Summary:
Introduce an new option options.check_flush_compaction_key_order, by default set to true, which checks key order of flush and compaction, and fail the operation if the order is violated.
Also did minor refactor hash checking code, which consolidates the hashing logic to a vlidation class, where the key ordering logic is added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7467
Test Plan: Add unit tests to validate the check can catch reordering in flush and compaction, and can be properly disabled.
Reviewed By: riversand963
Differential Revision: D24010683
fbshipit-source-id: 8dd6292d2cda8006054e9ded7cfa4bf405f0527c
Summary:
Replace FSWritableFile pointer with FSWritableFilePtr
object in WritableFileWriter.
This new object wraps FSWritableFile pointer.
Objective: If tracing is enabled, FSWritableFile Ptr returns
FSWritableFileTracingWrapper pointer that includes all necessary
information in IORecord and calls underlying FileSystem and invokes
IOTracer to dump that record in a binary file. If tracing is disabled
then, underlying FileSystem pointer is returned directly.
FSWritableFilePtr wrapper class is added to bypass the
FSWritableFileWrapper when
tracing is disabled.
Test Plan: make check -j64
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7193
Reviewed By: anand1976
Differential Revision: D23355915
Pulled By: akankshamahajan15
fbshipit-source-id: e62a27a13c1fd77e36a6dbafc7006d969bed25cf
Summary:
The patch makes sure that the functionality required for the new integrated
BlobDB implementation (most importantly, the classes related to reading and
writing blob files) is also built in LITE mode by removing the corresponding
`#ifndef`s.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7272
Test Plan: Ran `make check` in both regular and LITE mode.
Reviewed By: zhichao-cao
Differential Revision: D23173280
Pulled By: ltamasi
fbshipit-source-id: 1596bd1a76409a8a6d83d8f1dbfe08bfdea7ffe6
Summary:
As part of the IOTracing project, this PR
1. Caches "FileSystemPtr" object(wrapper class that returns file system pointer based on tracing enabled) instead of "FileSystem" pointer.
2. FileSystemPtr object is created using FileSystem pointer and IOTracer
pointer.
3. IOTracer shared_ptr is created in DBImpl and it is passed to different classes through constructor.
4. When tracing is enabled through DB::StartIOTrace, FileSystemPtr
returns FileSystemTracingWrapper pointer for tracing purpose and when
it is disabled underlying FileSystem pointer is returned.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7180
Test Plan:
make check -j64
COMPILE_WITH_TSAN=1 make check -j64
Reviewed By: anand1976
Differential Revision: D22987117
Pulled By: akankshamahajan15
fbshipit-source-id: 6073617e4c2d5bc363914f3a1f55ae3b0a58fbf1
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
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 the current code base, we use Status to get and store the returned status from the call. Specifically, for IO related functions, the current Status cannot reflect the IO Error details such as error scope, error retryable attribute, and others. With the implementation of https://github.com/facebook/rocksdb/issues/5761, we have the new Wrapper for IO, which returns IOStatus instead of Status. However, the IOStatus is purged at the lower level of write path and transferred to Status.
The first job of this PR is to pass the IOStatus to the write path (flush, WAL write, and Compaction). The second job is to identify the Retryable IO Error as HardError, and set the bg_error_ as HardError. In this case, the DB Instance becomes read only. User is informed of the Status and need to take actions to deal with it (e.g., call db->Resume()).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6487
Test Plan: Added the testing case to error_handler_fs_test. Pass make asan_check
Reviewed By: anand1976
Differential Revision: D20685017
Pulled By: zhichao-cao
fbshipit-source-id: ff85f042896243abcd6ef37877834e26f36b6eb0
Summary:
When dynamically linking two binaries together, different builds of RocksDB from two sources might cause errors. To provide a tool for user to solve the problem, the RocksDB namespace is changed to a flag which can be overridden in build time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6433
Test Plan: Build release, all and jtest. Try to build with ROCKSDB_NAMESPACE with another flag.
Differential Revision: D19977691
fbshipit-source-id: aa7f2d0972e1c31d75339ac48478f34f6cfcfb3e
Summary:
The current Env API encompasses both storage/file operations, as well as OS related operations. Most of the APIs return a Status, which does not have enough metadata about an error, such as whether its retry-able or not, scope (i.e fault domain) of the error etc., that may be required in order to properly handle a storage error. The file APIs also do not provide enough control over the IO SLA, such as timeout, prioritization, hinting about placement and redundancy etc.
This PR separates out the file/storage APIs from Env into a new FileSystem class. The APIs are updated to return an IOStatus with metadata about the error, as well as to take an IOOptions structure as input in order to allow more control over the IO.
The user can set both ```options.env``` and ```options.file_system``` to specify that RocksDB should use the former for OS related operations and the latter for storage operations. Internally, a ```CompositeEnvWrapper``` has been introduced that inherits from ```Env``` and redirects individual methods to either an ```Env``` implementation or the ```FileSystem``` as appropriate. When options are sanitized during ```DB::Open```, ```options.env``` is replaced with a newly allocated ```CompositeEnvWrapper``` instance if both env and file_system have been specified. This way, the rest of the RocksDB code can continue to function as before.
This PR also ports PosixEnv to the new API by splitting it into two - PosixEnv and PosixFileSystem. PosixEnv is defined as a sub-class of CompositeEnvWrapper, and threading/time functions are overridden with Posix specific implementations in order to avoid an extra level of indirection.
The ```CompositeEnvWrapper``` translates ```IOStatus``` return code to ```Status```, and sets the severity to ```kSoftError``` if the io_status is retryable. The error handling code in RocksDB can then recover the DB automatically.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5761
Differential Revision: D18868376
Pulled By: anand1976
fbshipit-source-id: 39efe18a162ea746fabac6360ff529baba48486f
Summary:
When there are concurrent flush job on the same CF, `OnFlushCompleted` can be called before the flush result being install to LSM. Fixing the issue by passing `FlushJobInfo` through `MemTable`, and the thread who commit the flush result can fetch the `FlushJobInfo` and fire `OnFlushCompleted` on behave of the thread actually writing the SST.
Fix https://github.com/facebook/rocksdb/issues/5892
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5908
Test Plan: Add new test. The test will fail without the fix.
Differential Revision: D17916144
Pulled By: riversand963
fbshipit-source-id: e18df67d9533b5baee52ae3605026cdeb05cbe10
Summary:
This is groundwork for adding garbage collection support to BlobDB. The
patch adds logic that keeps track of the oldest blob file referred to by
each SST file. The oldest blob file is identified during flush/
compaction (similarly to how the range of keys covered by the SST is
identified), and persisted in the manifest as a custom field of the new
file edit record. Blob indexes with TTL are ignored for the purposes of
identifying the oldest blob file (since such blob files are cleaned up by the
TTL logic in BlobDB).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5903
Test Plan:
Added new unit tests; also ran db_bench in BlobDB mode, inspected the
manifest using ldb, and confirmed (by scanning the SST files using
sst_dump) that the value of the oldest blob file number field matches
the contents of the file for each SST.
Differential Revision: D17859997
Pulled By: ltamasi
fbshipit-source-id: 21662c137c6259a6af70446faaf3a9912c550e90
Summary:
file_reader_writer.h and .cc contain several files and helper function, and it's hard to navigate. Separate it to multiple files and put them under file/
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5803
Test Plan: Build whole project using make and cmake.
Differential Revision: D17374550
fbshipit-source-id: 10efca907721e7a78ed25bbf74dc5410dea05987
Summary:
Each DB has a globally unique ID. A DB can be physically copied around, or backed-up and restored, and the users should be identify the same DB. This unique ID right now is stored as plain text in file IDENTITY under the DB directory. This approach introduces at least two problems: (1) the file is not checksumed; (2) the source of truth of a DB is the manifest file, which can be copied separately from IDENTITY file, causing the DB ID to be wrong.
The goal of this PR is solve this problem by moving the DB ID to manifest. To begin with we will write to both identity file and manifest. Write to Manifest is controlled via the flag write_dbid_to_manifest in Options and default is false.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5725
Test Plan: Added unit tests.
Differential Revision: D16963840
Pulled By: vjnadimpalli
fbshipit-source-id: 8a86a4c8c82c716003c40fd6b9d2d758030d92e9
Summary:
This PR integrates the block cache tracer class into db_impl.cc.
db_impl.cc contains a member variable of AtomicBlockCacheTraceWriter class and passes its reference to the block_based_table_reader.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5433
Differential Revision: D15728016
Pulled By: HaoyuHuang
fbshipit-source-id: 23d5659e8c82d556833dcc1a5558aac8c1f7db71
Summary:
There are too many types of files under util/. Some test related files don't belong to there or just are just loosely related. Mo
ve them to a new directory test_util/, so that util/ is cleaner.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5377
Differential Revision: D15551366
Pulled By: siying
fbshipit-source-id: 0f5c8653832354ef8caa31749c0143815d719e2c
Summary:
1. this commit fixes our handling of a combination of two separate edge
cases. If a flush job does not pick any memtable to flush (because another
flush job has already picked the same memtables), and the column family
assigned to the flush job is dropped right before RocksDB calls
rocksdb::InstallMemtableAtomicFlushResults, our original code passes
a FileMetaData object whose file number is 0, failing the assertion in
rocksdb::InstallMemtableAtomicFlushResults (assert(m->GetFileNumber() > 0)).
2. Also piggyback a small change: since we already create a local copy of column family's mutable CF options to eliminate potential race condition with `SetOptions` call, we might as well use the local copy in other function calls in the same scope.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4932
Differential Revision: D13901322
Pulled By: riversand963
fbshipit-source-id: b936580af7c127ea0c6c19ea10cd5fcede9fb0f9
Summary:
The vector returned by SnapshotList::GetAll could have duplicate entries if two separate snapshots have the same sequence number. However, when this vector is used in compaction the duplicate entires are of no use and could be safely ignored. Moreover not having duplicate entires simplifies reasoning in the compaction_iterator.cc code. For example when searching for the previous_snap we currently use the snapshot before the current one but the way the code uses that it expects it to be also less than the current snapshot, which would be simpler to read if there is no duplicate entry in the snapshot list.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4860
Differential Revision: D13615502
Pulled By: maysamyabandeh
fbshipit-source-id: d45bf01213ead5f39db811f951802da6fcc3332b
Summary:
as titled.
Since different bg flush threads can flush different sets of column families
(due to column family creation and drop), we decide not to let one thread
perform atomic flush result installation for other threads. Bg flush threads
will install their atomic flush results sequentially to MANIFEST, using
a conditional variable, i.e. atomic_flush_install_cv_ to coordinate.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4791
Differential Revision: D13498930
Pulled By: riversand963
fbshipit-source-id: dd7482fc41f4bd22dad1e1ef7d4764ef424688d7
Summary:
Ran the following commands to recursively change all the files under RocksDB:
```
find . -type f -name "*.cc" -exec sed -i 's/ unique_ptr/ std::unique_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/<unique_ptr/<std::unique_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/ shared_ptr/ std::shared_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/<shared_ptr/<std::shared_ptr/g' {} +
```
Running `make format` updated some formatting on the files touched.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4638
Differential Revision: D12934992
Pulled By: sagar0
fbshipit-source-id: 45a15d23c230cdd64c08f9c0243e5183934338a8
Summary:
Leverage existing `FlushJob` to implement atomic flush of multiple column families.
This PR depends on other PRs and is a subset of #3752 . This PR itself is not sufficient in fulfilling atomic flush.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4262
Differential Revision: D9283109
Pulled By: riversand963
fbshipit-source-id: 65401f913e4160b0a61c0be6cd02adc15dad28ed
Summary:
We want to sample the file I/O issued by RocksDB and report the function calls. This requires us to include the file paths otherwise it's hard to tell what has been going on.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4039
Differential Revision: D8670178
Pulled By: riversand963
fbshipit-source-id: 97ee806d1c583a2983e28e213ee764dc6ac28f7a
Summary:
RocksDB used to store global_seqno in external SST files written by
SstFileWriter. During file ingestion, RocksDB uses `pwrite` to update the
`global_seqno`. Since random write is not supported in some non-POSIX compliant
file systems, external SST file ingestion is not supported on these file
systems. To address this limitation, we no longer update `global_seqno` during
file ingestion. Later RocksDB uses the MANIFEST and other information in table
properties to deduce global seqno for externally-ingested SST files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4172
Differential Revision: D8961465
Pulled By: riversand963
fbshipit-source-id: 4382ec85270a96be5bc0cf33758ca2b167b05071
Summary:
The patch makes sure that two parallel test threads will operate on different db paths. This enables using open source tools such as gtest-parallel to run the tests of a file in parallel.
Example: ``` ~/gtest-parallel/gtest-parallel ./table_test```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4135
Differential Revision: D8846653
Pulled By: maysamyabandeh
fbshipit-source-id: 799bad1abb260e3d346bcb680d2ae207a852ba84
Summary:
This patch record min log number to keep to the manifest while flushing SST files to ignore them and any WAL older than them during recovery. This is to avoid scenarios when we have a gap between the WAL files are fed to the recovery procedure. The gap could happen by for example out-of-order WAL deletion. Such gap could cause problems in 2PC recovery where the prepared and commit entry are placed into two separate WAL and gap in the WALs could result into not processing the WAL with the commit entry and hence breaking the 2PC recovery logic.
Before the commit, for 2PC case, we determined which log number to keep in FindObsoleteFiles(). We looked at the earliest logs with outstanding prepare entries, or prepare entries whose respective commit or abort are in memtable. With the commit, the same calculation is done while we apply the SST flush. Just before installing the flush file, we precompute the earliest log file to keep after the flush finishes using the same logic (but skipping the memtables just flushed), record this information to the manifest entry for this new flushed SST file. This pre-computed value is also remembered in memory, and will later be used to determine whether a log file can be deleted. This value is unlikely to change until next flush because the commit entry will stay in memtable. (In WritePrepared, we could have removed the older log files as soon as all prepared entries are committed. It's not yet done anyway. Even if we do it, the only thing we loss with this new approach is earlier log deletion between two flushes, which does not guarantee to happen anyway because the obsolete file clean-up function is only executed after flush or compaction)
This min log number to keep is stored in the manifest using the safely-ignore customized field of AddFile entry, in order to guarantee that the DB generated using newer release can be opened by previous releases no older than 4.2.
Closes https://github.com/facebook/rocksdb/pull/3765
Differential Revision: D7747618
Pulled By: siying
fbshipit-source-id: d00c92105b4f83852e9754a1b70d6b64cb590729
Summary:
Add a new histogram stat called rocksdb.db.flush.micros for memtable
flush
Closes https://github.com/facebook/rocksdb/pull/3269
Differential Revision: D6559496
Pulled By: anand1976
fbshipit-source-id: f5c771ba2568630458751795e8c37a493ff9b14d
Summary:
Update Compaction/Flush to support WritePreparedTxnDB: Add SnapshotChecker which is a proxy to query WritePreparedTxnDB::IsInSnapshot. Pass SnapshotChecker to DBImpl on WritePreparedTxnDB open. CompactionIterator use it to check if a key has been committed and if it is visible to a snapshot. In CompactionIterator:
* check if key has been committed. If not, output uncommitted keys AS-IS.
* use SnapshotChecker to check if key is visible to a snapshot when in need.
* do not output key with seq = 0 if the key is not committed.
Closes https://github.com/facebook/rocksdb/pull/2926
Differential Revision: D5902907
Pulled By: yiwu-arbug
fbshipit-source-id: 945e037fdf0aa652dc5ba0ad879461040baa0320
Summary:
SUMMARY
Moves the bytes_per_sync and wal_bytes_per_sync options from immutableoptions to mutable options. Also if wal_bytes_per_sync is changed, the wal file and memtables are flushed.
TEST PLAN
ran make check
all passed
Two new tests SetBytesPerSync, SetWalBytesPerSync check that after issuing setoptions with a new value for the var, the db options have the new value.
Closes https://github.com/facebook/rocksdb/pull/2893
Reviewed By: yiwu-arbug
Differential Revision: D5845814
Pulled By: TheRushingWookie
fbshipit-source-id: 93b52d779ce623691b546679dcd984a06d2ad1bd
Summary:
This makes it easier to implement future optimizations like range collapsing.
Closes https://github.com/facebook/rocksdb/pull/1504
Differential Revision: D4172214
Pulled By: ajkr
fbshipit-source-id: ac4942f
Summary:
Changed BuildTable() (used for flush) to (1) add range
tombstones to the aggregator, which is used by CompactionIterator to
determine which keys can be removed; and (2) add aggregator's range
tombstones to the table that is output for the flush.
Closes https://github.com/facebook/rocksdb/pull/1438
Differential Revision: D4100025
Pulled By: ajkr
fbshipit-source-id: cb01a70
Summary: Use ImmutableDBOptions/MutableDBOptions internally and DBOptions only for user-facing APIs. MutableDBOptions is barely a placeholder for now. I'll start to move options to MutableDBOptions in following diffs.
Test Plan:
make all check
Reviewers: yhchiang, IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D64065
Summary: Multiput atomiciy is broken across multiple column families if we don't sync WAL before flushing one column family. The WAL file may contain a write batch containing writes to a key to the CF to be flushed and a key to other CF. If we don't sync WAL before flushing, if machine crashes after flushing, the write batch will only be partial recovered. Data to other CFs are lost.
Test Plan: Add a new unit test which will fail without the diff.
Reviewers: yhchiang, IslamAbdelRahman, igor, yiwu
Reviewed By: yiwu
Subscribers: yiwu, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D60915
Summary: Add option write_buffer_manager to help users control total memory spent on memtables across multiple DB instances.
Test Plan: Add a new unit test.
Reviewers: yhchiang, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: adela, benj, sumeet, muthu, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D59925
Summary: It is useful to print out IO stats in flush jobs too. Extend options.compaction_measure_io_stats to flush jobs and raname it.
Test Plan: Try db_bench and see the stats are printed out.
Reviewers: yhchiang
Reviewed By: yhchiang
Subscribers: kradhakrishnan, yiwu, IslamAbdelRahman, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56769
Summary:
Currently, transactions can fail even if there is no actual write conflict. This is due to relying on only the memtables to check for write-conflicts. Users have to tune memtable settings to try to avoid this, but it's hard to figure out exactly how to tune these settings.
With this diff, TransactionDB will use both memtables and SST files to determine if there are any write conflicts. This relies on the fact that BlockBasedTable stores sequence numbers for all writes that happen after any open snapshot. Also, D50295 is needed to prevent SingleDelete from disappearing writes (the TODOs in this test code will be fixed once the other diff is approved and merged).
Note that Optimistic transactions will still rely on tuning memtable settings as we do not want to read from SST while on the write thread. Also, memtable settings can still be used to reduce how often TransactionDB needs to read SST files.
Test Plan: unit tests, db bench
Reviewers: rven, yhchiang, kradhakrishnan, IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb, yoshinorim
Differential Revision: https://reviews.facebook.net/D50475
When we recycle log files, we need to mix the log number into the CRC
for each record. Note that for logs that don't get recycled (like the
manifest), we always pass a log_number of 0 and false.
Signed-off-by: Sage Weil <sage@redhat.com>
Summary:
This diff is a collection of cleanups that were initially part of D43179.
Additionally it adds a unified way of defining key-value maps that use a
Comparator for sorting (this was previously implemented in four different
places).
Test Plan: make clean check all
Reviewers: rven, anthony, yhchiang, sdong, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D45993
Summary:
Currently, we only purge duplicate keys and deletions during flush if `earliest_seqno_in_memtable <= newest_snapshot`. This means that the newest snapshot happened before we first created the memtable. This is almost never true for MyRocks and MongoRocks.
This patch makes purging during flush able to understand snapshots. The main logic is copied from compaction_job.cc, although the logic over there is much more complicated and extensive. However, we should try to merge the common functionality at some point.
I need this patch to implement no_overwrite_i_promise functionality for flush. We'll also need this to support SingleDelete() during Flush(). @yoshinorim requested the feature.
Test Plan:
make check
I had to adjust some unit tests to understand this new behavior
Reviewers: yhchiang, yoshinorim, anthony, sdong, noetzli
Reviewed By: noetzli
Subscribers: yoshinorim, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42087
Summary:
Changed compaction_job_test to support better/more thorough
tests and added two tests. Also changed MockFileContents
to order using InternalKeyComparator.
Test Plan: make compaction_job_test && ./compaction_job_test; make all && make check
Reviewers: sdong, rven, igor, yhchiang, anthony
Reviewed By: anthony
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42837
Summary: We want to keep Env a think layer for better portability. Less platform dependent codes should be moved out of Env. In this patch, I create a wrapper of file readers and writers, and put rate limiting, write buffering, as well as most perf context instrumentation and random kill out of Env. It will make it easier to maintain multiple Env in the future.
Test Plan: Run all existing unit tests.
Reviewers: anthony, kradhakrishnan, IslamAbdelRahman, yhchiang, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D42321
Summary: Optimistic transactions supporting begin/commit/rollback semantics. Currently relies on checking the memtable to determine if there are any collisions at commit time. Not yet implemented would be a way of enuring the memtable has some minimum amount of history so that we won't fail to commit when the memtable is empty. You should probably start with transaction.h to get an overview of what is currently supported.
Test Plan: Added a new test, but still need to look into stress testing.
Reviewers: yhchiang, igor, rven, sdong
Reviewed By: sdong
Subscribers: adamretter, MarkCallaghan, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D33435
Summary:
For transactions, we are using the memtables to validate that there are no write conflicts. But after flushing, we don't have any memtables, and transactions could fail to commit. So we want to someone keep around some extra history to use for conflict checking. In addition, we want to provide a way to increase the size of this history if too many transactions fail to commit.
After chatting with people, it seems like everyone prefers just using Memtables to store this history (instead of a separate history structure). It seems like the best place for this is abstracted inside the memtable_list. I decide to create a separate list in MemtableListVersion as using the same list complicated the flush/installalflushresults logic too much.
This diff adds a new parameter to control how much memtable history to keep around after flushing. However, it sounds like people aren't too fond of adding new parameters. So I am making the default size of flushed+not-flushed memtables be set to max_write_buffers. This should not change the maximum amount of memory used, but make it more likely we're using closer the the limit. (We are now postponing deleting flushed memtables until the max_write_buffer limit is reached). So while we might use more memory on average, we are still obeying the limit set (and you could argue it's better to go ahead and use up memory now instead of waiting for a write stall to happen to test this limit).
However, if people are opposed to this default behavior, we can easily set it to 0 and require this parameter be set in order to use transactions.
Test Plan: Added a xfunc test to play around with setting different values of this parameter in all tests. Added testing in memtablelist_test and planning on adding more testing here.
Reviewers: sdong, rven, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D37443
sdong