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454 commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Changyu Bi
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11d4ac87ea |
Add some missing status checks in SstFileWriter (#12281)
Summary: Add some missing status checks and documentation for SstFileWriter. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12281 Test Plan: existing unit tests. Reviewed By: jaykorean, ajkr Differential Revision: D53064036 Pulled By: cbi42 fbshipit-source-id: 686d90e24c18c8a4ee81668663a7780a69a45d4c |
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Peter Dillinger
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cb08a682d4 |
Fix/cleanup SeqnoToTimeMapping (#12253)
Summary: The SeqnoToTimeMapping class (RocksDB internal) used by the preserve_internal_time_seconds / preclude_last_level_data_seconds options was essentially in a prototype state with some significant flaws that would risk biting us some day. This is a big, complicated change because both the implementation and the behavioral requirements of the class needed to be upgraded together. In short, this makes SeqnoToTimeMapping more internally responsible for maintaining good invariants, so that callers don't easily encounter dangerous scenarios. * Some API functions were confusingly named and structured, so I fully refactored the APIs to use clear naming (e.g. `DecodeFrom` and `CopyFromSeqnoRange`), object states, function preconditions, etc. * Previously the object could informally be sorted / compacted or not, and there was limited checking or enforcement on these states. Now there's a well-defined "enforced" state that is consistently checked in debug mode for applicable operations. (I attempted to create a separate "builder" class for unenforced states, but IIRC found that more cumbersome for existing uses than it was worth.) * Previously operations would coalesce data in a way that was better for `GetProximalTimeBeforeSeqno` than for `GetProximalSeqnoBeforeTime` which is odd because the latter is the only one used by DB code currently (what is the seqno cut-off for data definitely older than this given time?). This is now reversed to consistently favor `GetProximalSeqnoBeforeTime`, with that logic concentrated in one place: `SeqnoToTimeMapping::SeqnoTimePair::Merge()`. Unfortunately, a lot of unit test logic was specifically testing the old, suboptimal behavior. * Previously, the natural behavior of SeqnoToTimeMapping was to THROW AWAY data needed to get reasonable answers to the important `GetProximalSeqnoBeforeTime` queries. This is because SeqnoToTimeMapping only had a FIFO policy for staying within the entry capacity (except in aggregate+sort+serialize mode). If the DB wasn't extremely careful to avoid gathering too many time mappings, it could lose track of where the seqno cutoff was for cold data (`GetProximalSeqnoBeforeTime()` returning 0) and preventing all further data migration to the cold tier--until time passes etc. for mappings to catch up with FIFO purging of them. (The problem is not so acute because SST files contain relevant snapshots of the mappings, but the problem would apply to long-lived memtables.) * Now the SeqnoToTimeMapping class has fully-integrated smarts for keeping a sufficiently complete history, within capacity limits, to give good answers to `GetProximalSeqnoBeforeTime` queries. * Fixes old `// FIXME: be smarter about how we erase to avoid data falling off the front prematurely.` * Fix an apparent bug in how entries are selected for storing into SST files. Previously, it only selected entries within the seqno range of the file, but that would easily leave a gap at the beginning of the timeline for data in the file for the purposes of answering GetProximalXXX queries with reasonable accuracy. This could probably lead to the same problem discussed above in naively throwing away entries in FIFO order in the old SeqnoToTimeMapping. The updated testing of GetProximalSeqnoBeforeTime in BasicSeqnoToTimeMapping relies on the fixed behavior. * Fix a potential compaction CPU efficiency/scaling issue in which each compaction output file would iterate over and sort all seqno-to-time mappings from all compaction input files. Now we distill the input file entries to a constant size before processing each compaction output file. Intended follow-up (me or others): * Expand some direct testing of SeqnoToTimeMapping APIs. Here I've focused on updating existing tests to make sense. * There are likely more gaps in availability of needed SeqnoToTimeMapping data when the DB shuts down and is restarted, at least with WAL. * The data tracked in the DB could be kept more accurate and limited if it used the oldest seqno of unflushed data. This might require some more API refactoring. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12253 Test Plan: unit tests updated Reviewed By: jowlyzhang Differential Revision: D52913733 Pulled By: pdillinger fbshipit-source-id: 020737fcbbe6212f6701191a6ab86565054c9593 |
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akankshamahajan
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5cb2d09d47 |
Refactor FilePrefetchBuffer code (#12097)
Summary: Summary - Refactor FilePrefetchBuffer code - Implementation: FilePrefetchBuffer maintains a deque of free buffers (free_bufs_) of size num_buffers_ and buffers (bufs_) which contains the prefetched data. Whenever a buffer is consumed or is outdated (w.r.t. to requested offset), that buffer is cleared and returned to free_bufs_. If a buffer is available in free_bufs_, it's moved to bufs_ and is sent for prefetching. num_buffers_ defines how many buffers are maintained that contains prefetched data. If num_buffers_ == 1, it's a sequential read flow. Read API will be called on that one buffer whenever the data is requested and is not in the buffer. If num_buffers_ > 1, then the data is prefetched asynchronosuly in the buffers whenever the data is consumed from the buffers and that buffer is freed. If num_buffers > 1, then requested data can be overlapping between 2 buffers. To return the continuous buffer overlap_bufs_ is used. The requested data is copied from 2 buffers to the overlap_bufs_ and overlap_bufs_ is returned to the caller. - Merged Sync and Async code flow into one in FilePrefetchBuffer. Test Plan - - Crash test passed - Unit tests - Pending - Benchmarks Pull Request resolved: https://github.com/facebook/rocksdb/pull/12097 Reviewed By: ajkr Differential Revision: D51759552 Pulled By: akankshamahajan15 fbshipit-source-id: 69a352945affac2ed22be96048d55863e0168ad5 |
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Peter Dillinger
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ed46981bea |
Fix and defend against FilePrefetchBuffer combined with mmap reads (#12206)
Summary: FilePrefetchBuffer makes an unchecked assumption about the behavior of RandomAccessFileReader::Read: that it will write to the provided buffer rather than returning the data in an alternate buffer. FilePrefetchBuffer has been quietly incompatible with mmap reads (e.g. allow_mmap_reads / use_mmap_reads) because in that case an alternate buffer is returned (mmapped memory). This incompatibility currently leads to quiet data corruption, as seen in amplified crash test failure in https://github.com/facebook/rocksdb/issues/12200. In this change, * Check whether RandomAccessFileReader::Read has the expected behavior, and fail if not. (Assertion failure in debug build, return Corruption in release build.) This will detect future regressions synchronously and precisely, rather than relying on debugging downstream data corruption. * Why not recover? My understanding is that FilePrefetchBuffer is not intended for use when RandomAccessFileReader::Read uses an alternate buffer, so quietly recovering could lead to undesirable (inefficient) behavior. * Mention incompatibility with mmap-based readers in the internal API comments for FilePrefetchBuffer * Fix two cases where FilePrefetchBuffer could be used with mmap, both stemming from SstFileDumper, though one fix is in BlockBasedTableReader. There is currently no way to ask a RandomAccessFileReader whether it's using mmap, so we currently have to rely on other options as clues. Keeping separate from https://github.com/facebook/rocksdb/issues/12200 in part because this change is more appropriate for backport than that one. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12206 Test Plan: * Manually verified that the new check aids in debugging. * Unit test added, that fails if either fix is missed. * Ran blackbox_crash_test for hours, with and without https://github.com/facebook/rocksdb/issues/12200 Reviewed By: akankshamahajan15 Differential Revision: D52551701 Pulled By: pdillinger fbshipit-source-id: dea87c5782b7c484a6c6e424585c8832dfc580dc |
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Hui Xiao
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06e593376c |
Group SST write in flush, compaction and db open with new stats (#11910)
Summary: ## Context/Summary Similar to https://github.com/facebook/rocksdb/pull/11288, https://github.com/facebook/rocksdb/pull/11444, categorizing SST/blob file write according to different io activities allows more insight into the activity. For that, this PR does the following: - Tag different write IOs by passing down and converting WriteOptions to IOOptions - Add new SST_WRITE_MICROS histogram in WritableFileWriter::Append() and breakdown FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS Some related code refactory to make implementation cleaner: - Blob stats - Replace high-level write measurement with low-level WritableFileWriter::Append() measurement for BLOB_DB_BLOB_FILE_WRITE_MICROS. This is to make FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS include blob file. As a consequence, this introduces some behavioral changes on it, see HISTORY and db bench test plan below for more info. - Fix bugs where BLOB_DB_BLOB_FILE_SYNCED/BLOB_DB_BLOB_FILE_BYTES_WRITTEN include file failed to sync and bytes failed to write. - Refactor WriteOptions constructor for easier construction with io_activity and rate_limiter_priority - Refactor DBImpl::~DBImpl()/BlobDBImpl::Close() to bypass thread op verification - Build table - TableBuilderOptions now includes Read/WriteOpitons so BuildTable() do not need to take these two variables - Replace the io_priority passed into BuildTable() with TableBuilderOptions::WriteOpitons::rate_limiter_priority. Similar for BlobFileBuilder. This parameter is used for dynamically changing file io priority for flush, see https://github.com/facebook/rocksdb/pull/9988?fbclid=IwAR1DtKel6c-bRJAdesGo0jsbztRtciByNlvokbxkV6h_L-AE9MACzqRTT5s for more - Update ThreadStatus::FLUSH_BYTES_WRITTEN to use io_activity to track flush IO in flush job and db open instead of io_priority ## Test ### db bench Flush ``` ./db_bench --statistics=1 --benchmarks=fillseq --num=100000 --write_buffer_size=100 rocksdb.sst.write.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377 rocksdb.file.write.flush.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377 rocksdb.file.write.compaction.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0 rocksdb.file.write.db.open.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0 ``` compaction, db oopen ``` Setup: ./db_bench --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench Run:./db_bench --statistics=1 --benchmarks=compact --db=../db_bench --use_existing_db=1 rocksdb.sst.write.micros P50 : 2.675325 P95 : 9.578788 P99 : 18.780000 P100 : 314.000000 COUNT : 638 SUM : 3279 rocksdb.file.write.flush.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0 rocksdb.file.write.compaction.micros P50 : 2.757353 P95 : 9.610687 P99 : 19.316667 P100 : 314.000000 COUNT : 615 SUM : 3213 rocksdb.file.write.db.open.micros P50 : 2.055556 P95 : 3.925000 P99 : 9.000000 P100 : 9.000000 COUNT : 23 SUM : 66 ``` blob stats - just to make sure they aren't broken by this PR ``` Integrated Blob DB Setup: ./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench Run:./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=compact --db=../db_bench --use_existing_db=1 pre-PR: rocksdb.blobdb.blob.file.write.micros P50 : 7.298246 P95 : 9.771930 P99 : 9.991813 P100 : 16.000000 COUNT : 235 SUM : 1600 rocksdb.blobdb.blob.file.synced COUNT : 1 rocksdb.blobdb.blob.file.bytes.written COUNT : 34842 post-PR: rocksdb.blobdb.blob.file.write.micros P50 : 2.000000 P95 : 2.829360 P99 : 2.993779 P100 : 9.000000 COUNT : 707 SUM : 1614 - COUNT is higher and values are smaller as it includes header and footer write - COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164 rocksdb.blobdb.blob.file.synced COUNT : 1 (stay the same) rocksdb.blobdb.blob.file.bytes.written COUNT : 34842 (stay the same) ``` ``` Stacked Blob DB Run: ./db_bench --use_blob_db=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench pre-PR: rocksdb.blobdb.blob.file.write.micros P50 : 12.808042 P95 : 19.674497 P99 : 28.539683 P100 : 51.000000 COUNT : 10000 SUM : 140876 rocksdb.blobdb.blob.file.synced COUNT : 8 rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445 post-PR: rocksdb.blobdb.blob.file.write.micros P50 : 1.657370 P95 : 2.952175 P99 : 3.877519 P100 : 24.000000 COUNT : 30001 SUM : 67924 - COUNT is higher and values are smaller as it includes header and footer write - COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164 rocksdb.blobdb.blob.file.synced COUNT : 8 (stay the same) rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445 (stay the same) ``` ### Rehearsal CI stress test Trigger 3 full runs of all our CI stress tests ### Performance Flush ``` TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=ManualFlush/key_num:524288/per_key_size:256 --benchmark_repetitions=1000 -- default: 1 thread is used to run benchmark; enable_statistics = true Pre-pr: avg 507515519.3 ns 497686074,499444327,500862543,501389862,502994471,503744435,504142123,504224056,505724198,506610393,506837742,506955122,507695561,507929036,508307733,508312691,508999120,509963561,510142147,510698091,510743096,510769317,510957074,511053311,511371367,511409911,511432960,511642385,511691964,511730908, Post-pr: avg 511971266.5 ns, regressed 0.88% 502744835,506502498,507735420,507929724,508313335,509548582,509994942,510107257,510715603,511046955,511352639,511458478,512117521,512317380,512766303,512972652,513059586,513804934,513808980,514059409,514187369,514389494,514447762,514616464,514622882,514641763,514666265,514716377,514990179,515502408, ``` Compaction ``` TEST_TMPDIR=/dev/shm ./db_basic_bench_{pre|post}_pr --benchmark_filter=ManualCompaction/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:1 --benchmark_repetitions=1000 -- default: 1 thread is used to run benchmark Pre-pr: avg 495346098.30 ns 492118301,493203526,494201411,494336607,495269217,495404950,496402598,497012157,497358370,498153846 Post-pr: avg 504528077.20, regressed 1.85%. "ManualCompaction" include flush so the isolated regression for compaction should be around 1.85-0.88 = 0.97% 502465338,502485945,502541789,502909283,503438601,504143885,506113087,506629423,507160414,507393007 ``` Put with WAL (in case passing WriteOptions slows down this path even without collecting SST write stats) ``` TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=DBPut/comp_style:0/max_data:107374182400/per_key_size:256/enable_statistics:1/wal:1 --benchmark_repetitions=1000 -- default: 1 thread is used to run benchmark Pre-pr: avg 3848.10 ns 3814,3838,3839,3848,3854,3854,3854,3860,3860,3860 Post-pr: avg 3874.20 ns, regressed 0.68% 3863,3867,3871,3874,3875,3877,3877,3877,3880,3881 ``` Pull Request resolved: https://github.com/facebook/rocksdb/pull/11910 Reviewed By: ajkr Differential Revision: D49788060 Pulled By: hx235 fbshipit-source-id: 79e73699cda5be3b66461687e5147c2484fc5eff |
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akankshamahajan
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e7c6259447 |
Make auto_readahead_size default true (#12080)
Summary: Make auto_readahead_size option default true Pull Request resolved: https://github.com/facebook/rocksdb/pull/12080 Test Plan: benchmarks and exisiting tests Reviewed By: anand1976 Differential Revision: D52152132 Pulled By: akankshamahajan15 fbshipit-source-id: f1515563564e77df457dff2e865e4ede8c3ddf44 |
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akankshamahajan
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d926593df5 |
Fix stress tests failure for auto_readahead_size (#12131)
Summary: When auto_readahead_size is enabled, Prev operation calls SeekForPrev in db_iter so that - BlockBasedTableIterator can point index_iter_ to the right block. - disable readahead_cache_lookup. However, there can be cases where SeekForPrev might not go through Version_set and call BlockBasedTableIterator SeekForPrev. In that case, when BlockBasedTableIterator::Prev is called, it returns NotSupported error. This more like a corner case. So to handle that case, removed SeekForPrev calling from db_iter and reseeking index_iter_ in Prev operation. block_iter_'s key already point to right block. So reseeking to index_iter_ solves the issue. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12131 Test Plan: - Tested on db_stress command that was failing - `./db_stress --acquire_snapshot_one_in=10000 --adaptive_readahead=1 --allow_data_in_errors=True --async_io=0 --atomic_flush=0 --auto_readahead_size=1 --avoid_flush_during_recovery=0 --avoid_unnecessary_blocking_io=1 --backup_max_size=104857600 --backup_one_in=100000 --batch_protection_bytes_per_key=0 --best_efforts_recovery=1 --block_protection_bytes_per_key=1 --block_size=16384 --bloom_before_level=2147483646 --bloom_bits=12 --bottommost_compression_type=none --bottommost_file_compaction_delay=0 --bytes_per_sync=262144 --cache_index_and_filter_blocks=0 --cache_size=33554432 --cache_type=lru_cache --charge_compression_dictionary_building_buffer=1 --charge_file_metadata=0 --charge_filter_construction=1 --charge_table_reader=1 --checkpoint_one_in=1000000 --checksum_type=kxxHash64 --clear_column_family_one_in=0 --column_families=1 --compact_files_one_in=1000000 --compact_range_one_in=1000000 --compaction_pri=4 --compaction_readahead_size=1048576 --compaction_ttl=10 --compressed_secondary_cache_size=16777216 --compression_checksum=0 --compression_max_dict_buffer_bytes=0 --compression_max_dict_bytes=0 --compression_parallel_threads=1 --compression_type=zlib --compression_use_zstd_dict_trainer=0 --compression_zstd_max_train_bytes=0 --continuous_verification_interval=0 --data_block_index_type=1 --db=/home/akankshamahajan/rocksdb_auto_tune/dev/shm/rocksdb_test/rocksdb_crashtest_blackbox --db_write_buffer_size=134217728 --delpercent=4 --delrangepercent=1 --destroy_db_initially=0 --detect_filter_construct_corruption=1 --disable_wal=1 --enable_compaction_filter=0 --enable_pipelined_write=0 --enable_thread_tracking=1 --expected_values_dir=/home/akankshamahajan/rocksdb_auto_tune/dev/shm/rocksdb_test/rocksdb_crashtest_expected --fail_if_options_file_error=1 --fifo_allow_compaction=1 --file_checksum_impl=big --flush_one_in=1000000 --format_version=6 --get_current_wal_file_one_in=0 --get_live_files_one_in=1000000 --get_property_one_in=1000000 --get_sorted_wal_files_one_in=0 --index_block_restart_interval=10 --index_type=0 --ingest_external_file_one_in=0 --initial_auto_readahead_size=0 --iterpercent=10 --key_len_percent_dist=1,30,69 --level_compaction_dynamic_level_bytes=1 --lock_wal_one_in=1000000 --long_running_snapshots=1 --manual_wal_flush_one_in=0 --mark_for_compaction_one_file_in=0 --max_auto_readahead_size=524288 --max_background_compactions=20 --max_bytes_for_level_base=10485760 --max_key=25000000 --max_key_len=3 --max_manifest_file_size=1073741824 --max_write_batch_group_size_bytes=16 --max_write_buffer_number=3 --max_write_buffer_size_to_maintain=4194304 --memtable_max_range_deletions=1000 --memtable_prefix_bloom_size_ratio=0 --memtable_protection_bytes_per_key=2 --memtable_whole_key_filtering=0 --memtablerep=skip_list --min_write_buffer_number_to_merge=1 --mmap_read=1 --mock_direct_io=False --nooverwritepercent=1 --num_file_reads_for_auto_readahead=1 --open_files=-1 --open_metadata_write_fault_one_in=0 --open_read_fault_one_in=0 --open_write_fault_one_in=0 --ops_per_thread=100000000 --optimize_filters_for_memory=1 --paranoid_file_checks=1 --partition_filters=0 --partition_pinning=1 --pause_background_one_in=1000000 --periodic_compaction_seconds=10 --prefix_size=-1 --prefixpercent=0 --prepopulate_block_cache=0 --preserve_internal_time_seconds=0 --progress_reports=0 --read_fault_one_in=1000 --readahead_size=524288 --readpercent=50 --recycle_log_file_num=0 --reopen=0 --secondary_cache_fault_one_in=0 --secondary_cache_uri= --set_options_one_in=10000 --skip_verifydb=1 --snapshot_hold_ops=100000 --sst_file_manager_bytes_per_sec=0 --sst_file_manager_bytes_per_truncate=0 --stats_dump_period_sec=0 --subcompactions=2 --sync=0 --sync_fault_injection=0 --target_file_size_base=2097152 --target_file_size_multiplier=2 --test_batches_snapshots=0 --top_level_index_pinning=3 --unpartitioned_pinning=3 --use_direct_io_for_flush_and_compaction=0 --use_direct_reads=0 --use_full_merge_v1=0 --use_get_entity=1 --use_merge=1 --use_multi_get_entity=0 --use_multiget=1 --use_put_entity_one_in=10 --use_write_buffer_manager=0 --user_timestamp_size=0 --value_size_mult=32 --verification_only=0 --verify_checksum=1 --verify_checksum_one_in=1000000 --verify_db_one_in=0 --verify_file_checksums_one_in=1000000 --verify_iterator_with_expected_state_one_in=5 --verify_sst_unique_id_in_manifest=1 --wal_bytes_per_sync=0 --wal_compression=zstd --write_buffer_size=4194304 --write_dbid_to_manifest=0 --write_fault_one_in=0 --writepercent=35` - make crash_test -j32 Reviewed By: anand1976 Differential Revision: D51986326 Pulled By: akankshamahajan15 fbshipit-source-id: 90e11e63d1f1894770b457a44d8b213ae5512df9 |
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Peter Dillinger
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c96d9a0fbb |
Allow TablePropertiesCollectorFactory to return null collector (#12129)
Summary: As part of building another feature, I wanted this: * Custom implementations of `TablePropertiesCollectorFactory` may now return a `nullptr` collector to decline processing a file, reducing callback overheads in such cases. * Polished, clarified some related API comments. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12129 Test Plan: unit test added Reviewed By: ltamasi Differential Revision: D51966667 Pulled By: pdillinger fbshipit-source-id: 2991c08fe6ce3a8c9f14c68f1495f5a17bca2770 |
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akankshamahajan
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c77b50a4fd |
Add AsyncIO support for tuning readahead_size by block cache lookup (#11936)
Summary:
Add support for tuning of readahead_size by block cache lookup for async_io.
**Design/ Implementation** -
**BlockBasedTableIterator.cc** -
`BlockCacheLookupForReadAheadSize` callback API lookups in the block cache and tries to reduce the start
and end offset passed. This function looks into the block cache for the blocks between `start_offset`
and `end_offset` and add all the handles in the queue.
It then iterates from the end in the handles to find first miss block and update the end offset to that block.
It also iterates from the start and find first miss block and update the start offset to that block.
```
_read_curr_block_ argument : True if this call was due to miss in the cache and caller wants to read that block
synchronously.
False if current call is to prefetch additional data in extra buffers
(due to ReadAsync call in FilePrefetchBuffer)
```
In case there is no data to be read in that callback (because of upper_bound or all blocks are in cache),
it updates start and end offset to be equal and that `FilePrefetchBuffer` interprets that as 0 length to be read.
**FilePrefetchBuffer.cc** -
FilePrefetchBuffer calls the callback - `ReadAheadSizeTuning` and pass the start and end offset to that
callback to get updated start and end offset to read based on cache hits/misses.
1. In case of Read calls (when offset passed to FilePrefetchBuffer is on cache miss and that data needs to be read), _read_curr_block_ is passed true.
2. In case of ReadAsync calls, when buffer is all consumed and can go for additional prefetching, the start offset passed is the initial end offset of prev buffer (without any updated offset based on cache hit/miss).
Foreg. if following are the data blocks with cache hit/miss and start offset
and Read API found miss on DB1 and based on readahead_size (50) it passes end offset to be 50.
[DB1 - miss- 0 ] [DB2 - hit -10] [DB3 - miss -20] [DB4 - miss-30] [DB5 - hit-40]
[DB6 - hit-50] [DB7 - miss-60] [DB8 - miss - 70] [DB9 - hit - 80] [DB6 - hit 90]
- For Read call - updated start offset remains 0 but end offset updates to DB4, as DB5 is in cache.
- Read calls saves initial end offset 50 as that was meant to be prefetched.
- Now for next ReadAsync call - the start offset will be 50 (previous buffer initial end offset) and based on readahead_size, end offset will be 100
- On callback, because of cache hits - callback will update the start offset to 60 and end offset to 80 to read only 2 data blocks (DB7 and DB8).
- And for that ReadAsync call - initial end offset will be set to 100 which will again used by next ReadAsync call as start offset.
- `initial_end_offset_` in `BufferInfo` is used to save the initial end offset of that buffer.
- If let's say DB5 and DB6 overlaps in 2 buffers (because of alignment), `prev_buf_end_offset` is passed to make sure already prefetched data is not prefetched again in second buffer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11936
Test Plan:
- Ran crash_test several times.
- New unit tests added.
Reviewed By: anand1976
Differential Revision: D50906217
Pulled By: akankshamahajan15
fbshipit-source-id: 0d75d3c98274e98aa34901b201b8fb05232139cf
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Andrew Kryczka
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be3bc36811 |
internal_repo_rocksdb (-8794174668376270091) (#12114)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/12114 Reviewed By: jowlyzhang Differential Revision: D51745613 Pulled By: ajkr fbshipit-source-id: 27ca4bda275cab057d3a3ec99f0f92cdb9be5177 |
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Yu Zhang
|
84a54e1e28 |
Fix some bugs in index builder and reader for the UDT in memtable only feature (#12062)
Summary: These bugs surfaced while I was trying to add the stress test for the feature: Bug 1) On the index building path: the optimization to use user key instead of internal key as separator needed a bit tweak for when user defined timestamps can be removed. Because even though the user key look different now and eligible to be used as separator, when their user-defined timestamps are removed, they could be equal and that invariant no longer stands. Bug 2) On the index reading path: one path that builds the second level index iterator for `PartitionedIndexReader` are not passing the corresponding `user_defined_timestamps_persisted` flag. As a result, the default `true` value be used leading to no minimum timestamps padded when they should be. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12062 Test Plan: For bug 1): added separate unit test `BlockBasedTableReaderTest::Get` to exercise the `Get` API. It's a different code path from `MultiGet` so worth having its own test. Also in order to cover the bug, the test is modified to generate key values with the same user provided key, different timestamps and different sequence numbers. The test reads back different versions of the same user provided key. `MultiGet` takes one `ReadOptions` with one read timestamp so we cannot test retrieving different versions of the same key easily. For bug 2): simply added options `BlockBasedTableOptions.metadata_cache_options.partition_pinning = PinningTier::kAll` to exercise all the index iterator creating paths. Reviewed By: ltamasi Differential Revision: D51508280 Pulled By: jowlyzhang fbshipit-source-id: 8b174d3d70373c0599266ac1f467f2bd4d7ea6e5 |
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Hui Xiao
|
f337533b6f |
Ensure and clarify how RocksDB calls TablePropertiesCollector's functions (#12053)
Summary: **Context/Summary:** It's intuitive for users to assume `TablePropertiesCollector::Finish()` is called only once by RocksDB internal by the word "finish". However, this is currently not true as RocksDB also calls this function in `BlockBased/PlainTableBuilder::GetTableProperties()` to populate user collected properties on demand. This PR avoids that by moving that populating to where we first call `Finish()` (i.e, `NotifyCollectTableCollectorsOnFinish`) Bonus: clarified in the API that `GetReadableProperties()` will be called after `Finish()` and added UT to ensure that. Pull Request resolved: https://github.com/facebook/rocksdb/pull/12053 Test Plan: - Modified test `DBPropertiesTest.GetUserDefinedTableProperties` to ensure `Finish()` only called once. - Existing test particularly `db_properties_test, table_properties_collector_test` verify the functionality `NotifyCollectTableCollectorsOnFinish` and `GetReadableProperties()` are not broken by this change. Reviewed By: ajkr Differential Revision: D51095434 Pulled By: hx235 fbshipit-source-id: 1c6275258f9b99dedad313ee8427119126817973 |
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anand76
|
e81393e81e |
Add some stats to observe the usefulness of scan prefetching (#11981)
Summary: Add stats for better observability of scan prefetching. Its only implemented for sync scan right now. These stats can help inform future improvements in scan prefetching. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11981 Test Plan: Add a new unit test Reviewed By: akankshamahajan15 Differential Revision: D50516505 Pulled By: anand1976 fbshipit-source-id: cb1cc6cf02df8295930a49c62b11870020df3f97 |
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akankshamahajan
|
9135a61ec6 |
Fix corruption error in stress test for auto_readahead_size enabled (#11961)
Summary: Fix corruption error - "Corruption: first key in index doesn't match first key in block". when auto_readahead_size is enabled. Error is because of bug when index_iter_ moves forward, first_internal_key of that index_iter_ is not copied. So the Slice points to a different key resulting in wrong comparison when doing comparison. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11961 Test Plan: Ran stress test which reproduced this error. Reviewed By: anand1976 Differential Revision: D50310589 Pulled By: akankshamahajan15 fbshipit-source-id: 95d8320b8388f1e3822c32024f84754f3a20a631 |
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Alan Paxton
|
b2fe14817e |
java API - load block based table config (#10826)
Summary: Closes https://github.com/facebook/rocksdb/issues/5297 The BlockBasedTableConfig (or more generally, the TableFormatConfig) of ColumnFamilyOptions, isn't being constructed when column family options are loaded. This happens in `OptionsUtil` which implements the loading. In `OptionsUtil` we add the method `private native static TableFormatConfig readTableFormatConfig(final long nativeHandle_)` which defers to a JNI method which creates a `TableFormatConfig` (specifically a `BlockBasedTableConfig`) for the supplied `ColumnFamilyOptions`, by copying the table format attached to the C++ column family options. A new Java constructor for `BlockBasedTableConfig` is implemented which is called from C++ with the parameters retrieved from the table format, and then returned to the calling `readTableFormatConfig`. At the Java side in `OptionsUtil`, the new `TableFormatConfig` is added as the `tableFormatConfig_` field of the `ColumnFamilyOptions`. To support this, the new class `BlockBasedTableOptionsJni` and associated support methods are added to 'portal.h'. `BloomFilter.java` has a constructor and field added so that the filter in use can be read back and inspected. `FilterPolicyType.java` implements an enum (shadowed in C++) to support transfer of filter policy information back to Java from being read at the C++ side. Tests written to cover the block based table config, and cleaned up and generalised a bit as some of the methods on OptionsUtil weren't tested; and these had their own unique JNI method variants which in turn were never exercised in test. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10826 Reviewed By: ajkr Differential Revision: D50136247 Pulled By: jowlyzhang fbshipit-source-id: 39387448147abc574e99f43979d89b0900e5f81d |
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akankshamahajan
|
97f6f475bc |
Fix various failures in auto_readahead_size (#11884)
Summary: 1. **Error** in TestIterateAgainstExpected API - `Assertion index < pre_read_expected_values.size() && index < post_read_expected_values.size() failed.` **Fix** - `Prev` op is not supported with `auto_readahead_size`. So added support to Reseek in db_iter, if Prev is called. In BlockBasedTableIterator, index_iter_ already moves forward. So there is no way to do Prev from BlockBasedTableIterator. 2. **Error** - `void rocksdb::BlockBasedTableIterator::BlockCacheLookupForReadAheadSize(uint64_t, size_t, size_t&): Assertion index_iter_->value().handle.offset() == offset` **Fix** - Remove prefetch_buffer to be used when uncompressed dict is read. 3. ** Error in TestPrefixScan API - `db_stress: db/db_iter.cc:369: bool rocksdb::DBIter::FindNextUserEntryInternal(bool, const rocksdb::Slice*): Assertion !skipping_saved_key || CompareKeyForSkip(ikey_.user_key, saved_key_.GetUserKey()) > 0 failed. Received signal 6 (Aborted) Invoking GDB for stack trace... db_stress: table/merging_iterator.cc:1036: bool rocksdb::MergingIterator::SkipNextDeleted(): Assertion comparator_->Compare(range_tombstone_iters_[i]->start_key(), pik) <= 0 failed` **Fix** - SeekPrev also calls 1) SeekPrev , 2)Seek and then 3)Prev in some cases in db_iter.cc leading to failure of Prev operation. These backward operations also call Seek. Added direction to disable lookup once direction is backwards in BlockBasedTableIterator.cc Pull Request resolved: https://github.com/facebook/rocksdb/pull/11884 Test Plan: Ran various flavors of crash tests locally for the whole duration Reviewed By: anand1976 Differential Revision: D49834201 Pulled By: akankshamahajan15 fbshipit-source-id: 9a007b4d46a48002c43dc4623a400ecf47d997fe |
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Hui Xiao
|
fce04587b8 |
Only fallback to RocksDB internal prefetching on unsupported FS prefetching (#11897)
Summary: **Context/Summary:** https://github.com/facebook/rocksdb/pull/11631 introduced an undesired fallback behavior to RocksDB internal prefetching even when FS prefetching return non-OK status other than "Unsupported". We only want to fall back when FS prefetching is not supported. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11897 Test Plan: CI Reviewed By: ajkr Differential Revision: D49667055 Pulled By: hx235 fbshipit-source-id: fa36e4e5d6dc9507080217035f9d6ff8e4abda28 |
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Hui Xiao
|
719f5511f6 |
No file system prefetching when Options::compaction_readahead_size is 0 (#11887)
Summary: **Context/Summary:** https://github.com/facebook/rocksdb/pull/11631 introduced `readahead()` system call for compaction read under non direct IO. When `Options::compaction_readahead_size` is 0, the `readahead()` will issued with a small size (i.e, the block size, by default 4KB) Benchmarks shows that such readahead() call regresses the compaction read compared with "no readahead()" case (see Test Plan for more). Therefore we decided to not issue such `readhead() ` when `Options::compaction_readahead_size` is 0. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11887 Test Plan: Settings: `compaction_readahead_size = 0, use_direct_reads=false` Setup: ``` TEST_TMPDIR=../ ./db_bench -benchmarks=filluniquerandom -disable_auto_compactions=true -write_buffer_size=1048576 -compression_type=none -value_size=10240 && tar -cf ../dbbench.tar -C ../dbbench/ . ``` Run: ``` for i in $(seq 3); do rm -rf ../dbbench/ && mkdir -p ../dbbench/ && tar -xf ../dbbench.tar -C ../dbbench/ . && sudo bash -c 'sync && echo 3 > /proc/sys/vm/drop_caches' && TEST_TMPDIR=../ /usr/bin/time ./db_bench_{pre_PR11631|PR11631|PR11631_with_improvementPR11887} -benchmarks=compact -use_existing_db=true -db=../dbbench/ -disable_auto_compactions=true -compression_type=none ; done |& grep elapsed ``` pre-PR11631("no readahead()" case): PR11631: PR11631+this improvement: Reviewed By: ajkr Differential Revision: D49607266 Pulled By: hx235 fbshipit-source-id: 2efa0dc91bac3c11cc2be057c53d894645f683ef |
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akankshamahajan
|
3d67b5e8e5 |
Lookup ahead in block cache ahead to tune Readaheadsize (#11860)
Summary: Implement block cache lookup to determine readahead_size during scans. It's enabled if auto_readahead_size, block_cache and iterate_upper_bound - all three are set. Design - 1. Whenever there is a cache miss and FilePrefetchBuffer is called, a callback is made to determine readahead_size for that prefetching. 2. The callback iterates over index and do block cache lookup for each data block handle until existing readahead_size is reached. Then It removes the cache hit data blocks from end to calculate optimized readahead_size. 3. Since index_iter_ is moved, it stores block handles in a queue, and use that queue to get block handle instead of doing index_iter_->Next(). 4. This is for Sync scans. Async scans support is in progress. NOTE: The issue right now is after Seek and Next, if Prev is called, there is no way to do Prev operation. index_iter_ is already pointing to a different block. So it returns "Not supported" in that case with error message - "auto tuning of readahead size is not supported with Prev op" Pull Request resolved: https://github.com/facebook/rocksdb/pull/11860 Test Plan: - Added new unit test - crash_tests - Running scans locally to check for any regression Reviewed By: anand1976 Differential Revision: D49548118 Pulled By: akankshamahajan15 fbshipit-source-id: f1aee409a71b4ad9e5bf3610f43edf30c6630c78 |
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anand76
|
269478ee46 |
Support compressed and local flash secondary cache stacking (#11812)
Summary: This PR implements support for a three tier cache - primary block cache, compressed secondary cache, and a nvm (local flash) secondary cache. This allows more effective utilization of the nvm cache, and minimizes the number of reads from local flash by caching compressed blocks in the compressed secondary cache. The basic design is as follows - 1. A new secondary cache implementation, ```TieredSecondaryCache```, is introduced. It keeps the compressed and nvm secondary caches and manages the movement of blocks between them and the primary block cache. To setup a three tier cache, we allocate a ```CacheWithSecondaryAdapter```, with a ```TieredSecondaryCache``` instance as the secondary cache. 2. The table reader passes both the uncompressed and compressed block to ```FullTypedCacheInterface::InsertFull```, allowing the block cache to optionally store the compressed block. 3. When there's a miss, the block object is constructed and inserted in the primary cache, and the compressed block is inserted into the nvm cache by calling ```InsertSaved```. This avoids the overhead of recompressing the block, as well as avoiding putting more memory pressure on the compressed secondary cache. 4. When there's a hit in the nvm cache, we attempt to insert the block in the compressed secondary cache and the primary cache, subject to the admission policy of those caches (i.e admit on second access). Blocks/items evicted from any tier are simply discarded. We can easily implement additional admission policies if desired. Todo (In a subsequent PR): 1. Add to db_bench and run benchmarks 2. Add to db_stress Pull Request resolved: https://github.com/facebook/rocksdb/pull/11812 Reviewed By: pdillinger Differential Revision: D49461842 Pulled By: anand1976 fbshipit-source-id: b40ac1330ef7cd8c12efa0a3ca75128e602e3a0b |
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akankshamahajan
|
5b5b011cdd |
Avoid double block cache lookup during Seek with async_io option (#11616)
Summary: With the async_io option, the Seek happens in 2 phases. Phase 1 starts an asynchronous read on a block cache miss, and phase 2 waits for it to complete and finishes the seek. In both phases, BlockBasedTable::NewDataBlockIterator is called, which tries to lookup the block cache for the data block first before looking in the prefetch buffer. It's optimized by doing the block cache lookup only in the first phase and save some CPU. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11616 Test Plan: Added unit test Reviewed By: jaykorean Differential Revision: D47477887 Pulled By: akankshamahajan15 fbshipit-source-id: 0355e0a68fc0ea2eb92340ae42735afcdbcbfd79 |
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Peter Dillinger
|
1c6faf3587 |
Make RibbonFilterPolicy::bloom_before_level mutable (SetOptions()) (#11838)
Summary: An internal user wants to be able to dynamically switch between Bloom and Ribbon filters, without a custom FilterPolicy. Making `filter_policy` mutable would actually make issue https://github.com/facebook/rocksdb/issues/10079 worse, because it would be a race on a pointer field, not just on scalars. As a reasonable compromise until that is fixed, I am enabling dynamic control over Bloom vs. Ribbon choice by making RibbonFilterPolicy::bloom_before_level mutable, and doing that safely by using an atomic. I've also slightly tweaked the interpretation of that field so that setting it to INT_MAX really means "always Bloom." Pull Request resolved: https://github.com/facebook/rocksdb/pull/11838 Test Plan: unit tests added/extended. crash test updated for SetOptions call and tested under TSAN with amplified probability (lower set_options_one_in). Reviewed By: ajkr Differential Revision: D49296284 Pulled By: pdillinger fbshipit-source-id: e4251c077510df9a9c719876f482448c0d15402a |
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|
leipeng
|
68ce5d84f6 |
Add new Iterator API Refresh(const snapshot*) (#10594)
Summary: This PR resolves https://github.com/facebook/rocksdb/issues/10487 & https://github.com/facebook/rocksdb/issues/10536, user code needs to call Refresh() periodically. The main code change is to support range deletions. A range tombstone iterator uses a sequence number as upper bound to decide which range tombstones are effective. During Iterator refresh, this sequence number upper bound needs to be updated for all range tombstone iterators under DBIter and LevelIterator. LevelIterator may create new table iterators and range tombstone iterator during scanning, so it needs to be aware of iterator refresh. The code path that propagates this change is `db_iter_->set_sequence(read_seq) -> MergingIterator::SetRangeDelReadSeqno() -> TruncatedRangeDelIterator::SetRangeDelReadSeqno() and LevelIterator::SetRangeDelReadSeqno()`. This change also fixes an issue where range tombstone iterators created by LevelIterator may access ReadOptions::snapshot, even though we do not explicitly require users to keep a snapshot alive after creating an Iterator. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10594 Test Plan: * New unit tests. * Add Iterator::Refresh(snapshot) to stress test. Note that this change only adds tests for refreshing to the same snapshot since this is the main target use case. TODO in a following PR: * Stress test Iterator::Refresh() to different snapshots or no snapshot. Reviewed By: ajkr Differential Revision: D48456896 Pulled By: cbi42 fbshipit-source-id: 2e642c04e91235cc9542ef4cd37b3c20823bd779 |
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akankshamahajan
|
1e2fd343bb |
Update upper_bound_offset when reseek changes iterate_upper_bound dynamically (#11775)
Summary: Update the logic in FilePrefetchBuffer to update `upper_bound_offset_` during reseek. During Reseek, `iterate_upper_bound` can be changed dynamically. So added an API to update that in FilePrefetchBuffer. Added unit test to confirm the behavior. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11775 Test Plan: - Check stress tests in case there is any failure after this diff. - make crash_test -j32 with auto_readahead_size=1 passed locally Reviewed By: anand1976 Differential Revision: D48815177 Pulled By: akankshamahajan15 fbshipit-source-id: 5f44fbb3af06c86a1c38f139c5fa4543891837f4 |
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akankshamahajan
|
6cbb104663 |
Fix seg fault in auto_readahead_size during IOError (#11761)
Summary: Fix seg fault in auto_readahead_size ``` db_stress: internal_repo_rocksdb/repo/table/block_based/partitioned_index_iterator.h:70: virtual rocksdb::IndexValue rocksdb::PartitionedIndexIterator::value() const: Assertion `Valid()' failed. ``` During seek, after calculating readahead_size, db_stress can inject IOError resulting in failure to index_iter_->Seek and making index_iter_ invalid. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11761 Test Plan: Reproducible locally and passed with this fix Reviewed By: anand1976 Differential Revision: D48696248 Pulled By: akankshamahajan15 fbshipit-source-id: 2be43bf56ad0fc2f95f9093c19c9a1b15a716091 |
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akankshamahajan
|
f65a0379f0 |
Implement trimming of readhead size when upper bound is specified (#11684)
Summary: Implement trimming of readahead_size under a new option ReadOptions.auto_readahead_size. It'll trim the readahead_size during prefetching upto iterate_upper_bound offset only when ReadOptions.iterate_upper_bound is set, therefore reducing the prefetching of data beyond upper_bound. It's enabled for both implicit auto readahead size and when ReadOptions.readahead_size is specified and for sync and async_io. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11684 Test Plan: Added new unit test Reviewed By: anand1976 Differential Revision: D48479723 Pulled By: akankshamahajan15 fbshipit-source-id: 2b1703579caf779105e836b580866ffd7db076fc |
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Changyu Bi
|
c2aad555c3 |
Add CompressionOptions::checksum for enabling ZSTD checksum (#11666)
Summary:
Optionally enable zstd checksum flag (
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Han Zhu
|
a67ef998dc |
Explicitly instantiate MaybeReadBlockAndLoadToCache as well (#11714)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/11714 Fixes T161017540. The staging build starts failing with an undefined symbol error: ``` ld.lld: error: undefined symbol: std::enable_if<rocksdb::ParsedFullFilterBlock::kCacheEntryRole == (rocksdb::CacheEntryRole)13 || true, rocksdb::Status>::type rocksdb::BlockBasedTable::MaybeReadBlockAndLoadToCache<rocksdb::ParsedFullFilterBlock>(rocksdb::FilePrefetchBuffer*, rocksdb::ReadOptions const&, rocksdb::BlockHandle const&, rocksdb::UncompressionDict const&, bool, rocksdb::CachableEntry<rocksdb::ParsedFullFilterBlock>*, rocksdb::GetContext*, rocksdb::BlockCacheLookupContext*, rocksdb::BlockContents*, bool) const ``` This is the `MaybeReadBlockAndLoadToCache` function where `TBlocklike = ParsedFullFilterBlock`. The trigger was an FDO profile update D48261413. `MaybeReadBlockAndLoadToCache` is used in the same translation unit `block_based_table_reader.cc`, and also in another file `partitioned_filter_block.cc`. The later was the file that couldn't find the symbol. It seems after the FDO profile update, `MaybeReadBlockAndLoadToCache` may've got inlined into its caller in `block_based_table_reader.cc`. And with no knowledge of other usages, the symbol got stripped. Explicitly instantiate the template similar to how `RetrieveBlock` was handled. Reviewed By: pdillinger, akankshamahajan15 Differential Revision: D48400574 fbshipit-source-id: d4a80999bfb6ce4afa80678444139fcd8ae84aa4 |
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Jay Huh
|
66643b8106 |
PutEntity Support in SST File Writer (#11688)
Summary: RocksDB provides APIs that enable creating SST files offline and then bulk loading them into the LSM tree quickly using metadata operations. Namely, clients can use the `SstFileWriter` class for the offline data preparation and then the IngestExternalFile family of APIs to perform the bulk loading. However, `SstFileWriter` currently does not support creating files with wide-column data in them. This PR adds `PutEntity` API implementation to `SstFileWriter` to support creating files with wide-column data. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11688 Test Plan: - `BasicWideColumn` test added in external_sst_file_test Reviewed By: ltamasi Differential Revision: D48243779 Pulled By: jaykorean fbshipit-source-id: 1697e5bd67121a648c03946f867416a94be0cadf |
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Hui Xiao
|
9a034801ce |
Group rocksdb.sst.read.micros stat by different user read IOActivity + misc (#11444)
Summary:
**Context/Summary:**
- Similar to https://github.com/facebook/rocksdb/pull/11288 but for user read such as `Get(), MultiGet(), DBIterator::XXX(), Verify(File)Checksum()`.
- For this, I refactored some user-facing `MultiGet` calls in `TransactionBase` and various types of `DB` so that it does not call a user-facing `Get()` but `GetImpl()` for passing the `ReadOptions::io_activity` check (see PR conversation)
- New user read stats breakdown are guarded by `kExceptDetailedTimers` since measurement shows they have 4-5% regression to the upstream/main.
- Misc
- More refactoring: with https://github.com/facebook/rocksdb/pull/11288, we complete passing `ReadOptions/IOOptions` to FS level. So we can now replace the previously [added](https://github.com/facebook/rocksdb/pull/9424) `rate_limiter_priority` parameter in `RandomAccessFileReader`'s `Read/MultiRead/Prefetch()` with `IOOptions::rate_limiter_priority`
- Also, `ReadAsync()` call time is measured in `SST_READ_MICRO` now
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11444
Test Plan:
- CI fake db crash/stress test
- Microbenchmarking
**Build** `make clean && ROCKSDB_NO_FBCODE=1 DEBUG_LEVEL=0 make -jN db_basic_bench`
- google benchmark version:
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Hui Xiao
|
09882a52d6 |
Prepare for deprecation of Options::access_hint_on_compaction_start (#11658)
Summary: **Context/Summary:** After https://github.com/facebook/rocksdb/pull/11631, file hint is not longer needed for compaction read. Therefore we can deprecate `Options::access_hint_on_compaction_start`. As this is a public API change, we should first mark the relevant APIs (including the Java's) deprecated and remove it in next major release 9.0. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11658 Test Plan: No code change Reviewed By: ajkr Differential Revision: D47997856 Pulled By: hx235 fbshipit-source-id: 16e015ae7728c224b1caef73143aa9915668f4ac |
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Peter Dillinger
|
7a1b0207e6 |
format_version=6 and context-aware block checksums (#9058)
Summary:
## Context checksum
All RocksDB checksums currently use 32 bits of checking
power, which should be 1 in 4 billion false negative (FN) probability (failing to
detect corruption). This is true for random corruptions, and in some cases
small corruptions are guaranteed to be detected. But some possible
corruptions, such as in storage metadata rather than storage payload data,
would have a much higher FN rate. For example:
* Data larger than one SST block is replaced by data from elsewhere in
the same or another SST file. Especially with block_align=true, the
probability of exact block size match is probably around 1 in 100, making
the FN probability around that same. Without `block_align=true` the
probability of same block start location is probably around 1 in 10,000,
for FN probability around 1 in a million.
To solve this problem in new format_version=6, we add "context awareness"
to block checksum checks. The stored and expected checksum value is
modified based on the block's position in the file and which file it is in. The
modifications are cleverly chosen so that, for example
* blocks within about 4GB of each other are guaranteed to use different context
* blocks that are offset by exactly some multiple of 4GiB are guaranteed to use
different context
* files generated by the same process are guaranteed to use different context
for the same offsets, until wrap-around after 2^32 - 1 files
Thus, with format_version=6, if a valid SST block and checksum is misplaced,
its checksum FN probability should be essentially ideal, 1 in 4B.
## Footer checksum
This change also adds checksum protection to the SST footer (with
format_version=6), for the first time without relying on whole file checksum.
To prevent a corruption of the format_version in the footer (e.g. 6 -> 5) to
defeat the footer checksum, we change much of the footer data format
including an "extended magic number" in format_version 6 that would be
interpreted as empty index and metaindex block handles in older footer
versions. We also change the encoding of handles to free up space for
other new data in footer.
## More detail: making space in footer
In order to keep footer the same size in format_version=6 (avoid change to IO
patterns), we have to free up some space for new data. We do this two ways:
* Metaindex block handle is encoded down to 4 bytes (from 10) by assuming
it immediately precedes the footer, and by assuming it is < 4GB.
* Index block handle is moved into metaindex. (I don't know why it was
in footer to begin with.)
## Performance
In case of small performance penalty, I've made a "pay as you go" optimization
to compensate: replace `MutableCFOptions` in BlockBasedTableBuilder::Rep
with the only field used in that structure after construction: `prefix_extractor`.
This makes the PR an overall performance improvement (results below).
Nevertheless I'm seeing essentially no difference going from fv=5 to fv=6,
even including that improvement for both. That's based on extreme case table
write performance testing, many files with many blocks. This is relatively
checksum intensive (small blocks) and salt generation intensive (small files).
```
(for I in `seq 1 100`; do TEST_TMPDIR=/dev/shm/dbbench2 ./db_bench -benchmarks=fillseq -memtablerep=vector -disable_wal=1 -allow_concurrent_memtable_write=false -num=3000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -write_buffer_size=100000 -compression_type=none -block_size=1000; done) 2>&1 | grep micros/op | tee out
awk '{ tot += $5; n += 1; } END { print int(1.0 * tot / n) }' < out
```
Each value below is ops/s averaged over 100 runs, run simultaneously with competing
configuration for load fairness
Before -> after (both fv=5): 483530 -> 483673 (negligible)
Re-run 1: 480733 -> 485427 (1.0% faster)
Re-run 2: 483821 -> 484541 (0.1% faster)
Before (fv=5) -> after (fv=6): 482006 -> 485100 (0.6% faster)
Re-run 1: 482212 -> 485075 (0.6% faster)
Re-run 2: 483590 -> 484073 (0.1% faster)
After fv=5 -> after fv=6: 483878 -> 485542 (0.3% faster)
Re-run 1: 485331 -> 483385 (0.4% slower)
Re-run 2: 485283 -> 483435 (0.4% slower)
Re-run 3: 483647 -> 486109 (0.5% faster)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9058
Test Plan:
unit tests included (table_test, db_properties_test, salt in env_test). General DB tests
and crash test updated to test new format_version.
Also temporarily updated the default format version to 6 and saw some test failures. Almost all
were due to an inadvertent additional read in VerifyChecksum to verify the index block checksum,
though it's arguably a bug that VerifyChecksum does not appear to (re-)verify the index block
checksum, just assuming it was verified in opening the index reader (probably *usually* true but
probably not always true). Some other concerns about VerifyChecksum are left in FIXME
comments. The only remaining test failure on change of default (in block_fetcher_test) now
has a comment about how to upgrade the test.
The format compatibility test does not need updating because we have not updated the default
format_version.
Reviewed By: ajkr, mrambacher
Differential Revision: D33100915
Pulled By: pdillinger
fbshipit-source-id: 8679e3e572fa580181a737fd6d113ed53c5422ee
|
||
|
Hui Xiao
|
629605d645 |
Move prefetching responsibility to page cache for compaction read under non directIO usecase (#11631)
Summary: **Context/Summary** As titled. The benefit of doing so is to explicitly call readahead() instead of relying page cache behavior for compaction read when we know that we most likely need readahead as compaction read is sequential read . **Test** Extended the existing UT to cover compaction read case Pull Request resolved: https://github.com/facebook/rocksdb/pull/11631 Reviewed By: ajkr Differential Revision: D47681437 Pulled By: hx235 fbshipit-source-id: 78792f64985c4dc44aa8f2a9c41ab3e8bbc0bc90 |
||
|
darionyaphet
|
df543460d5 |
Remove some useless qualifier (#11596)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/11596 Reviewed By: ajkr Differential Revision: D47635614 Pulled By: jowlyzhang fbshipit-source-id: 651a06049a54d15fd4b4f010bb4b82f53ff9c9d4 |
||
|
darionyaphet
|
64b0439bc1 |
fix typo (#11595)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/11595 Reviewed By: ajkr Differential Revision: D47600701 Pulled By: jowlyzhang fbshipit-source-id: 22375b51c726b176e4bc502b49cf3343f45f8a0a |
||
|
Yu Zhang
|
15053f3ab4 |
Logically strip timestamp during flush (#11557)
Summary:
Logically strip the user-defined timestamp when L0 files are created during flush when `AdvancedColumnFamilyOptions.persist_user_defined_timestamps` is false. Logically stripping timestamp here means replacing the original user-defined timestamp with a mininum timestamp, which for now is hard coded to be all zeros bytes.
While working on this, I caught a missing piece on the `BlockBuilder` level for this feature. The current quick path `std::min(buffer_size, last_key_size)` needs a bit tweaking to work for this feature. When user-defined timestamp is stripped during block building, on writing first entry or right after resetting, `buffer` is empty and `buffer_size` is zero as usual. However, in follow-up writes, depending on the size of the stripped user-defined timestamp, and the size of the value, what's in `buffer` can sometimes be smaller than `last_key_size`, leading `std::min(buffer_size, last_key_size)` to truncate the `last_key`. Previous test doesn't caught the bug because in those tests, the size of the stripped user-defined timestamps bytes is smaller than the length of the value. In order to avoid the conditional operation, this PR changed the original trivial `std::min` operation into an arithmetic operation. Since this is a change in a hot and performance critical path, I did the following benchmark to check no observable regression is introduced.
```TEST_TMPDIR=/dev/shm/rocksdb1 ./db_bench -benchmarks=fillseq -memtablerep=vector -allow_concurrent_memtable_write=false -num=50000000```
Compiled with DEBUG_LEVEL=0
Test vs. control runs simulaneous for better accuracy, units = ops/sec
PR vs base:
Round 1: 350652 vs 349055
Round 2: 365733 vs 364308
Round 3: 355681 vs 354475
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11557
Test Plan:
New timestamp specific test added or existing tests augmented, both are parameterized with `UserDefinedTimestampTestMode`:
`UserDefinedTimestampTestMode::kNormal` -> UDT feature enabled, write / read with min timestamp
`UserDefinedTimestampTestMode::kStripUserDefinedTimestamps` -> UDT feature enabled, write / read with min timestamp, set Options.persist_user_defined_timestamps to false.
```
make all check
./db_wal_test --gtest_filter="*WithTimestamp*"
./flush_job_test --gtest_filter="*WithTimestamp*"
./repair_test --gtest_filter="*WithTimestamp*"
./block_based_table_reader_test
```
Reviewed By: pdillinger
Differential Revision: D47027664
Pulled By: jowlyzhang
fbshipit-source-id: e729193b6334dfc63aaa736d684d907a022571f5
|
||
|
akankshamahajan
|
fbd2f563bb |
Add an interface to provide support for underlying FS to pass their own buffer during reads (#11324)
Summary: 1. Public API change: Replace `use_async_io` API in file_system with `SupportedOps` API which is used by underlying FileSystem to indicate to upper layers whether the FileSystem supports different operations introduced in `enum FSSupportedOps `. Right now operations are `async_io` and whether FS will provide its own buffer during reads or not. The api is changed to extend it to various FileSystem operations in one API rather than creating a separate API for each operation. 2. Provide support for underlying FS to pass their own buffer during Reads (async and sync read) instead of using RocksDB provided `scratch` (buffer) in `FSReadRequest`. Currently only MultiRead supports it and later will be extended to other reads as well (point lookup, scan etc). More details in how to enable in file_system.h Pull Request resolved: https://github.com/facebook/rocksdb/pull/11324 Test Plan: Tested locally Reviewed By: anand1976 Differential Revision: D44465322 Pulled By: akankshamahajan15 fbshipit-source-id: 9ec9e08f839b5cc815e75d5dade6cd549998d0ec |
||
|
Yu Zhang
|
7521478b43 |
Record the persist_user_defined_timestamps flag in manifest (#11515)
Summary: Start to record the value of the flag `AdvancedColumnFamilyOptions.persist_user_defined_timestamps` in the Manifest and table properties for a SST file when it is created. And use the recorded flag when creating a table reader for the SST file. This flag's default value is true, it is only explicitly recorded if it's false. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11515 Test Plan: ``` make all check ./version_edit_test ``` Reviewed By: ltamasi Differential Revision: D46920386 Pulled By: jowlyzhang fbshipit-source-id: 075c20363d3d2cc1368422ecc805617ed135cc26 |
||
|
Hui Xiao
|
1da9ac2363 |
Add UT to test BG read qps behavior during upgrade for pr11406 (#11522)
Summary: **Context/Summary:** When db is upgrading to adopt [pr11406](https://github.com/facebook/rocksdb/pull/11406/), it's possible for RocksDB to infer a small tail size to prefetch for pre-upgrade files. Such small tail size would have caused 1 file read per index or filter partition if partitioned index or filer is used. This PR provides a UT to show this would not happen. Misc: refactor the related UTs a bit to make this new UT more readable. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11522 Test Plan: - New UT If logic of upgrade is wrong e.g, ``` --- a/table/block_based/partitioned_index_reader.cc +++ b/table/block_based/partitioned_index_reader.cc @@ -166,7 +166,8 @@ Status PartitionIndexReader::CacheDependencies( uint64_t prefetch_len = last_off - prefetch_off; std::unique_ptr<FilePrefetchBuffer> prefetch_buffer; if (tail_prefetch_buffer == nullptr || !tail_prefetch_buffer->Enabled() || - tail_prefetch_buffer->GetPrefetchOffset() > prefetch_off) { + (false && tail_prefetch_buffer->GetPrefetchOffset() > prefetch_off)) { ``` , then the UT will fail like below ``` [ RUN ] PrefetchTailTest/PrefetchTailTest.UpgradeToTailSizeInManifest/0 file/prefetch_test.cc:461: Failure Expected: (db_open_file_read.count) < (num_index_partition), actual: 38 vs 33 Received signal 11 (Segmentation fault) ``` Reviewed By: pdillinger Differential Revision: D46546707 Pulled By: hx235 fbshipit-source-id: 9897b0a975e9055963edac5451fd1cd9d6c45d0e |
||
|
Yu Zhang
|
77dda0d9d8 |
Fix use after move in data block hash index (#11505)
Summary: Fix a use-after-move issue in block.cc and added some unit tests. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11505 Test Plan: ``` make all check ./block_test ``` Reviewed By: ltamasi Differential Revision: D46506188 Pulled By: jowlyzhang fbshipit-source-id: 316ed8ddd221c00b2bce2cf9fd47eea686cd74a5 |
||
|
Hui Xiao
|
3093d98c78 |
Fix higher read qps during db open caused by pr 11406 (#11516)
Summary: **Context:** [PR11406](https://github.com/facebook/rocksdb/pull/11406/) caused more frequent read during db open reading files with no `tail_size` in the manifest as part of the upgrade to 11406. This is due to that PR introduced - [smaller](https://github.com/facebook/rocksdb/pull/11406/files#diff-57ed8c49db2bdd4db7618646a177397674bbf25beacacecb104070071d30129fR833) prefetch tail buffer size compared to pre-11406 for small files (< 52 MB) when `tail_prefetch_stats` infers tail size to be 0 (usually happens when the stats does not have much historical data to infer early on) - more read (up to # of partitioned filter/index) when such small prefetch tail buffer does not contain all the partitioned filter/index needed in CacheDependencies() since the [fallback logic](https://github.com/facebook/rocksdb/pull/11406/files#diff-d98f1a83de24412ad7f3527725dae7e28851c7222622c3cdb832d3cdf24bbf9fR165-R179) that prefetches all partitions at once will be [skipped](url) when such a small prefetch tail buffer is passed in **Summary:** - Revert the fallback prefetch buffer size change to preserve existing behavior fully during upgrading in `BlockBasedTable::PrefetchTail()` - Use passed-in prefetch tail buffer in `CacheDependencies()` only if it has a smaller offset than the the offset of first partition filter/index, that is, at least as good as the existing prefetching behavior Pull Request resolved: https://github.com/facebook/rocksdb/pull/11516 Test Plan: - db bench Create db with small files prior to PR 11406 ``` ./db_bench -db=/tmp/testdb/ --partition_index_and_filters=1 --statistics=1 -benchmarks=fillseq -key_size=3200 -value_size=5 -num=1000000 -write_buffer_size=6550000 -disable_auto_compactions=true -compression_type=zstd` ``` Read db to see if post-pr has lower read qps (i.e, rocksdb.file.read.db.open.micros count) during db open. ``` ./db_bench -use_direct_reads=1 --file_opening_threads=1 --threads=1 --use_existing_db=1 --seed=1682546046158958 --partition_index_and_filters=1 --statistics=1 --db=/tmp/testdb/ --benchmarks=readrandom --key_size=3200 --value_size=5 --num=100 --disable_auto_compactions=true --compression_type=zstd ``` Pre-PR: ``` rocksdb.file.read.db.open.micros P50 : 3.399023 P95 : 5.924468 P99 : 12.408333 P100 : 29.000000 COUNT : 611 SUM : 2539 ``` Post-PR: ``` rocksdb.file.read.db.open.micros P50 : 593.736842 P95 : 861.605263 P99 : 1212.868421 P100 : 2663.000000 COUNT : 585 SUM : 345349 ``` _Note: To control the starting offset of the prefetch tail buffer easier, I manually override the following to eliminate the effect of alignment_ ``` class PosixRandomAccessFile : public FSRandomAccessFile { virtual size_t GetRequiredBufferAlignment() const override { - return logical_sector_size_; + return 1; } ``` - CI Reviewed By: pdillinger Differential Revision: D46472566 Pulled By: hx235 fbshipit-source-id: 2fe14ac8d489d15b0e08e6f8fe4f46d5f110978e |
||
|
Yu Zhang
|
9f7877f246 |
Add support to strip / pad timestamp when creating / reading a block based table (#11495)
Summary: Add support to strip timestamp in block based table builder and pad timestamp in block based table reader. On the write path, use the per column family option `AdvancedColumnFamilyOptions.persist_user_defined_timestamps` to indicate whether user-defined timestamps should be stripped for all block based tables created for the column family. On the read path, added a per table `TableReadOption.user_defined_timestamps_persisted` to flag whether the user keys in the table contains user defined timestamps. This patch is mostly passing the related flags down to the block building/parsing level with the exception of handling the `first_internal_key` in `IndexValue`, which is included in the `IndexBuilder` level. The value part of range deletion entries should have a similar handling, I haven't decided where to best fit this piece of logic, I will do it in a follow up. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11495 Test Plan: Existing test `BlockBasedTableReaderTest` is parameterized to run with: 1) different UDT test modes: kNone, kNormal, kStripUserDefinedTimestamp 2) all four index types, when index type is `kTwoLevelIndexSearch`, also enables partitioned filters 3) parallel vs non-parallel compression 4) enable/disable compression dictionary. Also added tests for API `BlockBasedTableReader::NewIterator`. `PartitionedFilterBlockTest` is parameterized to run with different UDT test modes:kNone, kNormal, kStripUserDefinedTimestamp. ``` make all check ./block_based_table_reader_test ./partitioned_filter_block_test ``` Reviewed By: ltamasi Differential Revision: D46344577 Pulled By: jowlyzhang fbshipit-source-id: 93ac8542b19319d1298712b8bed908c8831ba675 |
||
|
Yu Zhang
|
d1ae7f6c41 |
Add support to strip / pad timestamp when writing / reading a block (#11472)
Summary: This patch adds support in `BlockBuilder` to strip user-defined timestamp from the `key` added via `Add(key, value)` and its equivalent APIs. The stripping logic is different when the key is either a user key or an internal key, so the `BlockBuilder` is created with a flag to indicate that. This patch also add support on the read path to APIs `NewIndexIterator`, `NewDataIterator` to support pad a min timestamp. Pull Request resolved: https://github.com/facebook/rocksdb/pull/11472 Test Plan: Three test modes are added to parameterize existing tests: UserDefinedTimestampTestMode::kNone -> UDT feature is not enabled UserDefinedTimestampTestMode::kNormal -> UDT feature enabled, write / read with min timestamp UserDefinedTimestampTestMode::kStripUserDefinedTimestamps -> UDT feature enabled, write / read with min timestamp, set `persist_user_defined_timestamps` where it applies to false. The tests read/write with min timestamp so that point read and range scan can correctly read values in all three test modes. `block_test` are parameterized to run with above three test modes and some additional parameteriazation ``` make all check ./block_test --gtest_filter="P/BlockTest*" ./block_test --gtest_filter="P/IndexBlockTest*" ``` Reviewed By: ltamasi Differential Revision: D46200539 Pulled By: jowlyzhang fbshipit-source-id: 59f5d6b584639976b69c2943eba723bd47d9b3c0 |
||
|
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 |
||
|
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 |
||
|
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 |
||
|
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 |
||
|
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 |
||
|
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 |
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Hui Xiao
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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
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