessary checking
related to column families.
Updated HISTORY.md and warned potential future users of
DB::GetLiveFilesChecksumInfo()
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7309
Test Plan: updated unit test, before and after
Reviewed By: ajkr
Differential Revision: D23311994
Pulled By: pdillinger
fbshipit-source-id: 741e30a2dc1830e8208f7648fcc8c5f000d4e2d5
Summary:
Right now all I/O failures under PartitionIndexReader::CacheDependencies() is swallowed. This doesn't impact correctness but we've made a decision that any I/O error in read path now should be returned to users for awareness. Return errors in those cases instead.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7297
Test Plan: Add a new unit test that ingest errors in this code path and see Get() fails. Only one I/O path is hit in PartitionIndexReader::CacheDependencies(). Several option changes are attempt but not able to got other pread paths triggered. Not sure whether other failure cases would be even possible. Would rely on continuous stress test to validate it.
Reviewed By: anand1976
Differential Revision: D23257950
fbshipit-source-id: 859dbc92fa239996e1bb378329344d3d54168c03
Summary:
When SST file is created, application is able to know the file information through OnTableFileCreated callback in LogAndNotifyTableFileCreationFinished. Since file checksum information can be useful for application when the SST file is created, we add file_checksum and file_checksum_func_name information to TableFileCreationInfo, which will be passed through OnTableFileCreated.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7108
Test Plan: make check, listener_test.
Reviewed By: ajkr
Differential Revision: D22470240
Pulled By: zhichao-cao
fbshipit-source-id: 92c20344d9b986eadfe3480f3769bf4add0dbaae
Summary:
After releasing a snapshot, it checks whether it is suitable to trigger bottom compactions.
When disabling auto compactions, it may still schedule compaction when releasing a snapshot. Whereas no compaction job will be actually handled, so the state of LSM is not changed and compaction will be triggered again and again every time releasing a snapshot.
Too frequent compactions lead to high CPU usage and high db_mutex lock contention which affects foreground write duration finally.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7267
Test Plan:
- make check
- manual test
Reviewed By: akankshamahajan15
Differential Revision: D23252880
Pulled By: ajkr
fbshipit-source-id: 4431e071a35d9912a2a3592875db27bae521434b
Summary:
When a memtable is trimmed in MemTableListVersion, the memtable
is only added to delete list if it is
the last reference. However it is not the last reference as it is held
by the super version. But the super version would not be switched if the
delete list is empty. So the memtable is never destroyed and memory
usage increases beyond write_buffer_size +
max_write_buffer_size_to_maintain.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7296
Test Plan:
1. ./db_bench -benchmarks=randomtransaction
-optimistic_transaction_db=1 -statistics -stats_interval_seconds=1
-duration=90 -num=500000 --max_write_buffer_size_to_maintain=16000000
--transaction_set_snapshot
Reviewed By: ltamasi
Differential Revision: D23267395
Pulled By: akankshamahajan15
fbshipit-source-id: 3a8d437fe9f4015f851ff84c0e29528aa946b650
Summary:
On a read-write DB configured with
DBOptions::file_checksum_gen_factory, BackupEngine::CreateNewBackup can
fail intermittently, with non-OK status. This is due to a race between
GetLiveFiles and GetLiveFilesChecksumInfo in creating backups.
For patching 6.12 release (as this commit is intended for, except this is a
forward-merged version), we can simply treat files for which we falsely failed
to get checksum info as legacy files lacking checksum info.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7294
Test Plan: unit test reproducer included
Reviewed By: ajkr
Differential Revision: D23253489
Pulled By: pdillinger
fbshipit-source-id: 9e4945dad120b776ad3e753be10b962f61f28e14
Summary:
The two features are naturally incompatible. WAL recycling expects the recovery to succeed upon encountering a corrupt record at the point where new data ends and recycled data remains at the tail. However, `WALRecoveryMode::kTolerateCorruptedTailRecords` must fail upon encountering any such corrupt record, as it cannot differentiate between this and a real corruption, which would cause committed updates to be truncated.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7271
Reviewed By: riversand963
Differential Revision: D23169923
Pulled By: ajkr
fbshipit-source-id: 2cf8a3bcd2c9a0ecb0055a84725047a10fd4db50
Summary:
Add `kEntryDeleteWithTimestamp` to `EntryType` which is a public API.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7195
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D22914704
Pulled By: riversand963
fbshipit-source-id: 886f73c6b70c527cad1c8fc9fc8d3afe60e1ea39
Summary:
There is potential data race related CompactRange() with level refitting. After the compaction step and refitting step, some automatic compaction could put data to the destination level and cause the DB to be corrupted. Fix the bug by checking the target level to be empty.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7261
Test Plan: Add a unit test, which would fail with "Corruption: L1 have overlapping ranges '666F6F' seq:6, type:1 vs. '626172' seq:2, type:1", and now it succeeds.
Reviewed By: ajkr
Differential Revision: D23142269
fbshipit-source-id: 28bc14d5ac934c192260b23a4ce3f10a95e3ee91
Summary:
Have a global StatsDumpScheduler for all DB instance stats dumping, including `DumpStats()` and `PersistStats()`. Before this, there're 2 dedicate threads for every DB instance, one for DumpStats() one for PersistStats(), which could create lots of threads if there're hundreds DB instances.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7223
Reviewed By: riversand963
Differential Revision: D23056737
Pulled By: jay-zhuang
fbshipit-source-id: 0faa2311142a73433ebb3317361db7cbf43faeba
Summary:
Manual compaction with `CompactRangeOptions::change_levels` set could
refit to a level targeted by another manual compaction. If
force_consistency_checks were disabled, it could be possible for
overlapping files to be written at that target level.
This PR prevents the possibility by calling `DisableManualCompaction()`
prior to `ReFitLevel()`. It also improves the manual compaction disabling
mechanism to wait for pending manual compactions to complete before
returning, and support disabling from multiple threads.
Fixes https://github.com/facebook/rocksdb/issues/6432.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7250
Test Plan:
crash test command that repro'd the bug reliably:
```
$ TEST_TMPDIR=/dev/shm python tools/db_crashtest.py blackbox --simple -target_file_size_base=524288 -write_buffer_size=1048576 -clear_column_family_one_in=0 -reopen=0 -max_key=10000000 -column_families=1 -max_background_compactions=8 -compact_range_one_in=100000 -compression_type=none -compaction_style=1 -num_levels=5 -universal_min_merge_width=4 -universal_max_merge_width=8 -level0_file_num_compaction_trigger=12 -rate_limiter_bytes_per_sec=1048576000 -universal_max_size_amplification_percent=100 --duration=3600 --interval=60 --use_direct_io_for_flush_and_compaction=0 --use_direct_reads=0 --enable_compaction_filter=0
```
Reviewed By: ltamasi
Differential Revision: D23090800
Pulled By: ajkr
fbshipit-source-id: afcbcd51b42ce76789fdb907d8b9ada790709c13
Summary:
A new option `std::shared_ptr<FileChecksumGenFactory> backup_checksum_gen_factory` is added to `BackupableDBOptions`. This allows custom checksum functions to be used for creating, verifying, or restoring backups.
Tests are added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7085
Test Plan: Passed make check
Reviewed By: pdillinger
Differential Revision: D22390756
Pulled By: gg814
fbshipit-source-id: 3b7756ca444c2129844536b91c3ca09f53b6248f
Summary:
https://github.com/facebook/rocksdb/pull/5289 introduces a performance regression that caused an upper bound check within every BlockBasedTableIterator::Next(). This is unnecessary if we've checked the boundary key for current block and it is within upper bound.
Fix the bug. Also rename the boolean to a enum so that the code is slightly better readable. The original regression was probably to fix a bug that the block upper bound check status is not reset after a new block is created. Fix it bug so that the regression can be avoided without hitting the bug.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7209
Test Plan: Run all existing tests. Will run atomic black box crash test for a while.
Reviewed By: anand1976
Differential Revision: D22859246
fbshipit-source-id: cbdad1f5e656c55fd8b71726d5a4f6cb53ff9140
Summary:
SST Partitioner interface that allows to split SST files during compactions.
It basically instruct compaction to create a new file when needed. When one is using well defined prefixes and prefixed way of defining tables it is good to define also partitioning so that promotion of some SST file does not cover huge key space on next level (worst case complete space).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6957
Reviewed By: ajkr
Differential Revision: D22461239
fbshipit-source-id: 9ce07bba08b3ba89c2d45630520368f704d1316e
Summary:
When paraoid_files_checks=true, a rolling key-value hash is generated and compared to what is written to the file. If the values do not match, the SST file is rejected.
Code put in place for the check for both flush and compaction jobs. Corresponding test added to corruption_test.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7134
Reviewed By: cheng-chang
Differential Revision: D22646149
fbshipit-source-id: 8fde1984a1a11edd3bd82a413acffc5ea7aa683f
Summary:
Issue https://github.com/facebook/rocksdb/issues/7133 reported that using `system_clock` in `FileOperationInfo::TimePoint` causes the duration of file flush operation (which can be a noop on MacOS in some scenarios) appears to be 0 and fail an assertion in listener_test. Using `steady_clock` supposedly fixed the problem.
`steady_clock` actually fits better into the use cases of `FileOperationInfo::TimePoint` as all usages care about durations but not wall clock time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7153
Test Plan: make check.
Reviewed By: riversand963
Differential Revision: D22654136
Pulled By: roghnin
fbshipit-source-id: 5980b1080734bdae496a18071a2c2b5887c67d85
Summary:
BackupEngine requires computing table checksums twice when backing up table files to the `shared_checksum` directory.
The repeated computation can be avoided by utilizing the db session id stored as a part of the table properties.
Filenames of table files in the `shared_checksum` directory depend on the following conditions:
1. the naming scheme is `kOptionalChecksumAndDbSessionId`,
2. `db_session_id` is not empty,
3. checksum is available in the DB manifest.
If 1,2,3 are satisfied, then the filenames will be of the form `<file_number>_<checksum>_<db_session_id>.sst`.
If 1,2 are satisfied, then the filenames will be of the form `<file_number>_<db_session_id>.sst`.
In all other cases, the filenames are of the form `<file_number>_<checksum>_<size>.sst`.
Additionally, if `kOptionalChecksumAndDbSessionId` is used (and not falling back to `kChecksumAndFileSize`), the `<checksum>` appeared in the filenames is hexadecimally encoded, instead of being plain `uint32_t` value.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7110
Test Plan: backupable_db_test and manual tests.
Reviewed By: ajkr
Differential Revision: D22508992
Pulled By: gg814
fbshipit-source-id: 5669f0ea9ad5a097f69f6d87aca4abba15032389
Summary:
Previously when running `db_bench` with large value for `num_multi_dbs` and enabled `Options::dump_malloc_stats`, we would see most CPU spent in jemalloc locking. After this PR that no longer shows up at the top of the profile.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7145
Reviewed By: riversand963
Differential Revision: D22593031
Pulled By: ajkr
fbshipit-source-id: 3b3fc91f93249c6afee53f59f34c487c3fc5add6
Summary:
In current codebase, in write path, if Retryable IO Error happens, SetBGError is called. The retryable IO Error is converted to hard error and DB is in read only mode. User or application needs to resume it. In this PR, if Retryable IO Error happens in one DB, SetBGError will create a new thread to call Resume (auto resume). otpions.max_bgerror_resume_count controls if auto resume is enabled or not (if max_bgerror_resume_count<=0, auto resume will not be enabled). options.bgerror_resume_retry_interval controls the time interval to call Resume again if the previous resume fails due to the Retryable IO Error. If non-retryable error happens during resume, auto resume will terminate.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6765
Test Plan: Added the unit test cases in error_handler_fs_test and pass make asan_check
Reviewed By: anand1976
Differential Revision: D21916789
Pulled By: zhichao-cao
fbshipit-source-id: acb8b5e5dc3167adfa9425a5b7fc104f6b95cb0b
Summary:
Currently, RocksDB lets compaction to go through even in case of
corrupted keys, the number of which is reported in CompactionJobStats.
However, RocksDB does not check this value. We should let compaction run
in a stricter mode.
Temporarily disable two tests that allow corrupted keys in compaction.
With this PR, the two tests will assert(false) and terminate. Still need
to investigate what is the recommended google-test way of doing it.
Death test (EXPECT_DEATH) in gtest has warnings now.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7124
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D22530722
Pulled By: riversand963
fbshipit-source-id: 6a5a6a992028c6d4f92cb74693c92db462ae4ad6
Summary:
This is a followup to https://github.com/facebook/rocksdb/issues/6646. In that PR, for simplicity I just appended a comparison against the 0th restart key in case `BinarySeek()`'s binary search landed at index 0. As a result there were `2/(N+1) + log_2(N)` key comparisons. This PR does it differently. Now we expand the binary search range by one so it also covers the case where target is at or before the restart key at index 0. As a result, it involves `log_2(N+1)` key comparisons.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7068
Test Plan:
ran readrandom with mostly default settings and counted key comparisons
using `PerfContext`.
before: `user_key_comparison_count = 28881965`
after: `user_key_comparison_count = 27823245`
setup command:
```
$ TEST_TMPDIR=/dev/shm/dbbench ./db_bench -benchmarks=fillrandom,compact -write_buffer_size=1048576 -target_file_size_base=1048576 -max_bytes_for_level_base=4194304 -max_background_jobs=12 -level_compaction_dynamic_level_bytes=true -num=10000000
```
benchmark command:
```
$ TEST_TMPDIR=/dev/shm/dbbench/ ./db_bench -use_existing_db=true -benchmarks=readrandom -disable_auto_compactions=true -num=10000000 -compression_type=none -reads=1000000 -perf_level=3
```
Reviewed By: anand1976
Differential Revision: D22357032
Pulled By: ajkr
fbshipit-source-id: 8b01e9c1c2a4e9d02fc9dfe16c1cc0327f8bdf24
Summary:
When format_version is high enough to support user-key and
there are index entries for same user key that spans multiple data
blocks then it changes from user-key mode to internal-key mode. But the
flush policy is not reset to point to Block Builder of internal-keys.
After this switch, no entries are added to user key index partition
result, thus it never triggers flushing the block.
Fix: 1. After adding the entry in sub_builder_index_, if there is a switch
from user-key to internal-key, then flush policy is updated to point to
Block Builder of internal-keys index partition.
2. Set sub_builder_index_->seperator_is_key_plus_seq_ = true if
seperator_is_key_plus_seq_ is set to true so that subsequent partitions
can also use internal key mode.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7096
Test Plan: make check -j64
Reviewed By: ajkr
Differential Revision: D22416598
Pulled By: akankshamahajan15
fbshipit-source-id: 01fc2dc07ea1b32f8fb803995ebe6e9a3fbe67ac
Summary:
Currently, `EventListener` in listner.h only have callback functions for file read and write. One may favor extended callback functions for more file I/O operations like flush, sync and close. This PR tries to add those interface and have them called when appropriate throughout the code base.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7055
Test Plan:
Write an experimental listener with those new callback functions with log output in them; run experiments and check logs to see those functions are actually called.
Default test suits `make check` should also be included.
Reviewed By: riversand963
Differential Revision: D22380624
Pulled By: roghnin
fbshipit-source-id: 4121491d45c2c2aae8c255e7998090559a241c6a
Summary:
When table file checksums are enabled and stored in the DB manifest by using the RocksDB default crc32c checksum function, BackupEngine will calculate the crc32c checksum of the file to be copied and compare the calculated result with the one stored in the DB manifest before copying the file to the backup directory.
After copying to the backup directory, BackupEngine will verify the checksum of the copied file with the one calculated before copying. This helps detect some rare corruption events such as bit-flips during the copying process.
No verification with checksums in DB manifest will be performed if the table file checksum function is not the RocksDB default crc32c checksum function.
In addition, If `share_table_files` and `share_files_with_checksum` are true, BackupEngine will compare the checksums computed before and after copying of the table files.
Corresponding tests are added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7015
Test Plan: Passed make check
Reviewed By: pdillinger
Differential Revision: D22165732
Pulled By: gg814
fbshipit-source-id: ee0e8cc397c455eba64545c29380b9d9853588ec
Summary:
When format_version is high enough to support user-key and there are index entries for same user key that spans multiple data blocks then it changes from user-key mode to internal-key mode. But the flush policy is not reset to point to Block Builder of internal-keys. After this switch, no entries are added to user key index partition result, thus it never triggers flushing the block.
Fix: After adding the entry in sub_builder_index_, if there is a switch from user-key to internal-key, then flush policy is updated to point to Block Builder of internal-keys index partition.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7022
Test Plan:
1. make check -j64
2. Added one unit test case
Reviewed By: ajkr
Differential Revision: D22197734
Pulled By: akankshamahajan15
fbshipit-source-id: d87e9e46bccab8e896ee6979d6b79c51f73d479e
Summary:
`bool BackupableDBOptions::new_naming_for_backup_files` is updated to `BackupTableNameOption BackupableDBOptions::share_files_with_checksum_naming`, where `BackupTableNameOption` is an `enum` type with two enumerators `kChecksumAndFileSize` and `kChecksumAndFileSize`. This opens up possibilities of extenting the current naming scheme for backup table files. By default, `BackupTableNameOption BackupableDBOptions::share_files_with_checksum_naming` is set to `kChecksumAndDbSessionId`.
Revert `BackupEngine::VerifyBackup` to only check file sizes by default.
Also fix the construction of the `SstFileDumper` in `GetFileDbIdentities` by setting a proper `Env` of the `Options` passed in the constructor.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7032
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D22237763
Pulled By: gg814
fbshipit-source-id: 466902a4e731babd64e30f0e82ca1aa82962e52e
Summary:
Added compaction filter support for BlobDB non-TTL values. Same as vanilla RocksDB, user compaction filter applies to all k/v pairs of the compaction for non-TTL values. It honors `min_blob_size`, which potentially results value transitions between inlined data and stored-in-blob data when size of value is changed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6850
Reviewed By: siying
Differential Revision: D22263487
Pulled By: ltamasi
fbshipit-source-id: 8fc03f8cde2a5c831e63b436b3dbf1b7f90939e8
Summary:
A parameter `verify_with_checksum` is added to `BackupEngine::VerifyBackup`, which is true by default. So now `BackupEngine::VerifyBackup` verifies backup files with checksum AND file size by default. When `verify_with_checksum` is false, `BackupEngine::VerifyBackup` only compares file sizes to verify backup files.
Also add a test for the case when corruption does not change the file size.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7014
Test Plan: Passed backupable_db_test
Reviewed By: zhichao-cao
Differential Revision: D22165590
Pulled By: gg814
fbshipit-source-id: 606a7450714e868bceb38598c89fd356c6004f4f
Summary:
`DB::OpenForReadOnly()` now returns `Status::NotFound` when the specified DB directory does not exist. Previously the error returned depended on the underlying `Env`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7023
Reviewed By: ajkr
Differential Revision: D22207845
Pulled By: gg814
fbshipit-source-id: f35830811a0e67efb0ee82eda3a9739bc526baba
Summary:
`BackupableDBOptions::new_naming_for_backup_files` is added. This option is false by default. When it is true, backup table filenames under directory shared_checksum are of the form `<file_number>_<crc32c>_<db_session_id>.sst`.
Note that when this option is true, it comes into effect only when both `share_files_with_checksum` and `share_table_files` are true.
Three new test cases are added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6997
Test Plan: Passed make check.
Reviewed By: ajkr
Differential Revision: D22098895
Pulled By: gg814
fbshipit-source-id: a1d9145e7fe562d71cde7ac995e17cb24fd42e76
Summary:
This PR provides preliminary support for handling IO error during MANIFEST write.
File write/sync is not guaranteed to be atomic. If we encounter an IOError while writing/syncing to the MANIFEST file, we cannot be sure about the state of the MANIFEST file. The version edits may or may not have reached the file. During cleanup, if we delete the newly-generated SST files referenced by the pending version edit(s), but the version edit(s) actually are persistent in the MANIFEST, then next recovery attempt will process the version edits(s) and then fail since the SST files have already been deleted.
One approach is to truncate the MANIFEST after write/sync error, so that it is safe to delete the SST files. However, file truncation may not be supported on certain file systems. Therefore, we take the following approach.
If an IOError is detected during MANIFEST write/sync, we disable file deletions for the faulty database. Depending on whether the IOError is retryable (set by underlying file system), either RocksDB or application can call `DB::Resume()`, or simply shutdown and restart. During `Resume()`, RocksDB will try to switch to a new MANIFEST and write all existing in-memory version storage in the new file. If this succeeds, then RocksDB may proceed. If all recovery is completed, then file deletions will be re-enabled.
Note that multiple threads can call `LogAndApply()` at the same time, though only one of them will be going through the process MANIFEST write, possibly batching the version edits of other threads. When the leading MANIFEST writer finishes, all of the MANIFEST writing threads in this batch will have the same IOError. They will all call `ErrorHandler::SetBGError()` in which file deletion will be disabled.
Possible future directions:
- Add an `ErrorContext` structure so that it is easier to pass more info to `ErrorHandler`. Currently, as in this example, a new `BackgroundErrorReason` has to be added.
Test plan (dev server):
make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6949
Reviewed By: anand1976
Differential Revision: D22026020
Pulled By: riversand963
fbshipit-source-id: f3c68a2ef45d9b505d0d625c7c5e0c88495b91c8
Summary:
New experimental option BBTO::optimize_filters_for_memory builds
filters that maximize their use of "usable size" from malloc_usable_size,
which is also used to compute block cache charges.
Rather than always "rounding up," we track state in the
BloomFilterPolicy object to mix essentially "rounding down" and
"rounding up" so that the average FP rate of all generated filters is
the same as without the option. (YMMV as heavily accessed filters might
be unluckily lower accuracy.)
Thus, the option near-minimizes what the block cache considers as
"memory used" for a given target Bloom filter false positive rate and
Bloom filter implementation. There are no forward or backward
compatibility issues with this change, though it only works on the
format_version=5 Bloom filter.
With Jemalloc, we see about 10% reduction in memory footprint (and block
cache charge) for Bloom filters, but 1-2% increase in storage footprint,
due to encoding efficiency losses (FP rate is non-linear with bits/key).
Why not weighted random round up/down rather than state tracking? By
only requiring malloc_usable_size, we don't actually know what the next
larger and next smaller usable sizes for the allocator are. We pick a
requested size, accept and use whatever usable size it has, and use the
difference to inform our next choice. This allows us to narrow in on the
right balance without tracking/predicting usable sizes.
Why not weight history of generated filter false positive rates by
number of keys? This could lead to excess skew in small filters after
generating a large filter.
Results from filter_bench with jemalloc (irrelevant details omitted):
(normal keys/filter, but high variance)
$ ./filter_bench -quick -impl=2 -average_keys_per_filter=30000 -vary_key_count_ratio=0.9
Build avg ns/key: 29.6278
Number of filters: 5516
Total size (MB): 200.046
Reported total allocated memory (MB): 220.597
Reported internal fragmentation: 10.2732%
Bits/key stored: 10.0097
Average FP rate %: 0.965228
$ ./filter_bench -quick -impl=2 -average_keys_per_filter=30000 -vary_key_count_ratio=0.9 -optimize_filters_for_memory
Build avg ns/key: 30.5104
Number of filters: 5464
Total size (MB): 200.015
Reported total allocated memory (MB): 200.322
Reported internal fragmentation: 0.153709%
Bits/key stored: 10.1011
Average FP rate %: 0.966313
(very few keys / filter, optimization not as effective due to ~59 byte
internal fragmentation in blocked Bloom filter representation)
$ ./filter_bench -quick -impl=2 -average_keys_per_filter=1000 -vary_key_count_ratio=0.9
Build avg ns/key: 29.5649
Number of filters: 162950
Total size (MB): 200.001
Reported total allocated memory (MB): 224.624
Reported internal fragmentation: 12.3117%
Bits/key stored: 10.2951
Average FP rate %: 0.821534
$ ./filter_bench -quick -impl=2 -average_keys_per_filter=1000 -vary_key_count_ratio=0.9 -optimize_filters_for_memory
Build avg ns/key: 31.8057
Number of filters: 159849
Total size (MB): 200
Reported total allocated memory (MB): 208.846
Reported internal fragmentation: 4.42297%
Bits/key stored: 10.4948
Average FP rate %: 0.811006
(high keys/filter)
$ ./filter_bench -quick -impl=2 -average_keys_per_filter=1000000 -vary_key_count_ratio=0.9
Build avg ns/key: 29.7017
Number of filters: 164
Total size (MB): 200.352
Reported total allocated memory (MB): 221.5
Reported internal fragmentation: 10.5552%
Bits/key stored: 10.0003
Average FP rate %: 0.969358
$ ./filter_bench -quick -impl=2 -average_keys_per_filter=1000000 -vary_key_count_ratio=0.9 -optimize_filters_for_memory
Build avg ns/key: 30.7131
Number of filters: 160
Total size (MB): 200.928
Reported total allocated memory (MB): 200.938
Reported internal fragmentation: 0.00448054%
Bits/key stored: 10.1852
Average FP rate %: 0.963387
And from db_bench (block cache) with jemalloc:
$ ./db_bench -db=/dev/shm/dbbench.no_optimize -benchmarks=fillrandom -format_version=5 -value_size=90 -bloom_bits=10 -num=2000000 -threads=8 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=false
$ ./db_bench -db=/dev/shm/dbbench -benchmarks=fillrandom -format_version=5 -value_size=90 -bloom_bits=10 -num=2000000 -threads=8 -optimize_filters_for_memory -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=false
$ (for FILE in /dev/shm/dbbench.no_optimize/*.sst; do ./sst_dump --file=$FILE --show_properties | grep 'filter block' ; done) | awk '{ t += $4; } END { print t; }'
17063835
$ (for FILE in /dev/shm/dbbench/*.sst; do ./sst_dump --file=$FILE --show_properties | grep 'filter block' ; done) | awk '{ t += $4; } END { print t; }'
17430747
$ #^ 2.1% additional filter storage
$ ./db_bench -db=/dev/shm/dbbench.no_optimize -use_existing_db -benchmarks=readrandom,stats -statistics -bloom_bits=10 -num=2000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=false -duration=10 -cache_index_and_filter_blocks -cache_size=1000000000
rocksdb.block.cache.index.add COUNT : 33
rocksdb.block.cache.index.bytes.insert COUNT : 8440400
rocksdb.block.cache.filter.add COUNT : 33
rocksdb.block.cache.filter.bytes.insert COUNT : 21087528
rocksdb.bloom.filter.useful COUNT : 4963889
rocksdb.bloom.filter.full.positive COUNT : 1214081
rocksdb.bloom.filter.full.true.positive COUNT : 1161999
$ #^ 1.04 % observed FP rate
$ ./db_bench -db=/dev/shm/dbbench -use_existing_db -benchmarks=readrandom,stats -statistics -bloom_bits=10 -num=2000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=false -optimize_filters_for_memory -duration=10 -cache_index_and_filter_blocks -cache_size=1000000000
rocksdb.block.cache.index.add COUNT : 33
rocksdb.block.cache.index.bytes.insert COUNT : 8448592
rocksdb.block.cache.filter.add COUNT : 33
rocksdb.block.cache.filter.bytes.insert COUNT : 18220328
rocksdb.bloom.filter.useful COUNT : 5360933
rocksdb.bloom.filter.full.positive COUNT : 1321315
rocksdb.bloom.filter.full.true.positive COUNT : 1262999
$ #^ 1.08 % observed FP rate, 13.6% less memory usage for filters
(Due to specific key density, this example tends to generate filters that are "worse than average" for internal fragmentation. "Better than average" cases can show little or no improvement.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6427
Test Plan: unit test added, 'make check' with gcc, clang and valgrind
Reviewed By: siying
Differential Revision: D22124374
Pulled By: pdillinger
fbshipit-source-id: f3e3aa152f9043ddf4fae25799e76341d0d8714e
Summary:
EncryptEnv class is both declared and defined within env_encryption.cc. This makes it really tough to derive new classes from that base.
This branch moves declaration of the class to rocksdb/env_encryption.h. The change facilitates making new encryption modules (such as an upcoming openssl AES CTR pull request) possible / easy.
The only coding change was to add the EncryptEnv object to env_basic_test.cc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6830
Reviewed By: riversand963
Differential Revision: D21706593
Pulled By: ajkr
fbshipit-source-id: 64d2da95a1569ceeb9b1549c3bec5404cf4c89f0
Summary:
The bug fixed in https://github.com/facebook/rocksdb/pull/1816/ is now applicable to iterator too. This was not an issue but https://github.com/facebook/rocksdb/pull/2886 caused the regression. If a put and DB flush happens just between iterator to get latest sequence number and getting super version, empty result for the key or an older value can be returned, which is wrong.
Fix it in the same way as the fix in https://github.com/facebook/rocksdb/issues/1816, that is to get the sequence number after referencing the super version.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6973
Test Plan: Will run stress tests for a while to make sure there is no general regression.
Reviewed By: ajkr
Differential Revision: D22029348
fbshipit-source-id: 94390f93630906796d6e2fec321f44a920953fd1
Summary:
https://github.com/facebook/rocksdb/issues/5411 refactored `VersionSet::Recover` but introduced a bug, explained as follows.
Before, once a checksum mismatch happens, `reporter` will set `s` to be non-ok. Therefore, Recover will stop processing the MANIFEST any further.
```
// Correct
// Inside Recover
LogReporter reporter;
reporter.status = &s;
log::Reader reader(..., reporter);
while (reader.ReadRecord() && s.ok()) {
...
}
```
The bug is that, the local variable `s` in `ReadAndRecover` won't be updated by `reporter` while reading the MANIFEST. It is possible that the reader sees a checksum mismatch in a record, but `ReadRecord` retries internally read and finds the next valid record. The mismatched record will be ignored and no error is reported.
```
// Incorrect
// Inside Recover
LogReporter reporter;
reporter.status = &s;
log::Reader reader(..., reporter);
s = ReadAndRecover(reader, ...);
// Inside ReadAndRecover
Status s; // Shadows the s in Recover.
while (reader.ReadRecord() && s.ok()) {
...
}
```
`LogReporter` can use a separate `log_read_status` to track the errors while reading the MANIFEST. RocksDB can process more MANIFEST entries only if `log_read_status.ok()`.
Test plan (devserver):
make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6996
Reviewed By: ajkr
Differential Revision: D22105746
Pulled By: riversand963
fbshipit-source-id: b22f717a423457a41ca152a242abbb64cf91fc38
Summary:
Compressed block cache is disabled in https://github.com/facebook/rocksdb/pull/4650 for no good reason. Re-enable it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6990
Test Plan: Add a unit test to make sure a general function works with read-only DB + compressed block cache.
Reviewed By: ltamasi
Differential Revision: D22072755
fbshipit-source-id: 2a55df6363de23a78979cf6c747526359e5dc7a1
Summary:
`db_id` and `db_session_id` are now part of the table properties for all formats and stored in SST files. This adds about 99 bytes to each new SST file.
The `TablePropertiesNames` for these two identifiers are `rocksdb.creating.db.identity` and `rocksdb.creating.session.identity`.
In addition, SST files generated from SstFileWriter and Repairer have DB identity “SST Writer” and “DB Repairer”, respectively. Their DB session IDs are generated in the same way as `DB::GetDbSessionId`.
A table property test is added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6983
Test Plan: make check and some manual tests.
Reviewed By: zhichao-cao
Differential Revision: D22048826
Pulled By: gg814
fbshipit-source-id: afdf8c11424a6f509b5c0b06dafad584a80103c9
Summary:
In best-efforts recovery, an error that is not Corruption or IOError::kNotFound or IOError::kPathNotFound will be overwritten silently. Fix this by checking all non-ok cases and return early.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6989
Test Plan: make check
Reviewed By: ajkr
Differential Revision: D22071418
Pulled By: riversand963
fbshipit-source-id: 5a4ea5dfb1a41f41c7a3fdaf62b163007b42f04b
Summary:
Best-efforts recovery does not check the content of CURRENT file to determine which MANIFEST to recover from. However, it still checks the presence of CURRENT file to determine whether to create a new DB during `open()`. Therefore, we can tweak the logic in `open()` a little bit so that best-efforts recovery does not rely on CURRENT file at all.
Test plan (dev server):
make check
./db_basic_test --gtest_filter=DBBasicTest.RecoverWithNoCurrentFile
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6970
Reviewed By: anand1976
Differential Revision: D22013990
Pulled By: riversand963
fbshipit-source-id: db552a1868c60ed70e1f7cd252a3a076eb8ea58f
Summary:
Added DB::GetDbSessionId by using the same format and machinery as DB::GetDbIdentity.
The DB Session ID is generated (and therefore, updated) each time a DB object is opened. It is written to the LOG file right after the line of “DB SUMMARY”.
A test for the uniqueness, for different openings and during the same opening, is also added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6959
Test Plan: Passed make check
Reviewed By: zhichao-cao
Differential Revision: D21951721
Pulled By: gg814
fbshipit-source-id: 958a48a612db49a39998ea703cded45987d3fa8b
Summary:
Persistent cache feature caused rocks db crash on windows. I posted a issue for it, https://github.com/facebook/rocksdb/issues/6919. I found this is because no "persistent_cache_key_prefix" is generated for persistent cache. Looking repo history, "GetUniqueIdFromFile" is not implemented on Windows. So my fix is adding "NewId()" function in "persistent_cache" and using it to generate prefix for persistent cache. In this PR, i also re-enable related test cases defined in "db_test2" and "persistent_cache_test" for windows.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6932
Test Plan:
1. run related test cases in "db_test2" and "persistent_cache_test" on windows and see it passed.
2. manually run db_bench.exe with "read_cache_path" and verified.
Reviewed By: riversand963
Differential Revision: D21911608
Pulled By: cheng-chang
fbshipit-source-id: cdfd938d54a385edbb2836b13aaa1d39b0a6f1c2
Summary:
`Env::LowerThreadPoolCPUPriority` takes a new parameter `CpuPriority` to be able to lower to a specific priority such as `CpuPriority::kIdle`, previously, the priority is always lowered to `CpuPriority::kLow`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6969
Test Plan: unit test `EnvPosixTest::LowerThreadPoolCpuPriority` added to `env_test.cc`.
Reviewed By: siying
Differential Revision: D22011169
Pulled By: cheng-chang
fbshipit-source-id: 568878c24a924912e35cef00c552d4a63431cdf4
