5273 Commits (50046869a466efd19456562dad643951900acbb2)

Author	SHA1	Message	Date
Peter Dillinger	5724348689	Revamp, optimize new experimental clock cache (#10626) ... Summary: * Consolidates most metadata into a single word per slot so that more can be accomplished with a single atomic update. In the common case, Lookup was previously about 4 atomic updates, now just 1 atomic update. Common case Release was previously 1 atomic read + 1 atomic update, now just 1 atomic update. * Eliminate spins / waits / yields, which likely threaten some "lock free" benefits. Compare-exchange loops are only used in explicit Erase, and strict_capacity_limit=true Insert. Eviction uses opportunistic compare- exchange. * Relaxes some aggressiveness and guarantees. For example, * Duplicate Inserts will sometimes go undetected and the shadow duplicate will age out with eviction. * In many cases, the older Inserted value for a given cache key will be kept (i.e. Insert does not support overwrite). * Entries explicitly erased (rather than evicted) might not be freed immediately in some rare cases. * With strict_capacity_limit=false, capacity limit is not tracked/enforced as precisely as LRUCache, but is self-correcting and should only deviate by a very small number of extra or fewer entries. * Use smaller "computed default" number of cache shards in many cases, because benefits to larger usage tracking / eviction pools outweigh the small cost of more lock-free atomic contention. The improvement in CPU and I/O is dramatic in some limit-memory cases. * Even without the sharding change, the eviction algorithm is likely more effective than LRU overall because it's more stateful, even though the "hot path" state tracking for it is essentially free with ref counting. It is like a generalized CLOCK with aging (see code comments). I don't have performance numbers showing a specific improvement, but in theory, for a Poisson access pattern to each block, keeping some state allows better estimation of time to next access (Poisson interval) than strict LRU. The bounded randomness in CLOCK can also reduce "cliff" effect for repeated range scans approaching and exceeding cache size. ## Hot path algorithm comparison Rough descriptions, focusing on number and kind of atomic operations: * Old `Lookup()` (2-5 atomic updates per probe): ``` Loop: Increment internal ref count at slot If possible hit: Check flags atomic (and non-atomic fields) If cache hit: Three distinct updates to 'flags' atomic Increment refs for internal-to-external Return Decrement internal ref count while atomic read 'displacements' > 0 ``` * New `Lookup()` (1-2 atomic updates per probe): ``` Loop: Increment acquire counter in meta word (optimistic) If visible entry (already read meta word): If match (read non-atomic fields): Return Else: Decrement acquire counter in meta word Else if invisible entry (rare, already read meta word): Decrement acquire counter in meta word while atomic read 'displacements' > 0 ``` * Old `Release()` (1 atomic update, conditional on atomic read, rarely more): ``` Read atomic ref count If last reference and invisible (rare): Use CAS etc. to remove Return Else: Decrement ref count ``` * New `Release()` (1 unconditional atomic update, rarely more): ``` Increment release counter in meta word If last reference and invisible (rare): Use CAS etc. to remove Return ``` ## Performance test setup Build DB 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 -readonly -num=30000000 -bloom_bits=16 -cache_index_and_filter_blocks=1 -cache_size=${CACHE_MB}000000 -duration 60 -threads=$THREADS -statistics ``` Numbers on a single socket Skylake Xeon system with 48 hardware threads, DEBUG_LEVEL=0 PORTABLE=0. Very similar story on a dual socket system with 80 hardware threads. Using (every 2nd) Fibonacci MB cache sizes to sample the territory between powers of two. Configurations: base: LRUCache before this change, but with db_bench change to default cache_numshardbits=-1 (instead of fixed at 6) folly: LRUCache before this change, with folly enabled (distributed mutex) but on an old compiler (sorry) gt_clock: experimental ClockCache before this change new_clock: experimental ClockCache with this change ## Performance test results First test "hot path" read performance, with block cache large enough for whole DB: 4181MB 1thread base -> kops/s: 47.761 4181MB 1thread folly -> kops/s: 45.877 4181MB 1thread gt_clock -> kops/s: 51.092 4181MB 1thread new_clock -> kops/s: 53.944 4181MB 16thread base -> kops/s: 284.567 4181MB 16thread folly -> kops/s: 249.015 4181MB 16thread gt_clock -> kops/s: 743.762 4181MB 16thread new_clock -> kops/s: 861.821 4181MB 24thread base -> kops/s: 303.415 4181MB 24thread folly -> kops/s: 266.548 4181MB 24thread gt_clock -> kops/s: 975.706 4181MB 24thread new_clock -> kops/s: 1205.64 (~= 24 * 53.944) 4181MB 32thread base -> kops/s: 311.251 4181MB 32thread folly -> kops/s: 274.952 4181MB 32thread gt_clock -> kops/s: 1045.98 4181MB 32thread new_clock -> kops/s: 1370.38 4181MB 48thread base -> kops/s: 310.504 4181MB 48thread folly -> kops/s: 268.322 4181MB 48thread gt_clock -> kops/s: 1195.65 4181MB 48thread new_clock -> kops/s: 1604.85 (~= 24 * 1.25 * 53.944) 4181MB 64thread base -> kops/s: 307.839 4181MB 64thread folly -> kops/s: 272.172 4181MB 64thread gt_clock -> kops/s: 1204.47 4181MB 64thread new_clock -> kops/s: 1615.37 4181MB 128thread base -> kops/s: 310.934 4181MB 128thread folly -> kops/s: 267.468 4181MB 128thread gt_clock -> kops/s: 1188.75 4181MB 128thread new_clock -> kops/s: 1595.46 Whether we have just one thread on a quiet system or an overload of threads, the new version wins every time in thousand-ops per second, sometimes dramatically so. Mutex-based implementation quickly becomes contention-limited. New clock cache shows essentially perfect scaling up to number of physical cores (24), and then each hyperthreaded core adding about 1/4 the throughput of an additional physical core (see 48 thread case). Block cache miss rates (omitted above) are negligible across the board. With partitioned instead of full filters, the maximum speed-up vs. base is more like 2.5x rather than 5x. Now test a large block cache with low miss ratio, but some eviction is required: 1597MB 1thread base -> kops/s: 46.603 io_bytes/op: 1584.63 miss_ratio: 0.0201066 max_rss_mb: 1589.23 1597MB 1thread folly -> kops/s: 45.079 io_bytes/op: 1530.03 miss_ratio: 0.019872 max_rss_mb: 1550.43 1597MB 1thread gt_clock -> kops/s: 48.711 io_bytes/op: 1566.63 miss_ratio: 0.0198923 max_rss_mb: 1691.4 1597MB 1thread new_clock -> kops/s: 51.531 io_bytes/op: 1589.07 miss_ratio: 0.0201969 max_rss_mb: 1583.56 1597MB 32thread base -> kops/s: 301.174 io_bytes/op: 1439.52 miss_ratio: 0.0184218 max_rss_mb: 1656.59 1597MB 32thread folly -> kops/s: 273.09 io_bytes/op: 1375.12 miss_ratio: 0.0180002 max_rss_mb: 1586.8 1597MB 32thread gt_clock -> kops/s: 904.497 io_bytes/op: 1411.29 miss_ratio: 0.0179934 max_rss_mb: 1775.89 1597MB 32thread new_clock -> kops/s: 1182.59 io_bytes/op: 1440.77 miss_ratio: 0.0185449 max_rss_mb: 1636.45 1597MB 128thread base -> kops/s: 309.91 io_bytes/op: 1438.25 miss_ratio: 0.018399 max_rss_mb: 1689.98 1597MB 128thread folly -> kops/s: 267.605 io_bytes/op: 1394.16 miss_ratio: 0.0180286 max_rss_mb: 1631.91 1597MB 128thread gt_clock -> kops/s: 691.518 io_bytes/op: 9056.73 miss_ratio: 0.0186572 max_rss_mb: 1982.26 1597MB 128thread new_clock -> kops/s: 1406.12 io_bytes/op: 1440.82 miss_ratio: 0.0185463 max_rss_mb: 1685.63 610MB 1thread base -> kops/s: 45.511 io_bytes/op: 2279.61 miss_ratio: 0.0290528 max_rss_mb: 615.137 610MB 1thread folly -> kops/s: 43.386 io_bytes/op: 2217.29 miss_ratio: 0.0289282 max_rss_mb: 600.996 610MB 1thread gt_clock -> kops/s: 46.207 io_bytes/op: 2275.51 miss_ratio: 0.0290057 max_rss_mb: 637.934 610MB 1thread new_clock -> kops/s: 48.879 io_bytes/op: 2283.1 miss_ratio: 0.0291253 max_rss_mb: 613.5 610MB 32thread base -> kops/s: 306.59 io_bytes/op: 2250 miss_ratio: 0.0288721 max_rss_mb: 683.402 610MB 32thread folly -> kops/s: 269.176 io_bytes/op: 2187.86 miss_ratio: 0.0286938 max_rss_mb: 628.742 610MB 32thread gt_clock -> kops/s: 855.097 io_bytes/op: 2279.26 miss_ratio: 0.0288009 max_rss_mb: 733.062 610MB 32thread new_clock -> kops/s: 1121.47 io_bytes/op: 2244.29 miss_ratio: 0.0289046 max_rss_mb: 666.453 610MB 128thread base -> kops/s: 305.079 io_bytes/op: 2252.43 miss_ratio: 0.0288884 max_rss_mb: 723.457 610MB 128thread folly -> kops/s: 269.583 io_bytes/op: 2204.58 miss_ratio: 0.0287001 max_rss_mb: 676.426 610MB 128thread gt_clock -> kops/s: 53.298 io_bytes/op: 8128.98 miss_ratio: 0.0292452 max_rss_mb: 956.273 610MB 128thread new_clock -> kops/s: 1301.09 io_bytes/op: 2246.04 miss_ratio: 0.0289171 max_rss_mb: 788.812 The new version is still winning every time, sometimes dramatically so, and we can tell from the maximum resident memory numbers (which contain some noise, by the way) that the new cache is not cheating on memory usage. IMPORTANT: The previous generation experimental clock cache appears to hit a serious bottleneck in the higher thread count configurations, presumably due to some of its waiting functionality. (The same bottleneck is not seen with partitioned index+filters.) Now we consider even smaller cache sizes, with higher miss ratios, eviction work, etc. 233MB 1thread base -> kops/s: 10.557 io_bytes/op: 227040 miss_ratio: 0.0403105 max_rss_mb: 247.371 233MB 1thread folly -> kops/s: 15.348 io_bytes/op: 112007 miss_ratio: 0.0372238 max_rss_mb: 245.293 233MB 1thread gt_clock -> kops/s: 6.365 io_bytes/op: 244854 miss_ratio: 0.0413873 max_rss_mb: 259.844 233MB 1thread new_clock -> kops/s: 47.501 io_bytes/op: 2591.93 miss_ratio: 0.0330989 max_rss_mb: 242.461 233MB 32thread base -> kops/s: 96.498 io_bytes/op: 363379 miss_ratio: 0.0459966 max_rss_mb: 479.227 233MB 32thread folly -> kops/s: 109.95 io_bytes/op: 314799 miss_ratio: 0.0450032 max_rss_mb: 400.738 233MB 32thread gt_clock -> kops/s: 2.353 io_bytes/op: 385397 miss_ratio: 0.048445 max_rss_mb: 500.688 233MB 32thread new_clock -> kops/s: 1088.95 io_bytes/op: 2567.02 miss_ratio: 0.0330593 max_rss_mb: 303.402 233MB 128thread base -> kops/s: 84.302 io_bytes/op: 378020 miss_ratio: 0.0466558 max_rss_mb: 1051.84 233MB 128thread folly -> kops/s: 89.921 io_bytes/op: 338242 miss_ratio: 0.0460309 max_rss_mb: 812.785 233MB 128thread gt_clock -> kops/s: 2.588 io_bytes/op: 462833 miss_ratio: 0.0509158 max_rss_mb: 1109.94 233MB 128thread new_clock -> kops/s: 1299.26 io_bytes/op: 2565.94 miss_ratio: 0.0330531 max_rss_mb: 361.016 89MB 1thread base -> kops/s: 0.574 io_bytes/op: 5.35977e+06 miss_ratio: 0.274427 max_rss_mb: 91.3086 89MB 1thread folly -> kops/s: 0.578 io_bytes/op: 5.16549e+06 miss_ratio: 0.27276 max_rss_mb: 96.8984 89MB 1thread gt_clock -> kops/s: 0.512 io_bytes/op: 4.13111e+06 miss_ratio: 0.242817 max_rss_mb: 119.441 89MB 1thread new_clock -> kops/s: 48.172 io_bytes/op: 2709.76 miss_ratio: 0.0346162 max_rss_mb: 100.754 89MB 32thread base -> kops/s: 5.779 io_bytes/op: 6.14192e+06 miss_ratio: 0.320399 max_rss_mb: 311.812 89MB 32thread folly -> kops/s: 5.601 io_bytes/op: 5.83838e+06 miss_ratio: 0.313123 max_rss_mb: 252.418 89MB 32thread gt_clock -> kops/s: 0.77 io_bytes/op: 3.99236e+06 miss_ratio: 0.236296 max_rss_mb: 396.422 89MB 32thread new_clock -> kops/s: 1064.97 io_bytes/op: 2687.23 miss_ratio: 0.0346134 max_rss_mb: 155.293 89MB 128thread base -> kops/s: 4.959 io_bytes/op: 6.20297e+06 miss_ratio: 0.323945 max_rss_mb: 823.43 89MB 128thread folly -> kops/s: 4.962 io_bytes/op: 5.9601e+06 miss_ratio: 0.319857 max_rss_mb: 626.824 89MB 128thread gt_clock -> kops/s: 1.009 io_bytes/op: 4.1083e+06 miss_ratio: 0.242512 max_rss_mb: 1095.32 89MB 128thread new_clock -> kops/s: 1224.39 io_bytes/op: 2688.2 miss_ratio: 0.0346207 max_rss_mb: 218.223 ^ Now something interesting has happened: the new clock cache has gained a dramatic lead in the single-threaded case, and this is because the cache is so small, and full filters are so big, that dividing the cache into 64 shards leads to significant (random) imbalances in cache shards and excessive churn in imbalanced shards. This new clock cache only uses two shards for this configuration, and that helps to ensure that entries are part of a sufficiently big pool that their eviction order resembles the single-shard order. (This effect is not seen with partitioned index+filters.) Even smaller cache size: 34MB 1thread base -> kops/s: 0.198 io_bytes/op: 1.65342e+07 miss_ratio: 0.939466 max_rss_mb: 48.6914 34MB 1thread folly -> kops/s: 0.201 io_bytes/op: 1.63416e+07 miss_ratio: 0.939081 max_rss_mb: 45.3281 34MB 1thread gt_clock -> kops/s: 0.448 io_bytes/op: 4.43957e+06 miss_ratio: 0.266749 max_rss_mb: 100.523 34MB 1thread new_clock -> kops/s: 1.055 io_bytes/op: 1.85439e+06 miss_ratio: 0.107512 max_rss_mb: 75.3125 34MB 32thread base -> kops/s: 3.346 io_bytes/op: 1.64852e+07 miss_ratio: 0.93596 max_rss_mb: 180.48 34MB 32thread folly -> kops/s: 3.431 io_bytes/op: 1.62857e+07 miss_ratio: 0.935693 max_rss_mb: 137.531 34MB 32thread gt_clock -> kops/s: 1.47 io_bytes/op: 4.89704e+06 miss_ratio: 0.295081 max_rss_mb: 392.465 34MB 32thread new_clock -> kops/s: 8.19 io_bytes/op: 3.70456e+06 miss_ratio: 0.20826 max_rss_mb: 519.793 34MB 128thread base -> kops/s: 2.293 io_bytes/op: 1.64351e+07 miss_ratio: 0.931866 max_rss_mb: 449.484 34MB 128thread folly -> kops/s: 2.34 io_bytes/op: 1.6219e+07 miss_ratio: 0.932023 max_rss_mb: 396.457 34MB 128thread gt_clock -> kops/s: 1.798 io_bytes/op: 5.4241e+06 miss_ratio: 0.324881 max_rss_mb: 1104.41 34MB 128thread new_clock -> kops/s: 10.519 io_bytes/op: 2.39354e+06 miss_ratio: 0.136147 max_rss_mb: 1050.52 As the miss ratio gets higher (say, above 10%), the CPU time spent in eviction starts to erode the advantage of using fewer shards (13% miss rate much lower than 94%). LRU's O(1) eviction time can eventually pay off when there's enough block cache churn: 13MB 1thread base -> kops/s: 0.195 io_bytes/op: 1.65732e+07 miss_ratio: 0.946604 max_rss_mb: 45.6328 13MB 1thread folly -> kops/s: 0.197 io_bytes/op: 1.63793e+07 miss_ratio: 0.94661 max_rss_mb: 33.8633 13MB 1thread gt_clock -> kops/s: 0.519 io_bytes/op: 4.43316e+06 miss_ratio: 0.269379 max_rss_mb: 100.684 13MB 1thread new_clock -> kops/s: 0.176 io_bytes/op: 1.54148e+07 miss_ratio: 0.91545 max_rss_mb: 66.2383 13MB 32thread base -> kops/s: 3.266 io_bytes/op: 1.65544e+07 miss_ratio: 0.943386 max_rss_mb: 132.492 13MB 32thread folly -> kops/s: 3.396 io_bytes/op: 1.63142e+07 miss_ratio: 0.943243 max_rss_mb: 101.863 13MB 32thread gt_clock -> kops/s: 2.758 io_bytes/op: 5.13714e+06 miss_ratio: 0.310652 max_rss_mb: 396.121 13MB 32thread new_clock -> kops/s: 3.11 io_bytes/op: 1.23419e+07 miss_ratio: 0.708425 max_rss_mb: 321.758 13MB 128thread base -> kops/s: 2.31 io_bytes/op: 1.64823e+07 miss_ratio: 0.939543 max_rss_mb: 425.539 13MB 128thread folly -> kops/s: 2.339 io_bytes/op: 1.6242e+07 miss_ratio: 0.939966 max_rss_mb: 346.098 13MB 128thread gt_clock -> kops/s: 3.223 io_bytes/op: 5.76928e+06 miss_ratio: 0.345899 max_rss_mb: 1087.77 13MB 128thread new_clock -> kops/s: 2.984 io_bytes/op: 1.05341e+07 miss_ratio: 0.606198 max_rss_mb: 898.27 gt_clock is clearly blowing way past its memory budget for lower miss rates and best throughput. new_clock also seems to be exceeding budgets, and this warrants more investigation but is not the use case we are targeting with the new cache. With partitioned index+filter, the miss ratio is much better, and although still high enough that the eviction CPU time is definitely offsetting mutex contention: 13MB 1thread base -> kops/s: 16.326 io_bytes/op: 23743.9 miss_ratio: 0.205362 max_rss_mb: 65.2852 13MB 1thread folly -> kops/s: 15.574 io_bytes/op: 19415 miss_ratio: 0.184157 max_rss_mb: 56.3516 13MB 1thread gt_clock -> kops/s: 14.459 io_bytes/op: 22873 miss_ratio: 0.198355 max_rss_mb: 63.9688 13MB 1thread new_clock -> kops/s: 16.34 io_bytes/op: 24386.5 miss_ratio: 0.210512 max_rss_mb: 61.707 13MB 128thread base -> kops/s: 289.786 io_bytes/op: 23710.9 miss_ratio: 0.205056 max_rss_mb: 103.57 13MB 128thread folly -> kops/s: 185.282 io_bytes/op: 19433.1 miss_ratio: 0.184275 max_rss_mb: 116.219 13MB 128thread gt_clock -> kops/s: 354.451 io_bytes/op: 23150.6 miss_ratio: 0.200495 max_rss_mb: 102.871 13MB 128thread new_clock -> kops/s: 295.359 io_bytes/op: 24626.4 miss_ratio: 0.212452 max_rss_mb: 121.109 Pull Request resolved: https://github.com/facebook/rocksdb/pull/10626 Test Plan: updated unit tests, stress/crash test runs including with TSAN, ASAN, UBSAN Reviewed By: anand1976 Differential Revision: D39368406 Pulled By: pdillinger fbshipit-source-id: 5afc44da4c656f8f751b44552bbf27bd3ca6fef9	2 years ago
anand76	37b75e1364	Fix some MultiGet stats (#10673) ... Summary: The stats were not accurate for the coroutine version of MultiGet. This PR fixes it. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10673 Reviewed By: akankshamahajan15 Differential Revision: D39492615 Pulled By: anand1976 fbshipit-source-id: b46c04e15ea27e66f4c31f00c66497aa283bf9d3	2 years ago
anand76	c206aebd0b	Fix a MultiGet crash (#10688) ... Summary: Fix a bug in the async IO/coroutine version of MultiGet that may cause a segfault or assertion failure due to accessing an invalid file index in a LevelFilesBrief. The bug is that when a MultiGetRange is split into two, we may re-process keys in the original range that were already marked to be skipped (in ```current_level_range_```) due to not overlapping the level. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10688 Reviewed By: gitbw95 Differential Revision: D39556131 Pulled By: anand1976 fbshipit-source-id: 65e79438508a283cb19e64eca5c91d0714b81458	2 years ago
Jay Zhuang	849cf1bf68	Refactor Compaction file cut `ShouldStopBefore()` (#10629) ... Summary: Consolidate compaction output cut logic to `ShouldStopBefore()` and move it inside of CompactionOutputs class. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10629 Reviewed By: cbi42 Differential Revision: D39315536 Pulled By: jay-zhuang fbshipit-source-id: 7d81037babbd35c276bbaad02dbc2bb555fdac18	2 years ago
Yanqin Jin	ce2c11d848	Fix a bug by setting up subcompaction bounds properly (#10658) ... Summary: When user-defined timestamp is enabled, subcompaction bounds should be set up properly. When creating InputIterator for the compaction, the `start` and `end` should have their timestamp portions set to kMaxTimestamp, which is the highest possible timestamp. This is similar to what we do with setting up their sequence numbers to `kMaxSequenceNumber`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10658 Test Plan: ```bash make check rm -rf /dev/shm/rocksdb/* && mkdir /dev/shm/rocksdb/rocksdb_crashtest_expected && ./db_stress --allow_data_in_errors=True --clear_column_family_one_in=0 --continuous_verification_interval=0 --data_block_index_type=1 --db=/dev/shm/rocksdb//rocksdb_crashtest_blackbox --delpercent=5 --delrangepercent=0 --expected_values_dir=/dev/shm/rocksdb//rocksdb_crashtest_expected --iterpercent=0 --max_background_compactions=20 --max_bytes_for_level_base=10485760 --max_key=25000000 --max_write_batch_group_size_bytes=1048576 --nooverwritepercent=1 --ops_per_thread=300000 --paranoid_file_checks=1 --partition_filters=0 --prefix_size=8 --prefixpercent=5 --readpercent=30 --reopen=0 --snapshot_hold_ops=100000 --subcompactions=4 --target_file_size_base=65536 --target_file_size_multiplier=2 --test_batches_snapshots=0 --test_cf_consistency=0 --use_multiget=1 --user_timestamp_size=8 --value_size_mult=32 --verify_checksum=1 --write_buffer_size=65536 --writepercent=60 -disable_wal=1 -column_families=1 ``` Reviewed By: akankshamahajan15 Differential Revision: D39393402 Pulled By: riversand963 fbshipit-source-id: f276e35b19fce51a175c368a502fb0718d1f3871	2 years ago
Changyu Bi	be04a3b6cd	Fix data race in accessing `cached_range_tombstone_` (#10680) ... Summary: fix a data race introduced in https://github.com/facebook/rocksdb/issues/10547 (P5295241720), first reported by pdillinger. The race is between the `std::atomic_load_explicit` in NewRangeTombstoneIteratorInternal and the `std::atomic_store_explicit` in MemTable::Add() that operate on `cached_range_tombstone_`. P5295241720 shows that `atomic_store_explicit` initializes some mutex which `atomic_load_explicit` could be trying to call `lock()` on at the same time. This fix moves the initialization to memtable constructor. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10680 Test Plan: `USE_CLANG=1 COMPILE_WITH_TSAN=1 make -j24 whitebox_crash_test` Reviewed By: ajkr Differential Revision: D39528696 Pulled By: cbi42 fbshipit-source-id: ee740841044438e18ad2b8ea567444dd542dd8e2	2 years ago
anand76	bb9a6d4e4b	Bypass a MultiGet test when async_io is used (#10669) ... Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10669 Reviewed By: akankshamahajan15 Differential Revision: D39492658 Pulled By: anand1976 fbshipit-source-id: abef79808e30762654680f7dd7e46487c631febc	2 years ago
Levi Tamasi	06ab0a8b40	Add wide-column support to iterators (#10670) ... Summary: The patch extends the iterator API with a new `columns` method which can be used to retrieve all wide columns for the current key. Similarly to the `Get` and `GetEntity` APIs, the classic `value` API returns the value of the default (anonymous) column for wide-column entities, and `columns` returns an entity with a single default column for plain old key-values. (The goal here is to maintain the invariant that `value()` is the same as the value of the default column in `columns()`.) The patch also involves a smaller refactoring: historically, `value()` was implemented using a bunch of conditions, that is, the `Slice` to be returned was decided based on the direction of the iteration, whether a merge had been done etc. when the method was called; with the patch, the value to be exposed is stored in a member `Slice value_` when the iterator lands on a new key, and `value()` simply returns this `Slice`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10670 Test Plan: Ran `make check` and a simple blackbox crash test. Reviewed By: riversand963 Differential Revision: D39475551 Pulled By: ltamasi fbshipit-source-id: 29e7a6ed9ef340841aab36803b832b7c8f668b0b	2 years ago
Changyu Bi	f291eefb02	Cache fragmented range tombstone list for mutable memtables (#10547) ... Summary: Each read from memtable used to read and fragment all the range tombstones into a `FragmentedRangeTombstoneList`. https://github.com/facebook/rocksdb/issues/10380 improved the inefficient here by caching a `FragmentedRangeTombstoneList` with each immutable memtable. This PR extends the caching to mutable memtables. The fragmented range tombstone can be constructed in either read (This PR) or write path (https://github.com/facebook/rocksdb/issues/10584). With both implementation, each `DeleteRange()` will invalidate the cache, and the difference is where the cache is re-constructed.`CoreLocalArray` is used to store the cache with each memtable so that multi-threaded reads can be efficient. More specifically, each core will have a shared_ptr to a shared_ptr pointing to the current cache. Each read thread will only update the reference count in its core-local shared_ptr, and this is only needed when reading from mutable memtables. The choice between write path and read path is not an easy one: they are both improvement compared to no caching in the current implementation, but they favor different operations and could cause regression in the other operation (read vs write). The write path caching in (https://github.com/facebook/rocksdb/issues/10584) leads to a cleaner implementation, but I chose the read path caching here to avoid significant regression in write performance when there is a considerable amount of range tombstones in a single memtable (the number from the benchmark below suggests >1000 with concurrent writers). Note that even though the fragmented range tombstone list is only constructed in `DeleteRange()` operations, it could block other writes from proceeding, and hence affects overall write performance. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10547 Test Plan: - TestGet() in stress test is updated in https://github.com/facebook/rocksdb/issues/10553 to compare Get() result against expected state: `./db_stress_branch --readpercent=57 --prefixpercent=4 --writepercent=25 -delpercent=5 --iterpercent=5 --delrangepercent=4` - Perf benchmark: tested read and write performance where a memtable has 0, 1, 10, 100 and 1000 range tombstones. ``` ./db_bench --benchmarks=fillrandom,readrandom --writes_per_range_tombstone=200 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=200000 --reads=100000 --disable_auto_compactions --max_num_range_tombstones=1000 ``` Write perf regressed since the cost of constructing fragmented range tombstone list is shifted from every read to a single write. 6cbe5d8e172dc5f1ef65c9d0a6eedbd9987b2c72 is included in the last column as a reference to see performance impact on multi-thread reads if `CoreLocalArray` is not used. micros/op averaged over 5 runs: first 4 columns are for fillrandom, last 4 columns are for readrandom. | |fillrandom main | write path caching | read path caching |memtable V3 (https://github.com/facebook/rocksdb/issues/10308) | readrandom main | write path caching | read path caching |memtable V3 | |--- |--- |--- |--- |--- | --- | --- | --- | --- | | 0 |6.35 |6.15 |5.82 |6.12 |2.24 |2.26 |2.03 |2.07 | | 1 |5.99 |5.88 |5.77 |6.28 |2.65 |2.27 |2.24 |2.5 | | 10 |6.15 |6.02 |5.92 |5.95 |5.15 |2.61 |2.31 |2.53 | | 100 |5.95 |5.78 |5.88 |6.23 |28.31 |2.34 |2.45 |2.94 | | 100 25 threads |52.01 |45.85 |46.18 |47.52 |35.97 |3.34 |3.34 |3.56 | | 1000 |6.0 |7.07 |5.98 |6.08 |333.18 |2.86 |2.7 |3.6 | | 1000 25 threads |52.6 |148.86 |79.06 |45.52 |473.49 |3.66 |3.48 |4.38 | - Benchmark performance of`readwhilewriting` from https://github.com/facebook/rocksdb/issues/10552, 100 range tombstones are written: `./db_bench --benchmarks=readwhilewriting --writes_per_range_tombstone=500 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=100000 --reads=500000 --disable_auto_compactions --max_num_range_tombstones=10000 --finish_after_writes` readrandom micros/op: | |main |write path caching |read path caching |memtable V3 | |---|---|---|---|---| | single thread |48.28 |1.55 |1.52 |1.96 | | 25 threads |64.3 |2.55 |2.67 |2.64 | Reviewed By: ajkr Differential Revision: D38895410 Pulled By: cbi42 fbshipit-source-id: 930bfc309dd1b2f4e8e9042f5126785bba577559	2 years ago
Hui Xiao	f79b3d19a7	Inject spurious wakeup and sleep before acquiring db mutex to expose race condition (#10291) ... Summary: **Context/Summary:** Previous experience with bugs and flaky tests taught us there exist features in RocksDB vulnerable to race condition caused by acquiring db mutex at a particular timing. This PR aggressively exposes those vulnerable features by injecting spurious wakeup and sleep to cause acquiring db mutex at various timing in order to expose such race condition **Testing:** - `COERCE_CONTEXT_SWITCH=1 make -j56 check / make -j56 db_stress` should reveal - flaky tests caused by db mutex related race condition - Reverted https://github.com/facebook/rocksdb/pull/9528 - A/B testing on `COMPILE_WITH_TSAN=1 make -j56 listener_test` w/ and w/o `COERCE_CONTEXT_SWITCH=1` followed by `./listener_test --gtest_filter=EventListenerTest.MultiCF --gtest_repeat=10` - `COERCE_CONTEXT_SWITCH=1` can cause expected test failure (i.e, expose target TSAN data race error) within 10 run while the other couldn't. - This proves our injection can expose flaky tests caused by db mutex related race condition faster. - known or new race-condition-type of internal bug by continuously running this PR - Performance - High ops-threads time: COERCE_CONTEXT_SWITCH=1 regressed by 4 times slower (2:01.16 vs 0:22.10 elapsed ). This PR will be run as a separate CI job so this regression won't affect any existing job. ``` TEST_TMPDIR=$db /usr/bin/time ./db_stress \ --ops_per_thread=100000 --expected_values_dir=$exp --clear_column_family_one_in=0 \ --write_buffer_size=524288 —target_file_size_base=524288 —ingest_external_file_one_in=100 —compact_files_one_in=1000 —compact_range_one_in=1000 ``` - Start-up time: COERCE_CONTEXT_SWITCH=1 didn't regress by 25% (0:01.51 vs 0:01.29 elapsed) ``` TEST_TMPDIR=$db ./db_stress -ops_per_thread=100000000 -expected_values_dir=$exp --clear_column_family_one_in=0 & sleep 120; pkill -9 db_stress TEST_TMPDIR=$db /usr/bin/time ./db_stress \ --ops_per_thread=1 -reopen=0 --expected_values_dir=$exp --clear_column_family_one_in=0 --destroy_db_initially=0 ``` Pull Request resolved: https://github.com/facebook/rocksdb/pull/10291 Reviewed By: ajkr Differential Revision: D39231182 Pulled By: hx235 fbshipit-source-id: 7ab6695430460e0826727fd8c66679b32b3e44b6	2 years ago
Yanqin Jin	3d67d79154	Fix overlapping check by excluding timestamp (#10615) ... Summary: With user-defined timestamp, checking overlapping should exclude timestamp part from key. This has already been done for range checking for files in sstableKeyCompare(), but not yet done when checking with concurrent compactions. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10615 Test Plan: (Will add more tests) make check (Repro seems easier with this commit sha: git checkout 78bbdef530) rm -rf /dev/shm/rocksdb/* && mkdir /dev/shm/rocksdb/rocksdb_crashtest_expected && ./db_stress --allow_data_in_errors=True --clear_column_family_one_in=0 --continuous_verification_interval=0 --data_block_index_type=1 --db=/dev/shm/rocksdb//rocksdb_crashtest_blackbox --delpercent=5 --delrangepercent=0 --expected_values_dir=/dev/shm/rocksdb//rocksdb_crashtest_expected --iterpercent=0 --max_background_compactions=20 --max_bytes_for_level_base=10485760 --max_key=25000000 --max_write_batch_group_size_bytes=1048576 --nooverwritepercent=1 --ops_per_thread=1000000 --paranoid_file_checks=1 --partition_filters=0 --prefix_size=8 --prefixpercent=5 --readpercent=30 --reopen=0 --snapshot_hold_ops=100000 --subcompactions=1 --compaction_pri=3 --target_file_size_base=65536 --target_file_size_multiplier=2 --test_batches_snapshots=0 --test_cf_consistency=0 --use_multiget=1 --user_timestamp_size=8 --value_size_mult=32 --verify_checksum=1 --write_buffer_size=65536 --writepercent=60 -disable_wal=1 Reviewed By: akankshamahajan15 Differential Revision: D39146797 Pulled By: riversand963 fbshipit-source-id: 7fca800026ca6219220100b8b6cf84d907828163	2 years ago
Levi Tamasi	fe56cb9aa0	Eliminate some allocations/copies around the blob cache (#10647) ... Summary: Historically, `BlobFileReader` has returned the blob(s) read from the file in the `PinnableSlice` provided by the client. This interface was preserved when caching was implemented for blobs, which meant that the blob data was copied multiple times when caching was in use: first, into the client-provided `PinnableSlice` (by `BlobFileReader::SaveValue`), and then, into the object stored in the cache (by `BlobSource::PutBlobIntoCache`). The patch eliminates these copies and the related allocations by changing `BlobFileReader` so it returns its results in the form of heap-allocated `BlobContents` objects that can be directly inserted into the cache. The allocations backing these `BlobContents` objects are made using the blob cache's allocator if the blobs are to be inserted into the cache (i.e. if a cache is configured and the `fill_cache` read option is set). Note: this PR focuses on the common case when blobs are compressed; some further small optimizations are possible for uncompressed blobs. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10647 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D39335185 Pulled By: ltamasi fbshipit-source-id: 464503d60a5520d654c8273ffb8efd5d1bcd7b36	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
Bo Wang	d490bfcdb6	Avoid recompressing cold block in CompressedSecondaryCache (#10527) ... Summary: **Summary:** When a block is firstly `Lookup` from the secondary cache, we just insert a dummy block in the primary cache (charging the actual size of the block) and don’t erase the block from the secondary cache. A standalone handle is returned from `Lookup`. Only if the block is hit again, we erase it from the secondary cache and add it into the primary cache. When a block is firstly evicted from the primary cache to the secondary cache, we just insert a dummy block (size 0) in the secondary cache. When the block is evicted again, it is treated as a hot block and is inserted into the secondary cache. **Implementation Details** Add a new state of LRUHandle: The handle is never inserted into the LRUCache (both hash table and LRU list) and it doesn't experience the above three states. The entry can be freed when refs becomes 0. (refs >= 1 && in_cache == false && IS_STANDALONE == true) The behaviors of `LRUCacheShard::Lookup()` are updated if the secondary_cache is CompressedSecondaryCache: 1. If a handle is found in primary cache: 1.1. If the handle's value is not nullptr, it is returned immediately. 1.2. If the handle's value is nullptr, this means the handle is a dummy one. For a dummy handle, if it was retrieved from secondary cache, it may still exist in secondary cache. - 1.2.1. If no valid handle can be `Lookup` from secondary cache, return nullptr. - 1.2.2. If the handle from secondary cache is valid, erase it from the secondary cache and add it into the primary cache. 2. If a handle is not found in primary cache: 2.1. If no valid handle can be `Lookup` from secondary cache, return nullptr. 2.2. If the handle from secondary cache is valid, insert a dummy block in the primary cache (charging the actual size of the block) and return a standalone handle. The behaviors of `LRUCacheShard::Promote()` are updated as follows: 1. If `e->sec_handle` has value, one of the following steps can happen: 1.1. Insert a dummy handle and return a standalone handle to caller when `secondary_cache_` is `CompressedSecondaryCache` and e is a standalone handle. 1.2. Insert the item into the primary cache and return the handle to caller. 1.3. Exception handling. 3. If `e->sec_handle` has no value, mark the item as not in cache and charge the cache as its only metadata that'll shortly be released. The behavior of `CompressedSecondaryCache::Insert()` is updated: 1. If a block is evicted from the primary cache for the first time, a dummy item is inserted. 4. If a dummy item is found for a block, the block is inserted into the secondary cache. The behavior of `CompressedSecondaryCache:::Lookup()` is updated: 1. If a handle is not found or it is a dummy item, a nullptr is returned. 2. If `erase_handle` is true, the handle is erased. The behaviors of `LRUCacheShard::Release()` are adjusted for the standalone handles. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10527 Test Plan: 1. stress tests. 5. unit tests. 6. CPU profiling for db_bench. Reviewed By: siying Differential Revision: D38747613 Pulled By: gitbw95 fbshipit-source-id: 74a1eba7e1957c9affb2bd2ae3e0194584fa6eca	2 years ago
Levi Tamasi	c8543296ca	Support custom allocators for the blob cache (#10628) ... Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10628 Test Plan: `make check` Reviewed By: akankshamahajan15 Differential Revision: D39228165 Pulled By: ltamasi fbshipit-source-id: 591fdff08db400b170b26f0165551f86d33c1dbf	2 years ago
Andrew Kryczka	5a97e6b1d2	Deflake blob caching tests (#10636) ... Summary: Example failure: ``` db/blob/db_blob_basic_test.cc:226: Failure Expected equality of these values: i Which is: 1 num_blobs Which is: 5 ``` I can't repro locally, but it looks like the 2KB cache is too small to guarantee no eviction happens between loading all the data into cache and reading from `kBlockCacheTier`. This 2KB setting appears to have come from a test where the cached entries are pinned, where it makes sense to have a small setting. However, such a small setting makes less sense when the blocks are evictable but must remain cached per the test's expectation. This PR increases the capacity setting to 2MB for those cases. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10636 Reviewed By: cbi42 Differential Revision: D39250976 Pulled By: ajkr fbshipit-source-id: 769309f9a19cfac20b67b927805c8df5c1d2d1f5	2 years ago
Andrew Kryczka	1ffadbe9fc	Deflake DBErrorHandlingFSTest.*WALWriteError (#10642) ... Summary: Example flake: https://app.circleci.com/pipelines/github/facebook/rocksdb/17660/workflows/7a891875-f07b-4a67-b204-eaa7ca9f9aa2/jobs/467496 The test could get stuck in out-of-space due to a callback executing `SetFilesystemActive(false /* active */)` after the test executed `SetFilesystemActive(true /* active */)`. This could happen because background info logging went through the SyncPoint callback "WritableFileWriter::Append:BeforePrepareWrite", probably unintentionally. The solution of this PR is to call `ClearAllCallBacks()` to wait for any such pending callbacks to drain before calling `SetFilesystemActive(true /* active */)` Pull Request resolved: https://github.com/facebook/rocksdb/pull/10642 Reviewed By: cbi42 Differential Revision: D39265381 Pulled By: ajkr fbshipit-source-id: 9a2f4916ab19726c8fb4b3a3b590b1b9ed93de1b	2 years ago
Andrew Kryczka	fe5fbe32cb	Deflake DBBlockCacheTest1.WarmCacheWithBlocksDuringFlush (#10635) ... Summary: Previously, automatic compaction could be triggered prior to the test invoking CompactRange(). It could lead to the following flaky failure: ``` /root/project/db/db_block_cache_test.cc:753: Failure Expected equality of these values: 1 + kNumBlocks Which is: 11 options.statistics->getTickerCount(BLOCK_CACHE_INDEX_ADD) Which is: 10 ``` A sequence leading to this failure was: * Automatic compaction * files [1] [2] trivially moved * files [3] [4] [5] [6] trivially moved * CompactRange() * files [7] [8] [9] trivially moved * file [10] trivially moved In such a case, the index/filter block adds that the test expected did not happen since there were no new files. This PR just tweaks settings to ensure the `CompactRange()` produces one new file. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10635 Reviewed By: cbi42 Differential Revision: D39250869 Pulled By: ajkr fbshipit-source-id: a3c94c49069e28c49c40b4b80dae0059739d19fd	2 years ago
Changyu Bi	30bc495c03	Skip swaths of range tombstone covered keys in merging iterator (2022 edition) (#10449) ... Summary: Delete range logic is moved from `DBIter` to `MergingIterator`, and `MergingIterator` will seek to the end of a range deletion if possible instead of scanning through each key and check with `RangeDelAggregator`. With the invariant that a key in level L (consider memtable as the first level, each immutable and L0 as a separate level) has a larger sequence number than all keys in any level >L, a range tombstone `[start, end)` from level L covers all keys in its range in any level >L. This property motivates optimizations in iterator: - in `Seek(target)`, if level L has a range tombstone `[start, end)` that covers `target.UserKey`, then for all levels > L, we can do Seek() on `end` instead of `target` to skip some range tombstone covered keys. - in `Next()/Prev()`, if the current key is covered by a range tombstone `[start, end)` from level L, we can do `Seek` to `end` for all levels > L. This PR implements the above optimizations in `MergingIterator`. As all range tombstone covered keys are now skipped in `MergingIterator`, the range tombstone logic is removed from `DBIter`. The idea in this PR is similar to https://github.com/facebook/rocksdb/issues/7317, but this PR leaves `InternalIterator` interface mostly unchanged. **Credit**: the cascading seek optimization and the sentinel key (discussed below) are inspired by [Pebble](https://github.com/cockroachdb/pebble/blob/master/merging_iter.go) and suggested by ajkr in https://github.com/facebook/rocksdb/issues/7317. The two optimizations are mostly implemented in `SeekImpl()/SeekForPrevImpl()` and `IsNextDeleted()/IsPrevDeleted()` in `merging_iterator.cc`. See comments for each method for more detail. One notable change is that the minHeap/maxHeap used by `MergingIterator` now contains range tombstone end keys besides point key iterators. This helps to reduce the number of key comparisons. For example, for a range tombstone `[start, end)`, a `start` and an `end` `HeapItem` are inserted into the heap. When a `HeapItem` for range tombstone start key is popped from the minHeap, we know this range tombstone becomes "active" in the sense that, before the range tombstone's end key is popped from the minHeap, all the keys popped from this heap is covered by the range tombstone's internal key range `[start, end)`. Another major change, *delete range sentinel key*, is made to `LevelIterator`. Before this PR, when all point keys in an SST file are iterated through in `MergingIterator`, a level iterator would advance to the next SST file in its level. In the case when an SST file has a range tombstone that covers keys beyond the SST file's last point key, advancing to the next SST file would lose this range tombstone. Consequently, `MergingIterator` could return keys that should have been deleted by some range tombstone. We prevent this by pretending that file boundaries in each SST file are sentinel keys. A `LevelIterator` now only advance the file iterator once the sentinel key is processed. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10449 Test Plan: - Added many unit tests in db_range_del_test - Stress test: `./db_stress --readpercent=5 --prefixpercent=19 --writepercent=20 -delpercent=10 --iterpercent=44 --delrangepercent=2` - Additional iterator stress test is added to verify against iterators against expected state: https://github.com/facebook/rocksdb/issues/10538. This is based on ajkr's previous attempt https://github.com/facebook/rocksdb/pull/5506#issuecomment-506021913. ``` python3 ./tools/db_crashtest.py blackbox --simple --write_buffer_size=524288 --target_file_size_base=524288 --max_bytes_for_level_base=2097152 --compression_type=none --max_background_compactions=8 --value_size_mult=33 --max_key=5000000 --interval=10 --duration=7200 --delrangepercent=3 --delpercent=9 --iterpercent=25 --writepercent=60 --readpercent=3 --prefixpercent=0 --num_iterations=1000 --range_deletion_width=100 --verify_iterator_with_expected_state_one_in=1 ``` - Performance benchmark: I used a similar setup as in the blog [post](http://rocksdb.org/blog/2018/11/21/delete-range.html) that introduced DeleteRange, "a database with 5 million data keys, and 10000 range tombstones (ignoring those dropped during compaction) that were written in regular intervals after 4.5 million data keys were written". As expected, the performance with this PR depends on the range tombstone width. ``` # Setup: TEST_TMPDIR=/dev/shm ./db_bench_main --benchmarks=fillrandom --writes=4500000 --num=5000000 TEST_TMPDIR=/dev/shm ./db_bench_main --benchmarks=overwrite --writes=500000 --num=5000000 --use_existing_db=true --writes_per_range_tombstone=50 # Scan entire DB TEST_TMPDIR=/dev/shm ./db_bench_main --benchmarks=readseq[-X5] --use_existing_db=true --num=5000000 --disable_auto_compactions=true # Short range scan (10 Next()) TEST_TMPDIR=/dev/shm/width-100/ ./db_bench_main --benchmarks=seekrandom[-X5] --use_existing_db=true --num=500000 --reads=100000 --seek_nexts=10 --disable_auto_compactions=true # Long range scan(1000 Next()) TEST_TMPDIR=/dev/shm/width-100/ ./db_bench_main --benchmarks=seekrandom[-X5] --use_existing_db=true --num=500000 --reads=2500 --seek_nexts=1000 --disable_auto_compactions=true ``` Avg over of 10 runs (some slower tests had fews runs): For the first column (tombstone), 0 means no range tombstone, 100-10000 means width of the 10k range tombstones, and 1 means there is a single range tombstone in the entire DB (width is 1000). The 1 tombstone case is to test regression when there's very few range tombstones in the DB, as no range tombstone is likely to take a different code path than with range tombstones. - Scan entire DB | tombstone width | Pre-PR ops/sec | Post-PR ops/sec | ±% | | ------------- | ------------- | ------------- | ------------- | | 0 range tombstone |2525600 (± 43564) |2486917 (± 33698) |-1.53% | | 100 |1853835 (± 24736) |2073884 (± 32176) |+11.87% | | 1000 |422415 (± 7466) |1115801 (± 22781) |+164.15% | | 10000 |22384 (± 227) |227919 (± 6647) |+918.22% | | 1 range tombstone |2176540 (± 39050) |2434954 (± 24563) |+11.87% | - Short range scan | tombstone width | Pre-PR ops/sec | Post-PR ops/sec | ±% | | ------------- | ------------- | ------------- | ------------- | | 0 range tombstone |35398 (± 533) |35338 (± 569) |-0.17% | | 100 |28276 (± 664) |31684 (± 331) |+12.05% | | 1000 |7637 (± 77) |25422 (± 277) |+232.88% | | 10000 |1367 |28667 |+1997.07% | | 1 range tombstone |32618 (± 581) |32748 (± 506) |+0.4% | - Long range scan | tombstone width | Pre-PR ops/sec | Post-PR ops/sec | ±% | | ------------- | ------------- | ------------- | ------------- | | 0 range tombstone |2262 (± 33) |2353 (± 20) |+4.02% | | 100 |1696 (± 26) |1926 (± 18) |+13.56% | | 1000 |410 (± 6) |1255 (± 29) |+206.1% | | 10000 |25 |414 |+1556.0% | | 1 range tombstone |1957 (± 30) |2185 (± 44) |+11.65% | - Microbench does not show significant regression: https://gist.github.com/cbi42/59f280f85a59b678e7e5d8561e693b61 Reviewed By: ajkr Differential Revision: D38450331 Pulled By: cbi42 fbshipit-source-id: b5ef12e8d8c289ed2e163ccdf277f5039b511fca	2 years ago
Levi Tamasi	b07217da04	Pin the newly cached blob after insert (#10625) ... Summary: With the current code, when a blob isn't found in the cache and gets read from the blob file and then inserted into the cache, the application gets passed the self-contained `PinnableSlice` resulting from the blob file read. The patch changes this so that the `PinnableSlice` pins the cache entry instead in this case. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10625 Test Plan: `make check` Reviewed By: pdillinger Differential Revision: D39220904 Pulled By: ltamasi fbshipit-source-id: cb9c62881e3523b1e9f614e00bf503bac2fe3b0a	2 years ago
anand76	5fbcc8c54d	Update MULTIGET_IO_BATCH_SIZE for non-async MultiGet (#10622) ... Summary: This stat was only getting updated in the async (coroutine) version of MultiGet. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10622 Reviewed By: akankshamahajan15 Differential Revision: D39188790 Pulled By: anand1976 fbshipit-source-id: 7e231507f65fc94c8a006c38f79dfba182a2c24a	2 years ago
Changyu Bi	3a75219e5d	Validate option `memtable_protection_bytes_per_key` (#10621) ... Summary: sanity check value for option `memtable_protection_bytes_per_key` in `ColumnFamilyData::ValidateOptions()`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10621 Test Plan: `make check`, added unit test in ColumnFamilyTest. Reviewed By: ajkr Differential Revision: D39180133 Pulled By: cbi42 fbshipit-source-id: 009e0da3ccb332d1c9e14d20193304610bd4eb8a	2 years ago
Levi Tamasi	01e88dfeb4	Support using cache warming with the secondary blob cache (#10603) ... Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10603 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D39117952 Pulled By: ltamasi fbshipit-source-id: 5e956fa2fc18974876a5c87686acb50718e0edb7	2 years ago
Hui Xiao	8a85946f58	Add missing mutex when reading from shared variable bg_bottom_compaction_scheduled_, bg_compaction_scheduled_ (#10610) ... Summary: **Context/Summary:** According to https://github.com/facebook/rocksdb/blob/7.6.fb/db/compaction/compaction_job.h#L328-L332, any reading in the form of `*bg_compaction_scheduled_` , `*bg_bottom_compaction_scheduled_` should be protected by mutex, which isn't the case for some assert statement. This leads to a data race that can be repro-ed by the following command (command coming soon) ``` db=/dev/shm/rocksdb_crashtest_blackbox exp=/dev/shm/rocksdb_crashtest_expected rm -rf $db $exp mkdir -p $exp ./db_stress --clear_column_family_one_in=0 --column_families=1 --db=$db --delpercent=10 --delrangepercent=0 --destroy_db_initially=1 --expected_values_dir=$exp --iterpercent=0 --key_len_percent_dist=1,30,69 --max_key=1000000 --max_key_len=3 --prefixpercent=0 --readpercent=0 --reopen=0 --ops_per_thread=100000000 --value_size_mult=32 --writepercent=90 --compaction_pri=4 --use_txn=1 --level_compaction_dynamic_level_bytes=True --compaction_ttl=0 --compact_files_one_in=1000000 --compact_range_one_in=1000000 --value_size_mult=32 --verify_db_one_in=1000 --write_buffer_size=65536 --mark_for_compaction_one_file_in=10 --max_background_compactions=20 --max_key=25000000 --max_key_len=3 --max_write_buffer_number=3 --max_write_buffer_size_to_maintain=2097152 --target_file_size_base=2097152 --target_file_size_multiplier=2 ``` ``` WARNING: ThreadSanitizer: data race (pid=73424) Read of size 4 at 0x7b8c0000151c by thread T13: #0 ReleaseSubcompactionResources internal_repo_rocksdb/repo/db/compaction/compaction_job.cc:390 (db_stress+0x630aa3) https://github.com/facebook/rocksdb/issues/1 rocksdb::CompactionJob::Run() internal_repo_rocksdb/repo/db/compaction/compaction_job.cc:741 (db_stress+0x630aa3) https://github.com/facebook/rocksdb/issues/2 rocksdb::DBImpl::BackgroundCompaction(bool*, rocksdb::JobContext*, rocksdb::LogBuffer*, rocksdb::DBImpl::PrepickedCompaction*, rocksdb::Env::Priority) internal_repo_rocksdb/repo/db/db_impl/db_impl_compaction_flush.cc:3436 (db_stress+0x60b2cc) https://github.com/facebook/rocksdb/issues/3 rocksdb::DBImpl::BackgroundCallCompaction(rocksdb::DBImpl::PrepickedCompaction*, rocksdb::Env::Priority) internal_repo_rocksdb/repo/db/db_impl/db_impl_compaction_flush.cc:2950 (db_stress+0x606d79) https://github.com/facebook/rocksdb/issues/4 rocksdb::DBImpl::BGWorkCompaction(void*) internal_repo_rocksdb/repo/db/db_impl/db_impl_compaction_flush.cc:2693 (db_stress+0x60356a) Previous write of size 4 at 0x7b8c0000151c by thread T12 (mutexes: write M438955329917552448): #0 rocksdb::DBImpl::BackgroundCallCompaction(rocksdb::DBImpl::PrepickedCompaction*, rocksdb::Env::Priority) internal_repo_rocksdb/repo/db/db_impl/db_impl_compaction_flush.cc:3018 (db_stress+0x6072a1) https://github.com/facebook/rocksdb/issues/1 rocksdb::DBImpl::BGWorkCompaction(void*) internal_repo_rocksdb/repo/db/db_impl/db_impl_compaction_flush.cc:2693 (db_stress+0x60356a) Location is heap block of size 6720 at 0x7b8c00000000 allocated by main thread: #0 operator new(unsigned long, std::align_val_t) <null> (db_stress+0xbab5bb) https://github.com/facebook/rocksdb/issues/1 rocksdb::DBImpl::Open(rocksdb::DBOptions const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::vector<rocksdb::ColumnFamilyDescriptor, std::allocator<rocksdb::ColumnFamilyDescriptor> > const&, std::vector<rocksdb::ColumnFamilyHandle*, std::allocator<rocksdb::ColumnFamilyHandle*> >*, rocksdb::DB**, bool, bool) internal_repo_rocksdb/repo/db/db_impl/db_impl_open.cc:1811 (db_stress+0x69769a) https://github.com/facebook/rocksdb/issues/2 rocksdb::TransactionDB::Open(rocksdb::DBOptions const&, rocksdb::TransactionDBOptions const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::vector<rocksdb::ColumnFamilyDescriptor, std::allocator<rocksdb::ColumnFamilyDescriptor> > const&, std::vector<rocksdb::ColumnFamilyHandle*, std::allocator<rocksdb::ColumnFamilyHandle*> >*, rocksdb::TransactionDB**) internal_repo_rocksdb/repo/utilities/transactions/pessimistic_transaction_db.cc:258 (db_stress+0x8ae1f4) https://github.com/facebook/rocksdb/issues/3 rocksdb::StressTest::Open(rocksdb::SharedState*) internal_repo_rocksdb/repo/db_stress_tool/db_stress_test_base.cc:2611 (db_stress+0x32b927) https://github.com/facebook/rocksdb/issues/4 rocksdb::StressTest::InitDb(rocksdb::SharedState*) internal_repo_rocksdb/repo/db_stress_tool/db_stress_test_base.cc:290 (db_stress+0x34712c) ``` This PR added all the missing mutex that should've been in place Pull Request resolved: https://github.com/facebook/rocksdb/pull/10610 Test Plan: - Past repro command - Existing CI Reviewed By: riversand963 Differential Revision: D39143016 Pulled By: hx235 fbshipit-source-id: 51dd4db55ad306f3dbda5d0dd54d6f2513cf70f2	2 years ago
Yanqin Jin	7c0838e65e	Use std::make_unique when possible (#10578) ... Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10578 Test Plan: make check Reviewed By: ajkr Differential Revision: D39064748 Pulled By: riversand963 fbshipit-source-id: c7c135b7b713608edb14614846050ece6d4cc59d	2 years ago
Hui Xiao	e484b81eee	Sync dir containing CURRENT after RenameFile on CURRENT as much as possible (#10573) ... Summary: **Context:** Below crash test revealed a bug that directory containing CURRENT file (short for `dir_contains_current_file` below) was not always get synced after a new CURRENT is created and being called with `RenameFile` as part of the creation. This bug exposes a risk that such un-synced directory containing the updated CURRENT can’t survive a host crash (e.g, power loss) hence get corrupted. This then will be followed by a recovery from a corrupted CURRENT that we don't want. The root-cause is that a nullptr `FSDirectory* dir_contains_current_file` sometimes gets passed-down to `SetCurrentFile()` hence in those case `dir_contains_current_file->FSDirectory::FsyncWithDirOptions()` will be skipped (which otherwise will internally call`Env/FS::SyncDic()` ) ``` ./db_stress --acquire_snapshot_one_in=10000 --adaptive_readahead=1 --allow_data_in_errors=True --avoid_unnecessary_blocking_io=0 --backup_max_size=104857600 --backup_one_in=100000 --batch_protection_bytes_per_key=8 --block_size=16384 --bloom_bits=134.8015470676662 --bottommost_compression_type=disable --cache_size=8388608 --checkpoint_one_in=1000000 --checksum_type=kCRC32c --clear_column_family_one_in=0 --compact_files_one_in=1000000 --compact_range_one_in=1000000 --compaction_pri=2 --compaction_ttl=100 --compression_max_dict_buffer_bytes=511 --compression_max_dict_bytes=16384 --compression_type=zstd --compression_use_zstd_dict_trainer=1 --compression_zstd_max_train_bytes=65536 --continuous_verification_interval=0 --data_block_index_type=0 --db=$db --db_write_buffer_size=1048576 --delpercent=5 --delrangepercent=0 --destroy_db_initially=0 --disable_wal=0 --enable_compaction_filter=0 --enable_pipelined_write=1 --expected_values_dir=$exp --fail_if_options_file_error=1 --file_checksum_impl=none --flush_one_in=1000000 --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=4 --ingest_external_file_one_in=0 --iterpercent=10 --key_len_percent_dist=1,30,69 --level_compaction_dynamic_level_bytes=True --mark_for_compaction_one_file_in=10 --max_background_compactions=20 --max_bytes_for_level_base=10485760 --max_key=10000 --max_key_len=3 --max_manifest_file_size=16384 --max_write_batch_group_size_bytes=64 --max_write_buffer_number=3 --max_write_buffer_size_to_maintain=0 --memtable_prefix_bloom_size_ratio=0.001 --memtable_protection_bytes_per_key=1 --memtable_whole_key_filtering=1 --mmap_read=1 --nooverwritepercent=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_pinning=2 --pause_background_one_in=1000000 --periodic_compaction_seconds=0 --prefix_size=5 --prefixpercent=5 --prepopulate_block_cache=1 --progress_reports=0 --read_fault_one_in=1000 --readpercent=45 --recycle_log_file_num=0 --reopen=0 --ribbon_starting_level=999 --secondary_cache_fault_one_in=32 --secondary_cache_uri=compressed_secondary_cache://capacity=8388608 --set_options_one_in=10000 --snapshot_hold_ops=100000 --sst_file_manager_bytes_per_sec=0 --sst_file_manager_bytes_per_truncate=0 --subcompactions=3 --sync_fault_injection=1 --target_file_size_base=2097 --target_file_size_multiplier=2 --test_batches_snapshots=1 --top_level_index_pinning=1 --use_full_merge_v1=1 --use_merge=1 --value_size_mult=32 --verify_checksum=1 --verify_checksum_one_in=1000000 --verify_db_one_in=100000 --verify_sst_unique_id_in_manifest=1 --wal_bytes_per_sync=524288 --write_buffer_size=4194 --writepercent=35 ``` ``` stderr: WARNING: prefix_size is non-zero but memtablerep != prefix_hash db_stress: utilities/fault_injection_fs.cc:748: virtual rocksdb::IOStatus rocksdb::FaultInjectionTestFS::RenameFile(const std::string &, const std::string &, const rocksdb::IOOptions &, rocksdb::IODebugContext *): Assertion `tlist.find(tdn.second) == tlist.end()' failed.` ``` **Summary:** The PR ensured the non-test path pass down a non-null dir containing CURRENT (which is by current RocksDB assumption just db_dir) by doing the following: - Renamed `directory_to_fsync` as `dir_contains_current_file` in `SetCurrentFile()` to tighten the association between this directory and CURRENT file - Changed `SetCurrentFile()` API to require `dir_contains_current_file` being passed-in, instead of making it by default nullptr. - Because `SetCurrentFile()`'s `dir_contains_current_file` is passed down from `VersionSet::LogAndApply()` then `VersionSet::ProcessManifestWrites()` (i.e, think about this as a chain of 3 functions related to MANIFEST update), these 2 functions also got refactored to require `dir_contains_current_file` - Updated the non-test-path callers of these 3 functions to obtain and pass in non-nullptr `dir_contains_current_file`, which by current assumption of RocksDB, is the `FSDirectory* db_dir`. - `db_impl` path will obtain `DBImpl::directories_.getDbDir()` while others with no access to such `directories_` are obtained on the fly by creating such object `FileSystem::NewDirectory(..)` and manage it by unique pointers to ensure short life time. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10573 Test Plan: - `make check` - Passed the repro db_stress command - For future improvement, since we currently don't assert dir containing CURRENT to be non-nullptr due to https://github.com/facebook/rocksdb/pull/10573#pullrequestreview-1087698899, there is still chances that future developers mistakenly pass down nullptr dir containing CURRENT thus resulting skipped sync dir and cause the bug again. Therefore a smarter test (e.g, such as quoted from ajkr "(make) unsynced data loss to be dropping files corresponding to unsynced directory entries") is still needed. Reviewed By: ajkr Differential Revision: D39005886 Pulled By: hx235 fbshipit-source-id: 336fb9090d0cfa6ca3dd580db86268007dde7f5a	2 years ago
Levi Tamasi	7818560194	Add a dedicated cache entry role for blobs (#10601) ... Summary: The patch adds a dedicated cache entry role for blob values and switches to a registered deleter so that blobs show up as a separate bucket (as opposed to "Misc") in the cache occupancy statistics, e.g. ``` Block cache entry stats(count,size,portion): DataBlock(133515,531.73 MB,13.6866%) BlobValue(1824855,3.10 GB,81.7071%) Misc(1,0.00 KB,0%) ``` Pull Request resolved: https://github.com/facebook/rocksdb/pull/10601 Test Plan: Ran `make check` and tested the cache occupancy statistics using `db_bench`. Reviewed By: riversand963 Differential Revision: D39107915 Pulled By: ltamasi fbshipit-source-id: 8446c3b190a41a144030df73f318eeda4398c125	2 years ago
Peter Dillinger	c5afbbfe4b	Don't wait for indirect flush in read-only DB (#10569) ... Summary: Some APIs for getting live files, which are used by Checkpoint and BackupEngine, can optionally trigger and wait for a flush. These would deadlock when used on a read-only DB. Here we fix that by assuming the user wants the overall operation to succeed and is OK without flushing (because the DB is read-only). Follow-up work: the same or other issues can be hit by directly invoking some DB functions that are clearly not appropriate for read-only instance, but are not covered by overrides in DBImplReadOnly and CompactedDBImpl. These should be fixed to avoid similar problems on accidental misuse. (Long term, it would be nice to have a DBReadOnly class without those members, like BackupEngineReadOnly.) Pull Request resolved: https://github.com/facebook/rocksdb/pull/10569 Test Plan: tests updated to catch regression (hang before the fix) Reviewed By: riversand963 Differential Revision: D38995759 Pulled By: pdillinger fbshipit-source-id: f5f8bc7123e13cb45bd393dd974d7d6eda20bc68	2 years ago
Levi Tamasi	23376aa576	Improve the accounting of memory used by cached blobs (#10583) ... Summary: The patch improves the bookkeeping around the memory usage of cached blobs in two ways: 1) it uses `malloc_usable_size`, which accounts for allocator bin sizes etc., and 2) it also considers the memory usage of the `BlobContents` object in addition to the blob itself. Note: some unit tests had been relying on the cache charge being equal to the size of the cached blob; these were updated. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10583 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D39060680 Pulled By: ltamasi fbshipit-source-id: 3583adce2b4ce6e84861f3fadccbfd2e5a3cc482	2 years ago
Jay Zhuang	d9e71fb2c5	Fix periodic_task unable to re-register the same task type (#10379) ... Summary: Timer has a limitation that it cannot re-register a task with the same name, because the cancel only mark the task as invalid and wait for the Timer thread to clean it up later, before the task is cleaned up, the same task name cannot be added. Which makes the task option update likely to fail, which basically cancel and re-register the same task name. Change the periodic task name to a random unique id and store it in periodic_task_scheduler. Also refactor the `periodic_work` to `periodic_task` to make each job function as a `task`. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10379 Test Plan: unittests Reviewed By: ajkr Differential Revision: D38000615 Pulled By: jay-zhuang fbshipit-source-id: e4135f9422e3b53aaec8eda54f4e18ce633a279e	2 years ago
Levi Tamasi	3f57d84af4	Introduce a dedicated class to represent blob values (#10571) ... Summary: The patch introduces a new class called `BlobContents`, which represents a single uncompressed blob value. We currently use `std::string` for this purpose; `BlobContents` is somewhat smaller but the primary reason for a dedicated class is that it enables certain improvements and optimizations like eliding a copy when inserting a blob into the cache, using custom allocators, or more control over and better accounting of the memory usage of cached blobs (see https://github.com/facebook/rocksdb/issues/10484). (We plan to implement these in subsequent PRs.) Pull Request resolved: https://github.com/facebook/rocksdb/pull/10571 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D39000965 Pulled By: ltamasi fbshipit-source-id: f296eddf9dec4fc3e11cad525b462bdf63c78f96	2 years ago
Andrew Kryczka	7ad4b38617	Ensure writes to WAL tail during `FlushWAL(true /* sync */)` will be synced (#10560) ... Summary: WAL append and switch can both happen between `FlushWAL(true /* sync */)`'s sync operations and its call to `MarkLogsSynced()`. We permit this since locks need to be released for the sync operations. Such an appended/switched WAL is both inactive and incompletely synced at the time `MarkLogsSynced()` processes it. Prior to this PR, `MarkLogsSynced()` assumed all inactive WALs were fully synced and removed them from consideration for future syncs. That was wrong in the scenario described above and led to the latest append(s) never being synced. This PR changes `MarkLogsSynced()` to only remove inactive WALs from consideration for which all flushed data has been synced. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10560 Test Plan: repro unit test for the scenario described above. Without this PR, it fails on "key2" not found Reviewed By: riversand963 Differential Revision: D38957391 Pulled By: ajkr fbshipit-source-id: da77175eba97ff251a4219b227b3bb2d4843ed26	2 years ago
muthukrishnan.s	79ed4be80f	Add get_name, get_id for column family handle in C API (#10499) ... Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10499 Reviewed By: hx235 Differential Revision: D38523859 Pulled By: ajkr fbshipit-source-id: 268bba1fcce4a3e20c51e498a79d7b476f663aea	2 years ago
Levi Tamasi	78bbdef530	Fix a typo in BlobSecondaryCacheTest (#10566) ... Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10566 Test Plan: `make check` Reviewed By: riversand963 Differential Revision: D38989926 Pulled By: ltamasi fbshipit-source-id: 6402635fe745e4e7eb3083ef9ad9f04c0177d762	2 years ago
EdvardD	6e93d24935	Expose set_checksum function to C api (#10537) ... Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10537 Reviewed By: hx235 Differential Revision: D38797662 Pulled By: ajkr fbshipit-source-id: a8db723c3eb9d5592cd78f8be7e442e4826686ad	2 years ago
Chen Lixiang	9593fd1c82	Fix wrong compression type and options in universal compaction picker (#10515) ... Summary: In UniversalCompactionBuilder::PickCompactionToReduceSortedRuns, we passed start_level to get compression type and options. I think that is wrong and we should use output_level instead. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10515 Reviewed By: hx235 Differential Revision: D38611335 Pulled By: ajkr fbshipit-source-id: bb860caed4b6c6bbde8f75fc50cf875a9f04723d	2 years ago
anand76	35cdd3e71e	MultiGet async IO across multiple levels (#10535) ... Summary: This PR exploits parallelism in MultiGet across levels. It applies only to the coroutine version of MultiGet. Previously, MultiGet file reads from SST files in the same level were parallelized. With this PR, MultiGet batches with keys distributed across multiple levels are read in parallel. This is accomplished by splitting the keys not present in a level (determined by bloom filtering) into a separate batch, and processing the new batch in parallel with the original batch. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10535 Test Plan: 1. Ensure existing MultiGet unit tests pass, updating them as necessary 2. New unit tests - TODO 3. Run stress test - TODO No noticeable regression (<1%) without async IO - Without PR: `multireadrandom : 7.261 micros/op 1101724 ops/sec 60.007 seconds 66110936 operations; 571.6 MB/s (8168992 of 8168992 found)` With PR: `multireadrandom : 7.305 micros/op 1095167 ops/sec 60.007 seconds 65717936 operations; 568.2 MB/s (8271992 of 8271992 found)` For a fully cached DB, but with async IO option on, no regression observed (<1%) - Without PR: `multireadrandom : 5.201 micros/op 1538027 ops/sec 60.005 seconds 92288936 operations; 797.9 MB/s (11540992 of 11540992 found) ` With PR: `multireadrandom : 5.249 micros/op 1524097 ops/sec 60.005 seconds 91452936 operations; 790.7 MB/s (11649992 of 11649992 found) ` Reviewed By: akankshamahajan15 Differential Revision: D38774009 Pulled By: anand1976 fbshipit-source-id: c955e259749f1c091590ade73105b3ee46cd0007	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
Andrew Kryczka	91166012c8	Prevent a case of WriteBufferManager flush thrashing (#6364) ... Summary: Previously, the flushes triggered by `WriteBufferManager` could affect the same CF repeatedly if it happens to get consecutive writes. Such flushes are not particularly useful for reducing memory usage since they switch nearly-empty memtables to immutable while they've just begun filling their first arena block. In fact they may not even reduce the mutable memory count if they involve replacing one mutable memtable containing one arena block with a new mutable memtable containing one arena block. Further, if such switches happen even a few times before a flush finishes, the immutable memtable limit will be reached and writes will stall. This PR adds a heuristic to not switch memtables to immutable for CFs that already have one or more immutable memtables awaiting flush. There is a memory usage regression if the user continues writing to the same CF, that DB does not have any CFs eligible for switching, flushes are not finishing, and the `WriteBufferManager` was constructed with `allow_stall=false`. Before, it would grow by switching nearly empty memtables until writes stall. Now, it would grow by filling memtables until writes stall. This feels like an acceptable behavior change because users who prefer to stall over violate the memory limit should be using `allow_stall=true`, which is unaffected by this PR. Pull Request resolved: https://github.com/facebook/rocksdb/pull/6364 Test Plan: - Command: `rm -rf /dev/shm/dbbench/ && TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num_multi_db=8 -num_column_families=2 -write_buffer_size=4194304 -db_write_buffer_size=16777216 -compression_type=none -statistics=true -target_file_size_base=4194304 -max_bytes_for_level_base=16777216` - `rocksdb.db.write.stall` count before this PR: 175 - `rocksdb.db.write.stall` count after this PR: 0 Reviewed By: jay-zhuang Differential Revision: D20167197 Pulled By: ajkr fbshipit-source-id: 4a64064e9bc33d57c0a35f15547542d0191d0cb7	2 years ago
anand76	65814a4ae6	Fix range deletion handling in async MultiGet (#10534) ... Summary: The fix in https://github.com/facebook/rocksdb/issues/10513 was not complete w.r.t range deletion handling. It didn't handle the case where a file with a range tombstone covering a key also overlapped another key in the batch. In that case, ```mget_range``` would be non-empty. However, ```mget_range``` would only have the second key and, therefore, the first key would be skipped when iterating through the range tombstones in ```TableCache::MultiGet```. Test plan - 1. Add a unit test 2. Run stress tests Pull Request resolved: https://github.com/facebook/rocksdb/pull/10534 Reviewed By: akankshamahajan15 Differential Revision: D38773880 Pulled By: anand1976 fbshipit-source-id: dae491dbe52e18bbce5179b77b63f20771a66c00	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
sdong	bc575c614c	Fix two extra headers (#10525) ... Summary: Fix copyright for two more extra headers to make internal tool happy. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10525 Reviewed By: jay-zhuang Differential Revision: D38661390 fbshipit-source-id: ab2d055bfd145dfe82b5bae7a6c25cc338c8de94	2 years ago
Changyu Bi	fd165c869d	Add memtable per key-value checksum (#10281) ... Summary: Append per key-value checksum to internal key. These checksums are verified on read paths including Get, Iterator and during Flush. Get and Iterator will return `Corruption` status if there is a checksum verification failure. Flush will make DB become read-only upon memtable entry checksum verification failure. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10281 Test Plan: - Added new unit test cases: `make check` - Benchmark on memtable insert ``` TEST_TMPDIR=/dev/shm/memtable_write ./db_bench -benchmarks=fillseq -disable_wal=true -max_write_buffer_number=100 -num=10000000 -min_write_buffer_number_to_merge=100 # avg over 10 runs Baseline: 1166936 ops/sec memtable 2 bytes kv checksum : 1.11674e+06 ops/sec (-4%) memtable 2 bytes kv checksum + write batch 8 bytes kv checksum: 1.08579e+06 ops/sec (-6.95%) write batch 8 bytes kv checksum: 1.17979e+06 ops/sec (+1.1%) ``` - Benchmark on only memtable read: ops/sec dropped 31% for `readseq` due to time spend on verifying checksum. ops/sec for `readrandom` dropped ~6.8%. ``` # Readseq sudo TEST_TMPDIR=/dev/shm/memtable_read ./db_bench -benchmarks=fillseq,readseq"[-X20]" -disable_wal=true -max_write_buffer_number=100 -num=10000000 -min_write_buffer_number_to_merge=100 readseq [AVG 20 runs] : 7432840 (± 212005) ops/sec; 822.3 (± 23.5) MB/sec readseq [MEDIAN 20 runs] : 7573878 ops/sec; 837.9 MB/sec With -memtable_protection_bytes_per_key=2: readseq [AVG 20 runs] : 5134607 (± 119596) ops/sec; 568.0 (± 13.2) MB/sec readseq [MEDIAN 20 runs] : 5232946 ops/sec; 578.9 MB/sec # Readrandom sudo TEST_TMPDIR=/dev/shm/memtable_read ./db_bench -benchmarks=fillrandom,readrandom"[-X10]" -disable_wal=true -max_write_buffer_number=100 -num=1000000 -min_write_buffer_number_to_merge=100 readrandom [AVG 10 runs] : 140236 (± 3938) ops/sec; 9.8 (± 0.3) MB/sec readrandom [MEDIAN 10 runs] : 140545 ops/sec; 9.8 MB/sec With -memtable_protection_bytes_per_key=2: readrandom [AVG 10 runs] : 130632 (± 2738) ops/sec; 9.1 (± 0.2) MB/sec readrandom [MEDIAN 10 runs] : 130341 ops/sec; 9.1 MB/sec ``` - Stress test: `python3 -u tools/db_crashtest.py whitebox --duration=1800` Reviewed By: ajkr Differential Revision: D37607896 Pulled By: cbi42 fbshipit-source-id: fdaefb475629d2471780d4a5f5bf81b44ee56113	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
Peter Dillinger	9fa5c146d7	LOG more info on oldest snapshot and sequence numbers (#10454) ... Summary: The info LOG file does not currently give any direct information about the existence of old, live snapshots, nor how to estimate wall time from a sequence number within the scope of LOG history. This change addresses both with: * Logging smallest and largest seqnos for generated SST files, which can help associate sequence numbers with write time (based on flushes). * Logging oldest_snapshot_seqno for each compaction, which (along with that seqno info) helps us to determine how much old data might be kept around for old (leaked?) snapshots. Including the date here I thought might be excessive. I wanted to log the date and seqno of the oldest snapshot with periodic stats, but the current structure of the code doesn't really support that because `DumpDBStats` doesn't have access to the DB object. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10454 Test Plan: manual inspect LOG from `KEEP_DB=1 ./db_basic_test --gtest_filter=*CompactBetweenSnapshots*` Reviewed By: ajkr Differential Revision: D38326948 Pulled By: pdillinger fbshipit-source-id: 294918ffc04a419844146cd826045321b4d5c038	2 years ago
sdong	2297769b38	Fix regression issue of too large score (#10518) ... Summary: https://github.com/facebook/rocksdb/pull/10057 caused a regression bug: since the base level size is not adjusted based on L0 size anymore, L0 score might become very large. This makes compaction heavily favor L0->L1 compaction against L1->L2 compaction, and cause in some cases, data stuck in L1 without being moved down. We fix calculating a score of L0 by size(L0)/size(L1) in the case where L0 is large.. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10518 Test Plan: run db_bench against data on tmpfs and watch the behavior of data stuck in L1 goes away. Reviewed By: ajkr Differential Revision: D38603145 fbshipit-source-id: 4949e52dc28b54aacfe08417c6e6cc7e40a27225	2 years ago
sherriiiliu	4753e5a2e9	Fix wrong value passed in compaction filter in BlobDB (#10391) ... Summary: New blobdb has a bug in compaction filter, where `blob_value_` is not reset for next iterated key. This will cause blob_value_ not empty and previous value read from blob is passed into the filter function for next key, even if its value is not in blob. Fixed by reseting regardless of key type. Test Case: Add `FilterByValueLength` test case in `DBBlobCompactionTest` Pull Request resolved: https://github.com/facebook/rocksdb/pull/10391 Reviewed By: riversand963 Differential Revision: D38629900 Pulled By: ltamasi fbshipit-source-id: 47d23ff2e5ec697958a210db9e6ceeb8b2fc49fa	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
Jay Zhuang	5d3aefb682	Migrate to docker for CI run (#10496) ... Summary: Moved linux builds to using docker to avoid CI instability caused by dependency installation site down. Added the `Dockerfile` which is used to build the image. The build time is also significantly reduced, because no dependencies installation and with using 2xlarge+ instance for slow build (like tsan test). Also fixed a few issues detected while building this: * `DestoryDB()` Status not checked for a few tests * nullptr might be used in `inlineskiplist.cc` Pull Request resolved: https://github.com/facebook/rocksdb/pull/10496 Test Plan: CI Reviewed By: ajkr Differential Revision: D38554200 Pulled By: jay-zhuang fbshipit-source-id: 16e8fb2bf07b9c84bb27fb18421c4d54f2f248fd	2 years ago
Guido Tagliavini Ponce	a0798f6f92	Enable ClockCache in DB block cache test (#10482) ... Summary: A test in db_block_cache_test.cc was skipping ClockCache due to the 16-byte key length requirement. We fixed this. Along the way, we fixed a bug in ApplyToSomeEntries, which assumed the function being applied could modify handle metadata, and thus took an exclusive reference. This is incompatible with calls that need to inspect every element (including externally referenced ones) to gather stats. Pull Request resolved: https://github.com/facebook/rocksdb/pull/10482 Test Plan: ``make -j24 check`` Reviewed By: anand1976 Differential Revision: D38553073 Pulled By: guidotag fbshipit-source-id: 0ed63fed4d3b89e5056b35b7091fce579f5647ae	2 years ago