Summary:
Add the new Append and PositionedAppend API to env WritableFile. User is able to benefit from the write checksum handoff API when using the legacy Env classes. FileSystem already implemented the checksum handoff API.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8071
Test Plan: make check, added new unit test.
Reviewed By: anand1976
Differential Revision: D27177043
Pulled By: zhichao-cao
fbshipit-source-id: 430c8331fc81099fa6d00f4fff703b68b9e8080e
Summary:
These classes were wraps of Env that provided only extensions to the FileSystem functionality. Changed the classes to be FileSystems and the wraps to be of the CompositeEnvWrapper.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7968
Reviewed By: anand1976
Differential Revision: D26900253
Pulled By: mrambacher
fbshipit-source-id: 94001d8024a3c54a1c11adadca2bac66c3af2a77
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:
This API can be used for things like determining how much space
can be freed up by deleting a particular backup, etc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8042
Test Plan:
validation of the API added to many existing backup unit
tests
Reviewed By: mrambacher
Differential Revision: D26936577
Pulled By: pdillinger
fbshipit-source-id: f0bbd90f0917b9781a6837652fb4616d9247816a
Summary:
Removed confusing, awkward, and undocumented internal API
ReadOneLine and replaced with very simple LineFileReader.
In refactoring backupable_db.cc, this has the side benefit of
removing the arbitrary cap on the size of backup metadata files.
Also added Status::MustCheck to make it easy to mark a Status as
"must check." Using this, I can ensure that after
LineFileReader::ReadLine returns false the caller checks GetStatus().
Also removed some excessive conditional compilation in status.h
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8026
Test Plan: added unit test, and running tests with ASSERT_STATUS_CHECKED
Reviewed By: mrambacher
Differential Revision: D26831687
Pulled By: pdillinger
fbshipit-source-id: ef749c265a7a26bb13cd44f6f0f97db2955f6f0f
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:
The checkpointing logic supports passing file level checksums
to the copy_file_cb callback function which is used by the backup code
for detecting corruption during file copies.
However, this is currently implemented only for table files.
This PR extends the checksum retrieval to blob files as well.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8003
Test Plan: Add new test units
Reviewed By: ltamasi
Differential Revision: D26680701
Pulled By: akankshamahajan15
fbshipit-source-id: 1bd1e2464df6e9aa31091d35b8c72786d94cd1c5
Summary:
Allow applications to implement a custom compaction filter and pass it to BlobDB.
The compaction filter's custom logic can operate on blobs.
To do so, application needs to subclass `CompactionFilter` abstract class and implement `FilterV2()` method.
Optionally, a method called `ShouldFilterBlobByKey()` can be implemented if application's custom logic rely solely
on the key to make a decision without reading the blob, thus saving extra IO. Examples can be found in
db/blob/db_blob_compaction_test.cc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7974
Test Plan: make check
Reviewed By: ltamasi
Differential Revision: D26509280
Pulled By: riversand963
fbshipit-source-id: 59f9ae5614c4359de32f4f2b16684193cc537b39
Summary:
Fix this scenario:
trx1> acquire shared lock on $key
trx2> acquire shared lock on the same $key
trx1> attempt to acquire a unique lock on $key.
Lock acquisition will fail, and deadlock detection will start.
It will call iterate_and_get_overlapping_row_locks() which will
produce a list with two locks (shared locks by trx1 and trx2).
However the code in lock_request::build_wait_graph() was not prepared
to find the lock by the same transaction in the list of conflicting
locks. Fix it to ignore it.
(One may suggest to fix iterate_and_get_overlapping_row_locks() to not
include locks by trx1. This is not a good idea, because that function
is also used to report all locks currently held)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7938
Reviewed By: zhichao-cao
Differential Revision: D26529374
Pulled By: ajkr
fbshipit-source-id: d89cbed008db1a97a8f2351b9bfb75310750d16a
Summary:
TransactionDB uses read callback to filter out un-committed data before
a snapshot. But `MultiGet()` API doesn't use that at all, which causes
returning unwanted data.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7963
Test Plan: Added unittest to reproduce
Reviewed By: anand1976
Differential Revision: D26455851
Pulled By: jay-zhuang
fbshipit-source-id: 265276698cf9d8c4cd79e3250ef10d14375bac55
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:
in PR https://github.com/facebook/rocksdb/issues/7419 , we introduce the new Append and PositionedAppend APIs to WritableFile at File System, which enable RocksDB to pass the data verification information (e.g., checksum of the data) to the lower layer. In this PR, we use the new API in WritableFileWriter, such that the file created via WritableFileWrite can pass the checksum to the storage layer. To control which types file should apply the checksum handoff, we add checksum_handoff_file_types to DBOptions. User can use this option to control which file types (Currently supported file tyes: kLogFile, kTableFile, kDescriptorFile.) should use the new Append and PositionedAppend APIs to handoff the verification information.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7523
Test Plan: add new unit test, pass make check/ make asan_check
Reviewed By: pdillinger
Differential Revision: D24313271
Pulled By: zhichao-cao
fbshipit-source-id: aafd69091ae85c3318e3e17cbb96fe7338da11d0
Summary:
Explicitly reject all range deletions on `TransactionDB` or `OptimisticTransactionDB`, except when the user provides sufficient promises that allow us to proceed safely. The necessary promises are described in the API doc for `TransactionDB::DeleteRange()`. There is currently no way to provide enough promises to make it safe in `OptimisticTransactionDB`.
Fixes https://github.com/facebook/rocksdb/issues/7913.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7929
Test Plan: unit tests covering the cases it's permitted/rejected
Reviewed By: ltamasi
Differential Revision: D26240254
Pulled By: ajkr
fbshipit-source-id: 2834a0ce64cc3e4c3799e35b885a5e79c2f4f6d9
Summary:
Memtable bloom filter is useful in many use cases. A default value on with conservative 1.5% memory can benefit more use cases than use cases impacted.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6584
Test Plan: Run all existing tests.
Reviewed By: pdillinger
Differential Revision: D20626739
fbshipit-source-id: 1dd45532b932139552519b8c2682bd954550c2f9
Summary:
Removed the uses of the Legacy FileWrapper classes from the source code. The wrappers were creating an additional layer of indirection/wrapping, as the Env already has a FileSystem.
Moved the Custom FileWrapper classes into the CustomEnv, as these classes are really for the private use the the CustomEnv class.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7851
Reviewed By: anand1976
Differential Revision: D26114816
Pulled By: mrambacher
fbshipit-source-id: db32840e58d969d3a0fa6c25aaf13d6dcdc74150
Summary:
Introduces and uses a SystemClock class to RocksDB. This class contains the time-related functions of an Env and these functions can be redirected from the Env to the SystemClock.
Many of the places that used an Env (Timer, PerfStepTimer, RepeatableThread, RateLimiter, WriteController) for time-related functions have been changed to use SystemClock instead. There are likely more places that can be changed, but this is a start to show what can/should be done. Over time it would be nice to migrate most (if not all) of the uses of the time functions from the Env to the SystemClock.
There are several Env classes that implement these functions. Most of these have not been converted yet to SystemClock implementations; that will come in a subsequent PR. It would be good to unify many of the Mock Timer implementations, so that they behave similarly and be tested similarly (some override Sleep, some use a MockSleep, etc).
Additionally, this change will allow new methods to be introduced to the SystemClock (like https://github.com/facebook/rocksdb/issues/7101 WaitFor) in a consistent manner across a smaller number of classes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7858
Reviewed By: pdillinger
Differential Revision: D26006406
Pulled By: mrambacher
fbshipit-source-id: ed10a8abbdab7ff2e23d69d85bd25b3e7e899e90
Summary:
In the original stacked BlobDB implementation, which writes blobs to blob files
immediately and treats blob files as logs, it makes sense to flush the file after
writing each blob to protect against process crashes; however, in the integrated
implementation, which builds blob files in the background jobs, this unnecessarily
reduces performance. This patch fixes this by simply adding a `do_flush` flag to
`BlobLogWriter`, which is set to `true` by the stacked implementation and to `false`
by the new code. Note: the change itself is trivial but the tests needed some work;
since in the new implementation, blobs are now buffered, adding a blob to
`BlobFileBuilder` is no longer guaranteed to result in an actual I/O. Therefore, we can
no longer rely on `FaultInjectionTestEnv` when testing failure cases; instead, we
manipulate the return values of I/O methods directly using `SyncPoint`s.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7892
Test Plan: `make check`
Reviewed By: jay-zhuang
Differential Revision: D26022814
Pulled By: ltamasi
fbshipit-source-id: b3dce419f312137fa70d84cdd9b908fd5d60d8cd
Summary:
`CheckpointTest.CurrentFileModifiedWhileCheckpointing` could hang
because now create checkpoint triggers flush twice. The test should wait
both flush done.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7849
Test Plan: `gtest-parallel ./checkpoint_test --gtest_filter=CheckpointTest.CurrentFileModifiedWhileCheckpointing -r 100`
Reviewed By: ajkr
Differential Revision: D25860713
Pulled By: jay-zhuang
fbshipit-source-id: e1c2f23037dedc33e205519f4289a25e77816b41
Summary:
The main improvement here is to not include `.` or `..` in the results of `Env::GetChildren`. The occurrence of `.` or `..`; it is non-portable, dependent on the Operating System and the File System. See: https://www.gnu.org/software/libc/manual/html_node/Reading_002fClosing-Directory.html
There were lots of duplicate checks spread through the RocksDB codebase previously to skip `.` and `..`. This new removes the need for those at the source.
Also some minor fixes to `Env::GetChildren`:
* Improve error handling in POSIX implementation
* Remove unnecessary array allocation on Windows
* Fix struct name for Windows Non-UTF-8 API
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7819
Reviewed By: ajkr
Differential Revision: D25837394
Pulled By: jay-zhuang
fbshipit-source-id: 1e137e7218d38b450af9c083f73d5357abcbba2e
Summary:
Currently, manifest size is determined before getting min_log_num.
But between getting manifest size and getting min_log_num, concurrently, a flush might succeed, which will write new records to manifest to make some WALs become outdated, then min_log_num will be correspondingly increased, but the new records in manifest will not be copied into the checkpoint because the manifest's size is determined before them, then the newly outdated WALs will still exist in the checkpoint's manifest, but they are not linked/copied to the checkpoint because their log number is < min_log_num, so a corruption of missing WAL will be reported when restoring from the checkpoint.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7836
Test Plan: make crash_test
Reviewed By: ajkr
Differential Revision: D25788204
Pulled By: cheng-chang
fbshipit-source-id: a4e5acf30f08270b3c0a95304ff559a9e655252f
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
Summary:
Change the StringEnv and related classes to be based on FileSystem APIs rather than the corresponding Env ones. The StringSink and StringSource classes were changed to be based on the corresponding FS file classes.
Part of a cleanup to use the newer interfaces. This change also eliminates some of the casts/wrappers to LegacyFile classes.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7786
Reviewed By: jay-zhuang
Differential Revision: D25761460
Pulled By: anand1976
fbshipit-source-id: 428ae8e32b3db97dbeeca08c9d3bb0d9d4d3a38f
Summary:
1. Made `WriteBatchWithIndexInternal` into a class that stores the `DB*` or `DBOptions*`.
2. Changed the `GetFromBatch` method to be non-static and use an instance of the class. Added `MergeKey` methods to perform the merge itself and return any status.
This change unifies the multiple calls to the `MergeHelper` under a single wrapped API.
Closes https://github.com/facebook/rocksdb/issues/6683
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6851
Reviewed By: ajkr
Differential Revision: D21706574
Pulled By: pdillinger
fbshipit-source-id: 6860bd64d62669aaa591846e914eed3b674e68b1
Summary:
BasicLockEscalation will cause false-positive warnings under TSAN (this is a known issue in TSAN, see details in https://gist.github.com/spetrunia/77274cf2d5848e0a7e090d622695ed4e), skip this test if TSAN is enabled, or if we are not sure whether TSAN is enabled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7814
Test Plan: watch the tsan contrun test to pass.
Reviewed By: zhichao-cao
Differential Revision: D25708094
Pulled By: cheng-chang
fbshipit-source-id: 4fc813ff373301d033d086154cc7bb60a5e95889
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
Summary:
In a stress test failure, we observe that a WAL is skipped when creating checkpoint, although its log number >= MinLogNumberToKeep(). This might happen in the following case:
1. when creating the checkpoint, there are 2 column families: CF0 and CF1, and there are 2 WALs: 1, 2;
2. CF0's log number is 1, CF0's active memtable is empty, CF1's log number is 2, CF1's active memtable is not empty, WAL 2 is not empty, the sequence number points to WAL 2;
2. the checkpoint process flushes CF0, since CF0' active memtable is empty, there is no need to SwitchMemtable, thus no new WAL will be created, so CF0's log number is now 2, concurrently, some data is written to CF0 and WAL 2;
3. the checkpoint process flushes CF1, WAL 3 is created and CF1's log number is now 3, CF0's log number is still 2 because CF0 is not empty and WAL 2 contains its unflushed data concurrently written in step 2;
4. the checkpoint process determines that WAL 1 and 2 are no longer needed according to [live_wal_files[i]->StartSequence() >= *sequence_number](https://github.com/facebook/rocksdb/blob/master/utilities/checkpoint/checkpoint_impl.cc#L388), so it skips linking them to the checkpoint directory;
5. but according to `MinLogNumberToKeep()`, WAL 2 still needs to be kept because CF0's log number is 2.
If the checkpoint is reopened in read-only mode, and only read from the snapshot with the initial sequence number, then there will be no data loss or data inconsistency.
But if the checkpoint is reopened and read from the most recent sequence number, suppose in step 3, there are also data concurrently written to CF1 and WAL 3, then the most recent sequence number refers to the latest entry in WAL 3, so the data written in step 2 should also be visible, but since WAL 2 is discarded, those data are lost.
When tracking WAL in MANIFEST is enabled, when reopening the checkpoint, since WAL 2 is still tracked in MANIFEST as alive, but it's missing from the checkpoint directory, a corruption will be reported.
This PR makes the checkpoint process to only skip a WAL if its log number < `MinLogNumberToKeep`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7789
Test Plan: watch existing tests to pass.
Reviewed By: ajkr
Differential Revision: D25662346
Pulled By: cheng-chang
fbshipit-source-id: 136471095baa01886cf44809455cf855f24857a0
Summary:
Range Locking - an implementation based on the locktree library
- Add a RangeTreeLockManager and RangeTreeLockTracker which implement
range locking using the locktree library.
- Point locks are handled as locks on single-point ranges.
- Add a unit test: range_locking_test
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7506
Reviewed By: akankshamahajan15
Differential Revision: D25320703
Pulled By: cheng-chang
fbshipit-source-id: f86347384b42ba2b0257d67eca0f45f806b69da7
Summary:
This disables Linux/amd64 builds in Travis for PRs, and adds a
gcc-10+c++20 build in CircleCI, which should fill out sufficient coverage
vs. what we had in Travis
Fixed a use of std::is_pod, which is deprecated in c++20
Fixed ++ on a volatile in db_repl_stress.cc, with bigger refactoring.
Although ++ on this volatile was probably ok with one thread writer and
one thread reader, the code was still overly complex. There was a
deadcode check for error
`if (replThread.no_read < dataPump.no_records)` which can be proven
never to happen based on the structure of the code. It infinite loops
instead for the case intended to be checked. I just simplified the code
for what should be the same checking power.
Also most configurations seem to be using make parallelism = 2 * vcores,
so fixing / using that.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7791
Test Plan:
CI
and `while ./db_repl_stress; do echo again; done` for a while
Reviewed By: siying
Differential Revision: D25669834
Pulled By: pdillinger
fbshipit-source-id: b2c688053d0b1d52c989903449d3cd27a04130d6
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:
Some clients do not close their iterators until after the transaction finishes. To handle this case, we will invalidate any iterators on transaction clear.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7733
Reviewed By: cheng-chang
Differential Revision: D25261158
Pulled By: lth
fbshipit-source-id: b91320f00c54cbe0e6882b794b34f3bb5640dbc0
Summary:
To be used for implementing Range Locking.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7753
Reviewed By: zhichao-cao
Differential Revision: D25378980
Pulled By: cheng-chang
fbshipit-source-id: 801a9c5cd92a84654ca2586b73e8f69001e89320
Summary:
This PR has two commits:
1. Modify the code to allow different Lock Managers (of any kind) to be used. It is implied that a LockManager uses its own custom LockTracker.
2. Add definitions for Range Locking (class Endpoint and GetRangeLock() function.
cheng-chang, is this what you've had in mind (should the PR have both item 1 and item 2?)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7443
Reviewed By: zhichao-cao
Differential Revision: D24123172
Pulled By: cheng-chang
fbshipit-source-id: c6548ad6d4cc3c25f68d13b29147bc6fdf357185
Summary:
Handle misuse of snprintf return value to avoid Out of bound
read/write.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7686
Test Plan: make check -j64
Reviewed By: riversand963
Differential Revision: D25030831
Pulled By: akankshamahajan15
fbshipit-source-id: 1a1d181c067c78b94d720323ae00b79566b57cfa
Summary:
The patch adds iterator support to the integrated BlobDB implementation.
Whenever a blob reference is encountered during iteration, the corresponding
blob is retrieved by calling `Version::GetBlob`, assuming the `expose_blob_index`
(formerly `allow_blob`) flag is *not* set. (Note: the flag is set by the old stacked
BlobDB implementation, which has its own blob file handling/blob retrieval logic.)
In addition, `DBIter` now uniformly returns `Status::NotSupported` with the error
message `"BlobDB does not support merge operator."` when encountering a
blob reference while performing a merge (instead of potentially returning a
message that implies the database should be opened using the stacked BlobDB's
`Open`.)
TODO: We can implement support for lazily retrieving the blob value (or in other
words, bypassing the retrieval of blob values based on key) by extending the `Iterator`
API with a new `PrepareValue` method (similarly to `InternalIterator`, which already
supports lazy values).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7731
Test Plan: `make check`
Reviewed By: riversand963
Differential Revision: D25256293
Pulled By: ltamasi
fbshipit-source-id: c39cd782011495a526cdff99c16f5fca400c4811
Summary:
An application may accidentally write merge operands without properly configuring `merge_operator`. We should alert them as early as possible that there's an API misuse. Previously RocksDB only notified them when a query or background operation needed to merge but couldn't. With this PR, RocksDB notifies them of the problem before applying the merge operand to the memtable (although it may already be in WAL, which seems it'd cause a crash loop until they enable `merge_operator`).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7667
Reviewed By: riversand963
Differential Revision: D24933360
Pulled By: ajkr
fbshipit-source-id: 3a4a2ceb0b7aed184113dd03b8efd735a8332f7f
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:
The tests often times out in internal infra, skipping fsync should reduce test time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7641
Test Plan: watch existing tests to pass
Reviewed By: anand1976
Differential Revision: D24765098
Pulled By: cheng-chang
fbshipit-source-id: c62bf8110361aee901918d632cf4772435d05e8d
