Commit Graph

114 Commits

Author SHA1 Message Date
mrambacher
e628f59e87 Create a CustomEnv class; Add WinFileSystem; Make LegacyFileSystemWrapper private (#7703)
Summary:
This PR does the following:
-> Creates a WinFileSystem class.  This class is the Windows equivalent of the PosixFileSystem and will be used on Windows systems.
-> Introduces a CustomEnv class.  A CustomEnv is an Env that takes a FileSystem as constructor argument.  I believe there will only ever be two implementations of this class (PosixEnv and WinEnv).  There is still a CustomEnvWrapper class that takes an Env and a FileSystem and wraps the Env calls with the input Env but uses the FileSystem for the FileSystem calls
-> Eliminates the public uses of the LegacyFileSystemWrapper.

With this change in place, there are effectively the following patterns of Env:
- "Base Env classes" (PosixEnv, WinEnv).  These classes implement the core Env functions (e.g. Threads) and have a hard-coded input FileSystem.  These classes inherit from CompositeEnv, implement the core Env functions (threads) and delegate the FileSystem-like calls to the input file system.
- Wrapped Composite Env classes (MemEnv).  These classes take in an Env and a FileSystem.  The core env functions are re-directed to the wrapped env.  The file system calls are redirected to the input file system
- Legacy Wrapped Env classes.  These classes take in an Env input (but no FileSystem).  The core env functions are re-directed to the wrapped env.  A "Legacy File System" is created using this env and the file system calls directed to the env itself.

With these changes in place, the PosixEnv becomes a singleton -- there is only ever one created.  Any other use of the PosixEnv is via another wrapped env.  This cleans up some of the issues with the env construction and destruction.

Additionally, there were places in the code that required had an Env when they required a FileSystem.  Many of these places would wrap the Env with a LegacyFileSystemWrapper instead of using the env->GetFileSystem().  These places were changed, thereby removing layers of additional redirection (LegacyFileSystem --> Env --> Env::FileSystem).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7703

Reviewed By: zhichao-cao

Differential Revision: D25762190

Pulled By: anand1976

fbshipit-source-id: 1a088e97fc916f28ac69c149cd1dcad0ab31704b
2021-01-06 10:49:32 -08:00
Andrew Kryczka
225abffd8f Verify file checksum generator name (#7824)
Summary:
Previously we only had a debug assertion to check the right generator was being used for verification. However a user hit a problem in production where their factory was creating the wrong generator for some files, leading to checksum mismatches. It would have been easier to debug if we verified in optimized builds that the generator with the proper name is used. This PR adds such verification.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7824

Reviewed By: zhichao-cao

Differential Revision: D25740254

Pulled By: ajkr

fbshipit-source-id: a6231521747605021bad3231484b5d4f99f4044f
2021-01-04 11:51:50 -08:00
mrambacher
55e99688cc No elide constructors (#7798)
Summary:
Added "no-elide-constructors to the ASSERT_STATUS_CHECK builds.  This flag gives more errors/warnings for some of the Status checks where an inner class checks a Status and later returns it.  In this case,  without the elide check on, the returned status may not have been checked in the caller, thereby bypassing the checked code.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7798

Reviewed By: jay-zhuang

Differential Revision: D25680451

Pulled By: pdillinger

fbshipit-source-id: c3f14ed9e2a13f0a8c54d839d5fb4d1fc1e93917
2020-12-23 16:55:53 -08:00
Akanksha Mahajan
30a5ed9c53 Update "num_data_read" stat in RetrieveMultipleBlocks (#7770)
Summary:
RetrieveMultipleBlocks which is used by MultiGet to read data blocks is not updating num_data_read stat in
GetContextStats.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7770

Test Plan: make check -j64

Reviewed By: anand1976

Differential Revision: D25538982

Pulled By: akankshamahajan15

fbshipit-source-id: e3daedb035b1be8ab6af6f115cb3793ccc7b1ec6
2020-12-23 15:16:46 -08:00
anand76
8a1488efbf Ensure that MultiGet works properly with compressed cache (#7756)
Summary:
Ensure that when direct IO is enabled and a compressed block cache is
configured, MultiGet inserts compressed data blocks into the compressed
block cache.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7756

Test Plan: Add unit test to db_basic_test

Reviewed By: cheng-chang

Differential Revision: D25416240

Pulled By: anand1976

fbshipit-source-id: 75d57526370c9c0a45ff72651f3278dbd8a9086f
2020-12-09 17:01:13 -08:00
Cheng Chang
3c2a448856 Add a test for disabling tracking WAL (#7757)
Summary:
If WAL tracking was enabled, then disabled during reopen, the previously tracked WALs should be removed from MANIFEST.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7757

Test Plan: a new unit test `DBBasicTest.DisableTrackWal` is added.

Reviewed By: jay-zhuang

Differential Revision: D25410508

Pulled By: cheng-chang

fbshipit-source-id: 9d8d9e665066135930a7c1035bb8c2f68bded6a0
2020-12-09 16:58:26 -08:00
Cheng Chang
07030c6f4a Do not track obsolete WALs in MANIFEST even if they are synced (#7725)
Summary:
Consider the case:
1. All column families are flushed, so all WALs become obsolete, but no WAL is removed from disk yet because the removal is asynchronous, a VersionEdit is written to MANIFEST indicating that WALs before a certain WAL number are obsolete, let's say this number is 3;
2. `SyncWAL` is called, so all the on-disk WALs are synced, and if track_and_verify_wal_in_manifest=true, the WALs will be tracked in MANIFEST, let's say the WAL numbers are 1 and 2;
3. DB crashes;
4. During DB recovery, when replaying MANIFEST, we first see that WAL with number < 3 are obsolete, then we see that WAL 1 and 2 are synced, so according to current implementation of `WalSet`, the `WalSet` will be recovered to include WAL 1 and 2;
5. WAL 1 and 2 are asynchronously deleted from disk, then the WAL verification algorithm fails with `Corruption: missing WAL`.

The above case is reproduced in a new unit test `DBBasicTestTrackWal::DoNotTrackObsoleteWal`.

The fix is to maintain the upper bound of the obsolete WAL numbers, any WAL with number less than the maintained number is considered to be obsolete, so shouldn't be tracked even if they are later synced. The number is maintained in `WalSet`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7725

Test Plan:
1. a new unit test `DBBasicTestTrackWal::DoNotTrackObsoleteWal` is added.
2. run `make crash_test` on devserver.

Reviewed By: riversand963

Differential Revision: D25238914

Pulled By: cheng-chang

fbshipit-source-id: f5dccd57c3d89f19565ec5731f2d42f06d272b72
2020-12-08 10:58:04 -08:00
Yanqin Jin
869f0538dd Clean up after two test failures in db_basic_test (#7682)
Summary:
In db_basic_test.cc, there are two tests that rely on the underlying
system's `LockFile` support to function correctly:
DBBasicTest.OpenWhenOpen and DBBasicTest.CheckLock. In both tests,
re-opening a db using `DB::Open` is expected to fail because the second
open cannot lock the LOCK file. Some distributed file systems, e.g. HDFS
do not support the POSIX-style file lock. Therefore, these unit tests will cause
assertion failure and the second `Open` will create a db instance.
Currently, these db instances are not closed after the assertion
failure. Since these db instances are registered with some process-wide, static
data structures, e.g. `PeriodicWorkScheduler::Default()`, they can still be
accessed after the unit tests. However, the `Env` object created for this db
instance is destroyed when the test finishes in `~DBTestBase()`. Consequently,
it causes illegal memory access.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7682

Test Plan:
Run the following on a distrubited file system:
```
make check
```

Reviewed By: anand1976

Differential Revision: D25004215

Pulled By: riversand963

fbshipit-source-id: f4327d7716c0e72b13bb43737ec9a5d156da4d52
2020-11-16 22:09:01 -08:00
Cheng Chang
5e794b0841 Fix a recovery corner case (#7621)
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
2020-11-07 22:23:27 -08:00
Yanqin Jin
fde0cd7ced Add API to verify whole sst file checksum (#7578)
Summary:
Existing API `VerifyChecksum()` allows application to verify sst files' block checksums.
Since whole file, user-specified checksum is tracked in MANIFEST, we can expose a new
API to verify sst files' file checksums.

```
// Compute table file checksums if applicable and compare with MANIFEST.
// Returns OK if no file has mismatching whole-file checksum.
Status DB::VerifyFileChecksums(const ReadOptions& /*read_options*/);
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7578

Test Plan: make check

Reviewed By: pdillinger

Differential Revision: D24436783

Pulled By: riversand963

fbshipit-source-id: 52b51519b842f2b3c4e3351998a97c86cbec85b3
2020-11-03 20:34:56 -08:00
mrambacher
f35f7f2704 Fix many tests to run with MEM_ENV and ENCRYPTED_ENV; Introduce a MemoryFileSystem class (#7566)
Summary:
This PR does a few things:

1.  The MockFileSystem class was split out from the MockEnv.  This change would theoretically allow a MockFileSystem to be used by other Environments as well (if we created a means of constructing one).  The MockFileSystem implements a FileSystem in its entirety and does not rely on any Wrapper implementation.

2.  Make the RocksDB test suite work when MOCK_ENV=1 and ENCRYPTED_ENV=1 are set.  To accomplish this, a few things were needed:
- The tests that tried to use the "wrong" environment (Env::Default() instead of env_) were updated
- The MockFileSystem was changed to support the features it was missing or mishandled (such as recursively deleting files in a directory or supporting renaming of a directory).

3.  Updated the test framework to have a ROCKSDB_GTEST_SKIP macro.  This can be used to flag tests that are skipped.  Currently, this defaults to doing nothing (marks the test as SUCCESS) but will mark the tests as SKIPPED when RocksDB is upgraded to a version of gtest that supports this (gtest-1.10).

I have run a full "make check" with MEM_ENV, ENCRYPTED_ENV,  both, and neither under both MacOS and RedHat.  A few tests were disabled/skipped for the MEM/ENCRYPTED cases.  The error_handler_fs_test fails/hangs for MEM_ENV (presumably a timing problem) and I will introduce another PR/issue to track that problem.  (I will also push a change to disable those tests soon).  There is one more test in DBTest2 that also fails which I need to investigate or skip before this PR is merged.

Theoretically, this PR should also allow the test suite to run against an Env loaded from the registry, though I do not have one to try it with currently.

Finally, once this is accepted, it would be nice if there was a CircleCI job to run these tests on a checkin so this effort does not become stale.  I do not know how to do that, so if someone could write that job, it would be appreciated :)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7566

Reviewed By: zhichao-cao

Differential Revision: D24408980

Pulled By: jay-zhuang

fbshipit-source-id: 911b1554a4d0da06fd51feca0c090a4abdcb4a5f
2020-10-27 10:33:09 -07:00
Zhichao Cao
d8ec0a760a Make FileType Public and Replace kLogFile with kWalFile (#7580)
Summary:
As suggested by pdillinger ,The name of kLogFile is misleading, in some tests, kLogFile is defined as info log. Replace it with kWalFile and move it to public, which will be used in https://github.com/facebook/rocksdb/issues/7523

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7580

Test Plan: make check

Reviewed By: riversand963

Differential Revision: D24485420

Pulled By: zhichao-cao

fbshipit-source-id: 955e3dacc1021bb590fde93b0a568ffe9ad80799
2020-10-22 17:06:20 -07:00
Akanksha Mahajan
38d0a365e3 Add Stats for MultiGet (#7366)
Summary:
Add following stats for MultiGet in Histogram to get more insight on MultiGet.
    1. Number of index and filter blocks read from file as part of MultiGet
    request per level.
    2. Number of data blocks read from file per level.
    3. Number of SST files loaded from file system per level.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7366

Reviewed By: anand1976

Differential Revision: D24127040

Pulled By: akankshamahajan15

fbshipit-source-id: e63a003056b833729b277edc0639c08fb432756b
2020-10-07 13:28:48 -07:00
sdong
d08a9005b7 Make db_basic_test pass assert status checked (#7452)
Summary:
Add db_basic_test status check list. Some of the warnings are suppressed. It is possible that some of them are due to real bugs.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7452

Test Plan: See CI tests pass.

Reviewed By: zhichao-cao

Differential Revision: D23979764

fbshipit-source-id: 6151570c2a9b931b0fbb3fe939a94b2bd1583cbe
2020-09-29 09:49:04 -07:00
Peter Dillinger
93719fc953 Restore file size in backup table file names (and other cleanup) (#7400)
Summary:
Prior to 6.12, backup files using share_files_with_checksum had
the file size encoded in the file name, after the last '\_' and before
the last '.'. We considered this an implementation detail subject to
change, and indeed removed this information from the file name (with an
option to use old behavior) because it was considered
ineffective/inefficient for file name uniqueness. However, some
downstream RocksDB users were relying on this information since the file
size is not explicitly in the backup manifest file.

This primary purpose of this change is "retrofitting" the 6.12 release
(not yet a public release) to simultaneously support the benefits of the
new naming scheme (I/O performance and data correctness at scale) and
preserve the file size information, both as default behaviors. With this
change, we are essentially making the file size information encoded in
the file name an official, though obscure, extension of the backup meta
file format.

We preserve an option (kLegacyCrc32cAndFileSize) to use the original
"legacy" naming scheme, with its caveats, and make it easy to omit the
file size information (no kFlagIncludeFileSize), for more compact file
names. But note that changing the naming scheme used on an existing db
and backup directory can lead to transient space amplification, as some
files will be stored under two names in the shared_checksum directory.
Because some backups were saved using the original 6.12 naming scheme,
we offer two ways of dealing with those files: SST files generated by
older 6.12 versions can either use the default naming scheme in effect
when the SST files were generated (kFlagMatchInterimNaming, default, no
transient space amplification) or can use a new naming scheme (no
kFlagMatchInterimNaming, potential space amplification because some
already stored files getting a new name).

We don't have a natural way to detect which files were generated by
previous 6.12 versions, but this change hacks one in by changing DB
session ids to now use a more concise encoding, reducing file name
length, saving ~dozen bytes from SST files, and making them visually
distinct from DB ids so that they are less likely to be mixed up.

Two final auxiliary notes:
Recognizing that the backup file names have become a de facto part of
the backup meta schema, this change makes them easier to parse and
extend by putting a distinct marker, 's', before DB session ids embedded
in the name. When we extend this to allow custom checksums in the name,
they can get their own marker to ensure safe parsing. For backward
compatibility, file size does not get a marker but is assumed for
`_[0-9]+[.]`

Another change from initial 6.12 default behavior is never including
file custom checksum in the file name. Looking ahead to 6.13, we do not
want the default behavior to cause backup space amplification for
someone turning on file custom checksum checking in BackupEngine; we
want that to be an easy decision. When implemented, including file
custom checksums in backup file names will be a non-default option.

Actual file name patterns and priorities, as regexes:

    kLegacyCrc32cAndFileSize OR pre-6.12 SST file ->
      [0-9]+_[0-9]+_[0-9]+[.]sst
    kFlagMatchInterimNaming set (default) AND early 6.12 SST file ->
      [0-9]+_[0-9a-fA-F-]+[.]sst
    kUseDbSessionId AND NOT kFlagIncludeFileSize ->
      [0-9]+_s[0-9A-Z]{20}[.]sst
    kUseDbSessionId AND kFlagIncludeFileSize (default) ->
      [0-9]+_s[0-9A-Z]{20}_[0-9]+[.]sst

We might add opt-in options for more '\_' separated data in the name,
but embedded file size, if present, will always be after last '\_' and
before '.sst'.

This change was originally applied to version 6.12. (See https://github.com/facebook/rocksdb/issues/7390)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7400

Test Plan:
unit tests included. Sync point callbacks are used to mimic
previous version SST files.

Reviewed By: ajkr

Differential Revision: D23759587

Pulled By: pdillinger

fbshipit-source-id: f62d8af4e0978de0a34f26288cfbe66049b70025
2020-09-17 10:24:22 -07:00
Andrew Kryczka
9d3b2db9b5 Disable fsync in DB tests with timeouts (#7380)
Summary:
Some tests were encountering 600 second timeout in CI, such as `./db_universal_compaction_test --gtest_filter=NumLevels/DBTestUniversalCompaction.UniversalCompactionTrivialMoveTest2/5`, `./db_properties_test --gtest_filter=DBPropertiesTest.AggregatedTablePropertiesAtLevel`, and `./db_basic_test --gtest_filter=DBBasicTest.MultiGetBatchedSortedMultiFile`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7380

Test Plan:
- `./db_universal_compaction_test --gtest_filter=NumLevels/DBTestUniversalCompaction.UniversalCompactionTrivialMoveTest2/5`: 40 -> 3 seconds
- `./db_properties_test --gtest_filter=DBPropertiesTest.AggregatedTablePropertiesAtLevel`: 106 -> 1 second
- `./db_basic_test --gtest_filter=DBBasicTest.MultiGetBatchedSortedMultiFile`: 27 -> 1 second

Reviewed By: anand1976

Differential Revision: D23674570

Pulled By: ajkr

fbshipit-source-id: 4d4ca6a4e2d2e76fcf8b6f6cce91e0f98ba5050c
2020-09-15 18:55:08 -07:00
mrambacher
7d472accdc Bring the Configurable options together (#5753)
Summary:
This PR merges the functionality of making the ColumnFamilyOptions, TableFactory, and DBOptions into Configurable into a single PR, resolving any merge conflicts

Pull Request resolved: https://github.com/facebook/rocksdb/pull/5753

Reviewed By: ajkr

Differential Revision: D23385030

Pulled By: zhichao-cao

fbshipit-source-id: 8b977a7731556230b9b8c5a081b98e49ee4f160a
2020-09-14 17:01:01 -07:00
sdong
cecdd5d2ab Parameterize DBBasicTest.CompactBetweenSnapshots (#7301)
Summary:
DBBasicTest.CompactBetweenSnapshots can time-out in some slow-I/O hosts. Parameterize it so that single test runs shorter.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7301

Test Plan: Run the test and see see different runs are of different configerations in a hacky way.

Reviewed By: ltamasi

Differential Revision: D23277733

fbshipit-source-id: 1f717b4131322d175abf9e211131fe7e9b1ef758
2020-08-25 15:42:11 -07:00
sdong
b194c21bba Whole DBTest to skip fsync (#7274)
Summary:
After https://github.com/facebook/rocksdb/pull/7036, we still see extra DBTest that can timeout when running 10 or 20 in parallel. Expand skip-fsync mode in whole DBTest. Still preserve other tests from doing this mode to be conservative.

This commit reinstates https://github.com/facebook/rocksdb/issues/7049, whose un-revert was lost in an automatic
infrastructure mis-merge.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7274

Test Plan: Run all existing files.

Reviewed By: pdillinger

Differential Revision: D23177444

fbshipit-source-id: 1f61690b2ac6333c3b2c87176fef6b2cba086b33
2020-08-17 18:42:25 -07:00
Peter Dillinger
6ac1d25fd0 Fix+clean up handling of mock sleeps (#7101)
Summary:
We have a number of tests hanging on MacOS and windows due to
mishandling of code for mock sleeps. In addition, the code was in
terrible shape because the same variable (addon_time_) would sometimes
refer to microseconds and sometimes to seconds. One test even assumed it
was nanoseconds but was written to pass anyway.

This has been cleaned up so that DB tests generally use a SpecialEnv
function to mock sleep, for either some number of microseconds or seconds
depending on the function called. But to call one of these, the test must first
call SetMockSleep (precondition enforced with assertion), which also turns
sleeps in RocksDB into mock sleeps. To also removes accounting for actual
clock time, call SetTimeElapseOnlySleepOnReopen, which implies
SetMockSleep (on DB re-open). This latter setting only works by applying
on DB re-open, otherwise havoc can ensue if Env goes back in time with
DB open.

More specifics:

Removed some unused test classes, and updated comments on the general
problem.

Fixed DBSSTTest.GetTotalSstFilesSize using a sync point callback instead
of mock time. For this we have the only modification to production code,
inserting a sync point callback in flush_job.cc, which is not a change to
production behavior.

Removed unnecessary resetting of mock times to 0 in many tests. RocksDB
deals in relative time. Any behaviors relying on absolute date/time are likely
a bug. (The above test DBSSTTest.GetTotalSstFilesSize was the only one
clearly injecting a specific absolute time for actual testing convenience.) Just
in case I misunderstood some test, I put this note in each replacement:
// NOTE: Presumed unnecessary and removed: resetting mock time in env

Strengthened some tests like MergeTestTime, MergeCompactionTimeTest, and
FilterCompactionTimeTest in db_test.cc

stats_history_test and blob_db_test are each their own beast, rather deeply
dependent on MockTimeEnv. Each gets its own variant of a work-around for
TimedWait in a mock time environment. (Reduces redundancy and
inconsistency in stats_history_test.)

Intended follow-up:

Remove TimedWait from the public API of InstrumentedCondVar, and only
make that accessible through Env by passing in an InstrumentedCondVar and
a deadline. Then the Env implementations mocking time can fix this problem
without using sync points. (Test infrastructure using sync points interferes
with individual tests' control over sync points.)

With that change, we can simplify/consolidate the scattered work-arounds.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7101

Test Plan: make check on Linux and MacOS

Reviewed By: zhichao-cao

Differential Revision: D23032815

Pulled By: pdillinger

fbshipit-source-id: 7f33967ada8b83011fb54e8279365c008bd6610b
2020-08-11 12:41:30 -07:00
anand76
832b056a30 Enable IO timeouts for iterators (#7161)
Summary:
Introduce io_timeout in ReadOptions and enabled deadline/io_timeout for
Iterators.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7161

Test Plan: New unit tests in db_basic_test

Reviewed By: riversand963

Differential Revision: D22687352

Pulled By: anand1976

fbshipit-source-id: 67bbb0e6d7ae80b256589244468494292538c6ec
2020-08-07 12:01:08 -07:00
Andrew Kryczka
a4a4a2dabd dedup ReadOptions in iterator hierarchy (#7210)
Summary:
Previously, a `ReadOptions` object was stored in every `BlockBasedTableIterator`
and every `LevelIterator`. This redundancy consumes extra memory,
resulting in the `Arena` making more allocations, and iteration
observing worse cache performance.

This PR migrates callers of `NewInternalIterator()` and
`MakeInputIterator()` to provide a `ReadOptions` object guaranteed to
outlive the returned iterator. When the iterator's lifetime will be managed by the
user, this lifetime guarantee is achieved by storing the `ReadOptions`
value in `ArenaWrappedDBIter`. Then, sub-iterators of `NewInternalIterator()` and
`MakeInputIterator()` can hold a reference-to-const `ReadOptions`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7210

Test Plan:
- `make check` under ASAN and valgrind
- benchmark: on a DB with 2 L0 files and 3 L1+ levels, this PR reduced `Arena` allocation 4792 -> 4160 bytes.

Reviewed By: anand1976

Differential Revision: D22861323

Pulled By: ajkr

fbshipit-source-id: 54aebb3e89c872eeab0f5793b4b6e42878d093ce
2020-08-03 15:23:04 -07:00
mrambacher
c7c7b07f06 More Makefile Cleanup (#7097)
Summary:
Cleans up some of the dependencies on test code in the Makefile while building tools:
- Moves the test::RandomString, DBBaseTest::RandomString into Random
- Moves the test::RandomHumanReadableString into Random
- Moves the DestroyDir method into file_utils
- Moves the SetupSyncPointsToMockDirectIO into sync_point.
- Moves the FaultInjection Env and FS classes under env

These changes allow all of the tools to build without dependencies on test_util, thereby simplifying the build dependencies.  By moving the FaultInjection code, the dependency in db_stress on different libraries for debug vs release was eliminated.

Tested both release and debug builds via Make and CMake for both static and shared libraries.

More work remains to clean up how the tools are built and remove some unnecessary dependencies.  There is also more work that should be done to get the Makefile and CMake to align in their builds -- what is in the libraries and the sizes of the executables are different.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7097

Reviewed By: riversand963

Differential Revision: D22463160

Pulled By: pdillinger

fbshipit-source-id: e19462b53324ab3f0b7c72459dbc73165cc382b2
2020-07-09 14:35:17 -07:00
Jay Zhuang
00de699096 Replace reinterpret_cast with static_cast_with_check (#7067)
Summary:
Replace `reinterpret_cast` with `static_cast_with_check` for `DBImpl` and `ColumnFamilyHandleImpl`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7067

Reviewed By: siying

Differential Revision: D22361587

Pulled By: jay-zhuang

fbshipit-source-id: dfe9e8f3af39c3d27cc372c55ab9ad905eb0a5a1
2020-07-02 19:25:41 -07:00
Peter Dillinger
52d59e0c93 Revert "Whole DBTest to skip fsync (#7049)" (#7070)
Summary:
This reverts commit 4f1534bdb0.

This commit caused failures and deadlocks in
MultiThreadedDBTest.MultiThreaded/69 and others.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7070

Reviewed By: riversand963

Differential Revision: D22358778

Pulled By: pdillinger

fbshipit-source-id: faf8f2cb469a7063a113921c8e9c64a9f7610dac
2020-07-02 10:22:43 -07:00
sdong
4f1534bdb0 Whole DBTest to skip fsync (#7049)
Summary:
After https://github.com/facebook/rocksdb/pull/7036, we still see extra DBTest that can timeout when running 10 or 20 in parallel. Expand skip-fsync mode in whole DBTest. Still preserve other tests from doing this mode to be conservative.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7049

Test Plan: Run all existing files.

Reviewed By: pdillinger

Differential Revision: D22301700

fbshipit-source-id: f9a9e3b3b26ce640665a47cb8bff33ba0c89b565
2020-07-01 19:37:56 -07:00
Anand Ananthabhotla
9a5886bd8c Extend Get/MultiGet deadline support to table open (#6982)
Summary:
Current implementation of the ```read_options.deadline``` option only checks the deadline for random file reads during point lookups. This PR extends the checks to file opens, prefetches and preloads as part of table open.

The main changes are in the ```BlockBasedTable```, partitioned index and filter readers, and ```TableCache``` to take ReadOptions as an additional parameter. In ```BlockBasedTable::Open```, in order to retain existing behavior w.r.t checksum verification and block cache usage, we filter out most of the options in ```ReadOptions``` except ```deadline```. However, having the ```ReadOptions``` gives us more flexibility to honor other options like verify_checksums, fill_cache etc. in the future.

Additional changes in callsites due to function signature changes in ```NewTableReader()``` and ```FilePrefetchBuffer```.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6982

Test Plan: Add new unit tests in db_basic_test

Reviewed By: riversand963

Differential Revision: D22219515

Pulled By: anand1976

fbshipit-source-id: 8a3b92f4a889808013838603aa3ca35229cd501b
2020-06-29 14:53:17 -07:00
Yanqin Jin
e66199d848 First step towards handling MANIFEST write error (#6949)
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
2020-06-24 19:07:08 -07:00
Yanqin Jin
569b87e8c7 Fail recovery when MANIFEST record checksum mismatch (#6996)
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
2020-06-18 10:09:12 -07:00
Yanqin Jin
9bfd46d0d8 Let best-efforts recovery ignore CURRENT file (#6970)
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
2020-06-15 14:11:24 -07:00
Zitan Chen
88db97b06d Add a DB Session ID (#6959)
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
2020-06-15 10:47:02 -07:00
anand76
1fb3593f25 Fix a bug in looking up duplicate keys with MultiGet (#6953)
Summary:
When MultiGet is called with duplicate keys, and the key matches the
largest key in an SST file and the value type is merge, only the first
instance of the duplicate key is returned with correct results. This is
due to the incorrect assumption that if a key in a batch is equal to the
largest key in the file, the next key cannot be present in that file.

Tests:
Add a new unit test
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6953

Reviewed By: cheng-chang

Differential Revision: D21935898

Pulled By: anand1976

fbshipit-source-id: a2cc327a15150e23fd997546ca64d1c33021cb4c
2020-06-08 16:11:21 -07:00
sdong
afa3518839 Revert "Update googletest from 1.8.1 to 1.10.0 (#6808)" (#6923)
Summary:
This reverts commit 8d87e9cea1.

Based on offline discussions, it's too early to upgrade to gtest 1.10, as it prevents some developers from using an older version of gtest to integrate to some other systems. Revert it for now.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6923

Reviewed By: pdillinger

Differential Revision: D21864799

fbshipit-source-id: d0726b1ff649fc911b9378f1763316200bd363fc
2020-06-03 15:55:03 -07:00
Peter Dillinger
43f8a9dcce Some fixes for gcc 4.8 and add to Travis (#6915)
Summary:
People keep breaking the gcc 4.8 compilation due to different
warnings for shadowing member functions with locals. Adding to Travis
to keep compatibility. (gcc 4.8 is default on CentOS 7.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6915

Test Plan: local and Travis

Reviewed By: siying

Differential Revision: D21842894

Pulled By: pdillinger

fbshipit-source-id: bdcd4385127ee5d1cc222d87e53fb3695c32a9d4
2020-06-03 11:39:25 -07:00
Zhichao Cao
2adb7e3768 Fix potential overflow of unsigned type in for loop (#6902)
Summary:
x.size() -1 or y - 1 can overflow to an extremely large value when x.size() pr y is 0 when they are unsigned type. The end condition of i in the for loop will be extremely large, potentially causes segment fault. Fix them.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6902

Test Plan: pass make asan_check

Reviewed By: ajkr

Differential Revision: D21843767

Pulled By: zhichao-cao

fbshipit-source-id: 5b8b88155ac5a93d86246d832e89905a783bb5a1
2020-06-02 15:05:07 -07:00
Adam Retter
8d87e9cea1 Update googletest from 1.8.1 to 1.10.0 (#6808)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6808

Reviewed By: anand1976

Differential Revision: D21483984

Pulled By: pdillinger

fbshipit-source-id: 70c5eff2bd54ddba469761d95e4cd4611fb8e598
2020-06-01 20:33:42 -07:00
Akanksha Mahajan
bcefc59e9f Allow MultiGet users to limit cumulative value size (#6826)
Summary:
1. Add a value_size in read options which limits the cumulative value size of keys read in batches. Once the size exceeds read_options.value_size, all the remaining keys are returned with status Abort without further fetching any key.
2. Add a unit test case MultiGetBatchedValueSizeSimple the reads keys from memory and sst files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6826

Test Plan:
1. make check -j64
	   2. Add a new unit test case

Reviewed By: anand1976

Differential Revision: D21471483

Pulled By: akankshamahajan15

fbshipit-source-id: dea51b8e76d5d1df38ece8cdb29933b1d798b900
2020-05-27 13:07:14 -07:00
Yanqin Jin
e72e2167fd Fix a few bugs in best-efforts recovery (#6824)
Summary:
1. Update column_family_memtables_ to point to latest column_family_set in
   version_set after recovery.
2. Normalize file paths passed by application so that directories end with '/'
   or '\\'.
3. In addition to missing files, corrupted files are also ignored in
   best-efforts recovery.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6824

Test Plan: COMPILE_WITH_ASAN=1 make check

Reviewed By: anand1976

Differential Revision: D21463905

Pulled By: riversand963

fbshipit-source-id: c48db8843cc93c8c1c7139c474b64e6f775307d2
2020-05-08 13:01:42 -07:00
Peter Dillinger
b27a1448b6 Fix false NotFound from batched MultiGet with kHashSearch (#6821)
Summary:
The error is assigning KeyContext::s to NotFound status in a
table reader for a "not found in this table" case, which skips searching
in later tables, like only a delete should. (The hash search index iterator
is the only one that can return status NotFound even if Valid() == false.)

This was detected by intermittent failure in
MultiThreadedDBTest.MultiThreaded/5, a kHashSearch configuration.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6821

Test Plan: modified existing unit test to reproduce problem

Reviewed By: anand1976

Differential Revision: D21450469

Pulled By: pdillinger

fbshipit-source-id: 7478003684d637dbd491cdac81468041a791be2c
2020-05-07 15:41:37 -07:00
Peter Dillinger
2f1700c8c5 Fix failure to write output in SpecialEnv::GetCurrentTime (#6803)
Summary:
This very old test code bug was causing a new valgrind failure
in MultiGetDeadlineExceeded

Also fix hang in MultiGetDeadlineExceeded by unifying with some logic from another test.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6803

Test Plan: run that unit test under valgrind, make check

Reviewed By: siying

Differential Revision: D21388470

Pulled By: pdillinger

fbshipit-source-id: 0ce99d6d5eb8cd3195b17406892c8c5cff5fa5dd
2020-05-05 13:11:29 -07:00
Yanqin Jin
5584595f80 Do not swallow error returned from SaveTo() (#6801)
Summary:
With consistency check enabled, VersionBuilder::SaveTo() may return error once
corruption is detected while building versions. We should handle these errors.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6801

Test Plan: make check

Reviewed By: siying

Differential Revision: D21385045

Pulled By: riversand963

fbshipit-source-id: 98f6424e2a4699b62befa21e9fe00e70a771118e
2020-05-05 10:46:20 -07:00
anand76
ab13d43e1d Pass a timeout to FileSystem for random reads (#6751)
Summary:
Calculate ```IOOptions::timeout``` using ```ReadOptions::deadline``` and pass it to ```FileSystem::Read/FileSystem::MultiRead```. This allows us to impose a tighter bound on the time taken by Get/MultiGet on FileSystem/Envs that support IO timeouts. Even on those that don't support, check in ```RandomAccessFileReader::Read``` and ```MultiRead``` and return ```Status::TimedOut()``` if the deadline is exceeded.

For now, TableReader creation, which might do file opens and reads, are not covered. It will be implemented in another PR.

Tests:
Update existing unit tests to verify the correct timeout value is being passed
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6751

Reviewed By: riversand963

Differential Revision: D21285631

Pulled By: anand1976

fbshipit-source-id: d89af843e5a91ece866e87aa29438b52a65a8567
2020-04-30 14:50:39 -07:00
anand76
335ea73e49 Fix a valgrind failure due to DBBasicTestMultiGetDeadline (#6756)
Summary:
Fix a valgrind failure.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6756

Test Plan: valgrind_test

Reviewed By: pdillinger

Differential Revision: D21284660

Pulled By: anand1976

fbshipit-source-id: 39bf1bd130b6adb585ddbf2f9aa2f53dbf666f80
2020-04-28 20:06:06 -07:00
Peter Dillinger
249eff0f30 Stats for redundant insertions into block cache (#6681)
Summary:
Since read threads do not coordinate on loading data into block
cache, two threads between Lookup and Insert can end up loading and
inserting the same data. This is particularly concerning with
cache_index_and_filter_blocks since those are hot and more likely to
be race targets if ejected from (or not pre-populated in) the cache.

Particularly with moves toward disaggregated / network storage, the cost
of redundant retrieval might be high, and we should at least have some
hard statistics from which we can estimate impact.

Example with full filter thrashing "cliff":

    $ ./db_bench --benchmarks=fillrandom --num=15000000 --cache_index_and_filter_blocks -bloom_bits=10
    ...
    $ ./db_bench --db=/tmp/rocksdbtest-172704/dbbench --use_existing_db --benchmarks=readrandom,stats --num=200000 --cache_index_and_filter_blocks --cache_size=$((130 * 1024 * 1024)) --bloom_bits=10 --threads=16 -statistics 2>&1 | egrep '^rocksdb.block.cache.(.*add|.*redundant)' | grep -v compress | sort
    rocksdb.block.cache.add COUNT : 14181
    rocksdb.block.cache.add.failures COUNT : 0
    rocksdb.block.cache.add.redundant COUNT : 476
    rocksdb.block.cache.data.add COUNT : 12749
    rocksdb.block.cache.data.add.redundant COUNT : 18
    rocksdb.block.cache.filter.add COUNT : 1003
    rocksdb.block.cache.filter.add.redundant COUNT : 217
    rocksdb.block.cache.index.add COUNT : 429
    rocksdb.block.cache.index.add.redundant COUNT : 241
    $ ./db_bench --db=/tmp/rocksdbtest-172704/dbbench --use_existing_db --benchmarks=readrandom,stats --num=200000 --cache_index_and_filter_blocks --cache_size=$((120 * 1024 * 1024)) --bloom_bits=10 --threads=16 -statistics 2>&1 | egrep '^rocksdb.block.cache.(.*add|.*redundant)' | grep -v compress | sort
    rocksdb.block.cache.add COUNT : 1182223
    rocksdb.block.cache.add.failures COUNT : 0
    rocksdb.block.cache.add.redundant COUNT : 302728
    rocksdb.block.cache.data.add COUNT : 31425
    rocksdb.block.cache.data.add.redundant COUNT : 12
    rocksdb.block.cache.filter.add COUNT : 795455
    rocksdb.block.cache.filter.add.redundant COUNT : 130238
    rocksdb.block.cache.index.add COUNT : 355343
    rocksdb.block.cache.index.add.redundant COUNT : 172478
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6681

Test Plan: Some manual testing (above) and unit test covering key metrics is included

Reviewed By: ltamasi

Differential Revision: D21134113

Pulled By: pdillinger

fbshipit-source-id: c11497b5f00f4ffdfe919823904e52d0a1a91d87
2020-04-27 13:20:27 -07:00
Yanqin Jin
e04f3bce4f Update CURRENT file after best-efforts recovery (#6746)
Summary:
After a successful recovery, the CURRENT file should be updated to point to the valid MANIFEST.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6746

Test Plan: make check

Reviewed By: anand1976

Differential Revision: D21189876

Pulled By: riversand963

fbshipit-source-id: 7537b49988c5c425ebe9505a5cc260de351ad79b
2020-04-23 16:21:09 -07:00
anand76
c1ccd6b6af Implement deadline support for MultiGet (#6710)
Summary:
Initial implementation of ReadOptions.deadline for MultiGet. If the request takes longer than the deadline, the keys not yet found will be returned with Status::TimedOut(). This
implementation enforces the deadline in DBImpl, which is fairly high
level. Its best effort and may not check the deadline after every key
lookup, but may do so after a batch of keys.

In subsequent stages, we will extend this to passing a timeout down to the FileSystem.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6710

Test Plan: Add new unit tests

Reviewed By: riversand963

Differential Revision: D21149158

Pulled By: anand1976

fbshipit-source-id: 9f44eecffeb40873f5034ed59a66d21f9f88879e
2020-04-21 14:51:51 -07:00
Ziyue Yang
03a781a90c Add pipelined & parallel compression optimization (#6262)
Summary:
This PR adds support for pipelined & parallel compression optimization for `BlockBasedTableBuilder`. This optimization makes block building, block compression and block appending a pipeline, and uses multiple threads to accelerate block compression. Users can set `CompressionOptions::parallel_threads` greater than 1 to enable compression parallelism.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6262

Reviewed By: ajkr

Differential Revision: D20651306

fbshipit-source-id: 62125590a9c15b6d9071def9dc72589c1696a4cb
2020-04-01 16:40:18 -07:00
Levi Tamasi
e6f86cfb36 Revert the recent cache deleter change (#6620)
Summary:
Revert "Use function objects as deleters in the block cache (https://github.com/facebook/rocksdb/issues/6545)"

    This reverts commit 6301dbe7a7.

    Revert "Call out the cache deleter related interface change in HISTORY.md (https://github.com/facebook/rocksdb/issues/6606)"

    This reverts commit 3a35542f86.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6620

Test Plan: `make check`

Reviewed By: zhichao-cao

Differential Revision: D20773311

Pulled By: ltamasi

fbshipit-source-id: 7637a761f718f323ef0e7da959462e8fb06e7a2b
2020-03-31 16:11:06 -07:00
Levi Tamasi
6301dbe7a7 Use function objects as deleters in the block cache (#6545)
Summary:
As the first step of reintroducing eviction statistics for the block
cache, the patch switches from using simple function pointers as deleters
to function objects implementing an interface. This will enable using
deleters that have state, like a smart pointer to the statistics object
that is to be updated when an entry is removed from the cache. For now,
the patch adds a deleter template class `SimpleDeleter`, which simply
casts the `value` pointer to its original type and calls `delete` or
`delete[]` on it as appropriate. Note: to prevent object lifecycle
issues, deleters must outlive the cache entries referring to them;
`SimpleDeleter` ensures this by using the ("leaky") Meyers singleton
pattern.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6545

Test Plan: `make asan_check`

Reviewed By: siying

Differential Revision: D20475823

Pulled By: ltamasi

fbshipit-source-id: fe354c33dd96d9bafc094605462352305449a22a
2020-03-26 16:19:58 -07:00
Huisheng Liu
a6ce5c823b multiget support for timestamps (#6483)
Summary:
Add timestamp support for MultiGet().
timestamp from readoptions is honored, and timestamps can be returned along with values.

MultiReadRandom perf test (10 minutes) on the same development machine ram drive with the same DB data shows no regression (within marge of error). The test is adapted from https://github.com/facebook/rocksdb/wiki/RocksDB-In-Memory-Workload-Performance-Benchmarks.
base line (commit 17bef7d3a):
  multireadrandom :     104.173 micros/op 307167 ops/sec; (5462999 of 5462999 found)
This PR:
  multireadrandom :     104.199 micros/op 307095 ops/sec; (5307999 of 5307999 found)

.\db_bench --db=r:\rocksdb.github --num_levels=6 --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --cache_size=2147483648 --cache_numshardbits=6 --compression_type=none --compression_ratio=1 --min_level_to_compress=-1 --disable_seek_compaction=1 --hard_rate_limit=2 --write_buffer_size=134217728 --max_write_buffer_number=2 --level0_file_num_compaction_trigger=8 --target_file_size_base=134217728 --max_bytes_for_level_base=1073741824 --disable_wal=0 --wal_dir=r:\rocksdb.github\WAL_LOG --sync=0 --verify_checksum=1 --statistics=0 --stats_per_interval=0 --stats_interval=1048576 --histogram=0 --use_plain_table=1 --open_files=-1 --memtablerep=prefix_hash --bloom_bits=10 --bloom_locality=1 --duration=600 --benchmarks=multireadrandom --use_existing_db=1 --num=25000000 --threads=32 --allow_concurrent_memtable_write=0
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6483

Reviewed By: anand1976

Differential Revision: D20498373

Pulled By: riversand963

fbshipit-source-id: 8505f22bc40fd791bc7dd05e48d7e67c91edb627
2020-03-24 11:24:09 -07:00