Summary:
Since DynamicBloom is now only used in-memory, we're free to
change it without schema compatibility issues. The new implementation
is drawn from (with manifest permission)
303542a767/bloom_simulation_tests/foo.cc (L613)
This has several speed advantages over the prior implementation:
* Uses fastrange instead of %
* Minimum logic to determine first (and all) probed memory addresses
* (Major) Two probes per 64-bit memory fetch/write.
* Very fast and effective (murmur-like) hash expansion/re-mixing. (At
least on recent CPUs, integer multiplication is very cheap.)
While a Bloom filter with 512-bit cache locality has about a 1.15x FP
rate penalty (e.g. 0.84% to 0.97%), further restricting to two probes
per 64 bits incurs an additional 1.12x FP rate penalty (e.g. 0.97% to
1.09%). Nevertheless, the unit tests show no "mediocre" FP rate samples,
unlike the old implementation with more erratic FP rates.
Especially for the memtable, we expect speed to outweigh somewhat higher
FP rates. For example, a negative table query would have to be 1000x
slower than a BF query to justify doubling BF query time to shave 10% off
FP rate (working assumption around 1% FP rate). While that seems likely
for SSTs, my data suggests a speed factor of roughly 50x for the memtable
(vs. BF; ~1.5% lower write throughput when enabling memtable Bloom
filter, after this change). Thus, it's probably not worth even 5% more
time in the Bloom filter to shave off 1/10th of the Bloom FP rate, or 0.1%
in absolute terms, and it's probably at least 20% slower to recoup that
much FP rate from this new implementation. Because of this, we do not see
a need for a 'locality' option that affects the MemTable Bloom filter
and have decoupled the MemTable Bloom filter from Options::bloom_locality.
Note that just 3% more memory to the Bloom filter (10.3 bits per key vs.
just 10) is able to make up for the ~12% FP rate drop in the new
implementation:
[] # Nearly "ideal" FP-wise but reasonably fast cache-local implementation
[~/wormhashing/bloom_simulation_tests] ./foo_gcc_IMPL_CACHE_WORM64_FROM32_any.out 10000000 6 10 $RANDOM 100000000
./foo_gcc_IMPL_CACHE_WORM64_FROM32_any.out time: 3.29372 sampled_fp_rate: 0.00985956 ...
[] # Close match to this new implementation
[~/wormhashing/bloom_simulation_tests] ./foo_gcc_IMPL_CACHE_MUL64_BLOCK_FROM32_any.out 10000000 6 10.3 $RANDOM 100000000
./foo_gcc_IMPL_CACHE_MUL64_BLOCK_FROM32_any.out time: 2.10072 sampled_fp_rate: 0.00985655 ...
[] # Old locality=1 implementation
[~/wormhashing/bloom_simulation_tests] ./foo_gcc_IMPL_CACHE_ROCKSDB_DYNAMIC_any.out 10000000 6 10 $RANDOM 100000000
./foo_gcc_IMPL_CACHE_ROCKSDB_DYNAMIC_any.out time: 3.95472 sampled_fp_rate: 0.00988943 ...
Also note the dramatic speed improvement vs. alternatives.
--
Performance unit test: DynamicBloomTest.concurrent_with_perf is updated
to report more precise timing data. (Measure running time of each
thread, not just longest running thread, etc.) Results averaged over
various sizes enabled with --enable_perf and 20 runs each; old dynamic
bloom refers to locality=1, the faster of the old:
old dynamic bloom, avg add latency = 65.6468
new dynamic bloom, avg add latency = 44.3809
old dynamic bloom, avg query latency = 50.6485
new dynamic bloom, avg query latency = 43.2186
old avg parallel add latency = 41.678
new avg parallel add latency = 24.5238
old avg parallel hit latency = 14.6322
new avg parallel hit latency = 12.3939
old avg parallel miss latency = 16.7289
new avg parallel miss latency = 12.2134
Tested on a dedicated 64-bit production machine at Facebook. Significant
improvement all around.
Despite now using std::atomic<uint64_t>, quick before-and-after test on
a 32-bit machine (Intel Atom N270, released 2008) shows no regression in
performance, in some cases modest improvement.
--
Performance integration test (synthetic): with DEBUG_LEVEL=0, used
TEST_TMPDIR=/dev/shm ./db_bench --benchmarks=fillrandom,readmissing,readrandom,stats --num=2000000
and optionally with -memtable_whole_key_filtering -memtable_bloom_size_ratio=0.01
300 runs each configuration.
Write throughput change by enabling memtable bloom:
Old locality=0: -3.06%
Old locality=1: -2.37%
New: -1.50%
conclusion -> seems to substantially close the gap
Readmissing throughput change by enabling memtable bloom:
Old locality=0: +34.47%
Old locality=1: +34.80%
New: +33.25%
conclusion -> maybe a small new penalty from FP rate
Readrandom throughput change by enabling memtable bloom:
Old locality=0: +31.54%
Old locality=1: +31.13%
New: +30.60%
conclusion -> maybe also from FP rate (after memtable flush)
--
Another conclusion we can draw from this new implementation is that the
existing 32-bit hash function is not inherently crippling the Bloom
filter speed or accuracy, below about 5 million keys. For speed, the
implementation is essentially the same whether starting with 32-bits or
64-bits of hash; it just determines whether the first multiplication
after fastrange is a pseudorandom expansion or needed re-mix. Note that
this multiplication can occur while memory is fetching.
For accuracy, in a standard configuration, you need about 5 million
keys before you have about a 1.1x FP penalty due to using a
32-bit hash vs. 64-bit:
[~/wormhashing/bloom_simulation_tests] ./foo_gcc_IMPL_CACHE_MUL64_BLOCK_FROM32_any.out $((5 * 1000 * 1000 * 10)) 6 10 $RANDOM 100000000
./foo_gcc_IMPL_CACHE_MUL64_BLOCK_FROM32_any.out time: 2.52069 sampled_fp_rate: 0.0118267 ...
[~/wormhashing/bloom_simulation_tests] ./foo_gcc_IMPL_CACHE_MUL64_BLOCK_any.out $((5 * 1000 * 1000 * 10)) 6 10 $RANDOM 100000000
./foo_gcc_IMPL_CACHE_MUL64_BLOCK_any.out time: 2.43871 sampled_fp_rate: 0.0109059
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5762
Differential Revision: D17214194
Pulled By: pdillinger
fbshipit-source-id: ad9da031772e985fd6b62a0e1db8e81892520595
Summary:
DynamicBloom was being used both for memory-only and for on-disk filters, as part of the PlainTable format. To set up enhancements to the memtable Bloom filter, this splits the code into two copies and removes unused features from each copy. Adds test PlainTableDBTest.BloomSchema to ensure no accidental change to that format.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5767
Differential Revision: D17206963
Pulled By: pdillinger
fbshipit-source-id: 6cce8d55305ed0df051b4c58bdc98c8ad81d0553
Summary:
Adding a light weight API to get last live WAL file name and size. Meant to be used as a helper for backup/restore tooling in a larger ecosystem such as MySQL with a MyRocks storage engine.
Specifically within MySQL's backup/restore mechanism, this call can be made with a write lock on the mysql db to get a transactionally consistent snapshot of the current WAL file position along with other non-rocksdb log/data files.
Without this, the alternative would be to take the aforementioned lock, scan the WAL dir for all files, find the last file and note its exact size as the rocksdb 'checkpoint'.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5765
Differential Revision: D17172717
Pulled By: affandar
fbshipit-source-id: f2fabafd4c0e6fc45f126670c8c88a9f84cb8a37
Summary:
Each DB has a globally unique ID. A DB can be physically copied around, or backed-up and restored, and the users should be identify the same DB. This unique ID right now is stored as plain text in file IDENTITY under the DB directory. This approach introduces at least two problems: (1) the file is not checksumed; (2) the source of truth of a DB is the manifest file, which can be copied separately from IDENTITY file, causing the DB ID to be wrong.
The goal of this PR is solve this problem by moving the DB ID to manifest. To begin with we will write to both identity file and manifest. Write to Manifest is controlled via the flag write_dbid_to_manifest in Options and default is false.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5725
Test Plan: Added unit tests.
Differential Revision: D16963840
Pulled By: vjnadimpalli
fbshipit-source-id: 8a86a4c8c82c716003c40fd6b9d2d758030d92e9
Summary:
Before this PR, when the number of column families involved in a file ingestion exceeds 2, a bug in the looping logic prevents correct file number being assigned to each ingestion job.
Also skip deleting non-existing hard links during cleanup-after-failure.
Test plan (devserver)
```
$COMPILE_WITH_ASAN=1 make all
$./external_sst_file_test --gtest_filter=ExternalSSTFileTest/ExternalSSTFileTest.IngestFilesIntoMultipleColumnFamilies_*/*
$makke check
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5760
Differential Revision: D17142982
Pulled By: riversand963
fbshipit-source-id: 06c1847a4e7a402647bcf28d124e70f2a0f9daf6
Summary:
Before this PR, the following sequence of events can cause assertion failure as shown below.
Stack trace (partial):
```
(gdb) bt
2 0x00007f59b350ad15 in __assert_fail_base (fmt=<optimized out>, assertion=assertion@entry=0x9f8390 "mark_as_compacted ? !inputs_[i][j]->being_compacted : inputs_[i][j]->being_compacted", file=file@entry=0x9e347c "db/compaction/compaction.cc", line=line@entry=395, function=function@entry=0xa21ec0 <rocksdb::Compaction::MarkFilesBeingCompacted(bool)::__PRETTY_FUNCTION__> "void rocksdb::Compaction::MarkFilesBeingCompacted(bool)") at assert.c:92
3 0x00007f59b350adc3 in __GI___assert_fail (assertion=assertion@entry=0x9f8390 "mark_as_compacted ? !inputs_[i][j]->being_compacted : inputs_[i][j]->being_compacted", file=file@entry=0x9e347c "db/compaction/compaction.cc", line=line@entry=395, function=function@entry=0xa21ec0 <rocksdb::Compaction::MarkFilesBeingCompacted(bool)::__PRETTY_FUNCTION__> "void rocksdb::Compaction::MarkFilesBeingCompacted(bool)") at assert.c:101
4 0x0000000000492ccd in rocksdb::Compaction::MarkFilesBeingCompacted (this=<optimized out>, mark_as_compacted=<optimized out>) at db/compaction/compaction.cc:394
5 0x000000000049467a in rocksdb::Compaction::Compaction (this=0x7f59af013000, vstorage=0x7f581af53030, _immutable_cf_options=..., _mutable_cf_options=..., _inputs=..., _output_level=<optimized out>, _target_file_size=0, _max_compaction_bytes=0, _output_path_id=0, _compression=<incomplete type>, _compression_opts=..., _max_subcompactions=0, _grandparents=..., _manual_compaction=false, _score=4, _deletion_compaction=true, _compaction_reason=rocksdb::CompactionReason::kFIFOTtl) at db/compaction/compaction.cc:241
6 0x00000000004af9bc in rocksdb::FIFOCompactionPicker::PickTTLCompaction (this=0x7f59b31a6900, cf_name=..., mutable_cf_options=..., vstorage=0x7f581af53030, log_buffer=log_buffer@entry=0x7f59b1bfa930) at db/compaction/compaction_picker_fifo.cc:101
7 0x00000000004b0771 in rocksdb::FIFOCompactionPicker::PickCompaction (this=0x7f59b31a6900, cf_name=..., mutable_cf_options=..., vstorage=0x7f581af53030, log_buffer=0x7f59b1bfa930) at db/compaction/compaction_picker_fifo.cc:201
8 0x00000000004838cc in rocksdb::ColumnFamilyData::PickCompaction (this=this@entry=0x7f59b31b3700, mutable_options=..., log_buffer=log_buffer@entry=0x7f59b1bfa930) at db/column_family.cc:933
9 0x00000000004f3645 in rocksdb::DBImpl::BackgroundCompaction (this=this@entry=0x7f59b3176000, made_progress=made_progress@entry=0x7f59b1bfa6bf, job_context=job_context@entry=0x7f59b1bfa760, log_buffer=log_buffer@entry=0x7f59b1bfa930, prepicked_compaction=prepicked_compaction@entry=0x0, thread_pri=rocksdb::Env::LOW) at db/db_impl/db_impl_compaction_flush.cc:2541
10 0x00000000004f5e2a in rocksdb::DBImpl::BackgroundCallCompaction (this=this@entry=0x7f59b3176000, prepicked_compaction=prepicked_compaction@entry=0x0, bg_thread_pri=bg_thread_pri@entry=rocksdb::Env::LOW) at db/db_impl/db_impl_compaction_flush.cc:2312
11 0x00000000004f648e in rocksdb::DBImpl::BGWorkCompaction (arg=<optimized out>) at db/db_impl/db_impl_compaction_flush.cc:2087
```
This can be caused by the following sequence of events.
```
Time
| thr bg_compact_thr1 bg_compact_thr2
| write
| flush
| mark all l0 as being compacted
| write
| flush
| add cf to queue again
| mark all l0 as being
| compacted, fail the
| assertion
V
```
Test plan (on devserver)
Since bg_compact_thr1 and bg_compact_thr2 are two threads executing the same
code, it is difficult to use sync point dependency to
coordinate their execution. Therefore, I choose to use db_stress.
```
$TEST_TMPDIR=/dev/shm/rocksdb ./db_stress --periodic_compaction_seconds=1 --max_background_compactions=20 --format_version=2 --memtablerep=skip_list --max_write_buffer_number=3 --cache_index_and_filter_blocks=1 --reopen=20 --recycle_log_file_num=0 --acquire_snapshot_one_in=10000 --delpercent=4 --log2_keys_per_lock=22 --compaction_ttl=1 --block_size=16384 --use_multiget=1 --compact_files_one_in=1000000 --target_file_size_multiplier=2 --clear_column_family_one_in=0 --max_bytes_for_level_base=10485760 --use_full_merge_v1=1 --target_file_size_base=2097152 --checkpoint_one_in=1000000 --mmap_read=0 --compression_type=zstd --writepercent=35 --readpercent=45 --subcompactions=4 --use_merge=0 --write_buffer_size=4194304 --test_batches_snapshots=0 --db=/dev/shm/rocksdb/rocksdb_crashtest_whitebox --use_direct_reads=0 --compact_range_one_in=1000000 --open_files=-1 --destroy_db_initially=0 --progress_reports=0 --compression_zstd_max_train_bytes=0 --snapshot_hold_ops=100000 --enable_pipelined_write=0 --nooverwritepercent=1 --compression_max_dict_bytes=0 --max_key=1000000 --prefixpercent=5 --flush_one_in=1000000 --ops_per_thread=40000 --index_block_restart_interval=7 --cache_size=1048576 --compaction_style=2 --verify_checksum=1 --delrangepercent=1 --use_direct_io_for_flush_and_compaction=0
```
This should see no assertion failure.
Last but not least,
```
$COMPILE_WITH_ASAN=1 make -j32 all
$make check
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5754
Differential Revision: D17109791
Pulled By: riversand963
fbshipit-source-id: 25fc46101235add158554e096540b72c324be078
Summary:
Open-source users recently reported two occurrences of LSM-tree corruption (https://github.com/facebook/rocksdb/issues/5558 is one), which would be caught by options.force_consistency_checks = true. options.force_consistency_checks has a usability limitation because it crashes the service once inconsistency is detected. This makes the feature hard to use. Most users serve from multiple RocksDB shards per server and the impacts of crashing the service is higher than it should be.
Instead, we just pass the error back to users without killing the service, and ask them to deal with the problem accordingly.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5744
Differential Revision: D17096940
Pulled By: pdhandharia
fbshipit-source-id: b6780039044e265f26ed2ad03c51f4abbe8b603c
Summary:
Row cache is not supported in LITE mode. So disable the test in that mode.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5756
Test Plan: make LITE=1 all check
Differential Revision: D17115684
Pulled By: anand1976
fbshipit-source-id: e6433c2e528674645cea76cdfc80ddc473708fc2
Summary:
This condition is now a normal occurrence during write burst so there is
no need to warn the user about it. Here is a scenario where it happens
under completely normal conditions.
* Initially we have a DB of three levels (L0, L1, and L2) that is stable, i.e., compaction scores are all less than one.
* Now a write burst comes along. At first L0 blows up a bit in size as compaction hasn't had a chance to catch up.
* As a result of the above, `base_bytes_min` also increases since it is based on L0 size as of https://github.com/facebook/rocksdb/issues/4338
* If `base_bytes_min` increased enough (i.e., to be larger than L1), then we are shown the warning that the DB has more levels than necessary.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5742
Differential Revision: D17059221
fbshipit-source-id: e4a31d6eea42089a8d273095f19653991bd91bea
Summary:
in order to avoid reallocations for a scratch std::string on every call to Next().
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5702
Differential Revision: D16867803
fbshipit-source-id: 1391220a1b172b23336bbc71dc0c79ccf3b1c701
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:
The batched MultiGet() implementation was not correctly handling bloom filter lookups when whole_key_filtering is disabled. It was incorrectly skipping keys not in the prefix_extractor domain, and not calling transform for keys in domain. This PR fixes both problems by moving the domain check and transformation to the FilterBlockReader.
Tests:
Unit test (confirmed failed before the fix)
make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5665
Differential Revision: D16902380
Pulled By: anand1976
fbshipit-source-id: a6be81ad68a6e37134a65246aec7a2c590eccf00
Summary:
The comments of snap_refresh_nanos advertise that the snapshot refresh feature will be disabled when the option is set to 0. This contract is however not honored in the code: https://github.com/facebook/rocksdb/pull/5278
The patch fixes that and also adds an assert to ensure that the feature is not used when the option is zero.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5724
Differential Revision: D16918185
Pulled By: maysamyabandeh
fbshipit-source-id: fec167287df7d85093e087fc39c0eb243e3bbd7e
Summary:
Recently readahead is introduced for checksum verifying. However, users cannot override the setting for the checksum verifying before external SST file ingestion. Introduce a new option for the purpose.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5721
Test Plan: Add a new unit test for it.
Differential Revision: D16906896
fbshipit-source-id: 218ec37001ddcc05411cefddbe233d15ab308476
Summary:
We see this TSAN warning:
WARNING: ThreadSanitizer: data race (pid=282806)
Write of size 8 at 0x7b6c00000e38 by thread T16 (mutexes: write M1023578822185846136):
#0 operator delete(void*) <null> (libtsan.so.0+0x0000000795f8)
https://github.com/facebook/rocksdb/issues/1 rocksdb::DBImpl::BackgroundFlush(bool*, rocksdb::JobContext*, rocksdb::LogBuffer*, rocksdb::FlushReason*, rocksdb::Env::Priority) db/db_impl/db_impl_compaction_flush.cc:2202 (db_flush_test+0x00000060b462)
https://github.com/facebook/rocksdb/issues/2 rocksdb::DBImpl::BackgroundCallFlush(rocksdb::Env::Priority) db/db_impl/db_impl_compaction_flush.cc:2226 (db_flush_test+0x00000060cbd8)
https://github.com/facebook/rocksdb/issues/3 rocksdb::DBImpl::BGWorkFlush(void*) db/db_impl/db_impl_compaction_flush.cc:2073 (db_flush_test+0x00000060d5ac)
......
Previous atomic write of size 4 at 0x7b6c00000e38 by main thread:
#0 __tsan_atomic32_fetch_sub <null> (libtsan.so.0+0x00000006d721)
https://github.com/facebook/rocksdb/issues/1 std::__atomic_base<int>::fetch_sub(int, std::memory_order) /mnt/gvfs/third-party2/libgcc/c67031f0f739ac61575a061518d6ef5038f99f90/7.x/platform007/5620abc/include/c++/7.3.0/bits/atomic_base.h:524 (db_flush_test+0x0000005f9e38)
https://github.com/facebook/rocksdb/issues/2 rocksdb::ColumnFamilyData::Unref() db/column_family.h:286 (db_flush_test+0x0000005f9e38)
https://github.com/facebook/rocksdb/issues/3 rocksdb::DBImpl::FlushMemTable(rocksdb::ColumnFamilyData*, rocksdb::FlushOptions const&, rocksdb::FlushReason, bool) db/db_impl/db_impl_compaction_flush.cc:1624 (db_flush_test+0x0000005f9e38)
https://github.com/facebook/rocksdb/issues/4 rocksdb::DBImpl::TEST_FlushMemTable(rocksdb::ColumnFamilyData*, rocksdb::FlushOptions const&) db/db_impl/db_impl_debug.cc:127 (db_flush_test+0x00000061ace9)
https://github.com/facebook/rocksdb/issues/5 rocksdb::DBFlushTest_CFDropRaceWithWaitForFlushMemTables_Test::TestBody() db/db_flush_test.cc:320 (db_flush_test+0x0000004b44e5)
https://github.com/facebook/rocksdb/issues/6 void testing::internal::HandleSehExceptionsInMethodIfSupported<testing::Test, void>(testing::Test*, void (testing::Test::*)(), char const*) third-party/gtest-1.7.0/fused-src/gtest/gtest-all.cc:3824 (db_flush_test+0x000000be2988)
......
It's still very clear the cause of the warning is because that TSAN treats results from relaxed atomic::fetch_sub() as non-atomic with the operation itself. We can make it more explicit by bumping up the order to CS.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5723
Test Plan: Run all existing test.
Differential Revision: D16908250
fbshipit-source-id: bf17d39ed19058372bdf97f6440a743f88153021
Summary:
Right now VerifyChecksum() doesn't do read-ahead. In some use cases, users won't be able to achieve good performance. With this change, by default, RocksDB will do a default readahead, and users will be able to overwrite the readahead size by passing in a ReadOptions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5713
Test Plan: Add a new unit test.
Differential Revision: D16860874
fbshipit-source-id: 0cff0fe79ac855d3d068e6ccd770770854a68413
Summary:
VersionSet::ApproximateSize doesn't need to create two separate index iterators and do binary search for each in BlockBasedTable. So BlockBasedTable::ApproximateSize was added that creates the iterator once and uses it to calculate the data size between start and end keys.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5693
Differential Revision: D16774056
Pulled By: elipoz
fbshipit-source-id: 53ce262e1a057788243bf30cd9b8aa6581df1a18
Summary:
Add a command in ldb so that users can print out tombstones in SST files.
In order to test the code, change the interface of LDBCommandRunner::RunCommand() so that it doesn't return from the program, but return the status code.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5615
Test Plan: Add a new unit test
Differential Revision: D16550326
fbshipit-source-id: 88ddfe6984bdcbb3a528abdd115089df09eba52e
Summary:
Previously, the end key of a range deletion tombstone was considered exclusive for the purposes of deletion, but considered inclusive when checking if two SSTables overlap. For example, an SSTable with a range deletion tombstone [a, b) would be considered overlapping with an SSTable with a range deletion tombstone [b, c). This commit fixes this check.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5649
Differential Revision: D16808765
Pulled By: anand1976
fbshipit-source-id: 5c7ad1c027e4f778d35070e5dae1b8e6037e0d68
Summary:
PR https://github.com/facebook/rocksdb/pull/5676 added some test coverage for `TEST_ENV_URI`, which unfortunately isn't supported in lite mode, causing some test failures for rocksdb lite. For example,
```
db/db_test_util.cc: In constructor ‘rocksdb::DBTestBase::DBTestBase(std::__cxx11::string)’:
db/db_test_util.cc:57:16: error: ‘ObjectRegistry’ has not been declared
Status s = ObjectRegistry::NewInstance()->NewSharedObject(test_env_uri,
^
```
This PR fixes these errors by excluding the new code from test functions for lite mode.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5686
Differential Revision: D16749000
Pulled By: miasantreble
fbshipit-source-id: e8b3088c31a78b3dffc5fe7814261909d2c3e369
Summary:
Most existing RocksDB unit tests run on `Env::Default()`. It will be useful to port the unit tests to non-default environments, e.g. `HdfsEnv`, etc.
This pull request is one step towards this goal. If RocksDB unit tests are built with a static library exposing a function `RegisterCustomObjects()`, then it is possible to implement custom object registrar logic in the library. RocksDB unit test can call `RegisterCustomObjects()` at the beginning.
By default, `ROCKSDB_UNITTESTS_WITH_CUSTOM_OBJECTS_FROM_STATIC_LIBS` is not defined, thus this PR has no impact on existing RocksDB because `RegisterCustomObjects()` is a noop.
Test plan (on devserver):
```
$make clean && COMPILE_WITH_ASAN=1 make -j32 all
$make check
```
All unit tests must pass.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5676
Differential Revision: D16679157
Pulled By: riversand963
fbshipit-source-id: aca571af3fd0525277cdc674248d0fe06e060f9d
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:
Currently in `DBImpl::PurgeObsoleteFiles`, the list of candidate files is create through a combination of calling LogFileName using `log_delete_files` and `full_scan_candidate_files`.
In full_scan_candidate_files, the filenames look like this
{file_name = "074715.log", file_path = "/txlogs/3306"},
but LogFileName produces filenames like this that prepends a slash:
{file_name = "/074715.log", file_path = "/txlogs/3306"},
This confuses the dedup step here: bb4178066d/db/db_impl/db_impl_files.cc (L339-L345)
Because duplicates still exist, DeleteFile is called on the same file twice, and hits an error on the second try. Error message: Failed to mark /txlogs/3302/764418.log as trash.
The root cause is the use of `kDumbDbName` when generating file names, it creates file names like /074715.log. This PR removes the use of `kDumbDbName` and create paths without leading '/' when dbname can be ignored.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5603
Test Plan: make check
Differential Revision: D16413203
Pulled By: miasantreble
fbshipit-source-id: 6ba8288382c55f7d5e3892d722fc94b57d2e4491
Summary:
MergeOperatorPinningTest.Randomized frequently times out under TSAN
because it tests ~40 option configurations sequentially in a loop. The
patch parallelizes the tests of the various configurations to make the
test complete faster.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5659
Test Plan: Tested using buck test mode/dev-tsan ...
Differential Revision: D16587518
Pulled By: ltamasi
fbshipit-source-id: 65bd25c0ad9a23587fed5592e69c1a0097fa27f6
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 some cases, we don't have to get really accurate number. Something like 10% off is fine, we can create a new option for that use case. In this case, we can calculate size for full files first, and avoid estimation inside SST files if full files got us a huge number. For example, if we already covered 100GB of data, we should be able to skip partial dives into 10 SST files of 30MB.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5609
Differential Revision: D16433481
Pulled By: elipoz
fbshipit-source-id: 5830b31e1c656d0fd3a00d7fd2678ddc8f6e601b
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:
The new DB::GetApproximateSizes with SizeApproximationOptions argument, which allows to add more options/knobs to the DB::GetApproximateSizes call (beyond only the include_flags)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5626
Differential Revision: D16496913
Pulled By: elipoz
fbshipit-source-id: ee8c6c182330a285fa056ecfc3905a592b451720
Summary:
In previous https://github.com/facebook/rocksdb/issues/5079, we added user-specified timestamp to `DB::Get()` and `DB::Put()`. Limitation is that these two functions may cause extra memory allocation and key copy. The reason is that `WriteBatch` does not allocate extra memory for timestamps because it is not aware of timestamp size, and we did not provide an API to assign/update timestamp of each key within a `WriteBatch`.
We address these issues in this PR by doing the following.
1. Add a `timestamp_size_` to `WriteBatch` so that `WriteBatch` can take timestamps into account when calling `WriteBatch::Put`, `WriteBatch::Delete`, etc.
2. Add APIs `WriteBatch::AssignTimestamp` and `WriteBatch::AssignTimestamps` so that application can assign/update timestamps for each key in a `WriteBatch`.
3. Avoid key copy in `GetImpl` by adding new constructor to `LookupKey`.
Test plan (on devserver):
```
$make clean && COMPILE_WITH_ASAN=1 make -j32 all
$./db_basic_test --gtest_filter=Timestamp/DBBasicTestWithTimestampWithParam.PutAndGet/*
$make check
```
If the API extension looks good, I will add more unit tests.
Some simple benchmark using db_bench.
```
$rm -rf /dev/shm/dbbench/* && TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillseq,readrandom -num=1000000
$rm -rf /dev/shm/dbbench/* && TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num=1000000 -disable_wal=true
```
Master is at a78503bd6c.
```
| | readrandom | fillrandom |
| master | 15.53 MB/s | 25.97 MB/s |
| PR5502 | 16.70 MB/s | 25.80 MB/s |
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5502
Differential Revision: D16340894
Pulled By: riversand963
fbshipit-source-id: 51132cf792be07d1efc3ac33f5768c4ee2608bb8
Summary:
RocksDB has historically stored uncompression dictionary objects in the block
cache as opposed to storing just the block contents. This neccesitated
evicting the object upon table close. With the new code, only the raw blocks
are stored in the cache, eliminating the need for eviction.
In addition, the patch makes the following improvements:
1) Compression dictionary blocks are now prefetched/pinned similarly to
index/filter blocks.
2) A copy operation got eliminated when the uncompression dictionary is
retrieved.
3) Errors related to retrieving the uncompression dictionary are propagated as
opposed to silently ignored.
Note: the patch temporarily breaks the compression dictionary evicition stats.
They will be fixed in a separate phase.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5584
Test Plan: make asan_check
Differential Revision: D16344151
Pulled By: ltamasi
fbshipit-source-id: 2962b295f5b19628f9da88a3fcebbce5a5017a7b
Summary:
1. Avoid creating the iterator in order to call BlockBasedTable::ApproximateOffsetOf(). Instead, directly call into it.
2. Optimize BlockBasedTable::ApproximateOffsetOf() keeps the index block iterator in stack.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5613
Differential Revision: D16442660
Pulled By: elipoz
fbshipit-source-id: 9320be3e918c139b10e758cbbb684706d172e516
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:
Right now, users cannot take advantage of row cache, unless no snapshot is used, or Get() is repeated for the same snapshots. This limits the usage of row cache.
This change eliminate this restriction in some cases. If the snapshot used is newer than the largest sequence number in the file, and write callback function is not registered, the same row cache key is used as no snapshot is given. We still need the callback function restriction for now because the callback function may filter out different keys for different snapshots even if the snapshots are new.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5600
Test Plan: Add a unit test.
Differential Revision: D16386616
fbshipit-source-id: 6b7d214bd215d191b03ccf55926ad4b703ec2e53
Summary:
Added log_readahead_size option to control prefetching for Log::Reader.
This is mostly useful for reading a remotely located log, as it can save the number of round-trips when reading it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5592
Differential Revision: D16362989
Pulled By: elipoz
fbshipit-source-id: c5d4d5245a44008cd59879640efff70c091ad3e8
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:
RandomAccessFileReader.for_compaction_ doesn't seem to be used anymore. Remove it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5572
Test Plan: USE_CLANG=1 make all check -j
Differential Revision: D16286178
fbshipit-source-id: aa338049761033dfbe5e8b1707bbb0be2df5be7e
Summary:
Currently, when the block cache is used for the filter block, it is not
really the block itself that is stored in the cache but a FilterBlockReader
object. Since this object is not pure data (it has, for instance, pointers that
might dangle, including in one case a back pointer to the TableReader), it's not
really sharable. To avoid the issues around this, the current code erases the
cache entries when the TableReader is closed (which, BTW, is not sufficient
since a concurrent TableReader might have picked up the object in the meantime).
Instead of doing this, the patch moves the FilterBlockReader out of the cache
altogether, and decouples the filter reader object from the filter block.
In particular, instead of the TableReader owning, or caching/pinning the
FilterBlockReader (based on the customer's settings), with the change the
TableReader unconditionally owns the FilterBlockReader, which in turn
owns/caches/pins the filter block. This change also enables us to reuse the code
paths historically used for data blocks for filters as well.
Note:
Eviction statistics for filter blocks are temporarily broken. We plan to fix this in a
separate phase.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5504
Test Plan: make asan_check
Differential Revision: D16036974
Pulled By: ltamasi
fbshipit-source-id: 770f543c5fb4ed126fd1e04bfd3809cf4ff9c091
Summary:
`wal_batch.writeBatchPtr.release()` gives up the ownership of the original `WriteBatch`, but there is no new owner, which causes memory leak.
The patch is simple. Removing `release()` prevent ownership change. `std::move` is for speed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5515
Differential Revision: D16264281
Pulled By: riversand963
fbshipit-source-id: 51c556b7a1c977325c3aa24acb636303847151fa
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:
https://github.com/facebook/rocksdb/pull/5520 caused a buffer overflow bug in DBWALTest.kTolerateCorruptedTailRecords. Fix it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5550
Test Plan: Run the test in UBSAN. It used to fail. Not it succeeds.
Differential Revision: D16165516
fbshipit-source-id: 42c56a6bc64eb091f054b87757fcbef60da825f7
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
