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
Summary:
By supporting direct IO in RandomAccessFileReader::MultiRead, the benefits of parallel IO (IO uring) and direct IO can be combined.
In direct IO mode, read requests are aligned and merged together before being issued to RandomAccessFile::MultiRead, so blocks in the original requests might share the same underlying buffer, the shared buffers are returned in `aligned_bufs`, which is a new parameter of the `MultiRead` API.
For example, suppose alignment requirement for direct IO is 4KB, one request is (offset: 1KB, len: 1KB), another request is (offset: 3KB, len: 1KB), then since they all belong to page (offset: 0, len: 4KB), `MultiRead` only reads the page with direct IO into a buffer on heap, and returns 2 Slices referencing regions in that same buffer. See `random_access_file_reader_test.cc` for more examples.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6446
Test Plan: Added a new test `random_access_file_reader_test.cc`.
Reviewed By: anand1976
Differential Revision: D20097518
Pulled By: cheng-chang
fbshipit-source-id: ca48a8faf9c3af146465c102ef6b266a363e78d1
Summary:
Add sequence_number_ptr to the checkpoint interface to expose the sequence number during taking the checkpoint. The number will be consistent with the seq # in rocksdb log.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5528
Test Plan: make check -j64
Reviewed By: Winger1994
Differential Revision: D16080209
fbshipit-source-id: 6dc3c7680287ee97d673c5e61f89aae1f43e33df
Summary:
Preliminary support for iterator with user timestamp. Current implementation does not consider merge operator and reverse iterator. Auto compaction is also disabled in unit tests.
Create an iterator with timestamp.
```
...
read_opts.timestamp = &ts;
auto* iter = db->NewIterator(read_opts);
// target is key without timestamp.
for (iter->Seek(target); iter->Valid(); iter->Next()) {}
for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {}
delete iter;
read_opts.timestamp = &ts1;
// lower_bound and upper_bound are without timestamp.
read_opts.iterate_lower_bound = &lower_bound;
read_opts.iterate_upper_bound = &upper_bound;
auto* iter1 = db->NewIterator(read_opts);
// Do Seek or SeekToFirst()
delete iter1;
```
Test plan (dev server)
```
$make check
```
Simple benchmarking (dev server)
1. The overhead introduced by this PR even when timestamp is disabled.
key size: 16 bytes
value size: 100 bytes
Entries: 1000000
Data reside in main memory, and try to stress iterator.
Repeated three times on master and this PR.
- Seek without next
```
./db_bench -db=/dev/shm/rocksdbtest-1000 -benchmarks=fillseq,seekrandom -enable_pipelined_write=false -disable_wal=true -format_version=3
```
master: 159047.0 ops/sec
this PR: 158922.3 ops/sec (2% drop in throughput)
- Seek and next 10 times
```
./db_bench -db=/dev/shm/rocksdbtest-1000 -benchmarks=fillseq,seekrandom -enable_pipelined_write=false -disable_wal=true -format_version=3 -seek_nexts=10
```
master: 109539.3 ops/sec
this PR: 107519.7 ops/sec (2% drop in throughput)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6255
Differential Revision: D19438227
Pulled By: riversand963
fbshipit-source-id: b66b4979486f8474619f4aa6bdd88598870b0746
Summary:
In direct IO mode, RandomAccessFileReader::Read allocates an internal aligned buffer, and then copies the result into the scratch buffer. If the result is only temporarily used inside a function, there is no need to do the memcpy and just let the result Slice refer to the internally allocated buffer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6455
Test Plan: make check
Differential Revision: D20106753
Pulled By: cheng-chang
fbshipit-source-id: 44f505843837bba47a56e3fa2c4dd3bd76486b58
Summary:
In most places in the code the variable names are spelled correctly as
COMMITTED but in a couple places not. This fixes them and ensures the
variable is always called COMMITTED everywhere.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6481
Differential Revision: D20306776
Pulled By: pdillinger
fbshipit-source-id: b6c1bfe41db559b4bc6955c530934460c07f7022
Summary:
Added new Get() methods that return timestamp. Dummy implementation is given so that classes derived from DB don't need to be touched to provide their implementation. MultiGet is not included.
ReadRandom 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 72ee067b9):
101.712 micros/op 314602 ops/sec; 36.0 MB/s (5658999 of 5658999 found)
This PR:
100.288 micros/op 319071 ops/sec; 36.5 MB/s (5674999 of 5674999 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 --delete_obsolete_files_period_micros=314572800 --max_background_compactions=4 --max_background_flushes=0 --level0_slowdown_writes_trigger=16 --level0_stop_writes_trigger=24 --statistics=0 --stats_per_interval=0 --stats_interval=1048576 --histogram=0 --use_plain_table=1 --open_files=-1 --mmap_read=1 --mmap_write=0 --memtablerep=prefix_hash --bloom_bits=10 --bloom_locality=1 --duration=600 --benchmarks=readrandom --use_existing_db=1 --num=25000000 --threads=32
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6409
Differential Revision: D20200086
Pulled By: riversand963
fbshipit-source-id: 490edd74d924f62bd8ae9c29c2a6bbbb8410ca50
Summary:
Today `WriteUnpreparedTxn::RollbackInternal` will write the rollback batch assuming that there is only a single subbatch. However, because untracked_keys_ are currently not deduplicated, it's possible for duplicate keys to exist, and thus split the batch. Also, tracked_keys_ also does not support compators outside of the bytewise comparators, so it's possible for duplicates to occur there as well.
To solve this, just pass in the correct subbatch count.
Also, removed `WriteUnpreparedRollbackPreReleaseCallback` to unify the Commit/Rollback codepaths some more.
Also, fixed a bug in `CommitInternal` where if 1. two_write_queue is true and 2. include_data is true, then `WriteUnpreparedCommitEntryPreReleaseCallback` ends up calling `AddCommitted` on the commit time write batch a second time on the second write. To fix, `WriteUnpreparedCommitEntryPreReleaseCallback` is re-initialized.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6463
Differential Revision: D20150153
Pulled By: lth
fbshipit-source-id: df0b42d39406c75af73df995aa1138f0db539cd1
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:
For write unprepared, some applications may bypass the transaction api, and write keys directly into the write batch. However, since they are not tracked, rollbacks (both for savepoint and transaction) are not aware that these keys have to be rolled back.
The fix is to track them in `WriteUnpreparedTxn::untracked_keys_`. This is populated whenever we flush unprepared batches into the DB.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6404
Differential Revision: D19842023
Pulled By: lth
fbshipit-source-id: a9edfc643d5c905fc89da9a9a9094d30c9b70108
Summary:
I create a new branch from the branch new upsteram/master and "git merge --squash".
Maybe it will fix everything.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6420
Differential Revision: D19897152
Pulled By: zhichao-cao
fbshipit-source-id: 6575d9e3b23e360f42ee1480b43028b5fcc20136
Summary:
Unfortunately, it seems like mysqld reuses xids across machine restarts. When that happens, we could have something like the following happening:
```
BEGIN_PREPARE(unprepared) Put(a) END_PREPARE(xid = 1)
-- crash and recover with Put(a) rolled back as it was not prepared
BEGIN_PREPARE(prepared) Put(b) END_PREPARE(xid = 1)
COMMIT(xid = 1)
-- crash and recover with both a, b
```
To solve this, we will have to log the rollback batch into the WAL during recovery.
WritePrepared already logs the rollback batch into the WAL, if a rollback happens after prepare, so there is no problem there.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6418
Differential Revision: D19896151
Pulled By: lth
fbshipit-source-id: 2ff65ddc5fe75efd57736fed4b7cd7a109d26609
Summary:
A recent fix related to 2pc https://github.com/facebook/rocksdb/pull/6313/ writes something to WAL, but does not flush or sync. This causes assertion failure "impl->TEST_WALBufferIsEmpty()" if manual_wal_flush = true. We should fsync the entry to make sure a second power reset can recover.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6417
Test Plan: Add manual_wal_flush=true case in TransactionTest.DoubleCrashInRecovery and fix a bug in the test so that the bug can be reproduced. It passes with the fix.
Differential Revision: D19894537
fbshipit-source-id: f1e84e49e2269f583c6019743118292cd8b6598e
Summary:
to adapt the change in ceph upstream where the bufferlist::copy() method
was removed in
c724369010
Signed-off-by: Kefu Chai <tchaikov@gmail.com>
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6395
Differential Revision: D19816815
Pulled By: zhichao-cao
fbshipit-source-id: 9210767b91af0ecdcf5dfaa3e70edcaeea55135f
Summary:
Right, when reading from option files, no readahead is used and 8KB buffer is used. It might introduce high latency if the file system provide high latency and doesn't do readahead. Instead, introduce a readahead to the file. When calling inside DB, infer the value from options.log_readahead. Otherwise, a default 512KB readahead size is used.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6372
Test Plan: Add --log_readahead_size in db_bench. Run it with several options and observe read size from option files using strace.
Differential Revision: D19727739
fbshipit-source-id: e6d8053b0a64259abc087f1f388b9cd66fa8a583
Summary:
BlobDB keeps track of the mapping between SSTs and blob files using
the `OnFlushCompleted` and `OnCompactionCompleted` callbacks of
the `EventListener` interface: upon receiving a flush notification, a link
is added between the newly flushed SST and the corresponding blob file;
for compactions, links are removed for the inputs and added for the outputs.
The earlier code performed this link deletion and addition even for
trivially moved files; the new code walks through the two lists together
(in a fashion that's similar to merge sort) and skips such files.
This should mitigate https://github.com/facebook/rocksdb/issues/6338,
wherein an assertion is triggered with the earlier code when a compaction
notification for a trivial move precedes the flush notification for the
moved SST.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6381
Test Plan: make check
Differential Revision: D19773729
Pulled By: ltamasi
fbshipit-source-id: ae0f273ded061110dd9334e8fb99b0d7786650b0
Summary:
Unit test names, together with other components, are used to create log files
during some internal testing. Overly long names cause infra failure due to file
names being too long.
Look for internal tests.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6352
Differential Revision: D19649307
Pulled By: riversand963
fbshipit-source-id: 6f29de096e33c0eaa87d9c8702f810eda50059e7
Summary:
The patch adds statistics support to the new BlobDB garbage collection implementation;
namely, it adds support for the following (pre-existing) tickers:
`BLOB_DB_GC_NUM_FILES`: the number of blob files obsoleted by the GC logic.
`BLOB_DB_GC_NUM_NEW_FILES`: the number of new blob files generated by the GC logic.
`BLOB_DB_GC_FAILURES`: the number of failed GC passes (where a GC pass is
equivalent to a (sub)compaction).
`BLOB_DB_GC_NUM_KEYS_RELOCATED`: the number of blobs relocated to new blob
files by the GC logic.
`BLOB_DB_GC_BYTES_RELOCATED`: the total size of blobs relocated to new blob files.
The tickers `BLOB_DB_GC_NUM_KEYS_OVERWRITTEN`, `BLOB_DB_GC_NUM_KEYS_EXPIRED`,
`BLOB_DB_GC_BYTES_OVERWRITTEN`, `BLOB_DB_GC_BYTES_EXPIRED`, and
`BLOB_DB_GC_MICROS` are not relevant for the new GC logic, and are thus marked
deprecated.
The patch also adds a couple of log messages that log the number and total size of
blobs encountered and relocated during a GC pass, as well as the number of blob
files created and obsoleted.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6296
Test Plan: Extended unit tests and used the BlobDB mode of `db_bench`.
Differential Revision: D19402513
Pulled By: ltamasi
fbshipit-source-id: d53d2bfbf4928a1db1e9346c67ebb9007b8932ec
Summary:
In WritePrepared there could be gap in sequence numbers. This breaks the trick we use in kPointInTimeRecovery which assume the first seq in the log right after the corrupted log is one larger than the last seq we read from the logs. To let this trick keep working, we add a dummy entry with the expected sequence to the first log right after recovery.
Also in WriteCommitted, if the log right after the corrupted log is empty, since it has no sequence number to let the sequential trick work, it is assumed as unexpected behavior. This is however expected to happen if we close the db after recovering from a corruption and before writing anything new to it. To remedy that, we apply the same technique by writing a dummy entry to the log that is created after the corrupted log.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6313
Differential Revision: D19458291
Pulled By: maysamyabandeh
fbshipit-source-id: 09bc49e574690085df45b034ca863ff315937e2d
Summary:
This is a simple edit to have two #include file paths be consistent within range_del_aggregator.{h,cc} with everywhere else.
The impact of this inconsistency is that it actual breaks a Bazel based build on the Windows platform. The same pragma once failure occurs with both Windows Visual C++ 2019 and clang for Windows 9.0. Bazel's "sandboxing" of the builds causes both compilers to not properly recognize "rocksdb/types.h" and "include/rocksdb/types.h" to be the same file (also comparator.h). My guess is that the backslash versus forward slash mixing within path names is the underlying issue.
But, everything builds fine once the include paths in these two source files are consistent with the rest of the repository.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6321
Differential Revision: D19506585
Pulled By: ltamasi
fbshipit-source-id: 294c346607edc433ab99eaabc9c880ee7426817a
Summary:
In addition to removing the earlier partially implemented garbage collection
logic from the BlobDB codebase, the patch also removes the test cases (as well as
the related sync points, as appropriate) that were only relevant for the old
implementation, and reworks the remaining ones so they use the new GC logic.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6278
Test Plan: `make check`
Differential Revision: D19335226
Pulled By: ltamasi
fbshipit-source-id: 0cc1794bc9892feda1426ed5522a318f3cb1b692
Summary:
unordered_write is incompatible with non-zero max_successive_merges. Although we check this at runtime, we currently don't prevent the user from setting this combination in options. This has led to stress tests to fail with this combination is tried in ::SetOptions.
The patch fixes that and also reverts the changes performed by https://github.com/facebook/rocksdb/pull/6254, in which max_successive_merges was mistakenly declared incompatible with unordered_write.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6284
Differential Revision: D19356115
Pulled By: maysamyabandeh
fbshipit-source-id: f06dadec777622bd75f267361c022735cf8cecb6
Summary:
Some shadow warning shows up when using gcc 4.8. An example:
./utilities/blob_db/blob_compaction_filter.h: In constructor ‘rocksdb::blob_db::BlobIndexCompactionFilterFactoryBase::BlobIndexCompactionFilterFactoryBase(rocksdb::blob_db::lobDBImpl*, rocksdb::Env*, rocksdb::Statistics*)’:
./utilities/blob_db/blob_compaction_filter.h:121:7: error: declaration of ‘blob_db_impl’ shadows a member of 'this' [-Werror=shadow]
: blob_db_impl_(blob_db_impl), env_(_env), statistics_(_statistics) {}
^
Fix them.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6242
Test Plan: Build and see the warnings go away.
Differential Revision: D19217789
fbshipit-source-id: 8ef631941f23dab47a388e060adec24b72efd65e
Summary:
WritePreparedTxnDB calls CancelAllBackgroundWork in its destructor to avoid dangling references to it from background job's SnapshotChecker callback. However, if the DBImpl is already closed, the info log might be closed with it, which causes memory leak when CancelAllBackgroundWork tries to print to the info log. The patch fixes that by calling CancelAllBackgroundWork only if the db is not closed already.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6268
Differential Revision: D19303439
Pulled By: maysamyabandeh
fbshipit-source-id: 4228a6be7e78d43c90630347baa89b008200bd15
Summary:
This is a continuation of https://github.com/facebook/rocksdb/pull/5320/files
I open a new mr for these purposes, half a year has past since the old mr is posted so it's almost impossible to fulfill some points below on the old mr, especially 5)
1) add validation modes for optimistic txns
2) modify unittests to test both modes
3) make format
4) refine hash functor
5) push to master
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6240
Differential Revision: D19301296
fbshipit-source-id: 5b5b3cbd39558f43947f7d2dec6cd31a06386edb
Summary:
allow_concurrent_memtable_write is incompatible with non-zero max_successive_merges. Although we check this at runtime, we currently don't prevent the user from setting this combination in options. This has led to stress tests to fail with this combination is tried in ::SetOptions. The patch fixes that.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6254
Differential Revision: D19265819
Pulled By: maysamyabandeh
fbshipit-source-id: 47f2e2dc26fe0972c7152f4da15dadb9703f1179
Summary:
BlobDB currently only supports using the default column family. The earlier
code enforces this by comparing the `ColumnFamilyHandle` passed to the
`Get`/`Put`/etc. call with the handle returned by `DefaultColumnFamily`
(which, at the end of the day, comes from `DBImpl::default_cf_handle_`).
Since other `ColumnFamilyHandle`s can also point to the default column
family, this can reject legitimate requests as well. (As an example,
with the earlier code, the handle returned by `BlobDB::Open` cannot
actually be used in API calls.) The patch fixes this by comparing only
the IDs of the column family handles instead of the pointers themselves.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6226
Test Plan: `make check`
Differential Revision: D19187461
Pulled By: ltamasi
fbshipit-source-id: 54ce2e12ebb1f07e6d1e70e3b1e0213dfa94bda2
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6192
Test Plan:
Add a unit test that fails without the fix and passes now
make check
Differential Revision: D19124781
Pulled By: anand1976
fbshipit-source-id: 8c8cb6fa16c3fc23ec011e168561a13f76bbd783
Summary:
Periodic compactions ensure that even SSTs that do not get picked up
otherwise eventually go through compaction; used in conjunction with
BlobDB's garbage collection, they enable BlobDB to reclaim space when
old blob files are used by such straggling SSTs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6172
Test Plan: Ran `make check` and used the BlobDB mode of `db_bench`.
Differential Revision: D19045045
Pulled By: ltamasi
fbshipit-source-id: 04636ecc4b6cfe8d495bf656faa65d54a5eb1a93
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:
The patch adds logic that relocates live blobs from the oldest N non-TTL
blob files as they are encountered during compaction (assuming the BlobDB
configuration option `enable_garbage_collection` is `true`), where N is defined
as the number of immutable non-TTL blob files multiplied by the value of
a new BlobDB configuration option called `garbage_collection_cutoff`.
(The default value of this parameter is 0.25, that is, by default the valid blobs
residing in the oldest 25% of immutable non-TTL blob files are relocated.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6121
Test Plan: Added unit test and tested using the BlobDB mode of `db_bench`.
Differential Revision: D18785357
Pulled By: ltamasi
fbshipit-source-id: 8c21c512a18fba777ec28765c88682bb1a5e694e
Summary:
**NOTE**: this also needs to be back-ported to 6.4.6 and possibly older branches if further releases from them is envisaged.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6081
Differential Revision: D18710107
Pulled By: zhichao-cao
fbshipit-source-id: 03260f9316566e2bfc12c7d702d6338bb7941e01
Summary:
This patch factors out the logic that reads a (potentially compressed) blob
from a file into a separate helper method `GetRawBlobFromFile`, and cleans
up the code a bit. Also, errors during decompression are now logged/propagated
to the user by returning a `Status` code of `Corruption`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6093
Test Plan: `make check`
Differential Revision: D18716673
Pulled By: ltamasi
fbshipit-source-id: 44144bc064cab616862d5643f34384f2bae6eb78
Summary:
The patch refactors and cleans up the logic around creating new blob files
by moving the common code of `SelectBlobFile` and `SelectBlobFileTTL`
to a new helper method `CreateBlobFileAndWriter`, bringing the implementation
of `SelectBlobFile` and `SelectBlobFileTTL` into sync, and increasing encapsulation
by adding new constructors for `BlobFile` and `BlobLogHeader`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6066
Test Plan:
Ran `make check` and used the BlobDB mode of `db_bench` to sanity test both
the TTL and the non-TTL code paths.
Differential Revision: D18646921
Pulled By: ltamasi
fbshipit-source-id: e5705a84807932e31dccab4f49b3e64369cea26d
Summary:
This change ignores the value of BackupableDBOptions::max_valid_backups_to_open when a BackupEngine is not read-only.
Issue: https://github.com/facebook/rocksdb/issues/4997
Note on tests: I had to remove test case WriteOnlyEngine of BackupableDBTest because it was not consistent with the new semantic of BackupableDBOptions::max_valid_backups_to_open. Maybe, we should think about adding a new interface for append-only BackupEngines. On the other hand, I changed LimitBackupsOpened test case to use a read-only BackupEngine, and I added a new specific test case for the change.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6072
Reviewed By: pdillinger
Differential Revision: D18687364
Pulled By: sebastianopeluso
fbshipit-source-id: 77bc1f927d623964d59137a93de123bbd719da4e
Summary:
The patch adds logic to mark no longer needed blob files obsolete upon database open
and whenever a flush or compaction completes. Unneeded blob files are detected by
iterating through live immutable non-TTL blob files starting from the lowest-numbered one,
and stopping when a blob file used by any SSTs or potentially used by memtables is found.
(The latter is determined by comparing the sequence number at which the blob file
became immutable with the largest sequence number received in flush notifications.)
In addition, the patch cleans up the logic around closing and obsoleting blob files and
enforces invariants around this area (blob files are now guaranteed to go through the
stages mutable-non-obsolete, immutable-non-obsolete, and immutable-obsolete in this
order).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6032
Test Plan: Extended unit tests and tested using the BlobDB mode of `db_bench`.
Differential Revision: D18495610
Pulled By: ltamasi
fbshipit-source-id: 11825b84af74f3f4abfd9bcae04e80870ae58961
Summary:
SmallestUnCommittedSeq sometimes takes too long when run under Valgrind. The patch disables it when the tests are run under Valgrind.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6035
Differential Revision: D18509198
Pulled By: maysamyabandeh
fbshipit-source-id: 1191443b9fedb6b9c50d6b76f5c92371f5030230
Summary:
Production:
* Fixes GarbageCollect (and auto-GC triggered by PurgeOldBackups, DeleteBackup, or CreateNewBackup) to clean up backup directory independent of current settings (except max_valid_backups_to_open; see issue https://github.com/facebook/rocksdb/issues/4997) and prior settings used with same backup directory.
* Fixes GarbageCollect (and auto-GC) not to attempt to remove "." and ".." entries from directories.
* Clarifies contract with users in modifying BackupEngine operations. In short, leftovers from any incomplete operation are cleaned up by any subsequent call to that same kind of operation (PurgeOldBackups and DeleteBackup considered the same kind of operation). GarbageCollect is available to clean up after all kinds. (NB: right now PurgeOldBackups and DeleteBackup will clean up after incomplete CreateNewBackup, but we aren't promising to continue that behavior.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6023
Test Plan:
* Refactors open parameters to use an option enum, for readability, etc. (Also fixes an unused parameter bug in the redundant OpenDBAndBackupEngineShareWithChecksum.)
* Fixes an apparent bug in ShareTableFilesWithChecksumsTransition in which old backup data was destroyed in the transition to be tested. That test is now augmented to ensure GarbageCollect (or auto-GC) does not remove shared files when BackupEngine is opened with share_table_files=false.
* Augments DeleteTmpFiles test to ensure that CreateNewBackup does auto-GC when an incompletely created backup is detected.
Differential Revision: D18453559
Pulled By: pdillinger
fbshipit-source-id: 5e54e7b08d711b161bc9c656181012b69a8feac4
Summary:
Add a new API that allows a user to call MultiGet specifying multiple keys belonging to different column families. This is mainly useful for users who want to do a consistent read of keys across column families, with the added performance benefits of batching and returning values using PinnableSlice.
As part of this change, the code in the original multi-column family MultiGet for acquiring the super versions has been refactored into a separate function that can be used by both, the batching and the non-batching versions of MultiGet.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5816
Test Plan:
make check
make asan_check
asan_crash_test
Differential Revision: D18408676
Pulled By: anand1976
fbshipit-source-id: 933e7bec91dd70e7b633be4ff623a1116cc28c8d
Summary:
The patch adds logic to BlobDB to maintain the mapping between blob files
and SSTs for which the blob file in question is the oldest blob file referenced
by the SST file. The mapping is initialized during database open based on the
information retrieved using `GetLiveFilesMetaData`, and updated after
flushes/compactions based on the information received through the `EventListener`
interface (or, in the case of manual compactions issued through the `CompactFiles`
API, the `CompactionJobInfo` object).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6020
Test Plan: Added a unit test; also tested using the BlobDB mode of `db_bench`.
Differential Revision: D18410508
Pulled By: ltamasi
fbshipit-source-id: dd9e778af781cfdb0d7056298c54ba9cebdd54a5
Summary:
Only if there is a crash, power failure, or I/O error in
DeleteBackup, shared or private files from the backup might be left
behind that are not cleaned up by PurgeOldBackups or DeleteBackup-- only
by GarbageCollect. This makes the BackupEngine API "leaky by default."
Even if it means a modest performance hit, I think we should make
Delete and Purge do as they say, with ongoing best effort: i.e. future
calls will attempt to finish any incomplete work from earlier calls.
This change does that by having DeleteBackup and PurgeOldBackups do a
GarbageCollect, unless (to minimize performance hit) this BackupEngine
has already done a GarbageCollect and there have been no
deletion-related I/O errors in that GarbageCollect or since then.
Rejected alternative 1: remove meta file last instead of first. This would in theory turn partially deleted backups into corrupted backups, but code changes would be needed to allow the missing files and consider it acceptably corrupt, rather than failing to open the BackupEngine. This might be a reasonable choice, but I mostly rejected it because it doesn't solve the legacy problem of cleaning up existing lingering files.
Rejected alternative 2: use a deletion marker file. If deletion started with creating a file that marks a backup as flagged for deletion, then we could reliably detect partially deleted backups and efficiently finish removing them. In addition to not solving the legacy problem, this could be precarious if there's a disk full situation, and we try to create a new file in order to delete some files. Ugh.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6015
Test Plan: Updated unit tests
Differential Revision: D18401333
Pulled By: pdillinger
fbshipit-source-id: 12944e372ce6809f3f5a4c416c3b321a8927d925
Summary:
The patch exposes the file numbers of the SSTs as well as the oldest blob
files they contain a reference to through the GetColumnFamilyMetaData/
GetLiveFilesMetaData interface.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6011
Test Plan:
Fixed and extended the existing unit tests. (The earlier ColumnFamilyMetaDataTest
wasn't really testing anything because the generated memtables were never
flushed, so the metadata structure was essentially empty.)
Differential Revision: D18361697
Pulled By: ltamasi
fbshipit-source-id: d5ed1d94ac70858b84393c48711441ddfe1251e9
Summary:
According to
https://github.com/facebook/rocksdb/wiki/Rocksdb-BlockBasedTable-Format,
the block read by BlockBasedTable::ReadMetaBlock is actually the meta index
block. Therefore, it is better to rename the function to ReadMetaIndexBlock.
This PR also applies some format change to existing code.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6009
Test Plan: make check
Differential Revision: D18333238
Pulled By: riversand963
fbshipit-source-id: 2c4340a29b3edba53d19c132cbfd04caf6242aed
Summary:
For MDEV-19670: MyRocks: key lookups into deleted data are very slow
BaseDeltaIterator remembers iterate_upper_bound and will not let delta_iterator_
walk above the iterate_upper_bound if base_iterator_ is not valid
anymore.
== Rationale ==
The most straightforward way would be to make the delta_iterator
(which is a rocksdb::WBWIIterator) to support iterator bounds. But
checking for bounds has an extra CPU overhead.
So we put the check into BaseDeltaIterator, and only make it when
base_iterator_ is not valid.
(note: We could take it even further, and move the check a few lines
down, and only check iterator bounds ourselves if base_iterator_ is
not valid AND delta_iterator_ hit a tombstone).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5403
Differential Revision: D15863092
Pulled By: maysamyabandeh
fbshipit-source-id: 8da458e7b9af95ff49356666f69664b4a6ccf49b
Summary:
MaxCatchupWithNewSnapshot tests that the snapshot sequence number will be larger than the max sequence number when the snapshot was taken. However since the test does not have access to the max sequence number when the snapshot was taken, it uses max sequence number after that, which could have advanced the snapshot by then, thus making the test flaky.
The fix is to compare with max sequence number before the snapshot was taken, which is a lower bound for the value when the snapshot was taken.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5850
Test Plan: ~/gtest-parallel/gtest-parallel --repeat=12800 ./write_prepared_transaction_test --gtest_filter="*MaxCatchupWithNewSnapshot*"
Differential Revision: D17608926
Pulled By: maysamyabandeh
fbshipit-source-id: b122ae5a27f982b290bd60da852e28d3c5eb0136
Summary:
- Periodic compactions are auto-enabled if a compaction filter or a compaction filter factory is set, in Level Compaction.
- The default value of `periodic_compaction_seconds` is changed to UINT64_MAX, which lets RocksDB auto-tune periodic compactions as needed. An explicit value of 0 will still work as before ie. to disable periodic compactions completely. For now, on seeing a compaction filter along with a UINT64_MAX value for `periodic_compaction_seconds`, RocksDB will make SST files older than 30 days to go through periodic copmactions.
Some RocksDB users make use of compaction filters to control when their data can be deleted, usually with a custom TTL logic. But it is occasionally possible that the compactions get delayed by considerable time due to factors like low writes to a key range, data reaching bottom level, etc before the TTL expiry. Periodic Compactions feature was originally built to help such cases. Now periodic compactions are auto enabled by default when compaction filters or compaction filter factories are used, as it is generally helpful to all cases to collect garbage.
`periodic_compaction_seconds` is set to a large value, 30 days, in `SanitizeOptions` when RocksDB sees that a `compaction_filter` or `compaction_filter_factory` is used.
This is done only for Level Compaction style.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5865
Test Plan:
- Added a new test `DBCompactionTest.LevelPeriodicCompactionWithCompactionFilters` to make sure that `periodic_compaction_seconds` is set if either `compaction_filter` or `compaction_filter_factory` options are set.
- `COMPILE_WITH_ASAN=1 make check`
Differential Revision: D17659180
Pulled By: sagar0
fbshipit-source-id: 4887b9cf2e53cf2dc93a7b658c6b15e1181217ee
Summary:
- Updated our included xxhash implementation to version 0.7.2 (== the latest dev version as of 2019-10-09).
- Using XXH_NAMESPACE (like other fb projects) to avoid potential name collisions.
- Added fastrange64, and unit tests for it and fastrange32. These are faster alternatives to hash % range.
- Use preview version of XXH3 instead of MurmurHash64A for NPHash64
-- Had to update cache_test to increase probability of passing for any given hash function.
- Use fastrange64 instead of % with uses of NPHash64
-- Had to fix WritePreparedTransactionTest.CommitOfDelayedPrepared to avoid deadlock apparently caused by new hash collision.
- Set default seed for NPHash64 because specifying a seed rarely makes sense for it.
- Removed unnecessary include xxhash.h in a popular .h file
- Rename preview version of XXH3 to XXH3p for clarity and to ease backward compatibility in case final version of XXH3 is integrated.
Relying on existing unit tests for NPHash64-related changes. Each new implementation of fastrange64 passed unit tests when manipulating my local build to select it. I haven't done any integration performance tests, but I consider the improved performance of the pieces being swapped in to be well established.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5909
Differential Revision: D18125196
Pulled By: pdillinger
fbshipit-source-id: f6bf83d49d20cbb2549926adf454fd035f0ecc0d
Summary:
Since we do not evict a file's blocks from block cache before that file
is deleted, we require a file's cache ID prefix is both unique and
non-reusable. However, the Windows functionality we were relying on only
guaranteed uniqueness. That meant a newly created file could be assigned
the same cache ID prefix as a deleted file. If the newly created file
had block offsets matching the deleted file, full cache keys could be
exactly the same, resulting in obsolete data blocks returned from cache
when trying to read from the new file.
We noticed this when running on FAT32 where compaction was writing out
of order keys due to reading obsolete blocks from its input files. The
functionality is documented as behaving the same on NTFS, although I
wasn't able to repro it there.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5844
Test Plan:
we had a reliable repro of out-of-order keys on FAT32 that
was fixed by this change
Differential Revision: D17752442
fbshipit-source-id: 95d983f9196cf415f269e19293b97341edbf7e00
Summary:
This PR eliminates repeated lookups in associative or ordered containers when a single lookup suffices.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5875
Differential Revision: D17753172
Pulled By: anand1976
fbshipit-source-id: 796b02b760082521d8c42a1cb65a76bf0e6c1b8e
Summary:
Further apply formatter to more recent commits.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5830
Test Plan: Run all existing tests.
Differential Revision: D17488031
fbshipit-source-id: 137458fd94d56dd271b8b40c522b03036943a2ab
Summary:
Some recent commits might not have passed through the formatter. I formatted recent 45 commits. The script hangs for more commits so I stopped there.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5827
Test Plan: Run all existing tests.
Differential Revision: D17483727
fbshipit-source-id: af23113ee63015d8a43d89a3bc2c1056189afe8f
Summary:
clang-analyzer has uncovered a bunch of places where the code is relying
on pointers being valid and one case (in VectorIterator) where a moved-from
object is being used:
In file included from db/range_tombstone_fragmenter.cc:17:
./util/vector_iterator.h:23:18: warning: Method called on moved-from object 'keys' of type 'std::vector'
current_(keys.size()) {
^~~~~~~~~~~
1 warning generated.
utilities/persistent_cache/block_cache_tier_file.cc:39:14: warning: Called C++ object pointer is null
Status s = env->NewRandomAccessFile(filepath, file, opt);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
utilities/persistent_cache/block_cache_tier_file.cc:47:19: warning: Called C++ object pointer is null
Status status = env_->GetFileSize(Path(), size);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
utilities/persistent_cache/block_cache_tier_file.cc:290:14: warning: Called C++ object pointer is null
Status s = env_->FileExists(Path());
^~~~~~~~~~~~~~~~~~~~~~~~
utilities/persistent_cache/block_cache_tier_file.cc:363:35: warning: Called C++ object pointer is null
CacheWriteBuffer* const buf = alloc_->Allocate();
^~~~~~~~~~~~~~~~~~
utilities/persistent_cache/block_cache_tier_file.cc:399:41: warning: Called C++ object pointer is null
const uint64_t file_off = buf_doff_ * alloc_->BufferSize();
^~~~~~~~~~~~~~~~~~~~
utilities/persistent_cache/block_cache_tier_file.cc:463:33: warning: Called C++ object pointer is null
size_t start_idx = lba.off_ / alloc_->BufferSize();
^~~~~~~~~~~~~~~~~~~~
utilities/persistent_cache/block_cache_tier_file.cc:515:5: warning: Called C++ object pointer is null
alloc_->Deallocate(bufs_[i]);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
7 warnings generated.
ar: creating librocksdb_debug.a
utilities/memory/memory_test.cc:68:25: warning: Called C++ object pointer is null
cache_set->insert(db->GetDBOptions().row_cache.get());
^~~~~~~~~~~~~~~~~~
1 warning generated.
The patch fixes these by adding assertions and explicitly passing in zero
when initializing VectorIterator::current_ (which preserves the existing
behavior).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5821
Test Plan: Ran make check and make analyze to make sure the warnings have disappeared.
Differential Revision: D17455949
Pulled By: ltamasi
fbshipit-source-id: 363619618ea649a0674287f9f3b3393e390571ee
Summary:
For our default block cache, each additional entry has extra memory overhead. It include LRUHandle (72 bytes currently) and the cache key (two varint64, file id and offset). The usage is not negligible. For example for block_size=4k, the overhead accounts for an extra 2% memory usage for the cache. The patch charging the cache for the extra usage, reducing untracked memory usage outside block cache. The feature is enabled by default and can be disabled by passing kDontChargeCacheMetadata to the cache constructor.
This PR builds up on https://github.com/facebook/rocksdb/issues/4258
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5797
Test Plan:
- Existing tests are updated to either disable the feature when the test has too much dependency on the old way of accounting the usage or increasing the cache capacity to account for the additional charge of metadata.
- The Usage tests in cache_test.cc are augmented to test the cache usage under kFullChargeCacheMetadata.
Differential Revision: D17396833
Pulled By: maysamyabandeh
fbshipit-source-id: 7684ccb9f8a40ca595e4f5efcdb03623afea0c6f
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:
Move definition and implementation for ArenaWrappedDBIter into its own .h/.cc files. Also, change inlining of functions to better comply with the Google C++ style guide.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5801
Test Plan: make check
Differential Revision: D17371012
Pulled By: anand1976
fbshipit-source-id: c1361abc2851575111e357a63d88be3b3d6cb341
Summary:
Use delete to disable automatic generated methods instead of private, and put the constructor together for more clear.This modification cause the unused field warning, so add unused attribute to disable this warning.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5009
Differential Revision: D17288733
fbshipit-source-id: 8a767ce096f185f1db01bd28fc88fef1cdd921f3
Summary:
ReadYourOwnWriteStress occasionally times out on some platforms. The patch splits it to three.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5776
Differential Revision: D17231743
Pulled By: maysamyabandeh
fbshipit-source-id: d42eeaf22f61a48d50f9c404d98b1081ae8dac94
Summary:
This avoids rehashing the key in TrackKey() in case the key is not already
in the map of tracked keys, which will happen at least once per key used in a
transaction.
Additionally fix two typos.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5696
Differential Revision: D17210178
Pulled By: lth
fbshipit-source-id: 7e2c28e9e505c1d1c1535d435250cf2b191a6fdf
Summary:
Iterators reseek to the target key after iterating over max_sequential_skip_in_iterations invalid values. The logic is susceptible to an infinite loop bug, which has been present with WritePrepared Transactions up until 6.2 release. Although the bug is not present on master, the patch adds a unit test to prevent it from resurfacing again.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5727
Differential Revision: D16952759
Pulled By: maysamyabandeh
fbshipit-source-id: d0d973dddc8dfabd5a794931232aa4c862c74f51
Summary:
MyRocks currently sets `max_write_buffer_number_to_maintain` in order to maintain enough history for transaction conflict checking. The effectiveness of this approach depends on the size of memtables. When memtables are small, it may not keep enough history; when memtables are large, this may consume too much memory.
We are proposing a new way to configure memtable list history: by limiting the memory usage of immutable memtables. The new option is `max_write_buffer_size_to_maintain` and it will take precedence over the old `max_write_buffer_number_to_maintain` if they are both set to non-zero values. The new option accounts for the total memory usage of flushed immutable memtables and mutable memtable. When the total usage exceeds the limit, RocksDB may start dropping immutable memtables (which is also called trimming history), starting from the oldest one.
The semantics of the old option actually works both as an upper bound and lower bound. History trimming will start if number of immutable memtables exceeds the limit, but it will never go below (limit-1) due to history trimming.
In order the mimic the behavior with the new option, history trimming will stop if dropping the next immutable memtable causes the total memory usage go below the size limit. For example, assuming the size limit is set to 64MB, and there are 3 immutable memtables with sizes of 20, 30, 30. Although the total memory usage is 80MB > 64MB, dropping the oldest memtable will reduce the memory usage to 60MB < 64MB, so in this case no memtable will be dropped.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5022
Differential Revision: D14394062
Pulled By: miasantreble
fbshipit-source-id: 60457a509c6af89d0993f988c9b5c2aa9e45f5c5
Summary:
In valgrind_test, TransactionTest.GetWithoutSnapshot ran 2 hours and still didn't finish. Black list from valgrind_test to prevent timeout.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5715
Test Plan: run "make valgrind_test" and see whether the test is still generated.
Differential Revision: D16866009
fbshipit-source-id: 92c78049b0bc1c2b9a0dfc1b7c8a9206b36f02f0
Summary:
Fix a bug in write unprepared savepoints. When flushing the write batch according to savepoint boundaries, we were forgetting to flush the last write batch after the last savepoint, meaning that some data was not written to DB.
Also, add a small optimization where we avoid flushing empty batches.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5703
Differential Revision: D16811996
Pulled By: lth
fbshipit-source-id: 600c7e0e520ad7a8fad32d77e11d932453e68e3f
Summary:
Some accesses to blob_files_ and open_ttl_files_ in BlobDBImpl, as well
as to expiration_range_ in BlobFile were not properly synchronized.
The patch fixes this and also makes sure the invariant that obsolete_files_
is a subset of blob_files_ holds even when an attempt to delete an obsolete
blob file fails.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5698
Test Plan:
COMPILE_WITH_TSAN=1 make blob_db_test
gtest-parallel --repeat=1000 ./blob_db_test --gtest_filter="*ShutdownWait*"
The test fails with TSAN errors ~20 times out of 1000 without the patch but
completes successfully 1000 out of 1000 times with the fix.
Differential Revision: D16793235
Pulled By: ltamasi
fbshipit-source-id: 8034b987598d4fdc9f15098d4589cc49cde484e9
Summary:
In MyRocks, there are cases where we write while iterating through keys. This currently breaks WBWIIterator, because if a write batch flushes during iteration, the delta iterator would point to invalid memory.
For now, fix by disallowing flush if there are active iterators. In the future, we will loop through all the iterators on a transaction, and refresh the iterators when a write batch is flushed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5699
Differential Revision: D16794157
Pulled By: lth
fbshipit-source-id: 5d5bf70688bd68fe58e8a766475ae88fd1be3190
Summary:
Fix the following clang analyze failures:
```
In file included from utilities/transactions/transaction_test.cc:8:
./utilities/transactions/transaction_test.h:174:14: warning: Attempt to delete released memory
delete root_db;
^
```
The destructor of StackableDB already deletes the root db and there is no need to delete the db separately.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5700
Test Plan: USE_CLANG=1 TEST_TMPDIR=/dev/shm/rocksdb OPT=-g make -j24 analyze
Differential Revision: D16800579
Pulled By: maysamyabandeh
fbshipit-source-id: 64c2d70f23e07e6a15242add97c744902ea33be5
Summary:
Currently, if a write is done without a snapshot, then `largest_validated_seq_` is set to `kMaxSequenceNumber`. This is too aggressive, because an iterator with a snapshot created after this write should be valid.
Set `largest_validated_seq_` to `GetLastPublishedSequence` instead. The variable means that no keys in the current tracked key set has changed by other transactions since `largest_validated_seq_`.
Also, do some extra cleanup in Clear() for safety.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5697
Differential Revision: D16788613
Pulled By: lth
fbshipit-source-id: f2aa40b8b12e0c0cf9e38c940fecc8f1cc0d2385
Summary:
With changes made in https://github.com/facebook/rocksdb/pull/5664 we meant to pass snap_released parameter of ::IsInSnapshot from the read callbacks. Although the variable was defined, passing it to the callback in WritePreparedTxnReadCallback was missing, which is fixed in this PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5691
Differential Revision: D16767310
Pulled By: maysamyabandeh
fbshipit-source-id: 3bf53f5964a2756a66ceef7c8f6b3ac75f102f48
Summary:
The changes transaction_test to set `txn_db_options.default_write_batch_flush_threshold = 1` in order to give better test coverage for WriteUnprepared.
As part of the change, some tests had to be updated.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5658
Differential Revision: D16740468
Pulled By: lth
fbshipit-source-id: 3821eec20baf13917c8c1fab444332f75a509de9
Summary:
SmallestUnCommittedSeq reads two data structures, prepared_txns_ and delayed_prepared_. These two are updated in CheckPreparedAgainstMax when max_evicted_seq_ advances some prepared entires. To avoid the cost of acquiring a mutex, the read from them in SmallestUnCommittedSeq is not atomic. This creates a potential race condition.
The fix is to read the two data structures in the reverse order of their update. CheckPreparedAgainstMax copies the prepared entry to delayed_prepared_ before removing it from prepared_txns_ and SmallestUnCommittedSeq looks into prepared_txns_ before reading delayed_prepared_.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5683
Differential Revision: D16744699
Pulled By: maysamyabandeh
fbshipit-source-id: b1bdb134018beb0b9de58827f512662bea35cad0
Summary:
This PR adds four more eviction policies.
- OPT [1]
- Hyperbolic caching [2]
- ARC [3]
- GreedyDualSize [4]
[1] L. A. Belady. 1966. A Study of Replacement Algorithms for a Virtual-storage Computer. IBM Syst. J. 5, 2 (June 1966), 78-101. DOI=http://dx.doi.org/10.1147/sj.52.0078
[2] Aaron Blankstein, Siddhartha Sen, and Michael J. Freedman. 2017. Hyperbolic caching: flexible caching for web applications. In Proceedings of the 2017 USENIX Conference on Usenix Annual Technical Conference (USENIX ATC '17). USENIX Association, Berkeley, CA, USA, 499-511.
[3] Nimrod Megiddo and Dharmendra S. Modha. 2003. ARC: A Self-Tuning, Low Overhead Replacement Cache. In Proceedings of the 2nd USENIX Conference on File and Storage Technologies (FAST '03). USENIX Association, Berkeley, CA, USA, 115-130.
[4] N. Young. The k-server dual and loose competitiveness for paging. Algorithmica, June 1994, vol. 11,(no.6):525-41. Rewritten version of ''On-line caching as cache size varies'', in The 2nd Annual ACM-SIAM Symposium on Discrete Algorithms, 241-250, 1991.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5644
Differential Revision: D16548817
Pulled By: HaoyuHuang
fbshipit-source-id: 838f76db9179f07911abaab46c97e1c929cfcd63
Summary:
This is a new API added to db.h to allow for fetching all merge operands associated with a Key. The main motivation for this API is to support use cases where doing a full online merge is not necessary as it is performance sensitive. Example use-cases:
1. Update subset of columns and read subset of columns -
Imagine a SQL Table, a row is encoded as a K/V pair (as it is done in MyRocks). If there are many columns and users only updated one of them, we can use merge operator to reduce write amplification. While users only read one or two columns in the read query, this feature can avoid a full merging of the whole row, and save some CPU.
2. Updating very few attributes in a value which is a JSON-like document -
Updating one attribute can be done efficiently using merge operator, while reading back one attribute can be done more efficiently if we don't need to do a full merge.
----------------------------------------------------------------------------------------------------
API :
Status GetMergeOperands(
const ReadOptions& options, ColumnFamilyHandle* column_family,
const Slice& key, PinnableSlice* merge_operands,
GetMergeOperandsOptions* get_merge_operands_options,
int* number_of_operands)
Example usage :
int size = 100;
int number_of_operands = 0;
std::vector<PinnableSlice> values(size);
GetMergeOperandsOptions merge_operands_info;
db_->GetMergeOperands(ReadOptions(), db_->DefaultColumnFamily(), "k1", values.data(), merge_operands_info, &number_of_operands);
Description :
Returns all the merge operands corresponding to the key. If the number of merge operands in DB is greater than merge_operands_options.expected_max_number_of_operands no merge operands are returned and status is Incomplete. Merge operands returned are in the order of insertion.
merge_operands-> Points to an array of at-least merge_operands_options.expected_max_number_of_operands and the caller is responsible for allocating it. If the status returned is Incomplete then number_of_operands will contain the total number of merge operands found in DB for key.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5604
Test Plan:
Added unit test and perf test in db_bench that can be run using the command:
./db_bench -benchmarks=getmergeoperands --merge_operator=sortlist
Differential Revision: D16657366
Pulled By: vjnadimpalli
fbshipit-source-id: 0faadd752351745224ee12d4ae9ef3cb529951bf
Summary:
if read_options.snapshot is not set, ::Get will take the last sequence number after taking a super-version and uses that as the sequence number. Theoretically max_eviceted_seq_ could advance this sequence number. This could lead ::IsInSnapshot that will be invoked by the ReadCallback to notice the absence of the snapshot. In this case, the ReadCallback should have passed a non-value to snap_released so that it could be set by the ::IsInSnapshot. The patch does that, and adds a unit test to verify it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5664
Differential Revision: D16614033
Pulled By: maysamyabandeh
fbshipit-source-id: 06fb3fd4aacd75806ed1a1acec7961f5d02486f2
Summary:
It sometimes times out when run under valgrind taking around 20m. The patch skips the test under Valgrind.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5671
Differential Revision: D16652382
Pulled By: maysamyabandeh
fbshipit-source-id: 0f6f4f76d37337d56226b689e01b14523dd07aae
Summary:
Add savepoint support when the current transaction has flushed unprepared batches.
Rolling back to savepoint is similar to rolling back a transaction. It requires the set of keys that have changed since the savepoint, re-reading the keys at the snapshot at that savepoint, and the restoring the old keys by writing out another unprepared batch.
For this strategy to work though, we must be capable of reading keys at a savepoint. This does not work if keys were written out using the same sequence number before and after a savepoint. Therefore, when we flush out unprepared batches, we must split the batch by savepoint if any savepoints exist.
eg. If we have the following:
```
Put(A)
Put(B)
Put(C)
SetSavePoint()
Put(D)
Put(E)
SetSavePoint()
Put(F)
```
Then we will write out 3 separate unprepared batches:
```
Put(A) 1
Put(B) 1
Put(C) 1
Put(D) 2
Put(E) 2
Put(F) 3
```
This is so that when we rollback to eg. the first savepoint, we can just read keys at snapshot_seq = 1.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5627
Differential Revision: D16584130
Pulled By: lth
fbshipit-source-id: 6d100dd548fb20c4b76661bd0f8a2647e64477fa
Summary:
In DeferSnapshotSavePointTest, writes were failing with snapshot validation error because the key with the latest sequence number was an unprepared key from the current transaction.
Fix this by passing down the correct read callback.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5657
Differential Revision: D16582466
Pulled By: lth
fbshipit-source-id: 11645dac0e7c1374d917ef5fdf757d13c1d1108d
Summary:
The `TransactionTest.MultiGetBatchedTest` were failing with unprepared batches because we were not using the correct callbacks. Override MultiGet to pass down the correct ReadCallback. A similar problem is also fixed in WritePrepared.
This PR also fixes an issue similar to (https://github.com/facebook/rocksdb/pull/5147), but for MultiGet instead of Get.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5634
Differential Revision: D16552674
Pulled By: lth
fbshipit-source-id: 736eaf8e919c6b13d5f5655b1c0d36b57ad04804
Summary:
This PR optimizes the hybrid row-block cache simulator. If a Get request hits the cache, we treat all its future accesses as hits.
Consider a Get request (no snapshot) accesses multiple files, e.g, file1, file2, file3. We construct the row key as "fdnumber_key_0". Before this PR, if it hits the cache when searching the key in file1, we continue to process its accesses in file2 and file3 which is unnecessary.
With this PR, if "file1_key_0" is in the cache, we treat all future accesses of this Get request as hits.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5616
Differential Revision: D16453187
Pulled By: HaoyuHuang
fbshipit-source-id: 56f3169cc322322305baaf5543226a0824fae19f
Summary:
The ssize_t type was introduced in https://github.com/facebook/rocksdb/pull/5633, but it seems like it's a POSIX specific type.
I just need a signed type to represent number of bytes, so use int64_t instead. It seems like we have a typedef from SSIZE_T for Windows, but it doesn't seem like we ever include "port/port.h" in our public header files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5638
Differential Revision: D16526269
Pulled By: lth
fbshipit-source-id: 8d3a5c41003951b74b29bc5f1d949b2b22da0cee
Summary:
This test frequently times out under TSAN; reducing the number of random
iterations to make it complete faster.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5635
Test Plan: buck test mode/dev-tsan internal_repo_rocksdb/repo:compact_on_deletion_collector_test
Differential Revision: D16523505
Pulled By: ltamasi
fbshipit-source-id: 6a69909bce9d204c891150fcb3d536547b3253d0
Summary:
Instead of reusing `TransactionOptions::max_write_batch_size` for determining when to flush a write batch for write unprepared, add a new variable called `write_batch_flush_threshold` for this use case instead.
Also add `TransactionDBOptions::default_write_batch_flush_threshold` which sets the default value if `TransactionOptions::write_batch_flush_threshold` is unspecified.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5633
Differential Revision: D16520364
Pulled By: lth
fbshipit-source-id: d75ae5a2141ce7708982d5069dc3f0b58d250e8c
Summary:
Transaction::RollbackToSavePoint undos the modification made since the SavePoint beginning, and also unlocks the corresponding keys, which are tracked in the last SavePoint. Currently ::PopSavePoint simply discard these tracked keys, leaving them locked in the lock manager. This breaks a subsequent ::RollbackToSavePoint behavior as it loses track of such keys, and thus cannot unlock them. The patch fixes ::PopSavePoint by passing on the track key information to the previous SavePoint.
Fixes https://github.com/facebook/rocksdb/issues/5618
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5628
Differential Revision: D16505325
Pulled By: lth
fbshipit-source-id: 2bc3b30963ab4d36d996d1f66543c93abf358980
Summary:
Simplify WriteUnpreparedTxnReadCallback so we just have one function `CalcMaxVisibleSeq`. Also, there's no need for the read callback to hold onto the transaction any more, so just hold the set of unprep_seqs, reducing about of indirection in `IsVisibleFullCheck`.
Also, some comments about using transaction snapshot were out of date, so remove them.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5621
Differential Revision: D16459883
Pulled By: lth
fbshipit-source-id: cd581323fd18982e817d99af57b6eaba59e599bb
Summary:
The ObjectRegistry class replaces the Registrar and NewCustomObjects. Objects are registered with the registry by Type (the class must implement the static const char *Type() method).
This change is necessary for a few reasons:
- By having a class (rather than static template instances), the class can be passed between compilation units, meaning that objects could be registered and shared from a dynamic library with an executable.
- By having a class with instances, different units could have different objects registered. This could be useful if, for example, one Option allowed for a dynamic library and one did not.
When combined with some other PRs (being able to load shared libraries, a Configurable interface to configure objects to/from string), this code will allow objects in external shared libraries to be added to a RocksDB image at run-time, rather than requiring every new extension to be built into the main library and called explicitly by every program.
Test plan (on riversand963's devserver)
```
$COMPILE_WITH_ASAN=1 make -j32 all && sleep 1 && make check
```
All tests pass.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5293
Differential Revision: D16363396
Pulled By: riversand963
fbshipit-source-id: fbe4acb615bfc11103eef40a0b288845791c0180
Summary:
There are a number of fixes in this PR (with most bugs found via the added stress tests):
1. Re-enable reseek optimization. This was initially disabled to avoid infinite loops in https://github.com/facebook/rocksdb/pull/3955 but this can be resolved by remembering not to reseek after a reseek has already been done. This problem only affects forward iteration in `DBIter::FindNextUserEntryInternal`, as we already disable reseeking in `DBIter::FindValueForCurrentKeyUsingSeek`.
2. Verify that ReadOption.snapshot can be safely used for iterator creation. Some snapshots would not give correct results because snaphsot validation would not be enforced, breaking some assumptions in Prev() iteration.
3. In the non-snapshot Get() case, reads done at `LastPublishedSequence` may not be enough, because unprepared sequence numbers are not published. Use `std::max(published_seq, max_visible_seq)` to do lookups instead.
4. Add stress test to test reading own writes.
5. Minor bug in the allow_concurrent_memtable_write case where we forgot to pass in batch_per_txn_.
6. Minor performance optimization in `CalcMaxUnpreparedSequenceNumber` by assigning by reference instead of value.
7. Add some more comments everywhere.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5573
Differential Revision: D16276089
Pulled By: lth
fbshipit-source-id: 18029c944eb427a90a87dee76ac1b23f37ec1ccb
Summary:
- Compute correlation between a few features and predictions, e.g., number of accesses since the last access vs number of accesses till the next access on a block.
- Output human readable trace file so python can consume it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5596
Test Plan: make clean && USE_CLANG=1 make check -j32
Differential Revision: D16373200
Pulled By: HaoyuHuang
fbshipit-source-id: c848d26bc2e9210461f317d7dbee42d55be5a0cc
Summary:
This PR traces the referenced key for Get for all types of blocks. This is useful when evaluating hybrid row-block caches.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5548
Test Plan: make clean && USE_CLANG=1 make check -j32
Differential Revision: D16157979
Pulled By: HaoyuHuang
fbshipit-source-id: f6327411c9deb74e35e22a35f66cdbae09ab9d87
Summary:
Refresh of the earlier change here - https://github.com/facebook/rocksdb/issues/5135
This is a review request for code change needed for - https://github.com/facebook/rocksdb/issues/3469
"Add support for taking snapshot of a column family and creating column family from a given CF snapshot"
We have an implementation for this that we have been testing internally. We have two new APIs that together provide this functionality.
(1) ExportColumnFamily() - This API is modelled after CreateCheckpoint() as below.
// Exports all live SST files of a specified Column Family onto export_dir,
// returning SST files information in metadata.
// - SST files will be created as hard links when the directory specified
// is in the same partition as the db directory, copied otherwise.
// - export_dir should not already exist and will be created by this API.
// - Always triggers a flush.
virtual Status ExportColumnFamily(ColumnFamilyHandle* handle,
const std::string& export_dir,
ExportImportFilesMetaData** metadata);
Internally, the API will DisableFileDeletions(), GetColumnFamilyMetaData(), Parse through
metadata, creating links/copies of all the sst files, EnableFileDeletions() and complete the call by
returning the list of file metadata.
(2) CreateColumnFamilyWithImport() - This API is modeled after IngestExternalFile(), but invoked only during a CF creation as below.
// CreateColumnFamilyWithImport() will create a new column family with
// column_family_name and import external SST files specified in metadata into
// this column family.
// (1) External SST files can be created using SstFileWriter.
// (2) External SST files can be exported from a particular column family in
// an existing DB.
// Option in import_options specifies whether the external files are copied or
// moved (default is copy). When option specifies copy, managing files at
// external_file_path is caller's responsibility. When option specifies a
// move, the call ensures that the specified files at external_file_path are
// deleted on successful return and files are not modified on any error
// return.
// On error return, column family handle returned will be nullptr.
// ColumnFamily will be present on successful return and will not be present
// on error return. ColumnFamily may be present on any crash during this call.
virtual Status CreateColumnFamilyWithImport(
const ColumnFamilyOptions& options, const std::string& column_family_name,
const ImportColumnFamilyOptions& import_options,
const ExportImportFilesMetaData& metadata,
ColumnFamilyHandle** handle);
Internally, this API creates a new CF, parses all the sst files and adds it to the specified column family, at the same level and with same sequence number as in the metadata. Also performs safety checks with respect to overlaps between the sst files being imported.
If incoming sequence number is higher than current local sequence number, local sequence
number is updated to reflect this.
Note, as the sst files is are being moved across Column Families, Column Family name in sst file
will no longer match the actual column family on destination DB. The API does not modify Column
Family name or id in the sst files being imported.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5495
Differential Revision: D16018881
fbshipit-source-id: 9ae2251025d5916d35a9fc4ea4d6707f6be16ff9
Summary:
Currently, we are tracking keys we need to rollback via a separate structure specific to WriteUnprepared in write_set_keys_.
We already have a data structure called tracked_keys_ used to track which keys to unlock on transaction termination. This is exactly what we want, since we should only rollback keys that we have locked anyway.
Save some memory by reusing that data structure instead of making our own.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5562
Differential Revision: D16206484
Pulled By: lth
fbshipit-source-id: 5894d2b824a4b19062d84adbd6e6e86f00047488
Summary:
- Provide assignment operator in CompactionStats
- Provide a copy constructor for FileDescriptor
- Remove std::move from "return std::move(t)" in BoundedQueue
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5553
Differential Revision: D16230170
fbshipit-source-id: fd7c6e52390b2db1be24141e25649cf62424d078
Summary:
This PR adds a ghost cache for admission control. Specifically, it admits an entry on its second access.
It also adds a hybrid row-block cache that caches the referenced key-value pairs of a Get/MultiGet request instead of its blocks.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5534
Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32
Differential Revision: D16101124
Pulled By: HaoyuHuang
fbshipit-source-id: b99edda6418a888e94eb40f71ece45d375e234b1
Summary:
Previously `GetAllKeyVersions()` supports default column family only. This PR add support for other column families.
Test plan (devserver):
```
$make clean && COMPILE_WITH_ASAN=1 make -j32 db_basic_test
$./db_basic_test --gtest_filter=DBBasicTest.GetAllKeyVersions
```
All other unit tests must pass.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5544
Differential Revision: D16147551
Pulled By: riversand963
fbshipit-source-id: 5a61aece2a32d789e150226a9b8d53f4a5760168
Summary:
1. Cleanup WAL trash files on open
2. Don't apply deletion rate limit if WAL dir is different from db dir
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5520
Test Plan: Add new unit tests and make check
Differential Revision: D16096750
Pulled By: anand1976
fbshipit-source-id: 6f07858ad864b754b711db416f0389c45ede599b
Summary:
This PR creates cache_simulator.h file. It contains a CacheSimulator that runs against a block cache trace record. We can add alternative cache simulators derived from CacheSimulator later. For example, this PR adds a PrioritizedCacheSimulator that inserts filter/index/uncompressed dictionary blocks with high priority.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5517
Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32
Differential Revision: D16043689
Pulled By: HaoyuHuang
fbshipit-source-id: 65f28ed52b866ffb0e6eceffd7f9ca7c45bb680d
Summary:
~DBWithTTLImpl() fails after calling Close() function (will invoke the
Close() function of DBImpl), because the Close() function deletes
default_cf_handle_ which is used in the GetOptions() function called
in ~DBWithTTLImpl(), hence lead to segfault.
Fix by creating a Close() function for the DBWithTTLImpl class and do
the close and the work originally in ~DBWithTTLImpl(). If the Close()
function is not called, it will be called in the ~DBWithTTLImpl()
function.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5485
Test Plan: make clean; USE_CLANG=1 make all check -j
Differential Revision: D15924498
fbshipit-source-id: 567397fb972961059083a1ae0f9f99ff74872b78
Summary:
This PR adds a BlockCacheTraceSimulator that reports the miss ratios given different cache configurations. A cache configuration contains "cache_name,num_shard_bits,cache_capacities". For example, "lru, 1, 1K, 2K, 4M, 4G".
When we replay the trace, we also perform lookups and inserts on the simulated caches.
In the end, it reports the miss ratio for each tuple <cache_name, num_shard_bits, cache_capacity> in a output file.
This PR also adds a main source block_cache_trace_analyzer so that we can run the analyzer in command line.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5449
Test Plan:
Added tests for block_cache_trace_analyzer.
COMPILE_WITH_ASAN=1 make check -j32.
Differential Revision: D15797073
Pulled By: HaoyuHuang
fbshipit-source-id: aef0c5c2e7938f3e8b6a10d4a6a50e6928ecf408
Summary:
CLANG would complain if we pass const to lambda function and appveyor complains if we don't (https://github.com/facebook/rocksdb/pull/5443). The patch fixes that by using the default capture mode.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5447
Differential Revision: D15788722
Pulled By: maysamyabandeh
fbshipit-source-id: 47e7f49264afe31fdafe42cb8bf93da126abfca9
Summary:
CLANG complains that passing const to thread is not necessary. The patch removes it form PreparedHeap::Concurrent test.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5443
Differential Revision: D15781598
Pulled By: maysamyabandeh
fbshipit-source-id: 3aceb05d96182fa4726d6d37eed45fd3aac4c016
Summary:
Internally PreparedHeap is currently using a priority_queue. The rationale was the in the initial design PreparedHeap::AddPrepared could be called in arbitrary order. With the recent optimizations, we call ::AddPrepared only from the main write queue, which results into in-order insertion into PreparedHeap. The patch thus replaces the underlying priority_queue with a more efficient deque implementation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5436
Differential Revision: D15752147
Pulled By: maysamyabandeh
fbshipit-source-id: e6960f2b2097e13137dded1ceeff3b10b03b0aeb
Summary:
This is a port of this PR into WriteUnprepared:
https://github.com/facebook/rocksdb/pull/5014
This also reverts this test change to restore some flaky write unprepared
tests: https://github.com/facebook/rocksdb/pull/5315
Tested with:
$ gtest-parallel ./transaction_test --gtest_filter=MySQLStyleTransactionTest/MySQLStyleTransactionTest.TransactionStressTest/9 --repeat=128
[128/128] MySQLStyleTransactionTest/MySQLStyleTransactionTest.TransactionStressTest/9 (18250 ms)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5439
Differential Revision: D15761405
Pulled By: lth
fbshipit-source-id: ae2581fd942d8a5b3f9278fd6bc3c1ac0b2c964c
Summary:
If a memtable definitely covers a key, there isn't a need to check older memtables.
We can skip them by checking the earliest sequence number.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4941
Differential Revision: D13932666
fbshipit-source-id: b9d52f234b8ad9dd3bf6547645cd457175a3ca9b
Summary:
The patch reduces the contention over prepared_mutex_ using these techniques:
1) Move ::RemovePrepared() to be called from the commit callback when we have two write queues.
2) Use two separate mutex for PreparedHeap, one prepared_mutex_ needed for ::RemovePrepared, and one ::push_pop_mutex() needed for ::AddPrepared(). Given that we call ::AddPrepared only from the first write queue and ::RemovePrepared mostly from the 2nd, this will result into each the two write queues not competing with each other over a single mutex. ::RemovePrepared might occasionally need to acquire ::push_pop_mutex() if ::erase() ends up with calling ::pop()
3) Acquire ::push_pop_mutex() on the first callback of the write queue and release it on the last.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5420
Differential Revision: D15741985
Pulled By: maysamyabandeh
fbshipit-source-id: 84ce8016007e88bb6e10da5760ba1f0d26347735
Summary:
When using `PRIu64` type of printf specifier, current code base does the following:
```
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
```
However, this can be simplified to
```
#include <cinttypes>
```
as long as flag `-std=c++11` is used.
This should solve issues like https://github.com/facebook/rocksdb/issues/5159
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5402
Differential Revision: D15701195
Pulled By: miasantreble
fbshipit-source-id: 6dac0a05f52aadb55e9728038599d3d2e4b59d03
Summary:
Currently we validate options in DB::Open. However the validation step is missing when options are dynamically updated in ::SetOptions. The patch fixes that.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5368
Differential Revision: D15540101
Pulled By: maysamyabandeh
fbshipit-source-id: d27bbffd8f0252d1b50bcf59e0a70a278ed937f4
Summary:
util/ means for lower level libraries. trace_replay is highly integrated to DB and sometimes call DB. Move it out to a separate directory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5376
Differential Revision: D15550938
Pulled By: siying
fbshipit-source-id: f46dce5ceffdc05a73f26379c7bb1b79ebe6c207
Summary:
Many logging related source files are under util/. It will be more structured if they are together.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5387
Differential Revision: D15579036
Pulled By: siying
fbshipit-source-id: 3850134ed50b8c0bb40a0c8ae1f184fa4081303f
Summary:
Right now, with auto roll logger, options.keep_log_file_num enforcement is triggered by events like DB reopen or full obsolete scan happens. In the mean time, the size and number of log files can grow without a limit. We put a stronger enforcement to the option, so that the number of log files can always under control.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5370
Differential Revision: D15570413
Pulled By: siying
fbshipit-source-id: 0916c3c4d42ab8fdd29389ee7fd7e1557b03176e
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:
util/ means for lower level libraries, so it's a good idea to move the files which requires knowledge to DB out. Create a file/ and move some files there.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5375
Differential Revision: D15550935
Pulled By: siying
fbshipit-source-id: 61a9715dcde5386eebfb43e93f847bba1ae0d3f2
Summary:
This enables the user to set TransactionDBOptions::skip_concurrency_control so the standard `DB::Write(const WriteOptions& opts, WriteBatch* updates)` would skip the concurrency control. This would give higher throughput to the users who know their use case doesn't need concurrency control.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5330
Differential Revision: D15525932
Pulled By: maysamyabandeh
fbshipit-source-id: 68421ac1ba34f549a4a8de9ce4c2dccf6fb4b06b
Summary:
When committing a transaction without prepare, WritePrepared simply writes the batch to db and add the commit entry to CommitCache. When two_write_queues=true, following the rule of committing only from 2nd write queue, the first write, writes the batch and the only thing the 2nd write does is to write the commit entry to CommitCache. Currently the write batch in 2nd write is set to an empty LogData entry, while the write to the WAL could simply be entirely disabled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5327
Differential Revision: D15424546
Pulled By: maysamyabandeh
fbshipit-source-id: 3d9ea3922d5196984c584d62a3ed57e1f7ca7b9f
Summary:
WritePrepared transactions when configured with two_write_queues=true offers higher throughput with unordered_write feature without however compromising the rocksdb guarantees. This is because it performs ordering among writes in a 2nd step that is not tied to memtable write speed. The 2nd step is naturally provided by 2PC when the commit phase does the ordering as well. Without 2PC, the 2nd step would only be provided when we use two_write_queues=true, where WritePrepared after performing the writes, in a 2nd step uses the 2nd queue to assign order to the writes.
The patch clarifies the need for two_write_queues=true in the HISTORY and inline comments of unordered_writes. Moreover it extends the stress tests of WritePrepared to unordred_write.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5313
Differential Revision: D15379977
Pulled By: maysamyabandeh
fbshipit-source-id: 5b6f05b9b59285dcbf3b0532215ba9fe7d926e00
Summary:
They are kind of flaky at the moment. Will re-enable it when flakiness is fixed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5315
Differential Revision: D15382744
Pulled By: maysamyabandeh
fbshipit-source-id: 8b2f9d81a4bb34bfd51481727a682d5cd063c5e3
Summary:
The recent improvement in https://github.com/facebook/rocksdb/pull/3661 could cause a deadlock: When writing recoverable state, we also commit its sequence number to commit table, which could result into evicting existing commit entry, which could result into advancing max_evicted_seq_, which would need to get snapshots from database, which requires obtaining db mutex. The patch releases db_mutex before calling the callback in WriteRecoverableState to avoid the potential deadlock. It also improves the stress tests to let the issue be manifested in the tests.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5306
Differential Revision: D15341458
Pulled By: maysamyabandeh
fbshipit-source-id: 05dcbed7e21b789fd1e5fd5ee8eea08077162323
Summary:
Performing unordered writes in rocksdb when unordered_write option is set to true. When enabled the writes to memtable are done without joining any write thread. This offers much higher write throughput since the upcoming writes would not have to wait for the slowest memtable write to finish. The tradeoff is that the writes visible to a snapshot might change over time. If the application cannot tolerate that, it should implement its own mechanisms to work around that. Using TransactionDB with WRITE_PREPARED write policy is one way to achieve that. Doing so increases the max throughput by 2.2x without however compromising the snapshot guarantees.
The patch is prepared based on an original by siying
Existing unit tests are extended to include unordered_write option.
Benchmark Results:
```
TEST_TMPDIR=/dev/shm/ ./db_bench_unordered --benchmarks=fillrandom --threads=32 --num=10000000 -max_write_buffer_number=16 --max_background_jobs=64 --batch_size=8 --writes=3000000 -level0_file_num_compaction_trigger=99999 --level0_slowdown_writes_trigger=99999 --level0_stop_writes_trigger=99999 -enable_pipelined_write=false -disable_auto_compactions --unordered_write=1
```
With WAL
- Vanilla RocksDB: 78.6 MB/s
- WRITER_PREPARED with unordered_write: 177.8 MB/s (2.2x)
- unordered_write: 368.9 MB/s (4.7x with relaxed snapshot guarantees)
Without WAL
- Vanilla RocksDB: 111.3 MB/s
- WRITER_PREPARED with unordered_write: 259.3 MB/s MB/s (2.3x)
- unordered_write: 645.6 MB/s (5.8x with relaxed snapshot guarantees)
- WRITER_PREPARED with unordered_write disable concurrency control: 185.3 MB/s MB/s (2.35x)
Limitations:
- The feature is not yet extended to `max_successive_merges` > 0. The feature is also incompatible with `enable_pipelined_write` = true as well as with `allow_concurrent_memtable_write` = false.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5218
Differential Revision: D15219029
Pulled By: maysamyabandeh
fbshipit-source-id: 38f2abc4af8780148c6128acdba2b3227bc81759
Summary:
MultiGet batching was implemented in #5011 in order to reduce CPU utilization when looking up multiple keys at once. This PR implements corresponding ```MultiGet``` and ```MultiGetSingleCFForUpdate``` in ```rocksdb::Transaction``` that call the underlying batching implementation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5210
Differential Revision: D15048164
Pulled By: anand1976
fbshipit-source-id: c52f6043102ab0cbc723f4cba2a7b7d1767f6f52
Summary:
The existing implementation does not guarantee bytes reach disk every `bytes_per_sync` when writing SST files, or every `wal_bytes_per_sync` when writing WALs. This can cause confusing behavior for users who enable this feature to avoid large syncs during flush and compaction, but then end up hitting them anyways.
My understanding of the existing behavior is we used `sync_file_range` with `SYNC_FILE_RANGE_WRITE` to submit ranges for async writeback, such that we could continue processing the next range of bytes while that I/O is happening. I believe we can preserve that benefit while also limiting how far the processing can get ahead of the I/O, which prevents huge syncs from happening when the file finishes.
Consider this `sync_file_range` usage: `sync_file_range(fd_, 0, static_cast<off_t>(offset + nbytes), SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE)`. Expanding the range to start at 0 and adding the `SYNC_FILE_RANGE_WAIT_BEFORE` flag causes any pending writeback (like from a previous call to `sync_file_range`) to finish before it proceeds to submit the latest `nbytes` for writeback. The latest `nbytes` are still written back asynchronously, unless processing exceeds I/O speed, in which case the following `sync_file_range` will need to wait on it.
There is a second change in this PR to use `fdatasync` when `sync_file_range` is unavailable (determined statically) or has some known problem with the underlying filesystem (determined dynamically).
The above two changes only apply when the user enables a new option, `strict_bytes_per_sync`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5183
Differential Revision: D14953553
Pulled By: siying
fbshipit-source-id: 445c3862e019fb7b470f9c7f314fc231b62706e9
Summary:
Savepoints are assumed to be used in a stack-wise fashion (only
the top element should be used), so they were stored by `WriteBatch`
in a member variable `save_points` using an std::stack.
Conceptually this is fine, but the implementation had a few issues:
- the `save_points_` instance variable was a plain pointer to a heap-
allocated `SavePoints` struct. The destructor of `WriteBatch` simply
deletes this pointer. However, the copy constructor of WriteBatch
just copied that pointer, meaning that copying a WriteBatch with
active savepoints will very likely have crashed before. Now a proper
copy of the savepoints is made in the copy constructor, and not just
a copy of the pointer
- `save_points_` was an std::stack, which defaults to `std::deque` for
the underlying container. A deque is a bit over the top here, as we
only need access to the most recent savepoint (i.e. stack.top()) but
never any elements at the front. std::deque is rather expensive to
initialize in common environments. For example, the STL implementation
shipped with GNU g++ will perform a heap allocation of more than 500
bytes to create an empty deque object. Although the `save_points_`
container is created lazily by RocksDB, moving from a deque to a plain
`std::vector` is much more memory-efficient. So `save_points_` is now
a vector.
- `save_points_` was changed from a plain pointer to an `std::unique_ptr`,
making ownership more explicit.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5192
Differential Revision: D15024074
Pulled By: maysamyabandeh
fbshipit-source-id: 5b128786d3789cde94e46465c9e91badd07a25d7
Summary:
Depending on the config, manual compaction (leveled compaction style) does following compactions:
L0->L1
L1->L2
...
Ln-1 -> Ln
Ln -> Ln
The final Ln -> Ln compaction is partly unnecessary as it recompacts all the files that were just generated by the Ln-1 -> Ln. We should avoid recompacting such files. This rule should be applied to Lmax only.
Resolves issue https://github.com/facebook/rocksdb/issues/4995
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5138
Differential Revision: D14940106
Pulled By: miasantreble
fbshipit-source-id: 8d3cf5507a17e76f3333cfd4bac5256d005636e5
Summary:
This branch contains two small improvements:
* Create `LockMap` entries using `std::make_shared`. This saves one heap allocation per LockMap entry but also locates the control block and the LockMap object closely together in memory, which can help with caching
* Reorder the members of `TrackedTrxInfo`, so that the resulting struct uses less memory (at least on 64bit systems)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5193
Differential Revision: D14934536
Pulled By: maysamyabandeh
fbshipit-source-id: f7b49812bb4b6029eef9d131e7cd56260df5b28e
Summary:
In `PessimisticTransaction::TryLock`, we were calling `TrackKey` even when assume_tracked=true, which defeats the purpose of assume_tracked. Remove this.
For keys that are already tracked, TrackKey will actually bump some counters (num_reads/num_writes) which are consumed in `TransactionBaseImpl::GetTrackedKeysSinceSavePoint`, and this is used to determine which keys were tracked since the last savepoint. I believe this functionality should still work, since I think the user should not call GetForUpdate/Put(assume_tracked=true) across savepoints, and if they do, they should not expect the Put(assume_tracked=true) to show up as a tracked key in the second savepoint.
This is another 2-3% cpu improvement.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5173
Differential Revision: D14883809
Pulled By: lth
fbshipit-source-id: 7d09f0772da422384af0519773e310c22b0cbca3
Summary:
When ReadOption doesn't specify a snapshot, WritePrepared::Get used kMaxSequenceNumber to avoid the cost of creating a new snapshot object (that requires sync over db_mutex). This creates a race condition if it is reading from the writes of a transaction that had duplicate keys: each instance of duplicate key is inserted with a different sequence number and depending on the ordering the ::Get might skip the newer one and read the older one that is obsolete.
The patch fixes that by using last published seq as the snapshot sequence number. It also adds a check after the read is done to ensure that the max_evicted_seq has not advanced the aforementioned seq, which is a very unlikely event. If it did, then the read is not valid since the seq is not backed by an actually snapshot to let IsInSnapshot handle that properly when an overlapping commit is evicted from commit cache.
A unit test is added to reproduce the race condition with duplicate keys.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5147
Differential Revision: D14758815
Pulled By: maysamyabandeh
fbshipit-source-id: a56915657132cf6ba5e3f5ea1b5d78c803407719
Summary:
This PR introduces a new MultiGet() API, with the underlying implementation grouping keys based on SST file and batching lookups in a file. The reason for the new API is twofold - the definition allows callers to allocate storage for status and values on stack instead of std::vector, as well as return values as PinnableSlices in order to avoid copying, and it keeps the original MultiGet() implementation intact while we experiment with batching.
Batching is useful when there is some spatial locality to the keys being queries, as well as larger batch sizes. The main benefits are due to -
1. Fewer function calls, especially to BlockBasedTableReader::MultiGet() and FullFilterBlockReader::KeysMayMatch()
2. Bloom filter cachelines can be prefetched, hiding the cache miss latency
The next step is to optimize the binary searches in the level_storage_info, index blocks and data blocks, since we could reduce the number of key comparisons if the keys are relatively close to each other. The batching optimizations also need to be extended to other formats, such as PlainTable and filter formats. This also needs to be added to db_stress.
Benchmark results from db_bench for various batch size/locality of reference combinations are given below. Locality was simulated by offsetting the keys in a batch by a stride length. Each SST file is about 8.6MB uncompressed and key/value size is 16/100 uncompressed. To focus on the cpu benefit of batching, the runs were single threaded and bound to the same cpu to eliminate interference from other system events. The results show a 10-25% improvement in micros/op from smaller to larger batch sizes (4 - 32).
Batch Sizes
1 | 2 | 4 | 8 | 16 | 32
Random pattern (Stride length 0)
4.158 | 4.109 | 4.026 | 4.05 | 4.1 | 4.074 - Get
4.438 | 4.302 | 4.165 | 4.122 | 4.096 | 4.075 - MultiGet (no batching)
4.461 | 4.256 | 4.277 | 4.11 | 4.182 | 4.14 - MultiGet (w/ batching)
Good locality (Stride length 16)
4.048 | 3.659 | 3.248 | 2.99 | 2.84 | 2.753
4.429 | 3.728 | 3.406 | 3.053 | 2.911 | 2.781
4.452 | 3.45 | 2.833 | 2.451 | 2.233 | 2.135
Good locality (Stride length 256)
4.066 | 3.786 | 3.581 | 3.447 | 3.415 | 3.232
4.406 | 4.005 | 3.644 | 3.49 | 3.381 | 3.268
4.393 | 3.649 | 3.186 | 2.882 | 2.676 | 2.62
Medium locality (Stride length 4096)
4.012 | 3.922 | 3.768 | 3.61 | 3.582 | 3.555
4.364 | 4.057 | 3.791 | 3.65 | 3.57 | 3.465
4.479 | 3.758 | 3.316 | 3.077 | 2.959 | 2.891
dbbench command used (on a DB with 4 levels, 12 million keys)-
TEST_TMPDIR=/dev/shm numactl -C 10 ./db_bench.tmp -use_existing_db=true -benchmarks="readseq,multireadrandom" -write_buffer_size=4194304 -target_file_size_base=4194304 -max_bytes_for_level_base=16777216 -num=12000000 -reads=12000000 -duration=90 -threads=1 -compression_type=none -cache_size=4194304000 -batch_size=32 -disable_auto_compactions=true -bloom_bits=10 -cache_index_and_filter_blocks=true -pin_l0_filter_and_index_blocks_in_cache=true -multiread_batched=true -multiread_stride=4
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5011
Differential Revision: D14348703
Pulled By: anand1976
fbshipit-source-id: 774406dab3776d979c809522a67bedac6c17f84b
Summary:
The LockInfo struct is not easy to copy because it contains std::vector. Reduce copies by using move constructor and `unordered_map::emplace`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5172
Differential Revision: D14882053
Pulled By: lth
fbshipit-source-id: 93999ec6ab1a5841fb5115abb764b6c1831a6de1
Summary:
Create new function NPHash64() and GetSliceNPHash64(), which are currently
implemented using murmurhash.
Replace the current direct call of murmurhash() to use the new functions
if the hash results are not used in on-disk format.
This will make it easier to try out or switch to alternative functions
in the uses where data format compatibility doesn't need to be considered.
This part shouldn't have any performance impact.
Also, the sharded cache hash function is changed to the new format, because
it falls into this categoery. It doesn't show visible performance impact
in db_bench results. CPU showed by perf is increased from about 0.2% to 0.4%
in an extreme benchmark setting (4KB blocks, no-compression, everything
cached in block cache). We've known that the current hash function used,
our own Hash() has serious hash quality problem. It can generate a lots of
conflicts with similar input. In this use case, it means extra lock contention
for reads from the same file. This slight CPU regression is worthy to me
to counter the potential bad performance with hot keys. And hopefully this
will get further improved in the future with a better hash function.
cache_test's condition is relaxed a little bit to. The new hash is slightly
more skewed in this use case, but I manually checked the data and see
the hash results are still in a reasonable range.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5155
Differential Revision: D14834821
Pulled By: siying
fbshipit-source-id: ec9a2c0a2f8ae4b54d08b13a5c2e9cc97aa80cb5
Summary:
Annotate all of the logging functions to inform the compiler that these
use printf-style formatting arguments. This allows the compiler to emit
warnings if the format arguments are incorrect.
This also fixes many problems reported now that format string checking
is enabled. Many of these are simply mix-ups in the argument type (e.g,
int vs uint64_t), but in several cases the wrong number of arguments
were being passed in which can cause the code to crash.
The primary motivation for this was to fix the log message in
`DBImpl::SwitchMemtable()` which caused a segfault due to an extra %s
format parameter with no argument supplied.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5089
Differential Revision: D14574795
Pulled By: simpkins
fbshipit-source-id: 0921b03f0743652bf4ae21e414ff54b3bb65422a
Summary:
Ubsna complains that in initialization of WriteUnpreparedTxnReadCallback the method of the child class is used before the parent class is constructed. The patch fixes that by making the aforementioned method static.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5148
Differential Revision: D14760098
Pulled By: maysamyabandeh
fbshipit-source-id: cf19b7c1fdb5de0a54e62c1deebe09a0fa048ded
Summary:
In prepare phase of 2PC, the db promises to remember the prepared data, for possible future commits. To fulfill the promise the prepared data must be persisted in the WAL so that they could be recovered after a crash. The log that contains a prepare batch that is not committed yet, is marked so that it is not garbage collected before the transaction commits/rollbacks. The bug was that the write to the log file and the mark of the file was not atomic, and WAL gc could have happened before the WAL log is actually marked. This patch moves the marking logic to PreReleaseCallback so that the WAL gc logic that joins both write threads would see the WAL write and WAL mark atomically.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5121
Differential Revision: D14665210
Pulled By: maysamyabandeh
fbshipit-source-id: 1d66aeb1c66a296cb4899a5a20c4d40c59e4b534
Summary:
WriteUnPrepared adds a virtual function, MaxUnpreparedSequenceNumber, to ReadCallback, which returns 0 unless WriteUnPrepared is enabled and the transaction has uncommitted data written to the DB. Together with snapshot sequence number, this determines the last sequence that is visible to reads.
The patch clarifies the guarantees of the GetIterator API in WriteUnPrepared transactions and make use of that to statically initialize the read callback and thus avoid the virtual call.
Furthermore it increases the minimum value for min_uncommitted from 0 to 1 as seq 0 is used only for last level keys that are committed in all snapshots.
The following benchmark shows +0.26% higher throughput in seekrandom benchmark.
Benchmark:
./db_bench --benchmarks=fillrandom --use_existing_db=0 --num=1000000 --db=/dev/shm/dbbench
./db_bench --benchmarks=seekrandom[X10] --use_existing_db=1 --db=/dev/shm/dbbench --num=1000000 --duration=60 --seek_nexts=100
seekrandom [AVG 10 runs] : 20355 ops/sec; 225.2 MB/sec
seekrandom [MEDIAN 10 runs] : 20425 ops/sec; 225.9 MB/sec
./db_bench_lessvirtual3 --benchmarks=seekrandom[X10] --use_existing_db=1 --db=/dev/shm/dbbench --num=1000000 --duration=60 --seek_nexts=100
seekrandom [AVG 10 runs] : 20409 ops/sec; 225.8 MB/sec
seekrandom [MEDIAN 10 runs] : 20487 ops/sec; 226.6 MB/sec
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5049
Differential Revision: D14366459
Pulled By: maysamyabandeh
fbshipit-source-id: ebaff8908332a5ae9af7defeadabcb624be660ef
Summary:
Compaction would depend on max_evicted_seq_ value. The ::Initialize method should do that after max_evicted_seq_ is properly initialized. The patch also back ports #4853 from WritePrepared txn to WriteUnPrepared.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5128
Differential Revision: D14686562
Pulled By: maysamyabandeh
fbshipit-source-id: b2355025712a72676ac3b20a95258adcf4774490
