411 Commits (dcc6fc99f99821ef7c31853675c389cdef6cb9f7)

Author	SHA1	Message	Date
Peter Dillinger	39f5846ec7	Much better stats for seeks and prefix filtering (#11460) ... Summary: We want to know more about opportunities for better range filters, and the effectiveness of our own range filters. Currently the stats are very limited, essentially logging just hits and misses against prefix filters for range scans in BLOOM_FILTER_PREFIX_* without tracking the false positive rate. Perhaps confusingly, when prefix filters are used for point queries, the stats are currently going into the non-PREFIX tickers. This change does several things: * Introduce new stat tickers for seeks and related filtering, \*LEVEL_SEEK\* * Most importantly, allows us to see opportunities for range filtering. Specifically, we can count how many times a seek in an SST file accesses at least one data block, and how many times at least one value() is then accessed. If a data block was accessed but no value(), we can generally assume that the key(s) seen was(were) not of interest so could have been filtered with the right kind of filter, avoiding the data block access. * We can get the same level of detail when a filter (for now, prefix Bloom/ribbon) is used, or not. Specifically, we can infer a false positive rate for prefix filters (not available before) from the seek "false positive" rate: when a data block is accessed but no value() is called. (There can be other explanations for a seek false positive, but in typical iterator usage it would indicate a filter false positive.) * For efficiency, I wanted to avoid making additional calls to the prefix extractor (or key comparisons, etc.), which would be required if we wanted to more precisely detect filter false positives. I believe that instrumenting value() is the best balance of efficiency vs. accurately measuring what we are often interested in. * The stats are divided between last level and non-last levels, to help understand potential tiered storage use cases. * The old BLOOM_FILTER_PREFIX_* stats have a different meaning: no longer referring to iterators but to point queries using prefix filters. BLOOM_FILTER_PREFIX_TRUE_POSITIVE is added for computing the prefix false positive rate on point queries, which can be due to filter false positives as well as different keys with the same prefix. * Similarly, the non-PREFIX BLOOM_FILTER stats are now for whole key filtering only. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11460 Test Plan: unit tests updated, including updating many to pop the stat value since last read to improve test readability and maintainability. Performance test shows a consistent small improvement with these changes, both with clang and with gcc. CPU profile indicates that RecordTick is using less CPU, and this makes sense at least for a high filter miss rate. Before, we were recording two ticks per filter miss in iterators (CHECKED & USEFUL) and now recording just one (FILTERED). Create DB with ``` TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num=10000000 -disable_wal=1 -write_buffer_size=30000000 -bloom_bits=8 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=8 ``` And run simultaneous before&after with ``` TEST_TMPDIR=/dev/shm ./db_bench -readonly -benchmarks=seekrandom[-X1000] -num=10000000 -bloom_bits=8 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=8 -seek_nexts=1 -duration=20 -seed=43 -threads=8 -cache_size=1000000000 -statistics ``` Before: seekrandom [AVG 275 runs] : 189680 (± 222) ops/sec; 18.4 (± 0.0) MB/sec After: seekrandom [AVG 275 runs] : 197110 (± 208) ops/sec; 19.1 (± 0.0) MB/sec Reviewed By: ajkr Differential Revision: D46029177 Pulled By: pdillinger fbshipit-source-id: cdace79a2ea548d46c5900b068c5b7c3a02e5822	2 years ago
Peter Dillinger	206fdea3d9	Change internal headers with duplicate names (#11408) ... Summary: In IDE navigation I find it annoying that there are two statistics.h files (etc.) and often land on the wrong one. Here I migrate several headers to use the blah.h <- blah_impl.h <- blah.cc idiom. Although clang-format wants "blah.h" to be the top include for "blah.cc", I think overall this is an improvement. No public API changes. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11408 Test Plan: existing tests Reviewed By: ltamasi Differential Revision: D45456696 Pulled By: pdillinger fbshipit-source-id: 809d931253f3272c908cf5facf7e1d32fc507373	2 years ago
Andrew Kryczka	113f3250f1	Add block checksum mismatch ticker stat (#11438) ... Summary: Added a ticker stat, `BLOCK_CHECKSUM_MISMATCH_COUNT`, to count how many block checksum verifications detected a mismatch. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11438 Test Plan: new unit test Reviewed By: pdillinger Differential Revision: D45788179 Pulled By: ajkr fbshipit-source-id: e2b44eba7c23b3e110ebe69eaa78a710dec2590f	2 years ago
Hui Xiao	8f763bdeab	Record and use the tail size to prefetch table tail (#11406) ... Summary: **Context:** We prefetch the tail part of a SST file (i.e, the blocks after data blocks till the end of the file) during each SST file open in hope to prefetch all the stuff at once ahead of time for later read e.g, footer, meta index, filter/index etc. The existing approach to estimate the tail size to prefetch is through `TailPrefetchStats` heuristics introduced in https://github.com/facebook/rocksdb/pull/4156, which has caused small reads in unlucky case (e.g, small read into the tail buffer during table open in thread 1 under the same BlockBasedTableFactory object can make thread 2's tail prefetching use a small size that it shouldn't) and is hard to debug. Therefore we decide to record the exact tail size and use it directly to prefetch tail of the SST instead of relying heuristics. **Summary:** - Obtain and record in manifest the tail size in `BlockBasedTableBuilder::Finish()` - For backward compatibility, we fall back to TailPrefetchStats and last to simple heuristics that the tail size is a linear portion of the file size - see PR conversation for more. - Make`tail_start_offset` part of the table properties and deduct tail size to record in manifest for external files (e.g, file ingestion, import CF) and db repair (with no access to manifest). Pull Request resolved: https://github.com/facebook/rocksdb/pull/11406 Test Plan: 1. New UT 2. db bench Note: db bench on /tmp/ where direct read is supported is too slow to finish and the default pinning setting in db bench is not helpful to profile # sst read of Get. Therefore I hacked the following to obtain the following comparison. ``` diff --git a/table/block_based/block_based_table_reader.cc b/table/block_based/block_based_table_reader.cc index bd5669f0f..791484c1f 100644 --- a/table/block_based/block_based_table_reader.cc +++ b/table/block_based/block_based_table_reader.cc @@ -838,7 +838,7 @@ Status BlockBasedTable::PrefetchTail( &tail_prefetch_size); // Try file system prefetch - if (!file->use_direct_io() && !force_direct_prefetch) { + if (false && !file->use_direct_io() && !force_direct_prefetch) { if (!file->Prefetch(prefetch_off, prefetch_len, ro.rate_limiter_priority) .IsNotSupported()) { prefetch_buffer->reset(new FilePrefetchBuffer( diff --git a/tools/db_bench_tool.cc b/tools/db_bench_tool.cc index ea40f5fa0..39a0ac385 100644 --- a/tools/db_bench_tool.cc +++ b/tools/db_bench_tool.cc @@ -4191,6 +4191,8 @@ class Benchmark { std::shared_ptr<TableFactory>(NewCuckooTableFactory(table_options)); } else { BlockBasedTableOptions block_based_options; + block_based_options.metadata_cache_options.partition_pinning = + PinningTier::kAll; block_based_options.checksum = static_cast<ChecksumType>(FLAGS_checksum_type); if (FLAGS_use_hash_search) { ``` Create DB ``` ./db_bench --bloom_bits=3 --use_existing_db=1 --seed=1682546046158958 --partition_index_and_filters=1 --statistics=1 -db=/dev/shm/testdb/ -benchmarks=readrandom -key_size=3200 -value_size=512 -num=1000000 -write_buffer_size=6550000 -disable_auto_compactions=false -target_file_size_base=6550000 -compression_type=none ``` ReadRandom ``` ./db_bench --bloom_bits=3 --use_existing_db=1 --seed=1682546046158958 --partition_index_and_filters=1 --statistics=1 -db=/dev/shm/testdb/ -benchmarks=readrandom -key_size=3200 -value_size=512 -num=1000000 -write_buffer_size=6550000 -disable_auto_compactions=false -target_file_size_base=6550000 -compression_type=none ``` (a) Existing (Use TailPrefetchStats for tail size + use seperate prefetch buffer in PartitionedFilter/IndexReader::CacheDependencies()) ``` rocksdb.table.open.prefetch.tail.hit COUNT : 3395 rocksdb.sst.read.micros P50 : 5.655570 P95 : 9.931396 P99 : 14.845454 P100 : 585.000000 COUNT : 999905 SUM : 6590614 ``` (b) This PR (Record tail size + use the same tail buffer in PartitionedFilter/IndexReader::CacheDependencies()) ``` rocksdb.table.open.prefetch.tail.hit COUNT : 14257 rocksdb.sst.read.micros P50 : 5.173347 P95 : 9.015017 P99 : 12.912610 P100 : 228.000000 COUNT : 998547 SUM : 5976540 ``` As we can see, we increase the prefetch tail hit count and decrease SST read count with this PR 3. Test backward compatibility by stepping through reading with post-PR code on a db generated pre-PR. Reviewed By: pdillinger Differential Revision: D45413346 Pulled By: hx235 fbshipit-source-id: 7d5e36a60a72477218f79905168d688452a4c064	2 years ago
Changyu Bi	62fc15f009	Block per key-value checksum (#11287) ... Summary: add option `block_protection_bytes_per_key` and implementation for block per key-value checksum. The main changes are 1. checksum construction and verification in block.cc/h 2. pass the option `block_protection_bytes_per_key` around (mainly for methods defined in table_cache.h) 3. unit tests/crash test updates Tests: * Added unit tests * Crash test: `python3 tools/db_crashtest.py blackbox --simple --block_protection_bytes_per_key=1 --write_buffer_size=1048576` Follow up (maybe as a separate PR): make sure corruption status returned from BlockIters are correctly handled. Performance: Turning on block per KV protection has a non-trivial negative impact on read performance and costs additional memory. For memory, each block includes additional 24 bytes for checksum-related states beside checksum itself. For CPU, I set up a DB of size ~1.2GB with 5M keys (32 bytes key and 200 bytes value) which compacts to ~5 SST files (target file size 256 MB) in L6 without compression. I tested readrandom performance with various block cache size (to mimic various cache hit rates): ``` SETUP make OPTIMIZE_LEVEL="-O3" USE_LTO=1 DEBUG_LEVEL=0 -j32 db_bench ./db_bench -benchmarks=fillseq,compact0,waitforcompaction,compact,waitforcompaction -write_buffer_size=33554432 -level_compaction_dynamic_level_bytes=true -max_background_jobs=8 -target_file_size_base=268435456 --num=5000000 --key_size=32 --value_size=200 --compression_type=none BENCHMARK ./db_bench --use_existing_db -benchmarks=readtocache,readrandom[-X10] --num=5000000 --key_size=32 --disable_auto_compactions --reads=1000000 --block_protection_bytes_per_key=[0|1] --cache_size=$CACHESIZE The readrandom ops/sec looks like the following: Block cache size: 2GB 1.2GB * 0.9 1.2GB * 0.8 1.2GB * 0.5 8MB Main 240805 223604 198176 161653 139040 PR prot_bytes=0 238691 226693 200127 161082 141153 PR prot_bytes=1 214983 193199 178532 137013 108211 prot_bytes=1 vs -10% -15% -10.8% -15% -23% prot_bytes=0 ``` The benchmark has a lot of variance, but there was a 5% to 25% regression in this benchmark with different cache hit rates. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11287 Reviewed By: ajkr Differential Revision: D43970708 Pulled By: cbi42 fbshipit-source-id: ef98d898b71779846fa74212b9ec9e08b7183940	2 years ago
Peter Dillinger	d79be3dca2	Changes and enhancements to compression stats, thresholds (#11388) ... Summary: ## Option API updates * Add new CompressionOptions::max_compressed_bytes_per_kb, which corresponds to 1024.0 / min allowable compression ratio. This avoids the hard-coded minimum ratio of 8/7. * Remove unnecessary constructor for CompressionOptions. * Document undocumented CompressionOptions. Use idiom for default values shown clearly in one place (not precariously repeated). ## Stat API updates * Deprecate the BYTES_COMPRESSED, BYTES_DECOMPRESSED histograms. Histograms incur substantial extra space & time costs compared to tickers, and the distribution of uncompressed data block sizes tends to be uninteresting. If we're interested in that distribution, I don't see why it should be limited to blocks stored as compressed. * Deprecate the NUMBER_BLOCK_NOT_COMPRESSED ticker, because the name is very confusing. * New or existing tickers relevant to compression: * BYTES_COMPRESSED_FROM * BYTES_COMPRESSED_TO * BYTES_COMPRESSION_BYPASSED * BYTES_COMPRESSION_REJECTED * COMPACT_WRITE_BYTES + FLUSH_WRITE_BYTES (both existing) * NUMBER_BLOCK_COMPRESSED (existing) * NUMBER_BLOCK_COMPRESSION_BYPASSED * NUMBER_BLOCK_COMPRESSION_REJECTED * BYTES_DECOMPRESSED_FROM * BYTES_DECOMPRESSED_TO We can compute a number of things with these stats: * "Successful" compression ratio: BYTES_COMPRESSED_FROM / BYTES_COMPRESSED_TO * Compression ratio of data on which compression was attempted: (BYTES_COMPRESSED_FROM + BYTES_COMPRESSION_REJECTED) / (BYTES_COMPRESSED_TO + BYTES_COMPRESSION_REJECTED) * Compression ratio of data that could be eligible for compression: (BYTES_COMPRESSED_FROM + X) / (BYTES_COMPRESSED_TO + X) where X = BYTES_COMPRESSION_REJECTED + NUMBER_BLOCK_COMPRESSION_REJECTED * Overall SST compression ratio (compression disabled vs. actual): (Y - BYTES_COMPRESSED_TO + BYTES_COMPRESSED_FROM) / Y where Y = COMPACT_WRITE_BYTES + FLUSH_WRITE_BYTES Keeping _REJECTED separate from _BYPASSED helps us to understand "wasted" CPU time in compression. ## BlockBasedTableBuilder Various small refactorings, optimizations, and name clean-ups. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11388 Test Plan: unit tests added * `options_settable_test.cc`: use non-deprecated idiom for configuring CompressionOptions from string. The old idiom is tested elsewhere and does not need to be updated to support the new field. Reviewed By: ajkr Differential Revision: D45128202 Pulled By: pdillinger fbshipit-source-id: 5a652bf5c022b7ec340cf79018cccf0686962803	2 years ago
Hui Xiao	151242ce46	Group rocksdb.sst.read.micros stat by IOActivity flush and compaction (#11288) ... Summary: **Context:** The existing stat rocksdb.sst.read.micros does not reflect each of compaction and flush cases but aggregate them, which is not so helpful for us to understand IO read behavior of each of them. **Summary** - Update `StopWatch` and `RandomAccessFileReader` to record `rocksdb.sst.read.micros` and `rocksdb.file.{flush/compaction}.read.micros` - Fixed the default histogram in `RandomAccessFileReader` - New field `ReadOptions/IOOptions::io_activity`; Pass `ReadOptions` through paths under db open, flush and compaction to where we can prepare `IOOptions` and pass it to `RandomAccessFileReader` - Use `thread_status_util` for assertion in `DbStressFSWrapper` for continuous testing on we are passing correct `io_activity` under db open, flush and compaction Pull Request resolved: https://github.com/facebook/rocksdb/pull/11288 Test Plan: - **Stress test** - **Db bench 1: rocksdb.sst.read.micros COUNT ≈ sum of rocksdb.file.read.flush.micros's and rocksdb.file.read.compaction.micros's.** (without blob) - May not be exactly the same due to `HistogramStat::Add` only guarantees atomic not accuracy across threads. ``` ./db_bench -db=/dev/shm/testdb/ -statistics=true -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3 (-use_plain_table=1 -prefix_size=10) ``` ``` // BlockBasedTable rocksdb.sst.read.micros P50 : 2.009374 P95 : 4.968548 P99 : 8.110362 P100 : 43.000000 COUNT : 40456 SUM : 114805 rocksdb.file.read.flush.micros P50 : 1.871841 P95 : 3.872407 P99 : 5.540541 P100 : 43.000000 COUNT : 2250 SUM : 6116 rocksdb.file.read.compaction.micros P50 : 2.023109 P95 : 5.029149 P99 : 8.196910 P100 : 26.000000 COUNT : 38206 SUM : 108689 // PlainTable Does not apply ``` - **Db bench 2: performance** **Read** SETUP: db with 900 files ``` ./db_bench -db=/dev/shm/testdb/ -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=true -target_file_size_base=655 -compression_type=none ```run till convergence ``` ./db_bench -seed=1678564177044286 -use_existing_db=true -db=/dev/shm/testdb -benchmarks=readrandom[-X60] -statistics=true -num=1000000 -disable_auto_compactions=true -compression_type=none -bloom_bits=3 ``` Pre-change `readrandom [AVG 60 runs] : 21568 (± 248) ops/sec` Post-change (no regression, -0.3%) `readrandom [AVG 60 runs] : 21486 (± 236) ops/sec` **Compaction/Flush**run till convergence ``` ./db_bench -db=/dev/shm/testdb2/ -seed=1678564177044286 -benchmarks="fillseq[-X60]" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -disable_auto_compactions=false -target_file_size_base=655 -compression_type=none rocksdb.sst.read.micros COUNT : 33820 rocksdb.sst.read.flush.micros COUNT : 1800 rocksdb.sst.read.compaction.micros COUNT : 32020 ``` Pre-change `fillseq [AVG 46 runs] : 1391 (± 214) ops/sec; 0.7 (± 0.1) MB/sec` Post-change (no regression, ~-0.4%) `fillseq [AVG 46 runs] : 1385 (± 216) ops/sec; 0.7 (± 0.1) MB/sec` Reviewed By: ajkr Differential Revision: D44007011 Pulled By: hx235 fbshipit-source-id: a54c89e4846dfc9a135389edf3f3eedfea257132	2 years ago
Andrew Kryczka	0a774a102f	Clarify `SstFileWriter::DeleteRange()` ordering requirements (#11390) ... Summary: As titled Pull Request resolved: https://github.com/facebook/rocksdb/pull/11390 Reviewed By: cbi42 Differential Revision: D45148830 Pulled By: ajkr fbshipit-source-id: 9a8dfd040514bae3d8ed9e97a79cae7683f2749a	2 years ago
Peter Dillinger	f9db0c6e9c	Refactor block cache tracing w/improved MultiGet (#11339) ... Summary: After https://github.com/facebook/rocksdb/issues/11301, I wasn't sure whether I had regressed block cache tracing with MultiGet. Demo PR https://github.com/facebook/rocksdb/issues/11330 shows the flawed state of tracing MultiGet before my change, and based on the unit test, there was essentially no change in tracing behavior with https://github.com/facebook/rocksdb/issues/11301. This change is to leave that code and behavior better than I found it. This change is not intended to change any production behaviors except when block cache tracing is active, though might improve general read path efficiency by disabling some related tracking when such tracing is disabled. More detail on production code: * Refactoring to consolidate the construction of BlockCacheTraceRecord, and other related functionality, in block-based table reader, though it's somewhat awkward to preserve an optimization to avoid copying Slices into temporary strings in BlockCacheLookupContext. * Accurately track cache hits and misses (etc.) for each data block accessed by a MultiGet(). (Previously reported hits as misses.) * Reduced repeated checking of `block_cache_tracer_` state (by creating lookup_context only when active) for efficiency and to reduce the risk of corner case bugs where tracing is enabled or disabled for different parts of a read op. (See a TODO below) * Improved estimate calculation for num_keys_in_block (see code comment) Possible follow-up: * `XXX:` use_cache=true means double cache query? (possible double-query of block cache when allow_mmap_reads=true) * `TODO:` need more than one lookup_context here to track individual filter and index partition hits and misses * `TODO:` optimize more state checks of `block_cache_tracer_` down to `lookup_context != nullptr` * Pre-existing `XXX:` There appear to be 'break' statements above that bypass this writing of the block cache trace record * Expand test coverage (see below) Pull Request resolved: https://github.com/facebook/rocksdb/pull/11339 Test Plan: * Added a basic unit test for block cache tracing MultiGet, for now just covering one data block with two keys. * Added HitMissCountingCache to independently verify that the actual block cache trace and expected block cache trace also agree with the actual number of cache hits / misses (nothing missing or mislabeled). For now only used with MultiGet test. * Better testing of num_keys_in_block, for now just with MultiGet * Misc improvements to table_test to improve clarity, such as making it clear that certain keys are auto-inserted at the start of every test. Performance test: Testing multireadrandom as in https://github.com/facebook/rocksdb/issues/11301, except averaging over distinct runs rather than [-X30] which doesn't seem to sufficiently reset after each run to work as an independent test run. Base with revert of 11301: 3148926 ops/sec Base: 3019146 ops/sec New: 2999529 ops/sec Possibly a tiny MultiGet CPU regression with this change. We are now always allocating an additional vector for the LookupContexts. I'm still contemplating options to try to correct the regression in https://github.com/facebook/rocksdb/issues/11301. Testing readrandom: Base with revert of 11301: 2311988 Base: 2281726 New: 2299722 Possibly a tiny Get CPU improvement with this change. We are now avoiding some unnecessary LookupContext population. Reviewed By: akankshamahajan15 Differential Revision: D44557845 Pulled By: pdillinger fbshipit-source-id: b841691799d2a48fb59cc8880dc7cbb1e107ae3d	2 years ago
Changyu Bi	f631138e1c	Better support for merge operation with data block hash index (#11356) ... Summary: when data block hash index finds a key of op_type `kTypeMerge`, do not redo data block seek. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11356 Test Plan: - added new unit test - crash test: `python3 tools/db_crashtest.py whitebox --simple --use_merge=1 --data_block_index_type=1` - benchmark see slight improvement in read throughput: ``` TEST_TMPDIR=/dev/shm/hashindex ./db_bench -benchmarks=mergerandom -use_existing_db=false -num=10000000 -compression_type=none -level_compaction_dynamic_level_bytes=1 -merge_operator=PutOperator -write_buffer_size=1000000 --use_data_block_hash_index=1 TEST_TMPDIR=/dev/shm/hashindex ./db_bench -benchmarks=readrandom[-X10] -use_existing_db=true -num=10000000 -merge_operator=PutOperator -readonly=1 -disable_auto_compactions=1 -reads=100000 Main: readrandom [AVG 10 runs] : 29526 (± 1118) ops/sec; 2.1 (± 0.1) MB/sec Post-PR: readrandom [AVG 10 runs] : 31095 (± 662) ops/sec; 2.2 (± 0.0) MB/sec ``` Reviewed By: pdillinger Differential Revision: D44759895 Pulled By: cbi42 fbshipit-source-id: 387f0c35938c7e0e96b810ca3babf1967fc68191	2 years ago
Wentian Guo	0578d9f951	Filter table files by timestamp: Get operator (#11332) ... Summary: If RocksDB enables user-defined timestamp, then RocksDB read path can filter table files by the min/max timestamps of each file. If application wants to lookup a key that is the most recent and visible to a certain timestamp ts, then we can compare ts with the min_ts of each file. If ts < min_ts, then we know all keys in the file is not visible at time ts, then we do not have to open the file. This can also save an IO. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11332 Reviewed By: pdillinger Differential Revision: D44763497 Pulled By: guowentian fbshipit-source-id: abde346b9f18480fe03c04e4006e7d62aa9c22a8	2 years ago
Andrew Kryczka	b45738622a	Use user-provided ReadOptions for metadata block reads more often (#11208) ... Summary: This is mostly taken from https://github.com/facebook/rocksdb/issues/10427 with my own comments addressed. This PR plumbs the user’s `ReadOptions` down to `GetOrReadIndexBlock()`, `GetOrReadFilterBlock()`, and `GetFilterPartitionBlock()`. Now those functions no longer have to make up a `ReadOptions` with incomplete information. I also let `PartitionIndexReader::NewIterator()` pass through its caller's `ReadOptions::verify_checksums`, which was inexplicably dropped previously. Fixes https://github.com/facebook/rocksdb/issues/10463 Pull Request resolved: https://github.com/facebook/rocksdb/pull/11208 Test Plan: Functional: - Measured `-verify_checksum=false` applies to metadata blocks read outside of table open - setup command: `TEST_TMPDIR=/tmp/100M-DB/ ./db_bench -benchmarks=filluniquerandom,waitforcompaction -write_buffer_size=1048576 -target_file_size_base=1048576 -max_bytes_for_level_base=4194304 -compression_type=none -num=1638400 -key_size=8 -value_size=56` - run command: `TEST_TMPDIR=/tmp/100M-DB/ ./db_bench -benchmarks=readrandom -use_existing_db=true -write_buffer_size=1048576 -target_file_size_base=1048576 -max_bytes_for_level_base=4194304 -compression_type=none -num=1638400 -key_size=8 -value_size=56 -duration=10 -threads=32 -cache_size=131072 -statistics=true -verify_checksum=false -open_files=20 -cache_index_and_filter_blocks=true` - before: `rocksdb.block.checksum.compute.count COUNT : 384353` - after: `rocksdb.block.checksum.compute.count COUNT : 22` Performance: - Setup command (tmpfs, 128MB logical data size, cache indexes/filters without pinning so index/filter lookups go through table reader): `TEST_TMPDIR=/dev/shm/128M-DB/ ./db_bench -benchmarks=filluniquerandom,waitforcompaction -write_buffer_size=131072 -target_file_size_base=131072 -max_bytes_for_level_base=524288 -compression_type=none -num=4194304 -key_size=8 -value_size=24 -bloom_bits=8 -whole_key_filtering=1` - Measured point lookup performance. Database is fully cached to emphasize any new callstack overheads - Command: `TEST_TMPDIR=/dev/shm/128M-DB/ ./db_bench -benchmarks=readrandom[-W1][-X20] -use_existing_db=true -cache_index_and_filter_blocks=true -disable_auto_compactions=true -num=4194304 -key_size=8 -value_size=24 -bloom_bits=8 -whole_key_filtering=1 -duration=10 -cache_size=1048576000` - Before: `readrandom [AVG 20 runs] : 274848 (± 3717) ops/sec; 8.4 (± 0.1) MB/sec` - After: `readrandom [AVG 20 runs] : 277904 (± 4474) ops/sec; 8.5 (± 0.1) MB/sec` Reviewed By: hx235 Differential Revision: D43145366 Pulled By: ajkr fbshipit-source-id: 75ec062ece86a82cd788783de9de2c72df57f994	2 years ago
Peter Dillinger	3c17930ede	Change default block cache from 8MB to 32MB (#11350) ... Summary: ... which increases default number of shards from 16 to 64. Although the default block cache size is only recommended for applications where RocksDB is not performance-critical, under stress conditions, block cache mutex contention could become a performance bottleneck. This change of default should alleviate that. Note that reducing the size of cache shards (recommended minimum 512MB) could cause thrashing, e.g. on filter blocks, so capacity needs to increase to safely increase number of shards. The 8MB default dates back to 2011 or earlier (f779e7a5), when the most simultaneous threads you could get from a single CPU socket was 20 (e.g. Intel Xeon E7-8870). Now more than 100 is available. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11350 Test Plan: unit tests updated Reviewed By: cbi42 Differential Revision: D44674873 Pulled By: pdillinger fbshipit-source-id: 91ed3070789b42679283c7e6dc97c41a6a97bdf4	2 years ago
Peter Dillinger	204fcff751	HyperClockCache support for SecondaryCache, with refactoring (#11301) ... Summary: Internally refactors SecondaryCache integration out of LRUCache specifically and into a wrapper/adapter class that works with various Cache implementations. Notably, this relies on separating the notion of async lookup handles from other cache handles, so that HyperClockCache doesn't have to deal with the problem of allocating handles from the hash table for lookups that might fail anyway, and might be on the same key without support for coalescing. (LRUCache's hash table can incorporate previously allocated handles thanks to its pointer indirection.) Specifically, I'm worried about the case in which hundreds of threads try to access the same block and probing in the hash table degrades to linear search on the pile of entries with the same key. This change is a big step in the direction of supporting stacked SecondaryCaches, but there are obstacles to completing that. Especially, there is no SecondaryCache hook for evictions to pass from one to the next. It has been proposed that evictions be transmitted simply as the persisted data (as in SaveToCallback), but given the current structure provided by the CacheItemHelpers, that would require an extra copy of the block data, because there's intentionally no way to ask for a contiguous Slice of the data (to allow for flexibility in storage). `AsyncLookupHandle` and the re-worked `WaitAll()` should be essentially prepared for stacked SecondaryCaches, but several "TODO with stacked secondaries" issues remain in various places. It could be argued that the stacking instead be done as a SecondaryCache adapter that wraps two (or more) SecondaryCaches, but at least with the current API that would require an extra heap allocation on SecondaryCache Lookup for a wrapper SecondaryCacheResultHandle that can transfer a Lookup between secondaries. We could also consider trying to unify the Cache and SecondaryCache APIs, though that might be difficult if `AsyncLookupHandle` is kept a fixed struct. ## cache.h (public API) Moves `secondary_cache` option from LRUCacheOptions to ShardedCacheOptions so that it is applicable to HyperClockCache. ## advanced_cache.h (advanced public API) * Add `Cache::CreateStandalone()` so that the SecondaryCache support wrapper can use it. * Add `SetEvictionCallback()` / `eviction_callback_` so that the SecondaryCache support wrapper can use it. Only a single callback is supported for efficiency. If there is ever a need for more than one, hopefully that can be handled with a broadcast callback wrapper. These are essentially the two "extra" pieces of `Cache` for pulling out specific SecondaryCache support from the `Cache` implementation. I think it's a good trade-off as these are reasonable, limited, and reusable "cut points" into the `Cache` implementations. * Remove async capability from standard `Lookup()` (getting rid of awkward restrictions on pending Handles) and add `AsyncLookupHandle` and `StartAsyncLookup()`. As noted in the comments, the full struct of `AsyncLookupHandle` is exposed so that it can be stack allocated, for efficiency, though more data is being copied around than before, which could impact performance. (Lookup info -> AsyncLookupHandle -> Handle vs. Lookup info -> Handle) I could foresee a future in which a Cache internally saves a pointer to the AsyncLookupHandle, which means it's dangerous to allow it to be copyable or even movable. It also means it's not compatible with std::vector (which I don't like requiring as an API parameter anyway), so `WaitAll()` expects any contiguous array of AsyncLookupHandles. I believe this is best for common case efficiency, while behaving well in other cases also. For example, `WaitAll()` has no effect on default-constructed AsyncLookupHandles, which look like a completed cache miss. ## cacheable_entry.h A couple of functions are obsolete because Cache::Handle can no longer be pending. ## cache.cc Provides default implementations for new or revamped Cache functions, especially appropriate for non-blocking caches. ## secondary_cache_adapter.{h,cc} The full details of the Cache wrapper adding SecondaryCache support. Essentially replicates the SecondaryCache handling that was in LRUCache, but obviously refactored. There is a bit of logic duplication, where Lookup() is essentially a manually optimized version of StartAsyncLookup() and Wait(), but it's roughly a dozen lines of code. ## sharded_cache.h, typed_cache.h, charged_cache.{h,cc}, sim_cache.cc Simply updated for Cache API changes. ## lru_cache.{h,cc} Carefully remove SecondaryCache logic, implement `CreateStandalone` and eviction handler functionality. ## clock_cache.{h,cc} Expose existing `CreateStandalone` functionality, add eviction handler functionality. Light refactoring. ## block_based_table_reader* Mostly re-worked the only usage of async Lookup, which is in BlockBasedTable::MultiGet. Used arrays in place of autovector in some places for efficiency. Simplified some logic by not trying to process some cache results before they're all ready. Created new function `BlockBasedTable::GetCachePriority()` to reduce some pre-existing code duplication (and avoid making it worse). Fixed at least one small bug from the prior confusing mixture of async and sync Lookups. In MaybeReadBlockAndLoadToCache(), called by RetrieveBlock(), called by MultiGet() with wait=false, is_cache_hit for the block_cache_tracer entry would not be set to true if the handle was pending after Lookup and before Wait. ## Intended follow-up work * Figure out if there are any missing stats or block_cache_tracer work in refactored BlockBasedTable::MultiGet * Stacked secondary caches (see above discussion) * See if we can make up for the small MultiGet performance regression. * Study more performance with SecondaryCache * Items evicted from over-full LRUCache in Release were not being demoted to SecondaryCache, and still aren't to minimize unit test churn. Ideally they would be demoted, but it's an exceptional case so not a big deal. * Use CreateStandalone for cache reservations (save unnecessary hash table operations). Not a big deal, but worthy cleanup. * Somehow I got the contract for SecondaryCache::Insert wrong in #10945. (Doesn't take ownership!) That API comment needs to be fixed, but didn't want to mingle that in here. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11301 Test Plan: ## Unit tests Generally updated to include HCC in SecondaryCache tests, though HyperClockCache has some different, less strict behaviors that leads to some tests not really being set up to work with it. Some of the tests remain disabled with it, but I think we have good coverage without them. ## Crash/stress test Updated to use the new combination. ## Performance First, let's check for regression on caches without secondary cache configured. Adding support for the eviction callback is likely to have a tiny effect, but it shouldn't be worrisome. LRUCache could benefit slightly from less logic around SecondaryCache handling. We can test with cache_bench default settings, built with DEBUG_LEVEL=0 and PORTABLE=0. ``` (while :; do base/cache_bench --cache_type=hyper_clock_cache | grep Rough; done) | awk '{ sum += $9; count++; print $0; print "Average: " int(sum / count) }' ``` **Before** this and #11299 (which could also have a small effect), running for about an hour, before & after running concurrently for each cache type: HyperClockCache: 3168662 (average parallel ops/sec) LRUCache: 2940127 **After** this and #11299, running for about an hour: HyperClockCache: 3164862 (average parallel ops/sec) (0.12% slower) LRUCache: 2940928 (0.03% faster) This is an acceptable difference IMHO. Next, let's consider essentially the worst case of new CPU overhead affecting overall performance. MultiGet uses the async lookup interface regardless of whether SecondaryCache or folly are used. We can configure a benchmark where all block cache queries are for data blocks, and all are hits. Create DB and test (before and after tests running simultaneously): ``` TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num=30000000 -disable_wal=1 -bloom_bits=16 TEST_TMPDIR=/dev/shm base/db_bench -benchmarks=multireadrandom[-X30] -readonly -multiread_batched -batch_size=32 -num=30000000 -bloom_bits=16 -cache_size=6789000000 -duration 20 -threads=16 ``` **Before**: multireadrandom [AVG 30 runs] : 3444202 (± 57049) ops/sec; 240.9 (± 4.0) MB/sec multireadrandom [MEDIAN 30 runs] : 3514443 ops/sec; 245.8 MB/sec **After**: multireadrandom [AVG 30 runs] : 3291022 (± 58851) ops/sec; 230.2 (± 4.1) MB/sec multireadrandom [MEDIAN 30 runs] : 3366179 ops/sec; 235.4 MB/sec So that's roughly a 3% regression, on kind of a *worst case* test of MultiGet CPU. Similar story with HyperClockCache: **Before**: multireadrandom [AVG 30 runs] : 3933777 (± 41840) ops/sec; 275.1 (± 2.9) MB/sec multireadrandom [MEDIAN 30 runs] : 3970667 ops/sec; 277.7 MB/sec **After**: multireadrandom [AVG 30 runs] : 3755338 (± 30391) ops/sec; 262.6 (± 2.1) MB/sec multireadrandom [MEDIAN 30 runs] : 3785696 ops/sec; 264.8 MB/sec Roughly a 4-5% regression. Not ideal, but not the whole story, fortunately. Let's also look at Get() in db_bench: ``` TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=readrandom[-X30] -readonly -num=30000000 -bloom_bits=16 -cache_size=6789000000 -duration 20 -threads=16 ``` **Before**: readrandom [AVG 30 runs] : 2198685 (± 13412) ops/sec; 153.8 (± 0.9) MB/sec readrandom [MEDIAN 30 runs] : 2209498 ops/sec; 154.5 MB/sec **After**: readrandom [AVG 30 runs] : 2292814 (± 43508) ops/sec; 160.3 (± 3.0) MB/sec readrandom [MEDIAN 30 runs] : 2365181 ops/sec; 165.4 MB/sec That's showing roughly a 4% improvement, perhaps because of the secondary cache code that is no longer part of LRUCache. But weirdly, HyperClockCache is also showing 2-3% improvement: **Before**: readrandom [AVG 30 runs] : 2272333 (± 9992) ops/sec; 158.9 (± 0.7) MB/sec readrandom [MEDIAN 30 runs] : 2273239 ops/sec; 159.0 MB/sec **After**: readrandom [AVG 30 runs] : 2332407 (± 11252) ops/sec; 163.1 (± 0.8) MB/sec readrandom [MEDIAN 30 runs] : 2335329 ops/sec; 163.3 MB/sec Reviewed By: ltamasi Differential Revision: D44177044 Pulled By: pdillinger fbshipit-source-id: e808e48ff3fe2f792a79841ba617be98e48689f5	2 years ago
Peter Dillinger	ccaa3225b0	Simplify tracking entries already in SecondaryCache (#11299) ... Summary: In preparation for factoring secondary cache support out of individual Cache implementations, we can get rid of the "in secondary cache" flag on entries through a workable hack: when an entry is promoted from secondary, it is inserted in primary using a helper that lacks secondary cache support, thus preventing re-insertion into secondary cache through existing logic. This adds to the complexity of building CacheItemHelpers, because you always have to be able to get to an equivalent helper without secondary cache support, but that complexity is reasonably isolated within RocksDB typed_cache.h and test code. gcc-7 seems to have problems with constexpr constructor referencing `this` so removed constexpr support on CacheItemHelper. Also refactored some related test code to share common code / functionality. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11299 Test Plan: existing tests Reviewed By: anand1976 Differential Revision: D44101453 Pulled By: pdillinger fbshipit-source-id: 7a59d0a3938ee40159c90c3e65d7004f6a272345	2 years ago
Hui Xiao	bab5f9a6f2	Add new stat rocksdb.table.open.prefetch.tail.read.bytes, rocksdb.table.open.prefetch.tail.{miss|hit} (#11265) ... Summary: **Context/Summary:** We are adding new stats to measure behavior of prefetched tail size and look up into this buffer The stat collection is done in FilePrefetchBuffer but only for prefetched tail buffer during table open for now using FilePrefetchBuffer enum. It's cleaner than the alternative of implementing in upper-level call places of FilePrefetchBuffer for table open. It also has the benefit of extensible to other types of FilePrefetchBuffer if needed. See db bench for perf regression concern. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11265 Test Plan: **- Piggyback on existing test** **- rocksdb.table.open.prefetch.tail.miss is harder to UT so I manually set prefetch tail read bytes to be small and run db bench.** ``` ./db_bench -db=/tmp/testdb -statistics=true -benchmarks="fillseq" -key_size=32 -value_size=512 -num=5000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3 -use_direct_reads=true ``` ``` rocksdb.table.open.prefetch.tail.read.bytes P50 : 4096.000000 P95 : 4096.000000 P99 : 4096.000000 P100 : 4096.000000 COUNT : 225 SUM : 921600 rocksdb.table.open.prefetch.tail.miss COUNT : 91 rocksdb.table.open.prefetch.tail.hit COUNT : 1034 ``` **- No perf regression observed in db_bench** SETUP command: create same db with ~900 files for pre-change/post-change. ``` ./db_bench -db=/tmp/testdb -benchmarks="fillseq" -key_size=32 -value_size=512 -num=500000 -write_buffer_size=655360 -disable_auto_compactions=true -target_file_size_base=16777216 -compression_type=none ``` TEST command 60 runs or til convergence: as suggested by anand1976 and akankshamahajan15, vary `seek_nexts` and `async_io` in testing. ``` ./db_bench -use_existing_db=true -db=/tmp/testdb -statistics=false -cache_size=0 -cache_index_and_filter_blocks=false -benchmarks=seekrandom[-X60] -num=50000 -seek_nexts={10, 500, 1000} -async_io={0|1} -use_direct_reads=true ``` async io = 0, direct io read = true | seek_nexts = 10, 30 runs | seek_nexts = 500, 12 runs | seek_nexts = 1000, 6 runs -- | -- | -- | -- pre-post change | 4776 (± 28) ops/sec; 24.8 (± 0.1) MB/sec | 288 (± 1) ops/sec; 74.8 (± 0.4) MB/sec | 145 (± 4) ops/sec; 75.6 (± 2.2) MB/sec post-change | 4790 (± 32) ops/sec; 24.9 (± 0.2) MB/sec | 288 (± 3) ops/sec; 74.7 (± 0.8) MB/sec | 143 (± 3) ops/sec; 74.5 (± 1.6) MB/sec async io = 1, direct io read = true | seek_nexts = 10, 54 runs | seek_nexts = 500, 6 runs | seek_nexts = 1000, 4 runs -- | -- | -- | -- pre-post change | 3350 (± 36) ops/sec; 17.4 (± 0.2) MB/sec | 264 (± 0) ops/sec; 68.7 (± 0.2) MB/sec | 138 (± 1) ops/sec; 71.8 (± 1.0) MB/sec post-change | 3358 (± 27) ops/sec; 17.4 (± 0.1) MB/sec | 263 (± 2) ops/sec; 68.3 (± 0.8) MB/sec | 139 (± 1) ops/sec; 72.6 (± 0.6) MB/sec Reviewed By: ajkr Differential Revision: D43781467 Pulled By: hx235 fbshipit-source-id: a706a18472a8edb2b952bac3af40eec803537f2a	2 years ago
mrambacher	b6640c3117	Remove FactoryFunc from LoadXXXObject (#11203) ... Summary: The primary purpose of the FactoryFunc was to support LITE mode where the ObjectRegistry was not available. With the removal of LITE mode, the function was no longer required. Note that the MergeOperator had some private classes defined in header files. To gain access to their constructors (and name methods), the class definitions were moved into header files. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11203 Reviewed By: cbi42 Differential Revision: D43160255 Pulled By: pdillinger fbshipit-source-id: f3a465fd5d1a7049b73ecf31e4b8c3762f6dae6c	2 years ago
Andrew Kryczka	6aef1a05d6	Use CacheDependencies() at start of ApproximateKeyAnchors() (#11230) ... Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/11230 Test Plan: - setup command: `$ ./db_bench -benchmarks=fillrandom,compact -compression_type=none -num=1000000 -write_buffer_size=4194304 -target_file_size_base=4194304 -use_direct_io_for_flush_and_compaction=true -partition_index_and_filters=true -bloom_bits=10 -metadata_block_size=1024` - measure small read count bucketed by size: `$ strace -fye pread64 ./db_bench.ctrl -use_existing_db=true -benchmarks=compact -compaction_readahead_size=4194304 -compression_type=none -num=1000000 -write_buffer_size=4194304 -target_file_size_base=4194304 -use_direct_io_for_flush_and_compaction=true -partition_index_and_filters=true -bloom_bits=10 -metadata_block_size=1024 -subcompactions=4 -cache_size=1048576000 2>&1 >/dev/null | awk '/= [0-9]+$/{print "[", int($NF / 1024), "KB,", int(1 + $NF / 1024), "KB)"}' | sort -n -k 2 | uniq -c | head -3` - before: ``` 1119 [ 0 KB, 1 KB) 1 [ 6 KB, 7 KB) 2 [ 7 KB, 8 KB) ``` - after: ``` 242 [ 0 KB, 1 KB) 1 [ 6 KB, 7 KB) 2 [ 7 KB, 8 KB) ``` Reviewed By: pdillinger Differential Revision: D43388507 Pulled By: ajkr fbshipit-source-id: a02413c9f615b00784700646825a9870ee10f3a7	2 years ago
Levi Tamasi	9794acb597	Add a new MultiGetEntity API (#11222) ... Summary: The new `MultiGetEntity` API can be used to get a consistent view of a batch of keys, with the results presented as wide-column entities. Similarly to `GetEntity` and the iterator's `columns` API, if the entry corresponding to the key is a wide-column entity to start with, it is returned as-is, and if it is a plain key-value, it is wrapped into an entity with a single default column. Implementation-wise, the new API shares the logic of the batched `MultiGet` API (via the `MultiGetCommon` methods). Both single-CF and multi-CF `MultiGetEntity` APIs are provided, and blobs are also supported. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11222 Test Plan: `make check` Reviewed By: akankshamahajan15 Differential Revision: D43256950 Pulled By: ltamasi fbshipit-source-id: 47fb2cb7e2d0470e3580f43fdb2fe9e51f0e7005	2 years ago
Peter Dillinger	3cacd4b4ec	Put Cache and CacheWrapper in new public header (#11192) ... Summary: The definition of the Cache class should not be needed by the vast majority of RocksDB users, so I think it is just distracting to include it in cache.h, which is primarily needed for configuring and creating caches. This change moves the class to a new header advanced_cache.h. It is just cut-and-paste except for modifying the class API comment. In general, operations on shared_ptr<Cache> should continue to work when only a forward declaration of Cache is available, as long as all the Cache instances provided are already shared_ptr. See https://stackoverflow.com/a/17650101/454544 Also, the most common way to customize a Cache is by wrapping an existing implementation, so it makes sense to provide CacheWrapper in the public API. This was a cut-and-paste job except removing the implementation of Name() so that derived classes must provide it. Intended follow-up: consolidate Release() into one function to reduce customization bugs / confusion Pull Request resolved: https://github.com/facebook/rocksdb/pull/11192 Test Plan: `make check` Reviewed By: anand1976 Differential Revision: D43055487 Pulled By: pdillinger fbshipit-source-id: 7b05492df35e0f30b581b4c24c579bc275b6d110	2 years ago
Hui Xiao	6650ca244e	Remove a couple deprecated convenience.h APIs (#11120) ... Summary: **Context/Summary:** As instructed by convenience.h comments, a few deprecated APIs are removed. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11120 Test Plan: - make check & CI - eyeball check on test semantics. Reviewed By: pdillinger Differential Revision: D42937507 Pulled By: hx235 fbshipit-source-id: a9e4709387da01b1d0e9148c2e210f02e9746ee1	2 years ago
sdong	4720ba4391	Remove RocksDB LITE (#11147) ... Summary: We haven't been actively mantaining RocksDB LITE recently and the size must have been gone up significantly. We are removing the support. Most of changes were done through following comments: unifdef -m -UROCKSDB_LITE `git grep -l ROCKSDB_LITE | egrep '[.](cc|h)'` by Peter Dillinger. Others changes were manually applied to build scripts, CircleCI manifests, ROCKSDB_LITE is used in an expression and file db_stress_test_base.cc. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11147 Test Plan: See CI Reviewed By: pdillinger Differential Revision: D42796341 fbshipit-source-id: 4920e15fc2060c2cd2221330a6d0e5e65d4b7fe2	2 years ago
Karim TAAM	a1e92bd956	use verify checksum option in block based table reader Open() (#11099) ... Summary: ## Description In this issue https://github.com/facebook/rocksdb/issues/11002 we found that when we use rocksdb with the `verify checksum` read_option to false the verification is done anyway By analyzing the code along the stacktrace I saw that at the level of https://github.com/facebook/rocksdb/compare/main...matkt:feature/use-verify-checksum-in-block-based-table-reader?expand=1#diff-57ed8c49db2bdd4db7618646a177397674bbf25beacacecb104070071d30129f we are not keeping all the options and we forget the `verify_checksum` the comment in this class suggests that it should be managed https://github.com/facebook/rocksdb/compare/main...matkt:feature/use-verify-checksum-in-block-based-table-reader?expand=1#diff-57ed8c49db2bdd4db7618646a177397674bbf25beacacecb104070071d30129fL581 <img width="1724" alt="204511641-86ab4b9b-45e5-4a2b-a13d-81fa26435d38" src="https://user-images.githubusercontent.com/26581503/213152802-c46bc1c7-a3a2-4a6f-9bb1-bf92ee93af7a.png"> this PR just adds the line to manage the `verify checksum` ## Tests - Running unit tests - Test without setting `verify checksum` and verifying that we are calling the checksum code - Test by setting `verify checksum` to true and verifying that we are calling the checksum code - Test by setting `verify checksum` to false and verifying that we are **not** calling the checksum code Pull Request resolved: https://github.com/facebook/rocksdb/pull/11099 Reviewed By: cbi42 Differential Revision: D42679881 Pulled By: ajkr fbshipit-source-id: c7dd10768282fd0699f7e1bf397ceb7adbea4ab6	2 years ago
Heiko Becker	88edfbfb5e	Fix build with gcc 13 by including <cstdint> (#11118) ... Summary: Like other versions before, gcc 13 moved some includes around and as a result <cstdint> is no longer transitively included [1]. Explicitly include it for uint{32,64}_t. [1] https://gcc.gnu.org/gcc-13/porting_to.html#header-dep-changes Pull Request resolved: https://github.com/facebook/rocksdb/pull/11118 Reviewed By: cbi42 Differential Revision: D42711356 Pulled By: ajkr fbshipit-source-id: 5ea257b85b7017f40fd8fdbce965336da95c55b2	2 years ago
sdong	2800aa069a	Remove compressed block cache (#11117) ... Summary: Compressed block cache is replaced by compressed secondary cache. Remove the feature. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11117 Test Plan: See CI passes Reviewed By: pdillinger Differential Revision: D42700164 fbshipit-source-id: 6cbb24e460da29311150865f60ecb98637f9f67d	2 years ago
Peter Dillinger	9f7801c5f1	Major Cache refactoring, CPU efficiency improvement (#10975) ... Summary: This is several refactorings bundled into one to avoid having to incrementally re-modify uses of Cache several times. Overall, there are breaking changes to Cache class, and it becomes more of low-level interface for implementing caches, especially block cache. New internal APIs make using Cache cleaner than before, and more insulated from block cache evolution. Hopefully, this is the last really big block cache refactoring, because of rather effectively decoupling the implementations from the uses. This change also removes the EXPERIMENTAL designation on the SecondaryCache support in Cache. It seems reasonably mature at this point but still subject to change/evolution (as I warn in the API docs for Cache). The high-level motivation for this refactoring is to minimize code duplication / compounding complexity in adding SecondaryCache support to HyperClockCache (in a later PR). Other benefits listed below. * static_cast lines of code +29 -35 (net removed 6) * reinterpret_cast lines of code +6 -32 (net removed 26) ## cache.h and secondary_cache.h * Always use CacheItemHelper with entries instead of just a Deleter. There are several motivations / justifications: * Simpler for implementations to deal with just one Insert and one Lookup. * Simpler and more efficient implementation because we don't have to track which entries are using helpers and which are using deleters * Gets rid of hack to classify cache entries by their deleter. Instead, the CacheItemHelper includes a CacheEntryRole. This simplifies a lot of code (cache_entry_roles.h almost eliminated). Fixes https://github.com/facebook/rocksdb/issues/9428. * Makes it trivial to adjust SecondaryCache behavior based on kind of block (e.g. don't re-compress filter blocks). * It is arguably less convenient for many direct users of Cache, but direct users of Cache are now rare with introduction of typed_cache.h (below). * I considered and rejected an alternative approach in which we reduce customizability by assuming each secondary cache compatible value starts with a Slice referencing the uncompressed block contents (already true or mostly true), but we apparently intend to stack secondary caches. Saving an entry from a compressed secondary to a lower tier requires custom handling offered by SaveToCallback, etc. * Make CreateCallback part of the helper and introduce CreateContext to work with it (alternative to https://github.com/facebook/rocksdb/issues/10562). This cleans up the interface while still allowing context to be provided for loading/parsing values into primary cache. This model works for async lookup in BlockBasedTable reader (reader owns a CreateContext) under the assumption that it always waits on secondary cache operations to finish. (Otherwise, the CreateContext could be destroyed while async operation depending on it continues.) This likely contributes most to the observed performance improvement because it saves an std::function backed by a heap allocation. * Use char* for serialized data, e.g. in SaveToCallback, where void* was confusingly used. (We use `char*` for serialized byte data all over RocksDB, with many advantages over `void*`. `memcpy` etc. are legacy APIs that should not be mimicked.) * Add a type alias Cache::ObjectPtr = void*, so that we can better indicate the intent of the void* when it is to be the object associated with a Cache entry. Related: started (but did not complete) a refactoring to move away from "value" of a cache entry toward "object" or "obj". (It is confusing to call Cache a key-value store (like DB) when it is really storing arbitrary in-memory objects, not byte strings.) * Remove unnecessary key param from DeleterFn. This is good for efficiency in HyperClockCache, which does not directly store the cache key in memory. (Alternative to https://github.com/facebook/rocksdb/issues/10774) * Add allocator to Cache DeleterFn. This is a kind of future-proofing change in case we get more serious about using the Cache allocator for memory tracked by the Cache. Right now, only the uncompressed block contents are allocated using the allocator, and a pointer to that allocator is saved as part of the cached object so that the deleter can use it. (See CacheAllocationPtr.) If in the future we are able to "flatten out" our Cache objects some more, it would be good not to have to track the allocator as part of each object. * Removes legacy `ApplyToAllCacheEntries` and changes `ApplyToAllEntries` signature for Deleter->CacheItemHelper change. ## typed_cache.h Adds various "typed" interfaces to the Cache as internal APIs, so that most uses of Cache can use simple type safe code without casting and without explicit deleters, etc. Almost all of the non-test, non-glue code uses of Cache have been migrated. (Follow-up work: CompressedSecondaryCache deserves deeper attention to migrate.) This change expands RocksDB's internal usage of metaprogramming and SFINAE (https://en.cppreference.com/w/cpp/language/sfinae). The existing usages of Cache are divided up at a high level into these new interfaces. See updated existing uses of Cache for examples of how these are used. * PlaceholderCacheInterface - Used for making cache reservations, with entries that have a charge but no value. * BasicTypedCacheInterface<TValue> - Used for primary cache storage of objects of type TValue, which can be cleaned up with std::default_delete<TValue>. The role is provided by TValue::kCacheEntryRole or given in an optional template parameter. * FullTypedCacheInterface<TValue, TCreateContext> - Used for secondary cache compatible storage of objects of type TValue. In addition to BasicTypedCacheInterface constraints, we require TValue::ContentSlice() to return persistable data. This simplifies usage for the normal case of simple secondary cache compatibility (can give you a Slice to the data already in memory). In addition to TCreateContext performing the role of Cache::CreateContext, it is also expected to provide a factory function for creating TValue. * For each of these, there's a "Shared" version (e.g. FullTypedSharedCacheInterface) that holds a shared_ptr to the Cache, rather than assuming external ownership by holding only a raw `Cache*`. These interfaces introduce specific handle types for each interface instantiation, so that it's easy to see what kind of object is controlled by a handle. (Ultimately, this might not be worth the extra complexity, but it seems OK so far.) Note: I attempted to make the cache 'charge' automatically inferred from the cache object type, such as by expecting an ApproximateMemoryUsage() function, but this is not so clean because there are cases where we need to compute the charge ahead of time and don't want to re-compute it. ## block_cache.h This header is essentially the replacement for the old block_like_traits.h. It includes various things to support block cache access with typed_cache.h for block-based table. ## block_based_table_reader.cc Before this change, accessing the block cache here was an awkward mix of static polymorphism (template TBlocklike) and switch-case on a dynamic BlockType value. This change mostly unifies on static polymorphism, relying on minor hacks in block_cache.h to distinguish variants of Block. We still check BlockType in some places (especially for stats, which could be improved in follow-up work) but at least the BlockType is a static constant from the template parameter. (No more awkward partial redundancy between static and dynamic info.) This likely contributes to the overall performance improvement, but hasn't been tested in isolation. The other key source of simplification here is a more unified system of creating block cache objects: for directly populating from primary cache and for promotion from secondary cache. Both use BlockCreateContext, for context and for factory functions. ## block_based_table_builder.cc, cache_dump_load_impl.cc Before this change, warming caches was super ugly code. Both of these source files had switch statements to basically transition from the dynamic BlockType world to the static TBlocklike world. None of that mess is needed anymore as there's a new, untyped WarmInCache function that handles all the details just as promotion from SecondaryCache would. (Fixes `TODO akanksha: Dedup below code` in block_based_table_builder.cc.) ## Everything else Mostly just updating Cache users to use new typed APIs when reasonably possible, or changed Cache APIs when not. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10975 Test Plan: tests updated Performance test setup similar to https://github.com/facebook/rocksdb/issues/10626 (by cache size, LRUCache when not "hyper" for HyperClockCache): 34MB 1thread base.hyper -> kops/s: 0.745 io_bytes/op: 2.52504e+06 miss_ratio: 0.140906 max_rss_mb: 76.4844 34MB 1thread new.hyper -> kops/s: 0.751 io_bytes/op: 2.5123e+06 miss_ratio: 0.140161 max_rss_mb: 79.3594 34MB 1thread base -> kops/s: 0.254 io_bytes/op: 1.36073e+07 miss_ratio: 0.918818 max_rss_mb: 45.9297 34MB 1thread new -> kops/s: 0.252 io_bytes/op: 1.36157e+07 miss_ratio: 0.918999 max_rss_mb: 44.1523 34MB 32thread base.hyper -> kops/s: 7.272 io_bytes/op: 2.88323e+06 miss_ratio: 0.162532 max_rss_mb: 516.602 34MB 32thread new.hyper -> kops/s: 7.214 io_bytes/op: 2.99046e+06 miss_ratio: 0.168818 max_rss_mb: 518.293 34MB 32thread base -> kops/s: 3.528 io_bytes/op: 1.35722e+07 miss_ratio: 0.914691 max_rss_mb: 264.926 34MB 32thread new -> kops/s: 3.604 io_bytes/op: 1.35744e+07 miss_ratio: 0.915054 max_rss_mb: 264.488 233MB 1thread base.hyper -> kops/s: 53.909 io_bytes/op: 2552.35 miss_ratio: 0.0440566 max_rss_mb: 241.984 233MB 1thread new.hyper -> kops/s: 62.792 io_bytes/op: 2549.79 miss_ratio: 0.044043 max_rss_mb: 241.922 233MB 1thread base -> kops/s: 1.197 io_bytes/op: 2.75173e+06 miss_ratio: 0.103093 max_rss_mb: 241.559 233MB 1thread new -> kops/s: 1.199 io_bytes/op: 2.73723e+06 miss_ratio: 0.10305 max_rss_mb: 240.93 233MB 32thread base.hyper -> kops/s: 1298.69 io_bytes/op: 2539.12 miss_ratio: 0.0440307 max_rss_mb: 371.418 233MB 32thread new.hyper -> kops/s: 1421.35 io_bytes/op: 2538.75 miss_ratio: 0.0440307 max_rss_mb: 347.273 233MB 32thread base -> kops/s: 9.693 io_bytes/op: 2.77304e+06 miss_ratio: 0.103745 max_rss_mb: 569.691 233MB 32thread new -> kops/s: 9.75 io_bytes/op: 2.77559e+06 miss_ratio: 0.103798 max_rss_mb: 552.82 1597MB 1thread base.hyper -> kops/s: 58.607 io_bytes/op: 1449.14 miss_ratio: 0.0249324 max_rss_mb: 1583.55 1597MB 1thread new.hyper -> kops/s: 69.6 io_bytes/op: 1434.89 miss_ratio: 0.0247167 max_rss_mb: 1584.02 1597MB 1thread base -> kops/s: 60.478 io_bytes/op: 1421.28 miss_ratio: 0.024452 max_rss_mb: 1589.45 1597MB 1thread new -> kops/s: 63.973 io_bytes/op: 1416.07 miss_ratio: 0.0243766 max_rss_mb: 1589.24 1597MB 32thread base.hyper -> kops/s: 1436.2 io_bytes/op: 1357.93 miss_ratio: 0.0235353 max_rss_mb: 1692.92 1597MB 32thread new.hyper -> kops/s: 1605.03 io_bytes/op: 1358.04 miss_ratio: 0.023538 max_rss_mb: 1702.78 1597MB 32thread base -> kops/s: 280.059 io_bytes/op: 1350.34 miss_ratio: 0.023289 max_rss_mb: 1675.36 1597MB 32thread new -> kops/s: 283.125 io_bytes/op: 1351.05 miss_ratio: 0.0232797 max_rss_mb: 1703.83 Almost uniformly improving over base revision, especially for hot paths with HyperClockCache, up to 12% higher throughput seen (1597MB, 32thread, hyper). The improvement for that is likely coming from much simplified code for providing context for secondary cache promotion (CreateCallback/CreateContext), and possibly from less branching in block_based_table_reader. And likely a small improvement from not reconstituting key for DeleterFn. Reviewed By: anand1976 Differential Revision: D42417818 Pulled By: pdillinger fbshipit-source-id: f86bfdd584dce27c028b151ba56818ad14f7a432	2 years ago
anand76	bec4264813	Avoid mixing sync and async prefetch (#11050) ... Summary: Reading uncompression dict block always uses sync reads, while data blocks may use async reads and prefetching. This causes problems in FilePrefetchBuffer. So avoid mixing the two by reading the uncompression dict straight from the file. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11050 Test Plan: Crash test Reviewed By: akankshamahajan15 Differential Revision: D42194682 Pulled By: anand1976 fbshipit-source-id: aaa8b396fdfe966b157e210f5ef8501c45b7b69e	2 years ago
Arvid Lunnemark	00238a386b	replace sprintf with its safe version snprintf (v2) (#11011) ... Summary: same motivations as https://github.com/facebook/rocksdb/pull/5475, applied to the last remaining `sprintf`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11011 Reviewed By: pdillinger Differential Revision: D41673500 Pulled By: ajkr fbshipit-source-id: 88618ea791cafad86a9a491799c45979d46e3544	2 years ago
Peter Dillinger	433d7e4594	Improve error messages for SST footer and size errors (#11009) ... Summary: Previously, you could get a format_version error if SST file size was too small in manifest, or a weird "too short" error if too big in manifest. Now we ensure: * Magic number error is reported first if we attempt to open an SST file and the footer is completely bad. * Footer errors are reported with affected file. * If manifest file size doesn't match actual, then the error includes expected and actual sizes (if an error is reported; in some cases we allow the file to be too big) Pull Request resolved: https://github.com/facebook/rocksdb/pull/11009 Test Plan: unit tests added, some manual Previously, the code for "file too short" in footer processing was only covered by some tests attempting to verify SST checksums on non-SST files (fixed). Reviewed By: siying Differential Revision: D41656272 Pulled By: pdillinger fbshipit-source-id: 3da32702eb5aaedbea0e5e74742ad57edd7ad3df	2 years ago
Peter Dillinger	f321e8fc98	Don't attempt to use SecondaryCache on block_cache_compressed (#10944) ... Summary: Compressed block cache depends on reading the block compression marker beyond the payload block size. Only the payload bytes were being saved and loaded from SecondaryCache -> boom! This removes some unnecessary code attempting to combine these two competing features. Note that BlockContents was previously used for block-based filter in block cache, but that support has been removed. Also marking block_cache_compressed as deprecated in this commit as we expect it to be replaced with SecondaryCache. This problem was discovered during refactoring but didn't want to combine bug fix with that refactoring. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10944 Test Plan: test added that fails on base revision (at least with ASAN) Reviewed By: akankshamahajan15 Differential Revision: D41205578 Pulled By: pdillinger fbshipit-source-id: 1b29d36c7a6552355ac6511fcdc67038ef4af29f	2 years ago
Yanqin Jin	9079895aae	Fix deletion counting in memtable stats (#10886) ... Summary: Currently, a memtable's stats `num_deletes_` is incremented only if the entry is a regular delete (kTypeDeletion). We need to fix it by accounting for kTypeSingleDeletion and kTypeDeletionWithTimestamp. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10886 Test Plan: make check Reviewed By: ltamasi Differential Revision: D40740754 Pulled By: riversand963 fbshipit-source-id: 7bde62cd6df136585bc5bfb1c426c7a8276c08e1	2 years ago
sdong	3e686c7cbe	sst_dump --command=raw to add index offset information (#10873) ... Summary: Add some extra information in outputs of "sst_dump --command=raw" to help debug some issues. Right now, encoded block handle is printed out. It is more useful to directly print out offset and size. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10873 Test Plan: Manually run it against a file and check the output. Reviewed By: anand1976 Differential Revision: D40742289 fbshipit-source-id: 04d7de26e7f27e1595a7cc3ac1c1082e4e835b93	2 years ago
anand76	727bad78b8	Format files under table/ by clang-format (#10852) ... Summary: Run clang-format on files under the `table` directory. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10852 Reviewed By: ajkr Differential Revision: D40650732 Pulled By: anand1976 fbshipit-source-id: 2023a958e37fd6274040c5181130284600c9e0ef	2 years ago
Changyu Bi	7a95938899	Improve FragmentTombstones() speed by lazily initializing `seq_set_` (#10848) ... Summary: FragmentedRangeTombstoneList has a member variable `seq_set_` that contains the sequence numbers of all range tombstones in a set. The set is constructed in `FragmentTombstones()` and is used only in `FragmentedRangeTombstoneList::ContainsRange()` which only happens during compaction. This PR moves the initialization of `seq_set_` to `FragmentedRangeTombstoneList::ContainsRange()`. This should speed up `FragmentTombstones()` when the range tombstone list is used for read/scan requests. Microbench shows the speed improvement to be ~45%. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10848 Test Plan: - Existing tests and stress test: `python3 tools/db_crashtest.py whitebox --simple --verify_iterator_with_expected_state_one_in=5`. - Microbench: update `range_del_aggregator_bench` to benchmark speed of `FragmentTombstones()`: ``` ./range_del_aggregator_bench --num_range_tombstones=1000 --tombstone_start_upper_bound=50000000 --num_runs=10000 --tombstone_width_mean=200 --should_deletes_per_run=100 --use_compaction_range_del_aggregator=true Before this PR: ========================= Fragment Tombstones: 270.286 us AddTombstones: 1.28933 us ShouldDelete (first): 0.525528 us ShouldDelete (rest): 0.0797519 us After this PR: time to fragment tombstones is pushed to AddTombstones() which only happen during compaction. ========================= Fragment Tombstones: 149.879 us AddTombstones: 102.131 us ShouldDelete (first): 0.565871 us ShouldDelete (rest): 0.0729444 us ``` - db_bench: this should improve speed for fragmenting range tombstones for mutable memtable: ``` ./db_bench --benchmarks=readwhilewriting --writes_per_range_tombstone=100 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=500000 --reads=250000 --disable_auto_compactions --max_num_range_tombstones=100000 --finish_after_writes --write_buffer_size=1073741824 --threads=25 Before this PR: readwhilewriting : 18.301 micros/op 1310445 ops/sec 4.769 seconds 6250000 operations; 28.1 MB/s (41001 of 250000 found) After this PR: readwhilewriting : 16.943 micros/op 1439376 ops/sec 4.342 seconds 6250000 operations; 23.8 MB/s (28977 of 250000 found) ``` Reviewed By: ajkr Differential Revision: D40646227 Pulled By: cbi42 fbshipit-source-id: ea471667edb258f67d01cfd828588e80a89e4083	2 years ago
Peter Dillinger	7555243bcf	Refactor ShardedCache for more sharing, static polymorphism (#10801) ... Summary: The motivations for this change include * Free up space in ClockHandle so that we can add data for secondary cache handling while still keeping within single cache line (64 byte) size. * This change frees up space by eliminating the need for the `hash` field by making the fixed-size key itself a hash, using a 128-bit bijective (lossless) hash. * Generally more customizability of ShardedCache (such as hashing) without worrying about virtual call overheads * ShardedCache now uses static polymorphism (template) instead of dynamic polymorphism (virtual overrides) for the CacheShard. No obvious performance benefit is seen from the change (as mostly expected; most calls to virtual functions in CacheShard could already be optimized to static calls), but offers more flexibility without incurring the runtime cost of adhering to a common interface (without type parameters or static callbacks). * You'll also notice less `reinterpret_cast`ing and other boilerplate in the Cache implementations, as this can go in ShardedCache. More detail: * Don't have LRUCacheShard maintain `std::shared_ptr<SecondaryCache>` copies (extra refcount) when LRUCache can be in charge of keeping a `shared_ptr`. * Renamed `capacity_mutex_` to `config_mutex_` to better represent the scope of what it guards. * Some preparation for 64-bit hash and indexing in LRUCache, but didn't include the full change because of slight performance regression. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10801 Test Plan: Unit test updates were non-trivial because of major changes to the ClockCacheShard interface in handling of key vs. hash. Performance: Create with `TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num=30000000 -disable_wal=1 -bloom_bits=16` Test with ``` TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=readrandom[-X1000] -readonly -num=30000000 -bloom_bits=16 -cache_index_and_filter_blocks=1 -cache_size=610000000 -duration 20 -threads=16 ``` Before: `readrandom [AVG 150 runs] : 321147 (± 253) ops/sec` After: `readrandom [AVG 150 runs] : 321530 (± 326) ops/sec` So possibly ~0.1% improvement. And with `-cache_type=hyper_clock_cache`: Before: `readrandom [AVG 30 runs] : 614126 (± 7978) ops/sec` After: `readrandom [AVG 30 runs] : 645349 (± 8087) ops/sec` So roughly 5% improvement! Reviewed By: anand1976 Differential Revision: D40252236 Pulled By: pdillinger fbshipit-source-id: ff8fc70ef569585edc95bcbaaa0386f61355ae5b	2 years ago
Peter Dillinger	e466173d5c	Print stack traces on frozen tests in CI (#10828) ... Summary: Instead of existing calls to ps from gnu_parallel, call a new wrapper that does ps, looks for unit test like processes, and uses pstack or gdb to print thread stack traces. Also, using `ps -wwf` instead of `ps -wf` ensures output is not cut off. For security, CircleCI runs with security restrictions on ptrace (/proc/sys/kernel/yama/ptrace_scope = 1), and this change adds a work-around to `InstallStackTraceHandler()` (only used by testing tools) to allow any process from the same user to debug it. (I've also touched >100 files to ensure all the unit tests call this function.) Pull Request resolved: https://github.com/facebook/rocksdb/pull/10828 Test Plan: local manual + temporary infinite loop in a unit test to observe in CircleCI Reviewed By: hx235 Differential Revision: D40447634 Pulled By: pdillinger fbshipit-source-id: 718a4c4a5b54fa0f9af2d01a446162b45e5e84e1	2 years ago
Changyu Bi	9f2363f4c4	User-defined timestamp support for `DeleteRange()` (#10661) ... Summary: Add user-defined timestamp support for range deletion. The new API is `DeleteRange(opt, cf, begin_key, end_key, ts)`. Most of the change is to update the comparator to compare without timestamp. Other than that, major changes are - internal range tombstone data structures (`FragmentedRangeTombstoneList`, `RangeTombstone`, etc.) to store timestamps. - Garbage collection of range tombstones and range tombstone covered keys during compaction. - Get()/MultiGet() to return the timestamp of a range tombstone when needed. - Get/Iterator with range tombstones bounded by readoptions.timestamp. - timestamp crash test now issues DeleteRange by default. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10661 Test Plan: - Added unit test: `make check` - Stress test: `python3 tools/db_crashtest.py --enable_ts whitebox --readpercent=57 --prefixpercent=4 --writepercent=25 -delpercent=5 --iterpercent=5 --delrangepercent=4` - Ran `db_bench` to measure regression when timestamp is not enabled. The tests are for write (with some range deletion) and iterate with DB fitting in memory: `./db_bench--benchmarks=fillrandom,seekrandom --writes_per_range_tombstone=200 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=500000 --reads=500000 --seek_nexts=10 --disable_auto_compactions -disable_wal=true --max_num_range_tombstones=1000`. Did not see consistent regression in no timestamp case. | micros/op | fillrandom | seekrandom | | --- | --- | --- | |main| 2.58 |10.96| |PR 10661| 2.68 |10.63| Reviewed By: riversand963 Differential Revision: D39441192 Pulled By: cbi42 fbshipit-source-id: f05aca3c41605caf110daf0ff405919f300ddec2	2 years ago
Peter Dillinger	ef443cead4	Refactor to avoid confusing "raw block" (#10408) ... Summary: We have a lot of confusing code because of mixed, sometimes completely opposite uses of of the term "raw block" or "raw contents", sometimes within the same source file. For example, in `BlockBasedTableBuilder`, `raw_block_contents` and `raw_size` generally referred to uncompressed block contents and size, while `WriteRawBlock` referred to writing a block that is already compressed if it is going to be. Meanwhile, in `BlockBasedTable`, `raw_block_contents` either referred to a (maybe compressed) block with trailer, or a maybe compressed block maybe without trailer. (Note: left as follow-up work to use C++ typing to better sort out the various kinds of BlockContents.) This change primarily tries to apply some consistent terminology around the kinds of block representations, avoiding the unclear "raw". (Any meaning of "raw" assumes some bias toward the storage layer or toward the logical data layer.) Preferred terminology: * **Serialized block** - bytes that go into storage. For block-based table (usually the case) this includes the block trailer. WART: block `size` may or may not include the trailer; need to be clear about whether it does or not. * **Maybe compressed block** - like a serialized block, but without the trailer (or no promise of including a trailer). Must be accompanied by a CompressionType. * **Uncompressed block** - "payload" bytes that are either stored with no compression, used as input to compression function, or result of decompression function. * **Parsed block** - an in-memory form of a block in block cache, as it is used by the table reader. Different C++ types are used depending on the block type (see block_like_traits.h). Other refactorings: * Misc corrections/improvements of internal API comments * Remove a few misleading / unhelpful / redundant comments. * Use move semantics in some places to simplify contracts * Use better parameter names to indicate which parameters are used for outputs * Remove some extraneous `extern` * Various clean-ups to `CacheDumperImpl` (mostly unnecessary code) Pull Request resolved: https://github.com/facebook/rocksdb/pull/10408 Test Plan: existing tests Reviewed By: akankshamahajan15 Differential Revision: D38172617 Pulled By: pdillinger fbshipit-source-id: ccb99299f324ac5ca46996d34c5089621a4f260c	2 years ago
Akanksha Mahajan	bd2ad2f9a0	Fix stress test failure for async_io (#10660) ... Summary: Sanitize initial_auto_readahead_size if its greater than max_auto_readahead_size in case of async_io Pull Request resolved: https://github.com/facebook/rocksdb/pull/10660 Test Plan: Ran db_stress with intitial_auto_readahead_size greater than max_auto_readahead_size. Reviewed By: anand1976 Differential Revision: D39408095 Pulled By: akankshamahajan15 fbshipit-source-id: 07f933242f636cfbc7ccf042e0c8b959a8ec5f3a	2 years ago
Peter Dillinger	6de7081cf3	Always verify SST unique IDs on SST file open (#10532) ... Summary: Although we've been tracking SST unique IDs in the DB manifest unconditionally, checking has been opt-in and with an extra pass at DB::Open time. This changes the behavior of `verify_sst_unique_id_in_manifest` to check unique ID against manifest every time an SST file is opened through table cache (normal DB operations), replacing the explicit pass over files at DB::Open time. This change also enables the option by default and removes the "EXPERIMENTAL" designation. One possible criticism is that the option no longer ensures the integrity of a DB at Open time. This is far from an all-or-nothing issue. Verifying the IDs of all SST files hardly ensures all the data in the DB is readable. (VerifyChecksum is supposed to do that.) Also, with max_open_files=-1 (default, extremely common), all SST files are opened at DB::Open time anyway. Implementation details: * `VerifySstUniqueIdInManifest()` functions are the extra/explicit pass that is now removed. * Unit tests that manipulate/corrupt table properties have to opt out of this check, because that corrupts the "actual" unique id. (And even for testing we don't currently have a mechanism to set "no unique id" in the in-memory file metadata for new files.) * A lot of other unit test churn relates to (a) default checking on, and (b) checking on SST open even without DB::Open (e.g. on flush) * Use `FileMetaData` for more `TableCache` operations (in place of `FileDescriptor`) so that we have access to the unique_id whenever we might need to open an SST file. **There is the possibility of performance impact because we can no longer use the more localized `fd` part of an `FdWithKeyRange` but instead follow the `file_metadata` pointer. However, this change (possible regression) is only done for `GetMemoryUsageByTableReaders`.** * Removed a completely unnecessary constructor overload of `TableReaderOptions` Possible follow-up: * Verification only happens when opening through table cache. Are there more places where this should happen? * Improve error message when there is a file size mismatch vs. manifest (FIXME added in the appropriate place). * I'm not sure there's a justification for `FileDescriptor` to be distinct from `FileMetaData`. * I'm skeptical that `FdWithKeyRange` really still makes sense for optimizing some data locality by duplicating some data in memory, but I could be wrong. * An unnecessary overload of NewTableReader was recently added, in the public API nonetheless (though unusable there). It should be cleaned up to put most things under `TableReaderOptions`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10532 Test Plan: updated unit tests Performance test showing no significant difference (just noise I think): `./db_bench -benchmarks=readwhilewriting[-X10] -num=3000000 -disable_wal=1 -bloom_bits=8 -write_buffer_size=1000000 -target_file_size_base=1000000` Before: readwhilewriting [AVG 10 runs] : 68702 (± 6932) ops/sec After: readwhilewriting [AVG 10 runs] : 68239 (± 7198) ops/sec Reviewed By: jay-zhuang Differential Revision: D38765551 Pulled By: pdillinger fbshipit-source-id: a827a708155f12344ab2a5c16e7701c7636da4c2	2 years ago
Akanksha Mahajan	4cd16d65ae	Add new option num_file_reads_for_auto_readahead in BlockBasedTableOptions (#10556) ... Summary: RocksDB does auto-readahead for iterators on noticing more than two reads for a table file if user doesn't provide readahead_size and reads are sequential. A new option num_file_reads_for_auto_readahead is added which can be configured and indicates after how many sequential reads prefetching should be start. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10556 Test Plan: Existing and new unit test Reviewed By: anand1976 Differential Revision: D38947147 Pulled By: akankshamahajan15 fbshipit-source-id: c9eeab495f84a8df7f701c42f04894e46440ad97	2 years ago
Levi Tamasi	81388b36e0	Add support for wide-column point lookups (#10540) ... Summary: The patch adds a new API `GetEntity` that can be used to perform wide-column point lookups. It also extends the `Get` code path and the `MemTable` / `MemTableList` and `Version` / `GetContext` logic accordingly so that wide-column entities can be served from both memtables and SSTs. If the result of a lookup is a wide-column entity (`kTypeWideColumnEntity`), it is passed to the application in deserialized form; if it is a plain old key-value (`kTypeValue`), it is presented as a wide-column entity with a single default (anonymous) column. (In contrast, regular `Get` returns plain old key-values as-is, and returns the value of the default column for wide-column entities, see https://github.com/facebook/rocksdb/issues/10483 .) The result of `GetEntity` is a self-contained `PinnableWideColumns` object. `PinnableWideColumns` contains a `PinnableSlice`, which either stores the underlying data in its own buffer or holds on to a cache handle. It also contains a `WideColumns` instance, which indexes the contents of the `PinnableSlice`, so applications can access the values of columns efficiently. There are several pieces of functionality which are currently not supported for wide-column entities: there is currently no `MultiGetEntity` or wide-column iterator; also, `Merge` and `GetMergeOperands` are not supported, and there is no `GetEntity` implementation for read-only and secondary instances. We plan to implement these in future PRs. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10540 Test Plan: `make check` Reviewed By: akankshamahajan15 Differential Revision: D38847474 Pulled By: ltamasi fbshipit-source-id: 42311a34ccdfe88b3775e847a5e2a5296e002b5b	2 years ago
anand76	2553d1efa1	Revert "Avoid dynamic memory allocation on read path (#10453)" (#10541) ... Summary: This reverts commit 0d885e80d4. The original commit causes a ASAN stack-use-after-return failure due to the `CreateCallback` being allocated on stack and then used in another thread when a secondary cache object is promoted to the primary cache. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10541 Reviewed By: gitbw95 Differential Revision: D38850039 Pulled By: anand1976 fbshipit-source-id: 810c592b7de2523693f5bb267159b23b0ee9132c	2 years ago
Gang Liao	275cd80cdb	Add a blob-specific cache priority (#10461) ... Summary: RocksDB's `Cache` abstraction currently supports two priority levels for items: high (used for frequently accessed/highly valuable SST metablocks like index/filter blocks) and low (used for SST data blocks). Blobs are typically lower-value targets for caching than data blocks, since 1) with BlobDB, data blocks containing blob references conceptually form an index structure which has to be consulted before we can read the blob value, and 2) cached blobs represent only a single key-value, while cached data blocks generally contain multiple KVs. Since we would like to make it possible to use the same backing cache for the block cache and the blob cache, it would make sense to add a new, lower-than-low cache priority level (bottom level) for blobs so data blocks are prioritized over them. This task is a part of https://github.com/facebook/rocksdb/issues/10156 Pull Request resolved: https://github.com/facebook/rocksdb/pull/10461 Reviewed By: siying Differential Revision: D38672823 Pulled By: ltamasi fbshipit-source-id: 90cf7362036563d79891f47be2cc24b827482743	2 years ago
Peter Dillinger	86a1e3e0e7	Derive cache keys from SST unique IDs (#10394) ... Summary: ... so that cache keys can be derived from DB manifest data before reading the file from storage--so that every part of the file can potentially go in a persistent cache. See updated comments in cache_key.cc for technical details. Importantly, the new cache key encoding uses some fancy but efficient math to pack data into the cache key without depending on the sizes of the various pieces. This simplifies some existing code creating cache keys, like cache warming before the file size is known. This should provide us an essentially permanent mapping between SST unique IDs and base cache keys, with the ability to "upgrade" SST unique IDs (and thus cache keys) with new SST format_versions. These cache keys are of similar, perhaps indistinguishable quality to the previous generation. Before this change (see "corrected" days between collision): ``` ./cache_bench -stress_cache_key -sck_keep_bits=43 18 collisions after 2 x 90 days, est 10 days between (1.15292e+19 corrected) ``` After this change (keep 43 bits, up through 50, to validate "trajectory" is ok on "corrected" days between collision): ``` 19 collisions after 3 x 90 days, est 14.2105 days between (1.63836e+19 corrected) 16 collisions after 5 x 90 days, est 28.125 days between (1.6213e+19 corrected) 15 collisions after 7 x 90 days, est 42 days between (1.21057e+19 corrected) 15 collisions after 17 x 90 days, est 102 days between (1.46997e+19 corrected) 15 collisions after 49 x 90 days, est 294 days between (2.11849e+19 corrected) 15 collisions after 62 x 90 days, est 372 days between (1.34027e+19 corrected) 15 collisions after 53 x 90 days, est 318 days between (5.72858e+18 corrected) 15 collisions after 309 x 90 days, est 1854 days between (1.66994e+19 corrected) ``` However, the change does modify (probably weaken) the "guaranteed unique" promise from this > SST files generated in a single process are guaranteed to have unique cache keys, unless/until number session ids * max file number = 2**86 to this (see https://github.com/facebook/rocksdb/issues/10388) > With the DB id limitation, we only have nice guaranteed unique cache keys for files generated in a single process until biggest session_id_counter and offset_in_file reach combined 64 bits I don't think this is a practical concern, though. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10394 Test Plan: unit tests updated, see simulation results above Reviewed By: jay-zhuang Differential Revision: D38667529 Pulled By: pdillinger fbshipit-source-id: 49af3fe7f47e5b61162809a78b76c769fd519fba	2 years ago
sdong	9277569ba3	Add some missing headers (#10519) ... Summary: Some files miss headers. Also some headers are irregular. Fix them to make an internal checkup tool happy. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10519 Reviewed By: jay-zhuang Differential Revision: D38603291 fbshipit-source-id: 13b1bbd6d48f5ee15ba20da67544396de48238f1	2 years ago
sdong	911c0208b9	WritableFileWriter tries to skip operations after failure (#10489) ... Summary: A flag in WritableFileWriter is introduced to remember error has happened. Subsequent operations will fail with an assertion. Those operations, except Close() are not supposed to be called anyway. This change will help catch bug in tests and stress tests and limit damage of a potential bug of continue writing to a file after a failure. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10489 Test Plan: Fix existing unit tests and watch crash tests for a while. Reviewed By: anand1976 Differential Revision: D38473277 fbshipit-source-id: 09aafb971e56cfd7f9ef92ad15b883f54acf1366	2 years ago
Jay Zhuang	0d885e80d4	Avoid dynamic memory allocation on read path (#10453) ... Summary: lambda function dynamicly allocates memory from heap if it needs to capture multiple values, which could be expensive. Switch to explictly use local functor from stack. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10453 Test Plan: CI db_bench shows ~2-3% read improvement: ``` # before the change TEST_TMPDIR=/tmp/dbbench4 ./db_bench_main --benchmarks=filluniquerandom,readrandom -compression_type=none -max_background_jobs=12 -num=10000000 readrandom : 8.528 micros/op 117265 ops/sec 85.277 seconds 10000000 operations; 13.0 MB/s (10000000 of 10000000 found) # after the change TEST_TMPDIR=/tmp/dbbench5 ./db_bench_new --benchmarks=filluniquerandom,readrandom -compression_type=none -max_background_jobs=12 -num=10000000 readrandom : 8.263 micros/op 121015 ops/sec 82.634 seconds 10000000 operations; 13.4 MB/s (10000000 of 10000000 found) ``` details: https://gist.github.com/jay-zhuang/5ac0628db8fc9cbcb499e056d4cb5918 Micro-benchmark shows a similar improvement ~1-2%: before the change: https://gist.github.com/jay-zhuang/9dc0ebf51bbfbf4af82f6193d43cf75b after the change: https://gist.github.com/jay-zhuang/fc061f1813cd8f441109ad0b0fe7c185 Reviewed By: ajkr Differential Revision: D38345056 Pulled By: jay-zhuang fbshipit-source-id: f3597aeeee338a804d37bf2e81386d5a100665e0	2 years ago
anand76	bf4532eb5c	Break TableReader MultiGet into filter and lookup stages (#10432) ... Summary: This PR is the first step in enhancing the coroutines MultiGet to be able to lookup a batch in parallel across levels. By having a separate TableReader function for probing the bloom filters, we can quickly figure out which overlapping keys from a batch are definitely not in the file and can move on to the next level. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10432 Reviewed By: akankshamahajan15 Differential Revision: D38245910 Pulled By: anand1976 fbshipit-source-id: 3d20db2350378c3fe6f086f0c7ba5ff01d7f04de	2 years ago
anand76	54aebb2cc5	Fix cache metrics update when secondary cache is used (#10440) ... Summary: If a secondary cache is configured, its possible that a cache lookup will get a hit in the secondary cache. In that case, the ```LRUCacheShard::Lookup``` doesn't immediately update the ```total_charge``` for the item handle if the ```wait``` parameter is false (i.e caller will call later to check the completeness). However, ```BlockBasedTable::GetEntryFromCache``` assumes the handle is complete and calls ```UpdateCacheHitMetrics```, which checks the usage of the cache item and fails the assert in https://github.com/facebook/rocksdb/blob/main/cache/lru_cache.h#L237 (```assert(total_charge >= meta_charge)```). To fix this, we call ```UpdateCacheHitMetrics``` later in ```MultiGet```, after waiting for all cache lookup completions. Test plan - Run crash test with changes from https://github.com/facebook/rocksdb/issues/10160 Pull Request resolved: https://github.com/facebook/rocksdb/pull/10440 Reviewed By: gitbw95 Differential Revision: D38283968 Pulled By: anand1976 fbshipit-source-id: 31c54ef43517726c6e5fdda81899b364241dd7e1	2 years ago