Commit graph

169 commits

Author SHA1 Message Date
Andrew Kryczka cac3240cbf add property "rocksdb.obsolete-sst-files-size" (#11533)
Summary:
See "unreleased_history/new_features/obsolete_sst_files_size.md" for description

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11533

Test Plan: updated unit test

Reviewed By: jowlyzhang

Differential Revision: D46703152

Pulled By: ajkr

fbshipit-source-id: ea5e31cd6293eccc154130c13e66b5271f57c102
2023-06-13 15:52:45 -07:00
Changyu Bi 71ca9a1dcd Log correct compaction score for Universal Compaction (#11487)
Summary:
currently 0 is incorrectly logged as the compaction score for L0 when num_levels > 1. This PR fixes the issue to log the correct score.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11487

Test Plan:
```
./db_bench --benchmarks=fillrandom --max_background_jobs=8 --num=1000000  --compaction_style=1 --stats_dump_period_sec=20 --num_levels=7 --write_buffer_size=1048576

grep "L0   " /tmp/rocksdbtest-543376/dbbench/LOG

before:
** Compaction Stats [default] **
Priority    Files   Size     Score Read(GB)  Rn(GB) Rnp1(GB) Write(GB) Wnew(GB) Moved(GB) W-Amp Rd(MB/s) Wr(MB/s) Comp(sec) CompMergeCPU(sec) Comp(cnt) Avg(sec) KeyIn KeyDrop Rblob(GB) Wblob(GB)
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
L0      0/0    0.00 KB   0.0      0.0     0.0      0.0       0.0      0.0       0.0   1.0      0.0      9.9      0.42              0.33         9    0.046       0      0       0.0       0.0
L0      3/1    1.37 MB   0.0      0.0     0.0      0.0       0.0      0.0       0.0   1.1      0.6      9.6      3.76              3.03        76    0.050     34K    140       0.0       0.0
L0      2/0    2.26 MB   0.0      0.0     0.0      0.0       0.1      0.1       0.0   1.6      3.2      8.2     12.59             11.17       163    0.077    619K   5499       0.0       0.0

after: compaction scores are non-zero
L0      0/0    0.00 KB   0.8      0.0     0.0      0.0       0.0      0.0       0.0   1.0      0.0      9.6      0.43              0.34         9    0.048       0      0       0.0       0.0
L0      2/1   937.08 KB   1.0      0.0     0.0      0.0       0.0      0.0       0.0   1.1      0.6      9.3      3.85              3.07        75    0.051     34K    165       0.0       0.0
L0      2/2    1.82 MB   1.0      0.0     0.0      0.0       0.1      0.1       0.0   1.6      3.0      8.0     12.45             10.99       160    0.078    577K   5399       0.0       0.0

```

Reviewed By: ajkr

Differential Revision: D46293993

Pulled By: cbi42

fbshipit-source-id: 19753f7df68c5f54a84c4ed52794f83e510c9721
2023-06-01 15:36:19 -07:00
Andrew Kryczka fb636f2498 Fix write stall stats dump format (#11445)
Summary:
I noticed in https://github.com/facebook/rocksdb/issues/11426 there is a missing line break. Before this PR the output looked like

```
$ ./db_bench -stats_per_interval=1 -stats_interval=100000
...
Write Stall (count): cf-l0-file-count-limit-delays-with-ongoing-compaction: 0, cf-l0-file-count-limit-stops-with-ongoing-compaction: 0, l0-file-count-limit-delays: 0, l0-file-count-limit-stops: 0, memtable-limit-delays: 0, memtable-limit-stops: 0, pending-compaction-bytes-delays: 0, pending-compaction-bytes-stops: 0, total-delays: 0, total-stops: 0, Block cache LRUCache@0x7f8695831b50#2766536 capacity: 32.00 MB seed: 1155354975 usage: 0.09 KB table_size: 1024 occupancy: 1 collections: 1 last_copies: 0 last_secs: 9.3e-05 secs_since: 2
...
Write Stall (count): write-buffer-manager-limit-stops: 0, num-running-compactions: 0
...
```

After this PR it looks like

```
$ ./db_bench -stats_per_interval=1 -stats_interval=100000
...
Write Stall (count): cf-l0-file-count-limit-delays-with-ongoing-compaction: 0, cf-l0-file-count-limit-stops-with-ongoing-compaction: 0, l0-file-count-limit-delays: 0, l0-file-count-limit-stops: 0, memtable-limit-delays: 0, memtable-limit-stops: 0, pending-compaction-bytes-delays: 0, pending-compaction-bytes-stops: 0, total-delays: 0, total-stops: 0
Block cache LRUCache@0x7f8e0d231b50#2736585 capacity: 32.00 MB seed: 920433955 usage: 0.09 KB table_size: 1024 occupancy: 1 collections: 1 last_copies: 1 last_secs: 6.5e-05 secs_since: 4
...
Write Stall (count): write-buffer-manager-limit-stops: 0
num-running-compactions: 0
...
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11445

Reviewed By: hx235

Differential Revision: D45844752

Pulled By: ajkr

fbshipit-source-id: 1c708cb05b6e270922ac2fa95f5d011f273347eb
2023-05-15 11:47:17 -07:00
Peter Dillinger f4a02f2c52 Add hash_seed to Caches (#11391)
Summary:
See motivation and description in new ShardedCacheOptions::hash_seed option.

Updated db_bench so that its seed param is used for the cache hash seed.
Made its code more safe to ensure seed is set before use.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11391

Test Plan:
unit tests added / updated

**Performance** - no discernible difference seen running cache_bench repeatedly before & after. With lru_cache and hyper_clock_cache.

Reviewed By: hx235

Differential Revision: D45557797

Pulled By: pdillinger

fbshipit-source-id: 40bf4da6d66f9d41a8a0eb8e5cf4246a4aa07934
2023-05-09 22:24:26 -07:00
Hui Xiao 151242ce46 Group rocksdb.sst.read.micros stat by IOActivity flush and compaction (#11288)
Summary:
**Context:**
The existing stat rocksdb.sst.read.micros does not reflect each of compaction and flush cases but aggregate them, which is not so helpful for us to understand IO read behavior of each of them.

**Summary**
- Update `StopWatch` and `RandomAccessFileReader` to record `rocksdb.sst.read.micros` and `rocksdb.file.{flush/compaction}.read.micros`
   - Fixed the default histogram in `RandomAccessFileReader`
- New field `ReadOptions/IOOptions::io_activity`; Pass `ReadOptions` through paths under db open, flush and compaction to where we can prepare `IOOptions` and pass it to `RandomAccessFileReader`
- Use `thread_status_util` for assertion in `DbStressFSWrapper` for continuous testing on we are passing correct `io_activity` under db open, flush and compaction

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11288

Test Plan:
- **Stress test**
- **Db bench 1: rocksdb.sst.read.micros COUNT ≈ sum of rocksdb.file.read.flush.micros's and rocksdb.file.read.compaction.micros's.**  (without blob)
     - May not be exactly the same due to `HistogramStat::Add` only guarantees atomic not accuracy across threads.
```
./db_bench -db=/dev/shm/testdb/ -statistics=true -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3 (-use_plain_table=1 -prefix_size=10)
```
```
// BlockBasedTable
rocksdb.sst.read.micros P50 : 2.009374 P95 : 4.968548 P99 : 8.110362 P100 : 43.000000 COUNT : 40456 SUM : 114805
rocksdb.file.read.flush.micros P50 : 1.871841 P95 : 3.872407 P99 : 5.540541 P100 : 43.000000 COUNT : 2250 SUM : 6116
rocksdb.file.read.compaction.micros P50 : 2.023109 P95 : 5.029149 P99 : 8.196910 P100 : 26.000000 COUNT : 38206 SUM : 108689

// PlainTable
Does not apply
```
- **Db bench 2: performance**

**Read**

SETUP: db with 900 files
```
./db_bench -db=/dev/shm/testdb/ -benchmarks="fillseq" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655  -disable_auto_compactions=true -target_file_size_base=655 -compression_type=none
```run till convergence
```
./db_bench -seed=1678564177044286 -use_existing_db=true -db=/dev/shm/testdb -benchmarks=readrandom[-X60] -statistics=true -num=1000000 -disable_auto_compactions=true -compression_type=none -bloom_bits=3
```
Pre-change
`readrandom [AVG 60 runs] : 21568 (± 248) ops/sec`
Post-change (no regression, -0.3%)
`readrandom [AVG 60 runs] : 21486 (± 236) ops/sec`

**Compaction/Flush**run till convergence
```
./db_bench -db=/dev/shm/testdb2/ -seed=1678564177044286 -benchmarks="fillseq[-X60]" -key_size=32 -value_size=512 -num=50000 -write_buffer_size=655  -disable_auto_compactions=false -target_file_size_base=655 -compression_type=none

rocksdb.sst.read.micros  COUNT : 33820
rocksdb.sst.read.flush.micros COUNT : 1800
rocksdb.sst.read.compaction.micros COUNT : 32020
```
Pre-change
`fillseq [AVG 46 runs] : 1391 (± 214) ops/sec;    0.7 (± 0.1) MB/sec`

Post-change (no regression, ~-0.4%)
`fillseq [AVG 46 runs] : 1385 (± 216) ops/sec;    0.7 (± 0.1) MB/sec`

Reviewed By: ajkr

Differential Revision: D44007011

Pulled By: hx235

fbshipit-source-id: a54c89e4846dfc9a135389edf3f3eedfea257132
2023-04-21 09:07:18 -07:00
Hui Xiao cb58477185 New stat rocksdb.{cf|db}-write-stall-stats exposed in a structural way (#11300)
Summary:
**Context/Summary:**
Users are interested in figuring out what has caused write stall.
- Refactor write stall related stats from property `kCFStats` into its own db property `rocksdb.cf-write-stall-stats` as a map or string. For now, this only contains count of different combination of (CF-scope `WriteStallCause`) + (`WriteStallCondition`)
- Add new `WriteStallCause::kWriteBufferManagerLimit` to reflect write stall caused by write buffer manager
- Add new `rocksdb.db-write-stall-stats`. For now, this only contains `WriteStallCause::kWriteBufferManagerLimit` + `WriteStallCondition::kStopped`

- Expose functions in new class `WriteStallStatsMapKeys` for examining the above two properties returned as map
- Misc: rename/comment some write stall InternalStats for clarity

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11300

Test Plan:
- New UT
- Stress test
`python3 tools/db_crashtest.py blackbox --simple --get_property_one_in=1`
- Perf test: Both converge very slowly at similar rates but post-change has higher average ops/sec than pre-change even though they are run at the same time.
```
./db_bench -seed=1679014417652004 -db=/dev/shm/testdb/ -statistics=false -benchmarks="fillseq[-X60]" -key_size=32 -value_size=512 -num=100000 -db_write_buffer_size=655 -target_file_size_base=655 -disable_auto_compactions=false -compression_type=none -bloom_bits=3
```
pre-change:
```
fillseq [AVG 15 runs] : 1176 (± 732) ops/sec;    0.6 (± 0.4) MB/sec
fillseq      :    1052.671 micros/op 949 ops/sec 105.267 seconds 100000 operations;    0.5 MB/s
fillseq [AVG 16 runs] : 1162 (± 685) ops/sec;    0.6 (± 0.4) MB/sec
fillseq      :    1387.330 micros/op 720 ops/sec 138.733 seconds 100000 operations;    0.4 MB/s
fillseq [AVG 17 runs] : 1136 (± 646) ops/sec;    0.6 (± 0.3) MB/sec
fillseq      :    1232.011 micros/op 811 ops/sec 123.201 seconds 100000 operations;    0.4 MB/s
fillseq [AVG 18 runs] : 1118 (± 610) ops/sec;    0.6 (± 0.3) MB/sec
fillseq      :    1282.567 micros/op 779 ops/sec 128.257 seconds 100000 operations;    0.4 MB/s
fillseq [AVG 19 runs] : 1100 (± 578) ops/sec;    0.6 (± 0.3) MB/sec
fillseq      :    1914.336 micros/op 522 ops/sec 191.434 seconds 100000 operations;    0.3 MB/s
fillseq [AVG 20 runs] : 1071 (± 551) ops/sec;    0.6 (± 0.3) MB/sec
fillseq      :    1227.510 micros/op 814 ops/sec 122.751 seconds 100000 operations;    0.4 MB/s
fillseq [AVG 21 runs] : 1059 (± 525) ops/sec;    0.5 (± 0.3) MB/sec
```
post-change:
```
fillseq [AVG 15 runs] : 1226 (± 732) ops/sec;    0.6 (± 0.4) MB/sec
fillseq      :    1323.825 micros/op 755 ops/sec 132.383 seconds 100000 operations;    0.4 MB/s
fillseq [AVG 16 runs] : 1196 (± 687) ops/sec;    0.6 (± 0.4) MB/sec
fillseq      :    1223.905 micros/op 817 ops/sec 122.391 seconds 100000 operations;    0.4 MB/s
fillseq [AVG 17 runs] : 1174 (± 647) ops/sec;    0.6 (± 0.3) MB/sec
fillseq      :    1168.996 micros/op 855 ops/sec 116.900 seconds 100000 operations;    0.4 MB/s
fillseq [AVG 18 runs] : 1156 (± 611) ops/sec;    0.6 (± 0.3) MB/sec
fillseq      :    1348.729 micros/op 741 ops/sec 134.873 seconds 100000 operations;    0.4 MB/s
fillseq [AVG 19 runs] : 1134 (± 579) ops/sec;    0.6 (± 0.3) MB/sec
fillseq      :    1196.887 micros/op 835 ops/sec 119.689 seconds 100000 operations;    0.4 MB/s
fillseq [AVG 20 runs] : 1119 (± 550) ops/sec;    0.6 (± 0.3) MB/sec
fillseq      :    1193.697 micros/op 837 ops/sec 119.370 seconds 100000 operations;    0.4 MB/s
fillseq [AVG 21 runs] : 1106 (± 524) ops/sec;    0.6 (± 0.3) MB/sec
```

Reviewed By: ajkr

Differential Revision: D44159541

Pulled By: hx235

fbshipit-source-id: 8d29efb70001fdc52d34535eeb3364fc3e71e40b
2023-03-18 09:51:58 -07:00
Jaepil Jeong 969d4e1dd2 Fix compile errors in Clang due to unused variables depending on the build configuration (#11234)
Summary:
This PR fixes compilation errors in Clang due to unused variables like the below:
```
[109/329] Building CXX object CMakeFiles/rocksdb.dir/db/version_edit_handler.cc.o
FAILED: CMakeFiles/rocksdb.dir/db/version_edit_handler.cc.o
ccache /opt/homebrew/opt/llvm/bin/clang++ -DGFLAGS=1 -DGFLAGS_IS_A_DLL=0 -DHAVE_FULLFSYNC -DJEMALLOC_NO_DEMANGLE -DLZ4 -DOS_MACOSX -DROCKSDB_JEMALLOC -DROCKSDB_LIB_IO_POSIX -DROCKSDB_NO_DYNAMIC_EXTENSION -DROCKSDB_PLATFORM_POSIX -DSNAPPY -DTBB -DZLIB -DZSTD -I/Users/jaepil/work/deepsearch/deps/cpp/rocksdb -I/Users/jaepil/work/deepsearch/deps/cpp/rocksdb/include -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk -I/Users/jaepil/app/include -I/opt/homebrew/include -I/opt/homebrew/opt/llvm/include -I/opt/homebrew/opt/llvm/include/c++/v1 -W -Wextra -Wall -pthread -Wsign-compare -Wshadow -Wno-unused-parameter -Wno-unused-variable -Woverloaded-virtual -Wnon-virtual-dtor -Wno-missing-field-initializers -Wno-strict-aliasing -Wno-invalid-offsetof -fno-omit-frame-pointer -momit-leaf-frame-pointer -march=armv8-a+crc+crypto -Wno-unused-function -Werror -O2 -g -DNDEBUG -arch arm64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX13.1.sdk -std=gnu++20 -MD -MT CMakeFiles/rocksdb.dir/db/version_edit_handler.cc.o -MF CMakeFiles/rocksdb.dir/db/version_edit_handler.cc.o.d -o CMakeFiles/rocksdb.dir/db/version_edit_handler.cc.o -c /Users/jaepil/work/deepsearch/deps/cpp/rocksdb/db/version_edit_handler.cc
/Users/jaepil/work/deepsearch/deps/cpp/rocksdb/db/version_edit_handler.cc:30:10: error: variable 'recovered_edits' set but not used [-Werror,-Wunused-but-set-variable]
  size_t recovered_edits = 0;
         ^
1 error generated.
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11234

Reviewed By: cbi42

Differential Revision: D43458604

Pulled By: ajkr

fbshipit-source-id: d8c50e1a108887b037a120cd9f19374ddaeee817
2023-03-09 16:42:57 -08:00
sdong 4720ba4391 Remove RocksDB LITE (#11147)
Summary:
We haven't been actively mantaining RocksDB LITE recently and the size must have been gone up significantly. We are removing the support.

Most of changes were done through following comments:

unifdef -m -UROCKSDB_LITE `git grep -l ROCKSDB_LITE | egrep '[.](cc|h)'`

by Peter Dillinger. Others changes were manually applied to build scripts, CircleCI manifests, ROCKSDB_LITE is used in an expression and file db_stress_test_base.cc.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11147

Test Plan: See CI

Reviewed By: pdillinger

Differential Revision: D42796341

fbshipit-source-id: 4920e15fc2060c2cd2221330a6d0e5e65d4b7fe2
2023-01-27 13:14:19 -08:00
Peter Dillinger 9f7801c5f1 Major Cache refactoring, CPU efficiency improvement (#10975)
Summary:
This is several refactorings bundled into one to avoid having to incrementally re-modify uses of Cache several times. Overall, there are breaking changes to Cache class, and it becomes more of low-level interface for implementing caches, especially block cache. New internal APIs make using Cache cleaner than before, and more insulated from block cache evolution. Hopefully, this is the last really big block cache refactoring, because of rather effectively decoupling the implementations from the uses. This change also removes the EXPERIMENTAL designation on the SecondaryCache support in Cache. It seems reasonably mature at this point but still subject to change/evolution (as I warn in the API docs for Cache).

The high-level motivation for this refactoring is to minimize code duplication / compounding complexity in adding SecondaryCache support to HyperClockCache (in a later PR). Other benefits listed below.

* static_cast lines of code +29 -35 (net removed 6)
* reinterpret_cast lines of code +6 -32 (net removed 26)

## cache.h and secondary_cache.h
* Always use CacheItemHelper with entries instead of just a Deleter. There are several motivations / justifications:
  * Simpler for implementations to deal with just one Insert and one Lookup.
  * Simpler and more efficient implementation because we don't have to track which entries are using helpers and which are using deleters
  * Gets rid of hack to classify cache entries by their deleter. Instead, the CacheItemHelper includes a CacheEntryRole. This simplifies a lot of code (cache_entry_roles.h almost eliminated). Fixes https://github.com/facebook/rocksdb/issues/9428.
  * Makes it trivial to adjust SecondaryCache behavior based on kind of block (e.g. don't re-compress filter blocks).
  * It is arguably less convenient for many direct users of Cache, but direct users of Cache are now rare with introduction of typed_cache.h (below).
  * I considered and rejected an alternative approach in which we reduce customizability by assuming each secondary cache compatible value starts with a Slice referencing the uncompressed block contents (already true or mostly true), but we apparently intend to stack secondary caches. Saving an entry from a compressed secondary to a lower tier requires custom handling offered by SaveToCallback, etc.
* Make CreateCallback part of the helper and introduce CreateContext to work with it (alternative to https://github.com/facebook/rocksdb/issues/10562). This cleans up the interface while still allowing context to be provided for loading/parsing values into primary cache. This model works for async lookup in BlockBasedTable reader (reader owns a CreateContext) under the assumption that it always waits on secondary cache operations to finish. (Otherwise, the CreateContext could be destroyed while async operation depending on it continues.) This likely contributes most to the observed performance improvement because it saves an std::function backed by a heap allocation.
* Use char* for serialized data, e.g. in SaveToCallback, where void* was confusingly used. (We use `char*` for serialized byte data all over RocksDB, with many advantages over `void*`. `memcpy` etc. are legacy APIs that should not be mimicked.)
* Add a type alias Cache::ObjectPtr = void*, so that we can better indicate the intent of the void* when it is to be the object associated with a Cache entry. Related: started (but did not complete) a refactoring to move away from "value" of a cache entry toward "object" or "obj". (It is confusing to call Cache a key-value store (like DB) when it is really storing arbitrary in-memory objects, not byte strings.)
* Remove unnecessary key param from DeleterFn. This is good for efficiency in HyperClockCache, which does not directly store the cache key in memory. (Alternative to https://github.com/facebook/rocksdb/issues/10774)
* Add allocator to Cache DeleterFn. This is a kind of future-proofing change in case we get more serious about using the Cache allocator for memory tracked by the Cache. Right now, only the uncompressed block contents are allocated using the allocator, and a pointer to that allocator is saved as part of the cached object so that the deleter can use it. (See CacheAllocationPtr.) If in the future we are able to "flatten out" our Cache objects some more, it would be good not to have to track the allocator as part of each object.
* Removes legacy `ApplyToAllCacheEntries` and changes `ApplyToAllEntries` signature for Deleter->CacheItemHelper change.

## typed_cache.h
Adds various "typed" interfaces to the Cache as internal APIs, so that most uses of Cache can use simple type safe code without casting and without explicit deleters, etc. Almost all of the non-test, non-glue code uses of Cache have been migrated. (Follow-up work: CompressedSecondaryCache deserves deeper attention to migrate.) This change expands RocksDB's internal usage of metaprogramming and SFINAE (https://en.cppreference.com/w/cpp/language/sfinae).

The existing usages of Cache are divided up at a high level into these new interfaces. See updated existing uses of Cache for examples of how these are used.
* PlaceholderCacheInterface - Used for making cache reservations, with entries that have a charge but no value.
* BasicTypedCacheInterface<TValue> - Used for primary cache storage of objects of type TValue, which can be cleaned up with std::default_delete<TValue>. The role is provided by TValue::kCacheEntryRole or given in an optional template parameter.
* FullTypedCacheInterface<TValue, TCreateContext> - Used for secondary cache compatible storage of objects of type TValue. In addition to BasicTypedCacheInterface constraints, we require TValue::ContentSlice() to return persistable data. This simplifies usage for the normal case of simple secondary cache compatibility (can give you a Slice to the data already in memory). In addition to TCreateContext performing the role of Cache::CreateContext, it is also expected to provide a factory function for creating TValue.
* For each of these, there's a "Shared" version (e.g. FullTypedSharedCacheInterface) that holds a shared_ptr to the Cache, rather than assuming external ownership by holding only a raw `Cache*`.

These interfaces introduce specific handle types for each interface instantiation, so that it's easy to see what kind of object is controlled by a handle. (Ultimately, this might not be worth the extra complexity, but it seems OK so far.)

Note: I attempted to make the cache 'charge' automatically inferred from the cache object type, such as by expecting an ApproximateMemoryUsage() function, but this is not so clean because there are cases where we need to compute the charge ahead of time and don't want to re-compute it.

## block_cache.h
This header is essentially the replacement for the old block_like_traits.h. It includes various things to support block cache access with typed_cache.h for block-based table.

## block_based_table_reader.cc
Before this change, accessing the block cache here was an awkward mix of static polymorphism (template TBlocklike) and switch-case on a dynamic BlockType value. This change mostly unifies on static polymorphism, relying on minor hacks in block_cache.h to distinguish variants of Block. We still check BlockType in some places (especially for stats, which could be improved in follow-up work) but at least the BlockType is a static constant from the template parameter. (No more awkward partial redundancy between static and dynamic info.) This likely contributes to the overall performance improvement, but hasn't been tested in isolation.

The other key source of simplification here is a more unified system of creating block cache objects: for directly populating from primary cache and for promotion from secondary cache. Both use BlockCreateContext, for context and for factory functions.

## block_based_table_builder.cc, cache_dump_load_impl.cc
Before this change, warming caches was super ugly code. Both of these source files had switch statements to basically transition from the dynamic BlockType world to the static TBlocklike world. None of that mess is needed anymore as there's a new, untyped WarmInCache function that handles all the details just as promotion from SecondaryCache would. (Fixes `TODO akanksha: Dedup below code` in block_based_table_builder.cc.)

## Everything else
Mostly just updating Cache users to use new typed APIs when reasonably possible, or changed Cache APIs when not.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10975

Test Plan:
tests updated

Performance test setup similar to https://github.com/facebook/rocksdb/issues/10626 (by cache size, LRUCache when not "hyper" for HyperClockCache):

34MB 1thread base.hyper -> kops/s: 0.745 io_bytes/op: 2.52504e+06 miss_ratio: 0.140906 max_rss_mb: 76.4844
34MB 1thread new.hyper -> kops/s: 0.751 io_bytes/op: 2.5123e+06 miss_ratio: 0.140161 max_rss_mb: 79.3594
34MB 1thread base -> kops/s: 0.254 io_bytes/op: 1.36073e+07 miss_ratio: 0.918818 max_rss_mb: 45.9297
34MB 1thread new -> kops/s: 0.252 io_bytes/op: 1.36157e+07 miss_ratio: 0.918999 max_rss_mb: 44.1523
34MB 32thread base.hyper -> kops/s: 7.272 io_bytes/op: 2.88323e+06 miss_ratio: 0.162532 max_rss_mb: 516.602
34MB 32thread new.hyper -> kops/s: 7.214 io_bytes/op: 2.99046e+06 miss_ratio: 0.168818 max_rss_mb: 518.293
34MB 32thread base -> kops/s: 3.528 io_bytes/op: 1.35722e+07 miss_ratio: 0.914691 max_rss_mb: 264.926
34MB 32thread new -> kops/s: 3.604 io_bytes/op: 1.35744e+07 miss_ratio: 0.915054 max_rss_mb: 264.488
233MB 1thread base.hyper -> kops/s: 53.909 io_bytes/op: 2552.35 miss_ratio: 0.0440566 max_rss_mb: 241.984
233MB 1thread new.hyper -> kops/s: 62.792 io_bytes/op: 2549.79 miss_ratio: 0.044043 max_rss_mb: 241.922
233MB 1thread base -> kops/s: 1.197 io_bytes/op: 2.75173e+06 miss_ratio: 0.103093 max_rss_mb: 241.559
233MB 1thread new -> kops/s: 1.199 io_bytes/op: 2.73723e+06 miss_ratio: 0.10305 max_rss_mb: 240.93
233MB 32thread base.hyper -> kops/s: 1298.69 io_bytes/op: 2539.12 miss_ratio: 0.0440307 max_rss_mb: 371.418
233MB 32thread new.hyper -> kops/s: 1421.35 io_bytes/op: 2538.75 miss_ratio: 0.0440307 max_rss_mb: 347.273
233MB 32thread base -> kops/s: 9.693 io_bytes/op: 2.77304e+06 miss_ratio: 0.103745 max_rss_mb: 569.691
233MB 32thread new -> kops/s: 9.75 io_bytes/op: 2.77559e+06 miss_ratio: 0.103798 max_rss_mb: 552.82
1597MB 1thread base.hyper -> kops/s: 58.607 io_bytes/op: 1449.14 miss_ratio: 0.0249324 max_rss_mb: 1583.55
1597MB 1thread new.hyper -> kops/s: 69.6 io_bytes/op: 1434.89 miss_ratio: 0.0247167 max_rss_mb: 1584.02
1597MB 1thread base -> kops/s: 60.478 io_bytes/op: 1421.28 miss_ratio: 0.024452 max_rss_mb: 1589.45
1597MB 1thread new -> kops/s: 63.973 io_bytes/op: 1416.07 miss_ratio: 0.0243766 max_rss_mb: 1589.24
1597MB 32thread base.hyper -> kops/s: 1436.2 io_bytes/op: 1357.93 miss_ratio: 0.0235353 max_rss_mb: 1692.92
1597MB 32thread new.hyper -> kops/s: 1605.03 io_bytes/op: 1358.04 miss_ratio: 0.023538 max_rss_mb: 1702.78
1597MB 32thread base -> kops/s: 280.059 io_bytes/op: 1350.34 miss_ratio: 0.023289 max_rss_mb: 1675.36
1597MB 32thread new -> kops/s: 283.125 io_bytes/op: 1351.05 miss_ratio: 0.0232797 max_rss_mb: 1703.83

Almost uniformly improving over base revision, especially for hot paths with HyperClockCache, up to 12% higher throughput seen (1597MB, 32thread, hyper). The improvement for that is likely coming from much simplified code for providing context for secondary cache promotion (CreateCallback/CreateContext), and possibly from less branching in block_based_table_reader. And likely a small improvement from not reconstituting key for DeleterFn.

Reviewed By: anand1976

Differential Revision: D42417818

Pulled By: pdillinger

fbshipit-source-id: f86bfdd584dce27c028b151ba56818ad14f7a432
2023-01-11 14:20:40 -08:00
sdong d989300ad1 Avoid repeat periodic stats printing when there is no change (#10891)
Summary:
When there is a column family that doesn't get any traffic, its stats are still dumped when options.options.stats_dump_period_sec triggers. This sometimes spam the information logs. With this change, we skip the printing if there is not change, until 8 periods.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10891

Test Plan: Manually test the behavior with hacked db_bench setups.

Reviewed By: jay-zhuang

Differential Revision: D40777183

fbshipit-source-id: ef0b9a793e4f6282df099b464f01d1fb4c5a2cab
2022-10-31 09:51:38 -07:00
Andrew Kryczka 33ceea9b76 Add DB property for fast block cache stats collection (#10832)
Summary:
This new property allows users to trigger the background block cache stats collection mode through the `GetProperty()` and `GetMapProperty()` APIs. The background mode has much lower overhead at the expense of returning stale values in more cases.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10832

Test Plan: updated unit test

Reviewed By: pdillinger

Differential Revision: D40497883

Pulled By: ajkr

fbshipit-source-id: bdcc93402f426463abb2153756aad9e295447343
2022-10-20 15:04:29 -07:00
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
2022-09-16 00:24:11 -07:00
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
2022-08-25 18:52:37 -07:00
Gang Liao d7ebb58cb5 Add blob cache tickers, perf context statistics, and DB properties (#10203)
Summary:
In order to be able to monitor the performance of the new blob cache, we made the follow changes:
- Add blob cache hit/miss/insertion tickers (see https://github.com/facebook/rocksdb/wiki/Statistics)
- Extend the perf context similarly (see https://github.com/facebook/rocksdb/wiki/Perf-Context-and-IO-Stats-Context)
- Implement new DB properties (see e.g. https://github.com/facebook/rocksdb/blob/main/include/rocksdb/db.h#L1042-L1051) that expose the capacity and current usage of the blob cache.

This PR is a part of https://github.com/facebook/rocksdb/issues/10156

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10203

Reviewed By: ltamasi

Differential Revision: D37478658

Pulled By: gangliao

fbshipit-source-id: d8ee3f41d47315ef725e4551226330b4b6832e40
2022-06-28 13:52:35 -07:00
sdong 736a7b5433 Remove own ToString() (#9955)
Summary:
ToString() is created as some platform doesn't support std::to_string(). However, we've already used std::to_string() by mistake for 16 months (in db/db_info_dumper.cc). This commit just remove ToString().

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9955

Test Plan: Watch CI tests

Reviewed By: riversand963

Differential Revision: D36176799

fbshipit-source-id: bdb6dcd0e3a3ab96a1ac810f5d0188f684064471
2022-05-06 13:03:58 -07:00
Andrew Kryczka d6e016be6d Expose CacheEntryRole and map keys for block cache stat collections (#9838)
Summary:
This gives users the ability to examine the map populated by `GetMapProperty()` with property `kBlockCacheEntryStats`. It also sets us up for a possible future where cache reservations are configured according to `CacheEntryRole`s rather than flags coupled to roles.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9838

Test Plan:
- migrated test DBBlockCacheTest.CacheEntryRoleStats to use this API. That test verifies some of the contents are as expected
- added a DBPropertiesTest to verify the public map keys are present, and nothing else

Reviewed By: hx235

Differential Revision: D35629493

Pulled By: ajkr

fbshipit-source-id: 5c4356b8560e85d1f881fd32c44c15960b02fc68
2022-04-14 09:38:55 -07:00
Levi Tamasi 5645207758 Expose the amount of garbage in live blob files as a dedicated DB property (#9835)
Summary:
This information has been already available as part of the `rocksdb.blob-stats`
string property. The patch adds a dedicated integer property to make it easier
to surface this information in monitoring systems.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9835

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D35619495

Pulled By: ltamasi

fbshipit-source-id: 03fb0b228aa27d3859a1e3783bcb7eca095607f8
2022-04-13 13:36:30 -07:00
Peter Dillinger efd035164b Meta-internal folly integration with F14FastMap (#9546)
Summary:
Especially after updating to C++17, I don't see a compelling case for
*requiring* any folly components in RocksDB. I was able to purge the existing
hard dependencies, and it can be quite difficult to strip out non-trivial components
from folly for use in RocksDB. (The prospect of doing that on F14 has changed
my mind on the best approach here.)

But this change creates an optional integration where we can plug in
components from folly at compile time, starting here with F14FastMap to replace
std::unordered_map when possible (probably no public APIs for example). I have
replaced the biggest CPU users of std::unordered_map with compile-time
pluggable UnorderedMap which will use F14FastMap when USE_FOLLY is set.
USE_FOLLY is always set in the Meta-internal buck build, and a simulation of
that is in the Makefile for public CI testing. A full folly build is not needed, but
checking out the full folly repo is much simpler for getting the dependency,
and anything else we might want to optionally integrate in the future.

Some picky details:
* I don't think the distributed mutex stuff is actually used, so it was easy to remove.
* I implemented an alternative to `folly::constexpr_log2` (which is much easier
in C++17 than C++11) so that I could pull out the hard dependencies on
`ConstexprMath.h`
* I had to add noexcept move constructors/operators to some types to make
F14's complainUnlessNothrowMoveAndDestroy check happy, and I added a
macro to make that easier in some common cases.
* Updated Meta-internal buck build to use folly F14Map (always)

No updates to HISTORY.md nor INSTALL.md as this is not (yet?) considered a
production integration for open source users.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9546

Test Plan:
CircleCI tests updated so that a couple of them use folly.

Most internal unit & stress/crash tests updated to use Meta-internal latest folly.
(Note: they should probably use buck but they currently use Makefile.)

Example performance improvement: when filter partitions are pinned in cache,
they are tracked by PartitionedFilterBlockReader::filter_map_ and we can build
a test that exercises that heavily. Build DB with

```
TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -benchmarks=fillrandom -num=10000000 -disable_wal=1 -write_buffer_size=30000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -partition_index_and_filters
```

and test with (simultaneous runs with & without folly, ~20 times each to see
convergence)

```
TEST_TMPDIR=/dev/shm/rocksdb ./db_bench_folly -readonly -use_existing_db -benchmarks=readrandom -num=10000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -partition_index_and_filters -duration=40 -pin_l0_filter_and_index_blocks_in_cache
```

Average ops/s no folly: 26229.2
Average ops/s with folly: 26853.3 (+2.4%)

Reviewed By: ajkr

Differential Revision: D34181736

Pulled By: pdillinger

fbshipit-source-id: ffa6ad5104c2880321d8a1aa7187e00ab0d02e94
2022-04-13 07:34:01 -07:00
Peter Dillinger a8a422e962 Add manifest fix-up utility for file temperatures (#9683)
Summary:
The goal of this change is to allow changes to the "current" (in
FileSystem) file temperatures to feed back into DB metadata, so that
they can inform decisions and stats reporting. In part because of
modular code factoring, it doesn't seem easy to do this automagically,
where opening an SST file and observing current Temperature different
from expected would trigger a change in metadata and DB manifest write
(essentially giving the deep read path access to the write path). It is also
difficult to do this while the DB is open because of the limitations of
LogAndApply.

This change allows updating file temperature metadata on a closed DB
using an experimental utility function UpdateManifestForFilesState()
or `ldb update_manifest --update_temperatures`. This should suffice for
"migration" scenarios where outside tooling has placed or re-arranged DB
files into a (different) tiered configuration without going through
RocksDB itself (currently, only compaction can change temperature
metadata).

Some details:
* Refactored and added unit test for `ldb unsafe_remove_sst_file` because
of shared functionality
* Pulled in autovector.h changes from https://github.com/facebook/rocksdb/issues/9546 to fix SuperVersionContext
move constructor (related to an older draft of this change)

Possible follow-up work:
* Support updating manifest with file checksums, such as when a
new checksum function is used and want existing DB metadata updated
for it.
* It's possible that for some repair scenarios, lighter weight than
full repair, we might want to support UpdateManifestForFilesState() to
modify critical file details like size or checksum using same
algorithm. But let's make sure these are differentiated from modifying
file details in ways that don't suspect corruption (or require extreme
trust).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9683

Test Plan: unit tests added

Reviewed By: jay-zhuang

Differential Revision: D34798828

Pulled By: pdillinger

fbshipit-source-id: cfd83e8fb10761d8c9e7f9c020d68c9106a95554
2022-03-18 16:35:51 -07:00
Levi Tamasi 073ac54739 Log blob file space amp and expose it via the rocksdb.blob-stats DB property (#9538)
Summary:
Extend the periodic statistics in the info log with the total amount of garbage
in blob files and the space amplification pertaining to blob files, where the
latter is defined as `total_blob_file_size / (total_blob_file_size - total_blob_garbage_size)`.
Also expose the space amp via the `rocksdb.blob-stats` DB property.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9538

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D34126855

Pulled By: ltamasi

fbshipit-source-id: 3153e7a0fe0eca440322db273f4deaabaccc51b2
2022-02-10 12:42:11 -08:00
Levi Tamasi 320d9a8e8a Use a sorted vector instead of a map to store blob file metadata (#9526)
Summary:
The patch replaces `std::map` with a sorted `std::vector` for
`VersionStorageInfo::blob_files_` and preallocates the space
for the `vector` before saving the `BlobFileMetaData` into the
new `VersionStorageInfo` in `VersionBuilder::Rep::SaveBlobFilesTo`.
These changes reduce the time the DB mutex is held while
saving new `Version`s, and using a sorted `vector` also makes
lookups faster thanks to better memory locality.

In addition, the patch introduces helper methods
`VersionStorageInfo::GetBlobFileMetaData` and
`VersionStorageInfo::GetBlobFileMetaDataLB` that can be used by
clients to perform lookups in the `vector`, and does some general
cleanup in the parts of code where blob file metadata are used.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9526

Test Plan:
Ran `make check` and the crash test script for a while.

Performance was tested using a load-optimized benchmark (`fillseq` with vector memtable, no WAL) and small file sizes so that a significant number of files are produced:

```
numactl --interleave=all ./db_bench --benchmarks=fillseq --allow_concurrent_memtable_write=false --level0_file_num_compaction_trigger=4 --level0_slowdown_writes_trigger=20 --level0_stop_writes_trigger=30 --max_background_jobs=8 --max_write_buffer_number=8 --db=/data/ltamasi-dbbench --wal_dir=/data/ltamasi-dbbench --num=800000000 --num_levels=8 --key_size=20 --value_size=400 --block_size=8192 --cache_size=51539607552 --cache_numshardbits=6 --compression_max_dict_bytes=0 --compression_ratio=0.5 --compression_type=lz4 --bytes_per_sync=8388608 --cache_index_and_filter_blocks=1 --cache_high_pri_pool_ratio=0.5 --benchmark_write_rate_limit=0 --write_buffer_size=16777216 --target_file_size_base=16777216 --max_bytes_for_level_base=67108864 --verify_checksum=1 --delete_obsolete_files_period_micros=62914560 --max_bytes_for_level_multiplier=8 --statistics=0 --stats_per_interval=1 --stats_interval_seconds=20 --histogram=1 --memtablerep=skip_list --bloom_bits=10 --open_files=-1 --subcompactions=1 --compaction_style=0 --min_level_to_compress=3 --level_compaction_dynamic_level_bytes=true --pin_l0_filter_and_index_blocks_in_cache=1 --soft_pending_compaction_bytes_limit=167503724544 --hard_pending_compaction_bytes_limit=335007449088 --min_level_to_compress=0 --use_existing_db=0 --sync=0 --threads=1 --memtablerep=vector --allow_concurrent_memtable_write=false --disable_wal=1 --enable_blob_files=1 --blob_file_size=16777216 --min_blob_size=0 --blob_compression_type=lz4 --enable_blob_garbage_collection=1 --seed=<some value>
```

Final statistics before the patch:

```
Cumulative writes: 0 writes, 700M keys, 0 commit groups, 0.0 writes per commit group, ingest: 284.62 GB, 121.27 MB/s
Interval writes: 0 writes, 334K keys, 0 commit groups, 0.0 writes per commit group, ingest: 139.28 MB, 72.46 MB/s
```

With the patch:

```
Cumulative writes: 0 writes, 760M keys, 0 commit groups, 0.0 writes per commit group, ingest: 308.66 GB, 131.52 MB/s
Interval writes: 0 writes, 445K keys, 0 commit groups, 0.0 writes per commit group, ingest: 185.35 MB, 93.15 MB/s
```

Total time to complete the benchmark is 2611 seconds with the patch, down from 2986 secs.

Reviewed By: riversand963

Differential Revision: D34082728

Pulled By: ltamasi

fbshipit-source-id: fc598abf676dce436734d06bb9d2d99a26a004fc
2022-02-09 12:36:43 -08:00
leipeng 01bd86ad35 InternalStats::DumpCFMapStat: fix sum.w_amp (#9065)
Summary:
sum `w_amp` will be a very large number`(bytes_written + bytes_written_blob)` when there is no any flush and ingest.

This PR set sum `w_amp` to zero if there is no any flush and ingest, this is conform to per-level `w_amp` computation.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9065

Reviewed By: ajkr

Differential Revision: D31943994

Pulled By: riversand963

fbshipit-source-id: acbef5e331debebfad09e0e0d8d0885ebbc00609
2021-10-31 23:11:43 -07:00
Andrew Kryczka 4217d1bce7 Support GetMapProperty() with "rocksdb.dbstats" (#9057)
Summary:
This PR supports querying `GetMapProperty()` with "rocksdb.dbstats" to get the DB-level stats in a map format. It only reports cumulative stats over the DB lifetime and, as such, does not update the baseline for interval stats. Like other map properties, the string keys are not (yet) exposed in the public API.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9057

Test Plan: new unit test

Reviewed By: zhichao-cao

Differential Revision: D31781495

Pulled By: ajkr

fbshipit-source-id: 6f77d3aee8b4b1a015061b8c260a123859ceaf9b
2021-10-20 13:17:00 -07:00
Levi Tamasi 306b779957 Use GetBlobFileSize instead of GetTotalBlobBytes in DB properties (#8902)
Summary:
The patch adjusts the definition of BlobDB's DB properties a bit by
switching to `GetBlobFileSize` from `GetTotalBlobBytes`. The
difference is that the value returned by `GetBlobFileSize` includes
the blob file header and footer as well, and thus matches the on-disk
size of blob files. In addition, the patch removes the `Version` number
from the `blob_stats` property, and updates/extends the unit tests a little.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8902

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D30859542

Pulled By: ltamasi

fbshipit-source-id: e3426d2d567bd1bd8c8636abdafaafa0743c854c
2021-09-13 10:47:16 -07:00
Zhiyi Zhang 0cb0fc6fd3 Add DB properties for BlobDB (#8734)
Summary:
RocksDB exposes certain internal statistics via the DB property interface.
However, there are currently no properties related to BlobDB.

For starters, we would like to add the following BlobDB properties:
`rocksdb.num-blob-files`: number of blob files in the current Version (kind of like `num-files-at-level` but note this is not per level, since blob files are not part of the LSM tree).
`rocksdb.blob-stats`: this could return the total number and size of all blob files, and potentially also the total amount of garbage (in bytes) in the blob files in the current Version.
`rocksdb.total-blob-file-size`: the total size of all blob files (as a blob counterpart for `total-sst-file-size`) of all Versions.
`rocksdb.live-blob-file-size`: the total size of all blob files in the current Version.
`rocksdb.estimate-live-data-size`: this is actually an existing property that we can extend so it considers blob files as well. When it comes to blobs, we actually have an exact value for live bytes. Namely, live bytes can be computed simply as total bytes minus garbage bytes, summed over the entire set of blob files in the Version.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8734

Test Plan:
```
➜  rocksdb git:(new_feature_blobDB_properties) ./db_blob_basic_test
[==========] Running 16 tests from 2 test cases.
[----------] Global test environment set-up.
[----------] 10 tests from DBBlobBasicTest
[ RUN      ] DBBlobBasicTest.GetBlob
[       OK ] DBBlobBasicTest.GetBlob (12 ms)
[ RUN      ] DBBlobBasicTest.MultiGetBlobs
[       OK ] DBBlobBasicTest.MultiGetBlobs (11 ms)
[ RUN      ] DBBlobBasicTest.GetBlob_CorruptIndex
[       OK ] DBBlobBasicTest.GetBlob_CorruptIndex (10 ms)
[ RUN      ] DBBlobBasicTest.GetBlob_InlinedTTLIndex
[       OK ] DBBlobBasicTest.GetBlob_InlinedTTLIndex (12 ms)
[ RUN      ] DBBlobBasicTest.GetBlob_IndexWithInvalidFileNumber
[       OK ] DBBlobBasicTest.GetBlob_IndexWithInvalidFileNumber (9 ms)
[ RUN      ] DBBlobBasicTest.GenerateIOTracing
[       OK ] DBBlobBasicTest.GenerateIOTracing (11 ms)
[ RUN      ] DBBlobBasicTest.BestEffortsRecovery_MissingNewestBlobFile
[       OK ] DBBlobBasicTest.BestEffortsRecovery_MissingNewestBlobFile (13 ms)
[ RUN      ] DBBlobBasicTest.GetMergeBlobWithPut
[       OK ] DBBlobBasicTest.GetMergeBlobWithPut (11 ms)
[ RUN      ] DBBlobBasicTest.MultiGetMergeBlobWithPut
[       OK ] DBBlobBasicTest.MultiGetMergeBlobWithPut (14 ms)
[ RUN      ] DBBlobBasicTest.BlobDBProperties
[       OK ] DBBlobBasicTest.BlobDBProperties (21 ms)
[----------] 10 tests from DBBlobBasicTest (124 ms total)

[----------] 6 tests from DBBlobBasicTest/DBBlobBasicIOErrorTest
[ RUN      ] DBBlobBasicTest/DBBlobBasicIOErrorTest.GetBlob_IOError/0
[       OK ] DBBlobBasicTest/DBBlobBasicIOErrorTest.GetBlob_IOError/0 (12 ms)
[ RUN      ] DBBlobBasicTest/DBBlobBasicIOErrorTest.GetBlob_IOError/1
[       OK ] DBBlobBasicTest/DBBlobBasicIOErrorTest.GetBlob_IOError/1 (10 ms)
[ RUN      ] DBBlobBasicTest/DBBlobBasicIOErrorTest.MultiGetBlobs_IOError/0
[       OK ] DBBlobBasicTest/DBBlobBasicIOErrorTest.MultiGetBlobs_IOError/0 (10 ms)
[ RUN      ] DBBlobBasicTest/DBBlobBasicIOErrorTest.MultiGetBlobs_IOError/1
[       OK ] DBBlobBasicTest/DBBlobBasicIOErrorTest.MultiGetBlobs_IOError/1 (10 ms)
[ RUN      ] DBBlobBasicTest/DBBlobBasicIOErrorTest.CompactionFilterReadBlob_IOError/0
[       OK ] DBBlobBasicTest/DBBlobBasicIOErrorTest.CompactionFilterReadBlob_IOError/0 (1011 ms)
[ RUN      ] DBBlobBasicTest/DBBlobBasicIOErrorTest.CompactionFilterReadBlob_IOError/1
[       OK ] DBBlobBasicTest/DBBlobBasicIOErrorTest.CompactionFilterReadBlob_IOError/1 (1013 ms)
[----------] 6 tests from DBBlobBasicTest/DBBlobBasicIOErrorTest (2066 ms total)

[----------] Global test environment tear-down
[==========] 16 tests from 2 test cases ran. (2190 ms total)
[  PASSED  ] 16 tests.
```

Reviewed By: ltamasi

Differential Revision: D30690849

Pulled By: Zhiyi-Zhang

fbshipit-source-id: a7567319487ad76bd1a2e24bf143afdbbd9e4346
2021-09-08 12:22:04 -07:00
Peter Dillinger 318fe6941a Add port::GetProcessID() (#8693)
Summary:
Useful in some places for object uniqueness across processes.
Currently used for generating a host-wide identifier of Cache objects
but expected to be used soon in some unique id generation code.

`int64_t` is chosen for return type because POSIX uses signed integer type,
usually `int`, for `pid_t` and Windows uses `DWORD`, which is `uint32_t`.

Future work: avoid copy-pasted declarations in port_*.h, perhaps with
port_common.h always included from port.h

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8693

Test Plan: manual for now

Reviewed By: ajkr, anand1976

Differential Revision: D30492876

Pulled By: pdillinger

fbshipit-source-id: 39fc2788623cc9f4787866bdb67a4d183dde7eef
2021-08-24 17:46:14 -07:00
Jay Zhuang c55460c734 Add property LiveSstFilesSizeAtTemperature for tiered storage (#8644)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/8644

Reviewed By: siying, zhichao-cao

Differential Revision: D30236535

Pulled By: jay-zhuang

fbshipit-source-id: 1758d1c46d83a5087560fb63d53a016bf999da81
2021-08-15 14:17:45 -07:00
Peter Dillinger df5dc73bec Don't hold DB mutex for block cache entry stat scans (#8538)
Summary:
I previously didn't notice the DB mutex was being held during
block cache entry stat scans, probably because I primarily checked for
read performance regressions, because they require the block cache and
are traditionally latency-sensitive.

This change does some refactoring to avoid holding DB mutex and to
avoid triggering and waiting for a scan in GetProperty("rocksdb.cfstats").
Some tests have to be updated because now the stats collector is
populated in the Cache aggressively on DB startup rather than lazily.
(I hope to clean up some of this added complexity in the future.)

This change also ensures proper treatment of need_out_of_mutex for
non-int DB properties.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8538

Test Plan:
Added unit test logic that uses sync points to fail if the DB mutex
is held during a scan, covering the various ways that a scan might be
triggered.

Performance test - the known impact to holding the DB mutex is on
TransactionDB, and the easiest way to see the impact is to hack the
scan code to almost always miss and take an artificially long time
scanning. Here I've injected an unconditional 5s sleep at the call to
ApplyToAllEntries.

Before (hacked):

    $ TEST_TMPDIR=/dev/shm ./db_bench.base_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     433.219 micros/op 2308 ops/sec;    0.1 MB/s ( transactions:78999 aborts:0)
    rocksdb.db.write.micros P50 : 16.135883 P95 : 36.622503 P99 : 66.036115 P100 : 5000614.000000 COUNT : 149677 SUM : 8364856
    $ TEST_TMPDIR=/dev/shm ./db_bench.base_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     448.802 micros/op 2228 ops/sec;    0.1 MB/s ( transactions:75999 aborts:0)
    rocksdb.db.write.micros P50 : 16.629221 P95 : 37.320607 P99 : 72.144341 P100 : 5000871.000000 COUNT : 143995 SUM : 13472323

Notice the 5s P100 write time.

After (hacked):

    $ TEST_TMPDIR=/dev/shm ./db_bench.new_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     303.645 micros/op 3293 ops/sec;    0.1 MB/s ( transactions:98999 aborts:0)
    rocksdb.db.write.micros P50 : 16.061871 P95 : 33.978834 P99 : 60.018017 P100 : 616315.000000 COUNT : 187619 SUM : 4097407
    $ TEST_TMPDIR=/dev/shm ./db_bench.new_xxx -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     310.383 micros/op 3221 ops/sec;    0.1 MB/s ( transactions:96999 aborts:0)
    rocksdb.db.write.micros P50 : 16.270026 P95 : 35.786844 P99 : 64.302878 P100 : 603088.000000 COUNT : 183819 SUM : 4095918

P100 write is now ~0.6s. Not good, but it's the same even if I completely bypass all the scanning code:

    $ TEST_TMPDIR=/dev/shm ./db_bench.new_skip -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     311.365 micros/op 3211 ops/sec;    0.1 MB/s ( transactions:96999 aborts:0)
    rocksdb.db.write.micros P50 : 16.274362 P95 : 36.221184 P99 : 68.809783 P100 : 649808.000000 COUNT : 183819 SUM : 4156767
    $ TEST_TMPDIR=/dev/shm ./db_bench.new_skip -benchmarks=randomtransaction,stats -cache_index_and_filter_blocks=1 -bloom_bits=10 -partition_index_and_filters=1 -duration=30 -stats_dump_period_sec=12 -cache_size=100000000 -statistics -transaction_db 2>&1 | egrep 'db.db.write.micros|micros/op'
    randomtransaction :     308.395 micros/op 3242 ops/sec;    0.1 MB/s ( transactions:97999 aborts:0)
    rocksdb.db.write.micros P50 : 16.106222 P95 : 37.202403 P99 : 67.081875 P100 : 598091.000000 COUNT : 185714 SUM : 4098832

No substantial difference.

Reviewed By: siying

Differential Revision: D29738847

Pulled By: pdillinger

fbshipit-source-id: 1c5c155f5a1b62e4fea0fd4eeb515a8b7474027b
2021-07-16 14:13:08 -07:00
Peter Dillinger d5a46c40e5 Pin CacheEntryStatsCollector to fix performance bug (#8385)
Summary:
If the block Cache is full with strict_capacity_limit=false,
then our CacheEntryStatsCollector could be immediately evicted on
release, so iterating through column families with shared block cache
could trigger re-scan for each CF. This change fixes that problem by
pinning the CacheEntryStatsCollector from InternalStats so that it's not
evicted.

I had originally thought that this object could participate in LRU like
everything else, but even though a re-load+re-scan only touches memory,
it can be orders of magnitude more expensive than other cache misses.
One service in Facebook has scans that take ~20s over 100GB block cache
that is mostly 4KB entries. (The up-side of this bug and https://github.com/facebook/rocksdb/issues/8369 is that
we had a natural experiment on the effect on some service metrics even
with block cache scans running continuously in the background--a kind
of worst case scenario. Metrics like latency were not affected enough
to trigger warnings.)

Other smaller fixes:

20s is already a sizable portion of 600s stats dump period, or 180s
default max age to force re-scan, so added logic to ensure that (for
each block cache) we don't spend more than 0.2% of our background thread
time scanning it. Nevertheless, "foreground" requests for cache entry
stats (calls to `db->GetMapProperty(DB::Properties::kBlockCacheEntryStats)`)
are permitted to consume more CPU.

Renamed field to cache_entry_stats_ to match code style.

This change is intended for patching in 6.21 release.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8385

Test Plan:
unit test expanded to cover new logic (detect regression),
some manual testing with db_bench

Reviewed By: ajkr

Differential Revision: D29042759

Pulled By: pdillinger

fbshipit-source-id: 236faa902397f50038c618f50fbc8cf3f277308c
2021-06-14 08:15:11 -07:00
Peter Dillinger 2f93a3b809 Fix a major performance bug in 6.21 for cache entry stats (#8369)
Summary:
In final polishing of https://github.com/facebook/rocksdb/issues/8297 (after most manual testing), I
broke my own caching layer by sanitizing an input parameter with
std::min(0, x) instead of std::max(0, x). I resisted unit testing the
timing part of the result caching because historically, these test
are either flaky or difficult to write, and this was not a correctness
issue. This bug is essentially unnoticeable with a small number
of column families but can explode background work with a
large number of column families.

This change fixes the logical error, removes some unnecessary related
optimization, and adds mock time/sleeps to the unit test to ensure we
can cache hit within the age limit.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8369

Test Plan: added time testing logic to existing unit test

Reviewed By: ajkr

Differential Revision: D28950892

Pulled By: pdillinger

fbshipit-source-id: e79cd4ff3eec68fd0119d994f1ed468c38026c3b
2021-06-08 05:03:32 -07:00
PiyushDatta 2655477c67 Fix "Interval WAL" bytes to say GB instead of MB (#8350)
Summary:
Reference: https://github.com/facebook/rocksdb/issues/7201

Before fix:
`/tmp/rocksdb_test_file/LOG.old.1622492586055679:Interval WAL: 0 writes, 0 syncs, 0.00 writes per sync, written: 0.00 MB, 0.00 MB/s`

After fix:
`/tmp/rocksdb_test_file/LOG:Interval WAL: 0 writes, 0 syncs, 0.00 writes per sync, written: 0.00 GB, 0.00 MB/s`

Tests:
```
Computer:jobs running/jobs completed/%of started jobs/Average seconds to complete
ETA: 0s Left: 0 AVG: 0.05s  local:0/7720/100%/0.0s
rm -rf /dev/shm/rocksdb.CLRh
/usr/bin/python3 tools/check_all_python.py
No syntax errors in 34 .py files
/usr/bin/python3 tools/ldb_test.py
Running testCheckConsistency...
.Running testColumnFamilies...
.Running testCountDelimDump...
.Running testCountDelimIDump...
.Running testDumpLiveFiles...
.Running testDumpLoad...
Warning: 7 bad lines ignored.
.Running testGetProperty...
.Running testHexPutGet...
.Running testIDumpBasics...
.Running testIngestExternalSst...
.Running testInvalidCmdLines...
.Running testListColumnFamilies...
.Running testManifestDump...
.Running testMiscAdminTask...
Sequence,Count,ByteSize,Physical Offset,Key(s)
.Running testSSTDump...
.Running testSimpleStringPutGet...
.Running testStringBatchPut...
.Running testTtlPutGet...
.Running testWALDump...
.
----------------------------------------------------------------------
Ran 19 tests in 15.945s

OK
sh tools/rocksdb_dump_test.sh
make check-format
make[1]: Entering directory '/home/piydatta/Documents/rocksdb'
$DEBUG_LEVEL is 1
Makefile:176: Warning: Compiling in debug mode. Don't use the resulting binary in production
build_tools/format-diff.sh -c
Checking format of uncommitted changes...
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8350

Reviewed By: jay-zhuang

Differential Revision: D28790567

Pulled By: zhichao-cao

fbshipit-source-id: dcb1e4c124361156435122f21f0a288335b2c8c8
2021-06-01 15:19:21 -07:00
Peter Dillinger 311a544c2a Use deleters to label cache entries and collect stats (#8297)
Summary:
This change gathers and publishes statistics about the
kinds of items in block cache. This is especially important for
profiling relative usage of cache by index vs. filter vs. data blocks.
It works by iterating over the cache during periodic stats dump
(InternalStats, stats_dump_period_sec) or on demand when
DB::Get(Map)Property(kBlockCacheEntryStats), except that for
efficiency and sharing among column families, saved data from
the last scan is used when the data is not considered too old.

The new information can be seen in info LOG, for example:

    Block cache LRUCache@0x7fca62229330 capacity: 95.37 MB collections: 8 last_copies: 0 last_secs: 0.00178 secs_since: 0
    Block cache entry stats(count,size,portion): DataBlock(7092,28.24 MB,29.6136%) FilterBlock(215,867.90 KB,0.888728%) FilterMetaBlock(2,5.31 KB,0.00544%) IndexBlock(217,180.11 KB,0.184432%) WriteBuffer(1,256.00 KB,0.262144%) Misc(1,0.00 KB,0%)

And also through DB::GetProperty and GetMapProperty (here using
ldb just for demonstration):

    $ ./ldb --db=/dev/shm/dbbench/ get_property rocksdb.block-cache-entry-stats
    rocksdb.block-cache-entry-stats.bytes.data-block: 0
    rocksdb.block-cache-entry-stats.bytes.deprecated-filter-block: 0
    rocksdb.block-cache-entry-stats.bytes.filter-block: 0
    rocksdb.block-cache-entry-stats.bytes.filter-meta-block: 0
    rocksdb.block-cache-entry-stats.bytes.index-block: 178992
    rocksdb.block-cache-entry-stats.bytes.misc: 0
    rocksdb.block-cache-entry-stats.bytes.other-block: 0
    rocksdb.block-cache-entry-stats.bytes.write-buffer: 0
    rocksdb.block-cache-entry-stats.capacity: 8388608
    rocksdb.block-cache-entry-stats.count.data-block: 0
    rocksdb.block-cache-entry-stats.count.deprecated-filter-block: 0
    rocksdb.block-cache-entry-stats.count.filter-block: 0
    rocksdb.block-cache-entry-stats.count.filter-meta-block: 0
    rocksdb.block-cache-entry-stats.count.index-block: 215
    rocksdb.block-cache-entry-stats.count.misc: 1
    rocksdb.block-cache-entry-stats.count.other-block: 0
    rocksdb.block-cache-entry-stats.count.write-buffer: 0
    rocksdb.block-cache-entry-stats.id: LRUCache@0x7f3636661290
    rocksdb.block-cache-entry-stats.percent.data-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.deprecated-filter-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.filter-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.filter-meta-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.index-block: 2.133751
    rocksdb.block-cache-entry-stats.percent.misc: 0.000000
    rocksdb.block-cache-entry-stats.percent.other-block: 0.000000
    rocksdb.block-cache-entry-stats.percent.write-buffer: 0.000000
    rocksdb.block-cache-entry-stats.secs_for_last_collection: 0.000052
    rocksdb.block-cache-entry-stats.secs_since_last_collection: 0

Solution detail - We need some way to flag what kind of blocks each
entry belongs to, preferably without changing the Cache API.
One of the complications is that Cache is a general interface that could
have other users that don't adhere to whichever convention we decide
on for keys and values. Or we would pay for an extra field in the Handle
that would only be used for this purpose.

This change uses a back-door approach, the deleter, to indicate the
"role" of a Cache entry (in addition to the value type, implicitly).
This has the added benefit of ensuring proper code origin whenever we
recognize a particular role for a cache entry; if the entry came from
some other part of the code, it will use an unrecognized deleter, which
we simply attribute to the "Misc" role.

An internal API makes for simple instantiation and automatic
registration of Cache deleters for a given value type and "role".

Another internal API, CacheEntryStatsCollector, solves the problem of
caching the results of a scan and sharing them, to ensure scans are
neither excessive nor redundant so as not to harm Cache performance.

Because code is added to BlocklikeTraits, it is pulled out of
block_based_table_reader.cc into its own file.

This is a reformulation of https://github.com/facebook/rocksdb/issues/8276, without the type checking option
(could still be added), and with actual stat gathering.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8297

Test Plan: manual testing with db_bench, and a couple of basic unit tests

Reviewed By: ltamasi

Differential Revision: D28488721

Pulled By: pdillinger

fbshipit-source-id: 472f524a9691b5afb107934be2d41d84f2b129fb
2021-05-19 16:51:13 -07:00
mrambacher 01e460d538 Make types of Immutable/Mutable Options fields match that of the underlying Option (#8176)
Summary:
This PR is a first step at attempting to clean up some of the Mutable/Immutable Options code.  With this change, a DBOption and a ColumnFamilyOption can be reconstructed from their Mutable and Immutable equivalents, respectively.

readrandom tests do not show any performance degradation versus master (though both are slightly slower than the current 6.19 release).

There are still fields in the ImmutableCFOptions that are not CF options but DB options.  Eventually, I would like to move those into an ImmutableOptions (= ImmutableDBOptions+ImmutableCFOptions).  But that will be part of a future PR to minimize changes and disruptions.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8176

Reviewed By: pdillinger

Differential Revision: D27954339

Pulled By: mrambacher

fbshipit-source-id: ec6b805ba9afe6e094bffdbd76246c2d99aa9fad
2021-04-22 20:43:54 -07:00
Levi Tamasi 0c6e4674a6 Fix a data race related to DB properties (#8206)
Summary:
Historically, the DB properties `rocksdb.cur-size-active-mem-table`,
`rocksdb.cur-size-all-mem-tables`, and `rocksdb.size-all-mem-tables` called
the method `MemTable::ApproximateMemoryUsage` for mutable memtables,
which is not safe without synchronization. This resulted in data races with
memtable inserts. The patch changes the code handling these properties
to use `MemTable::ApproximateMemoryUsageFast` instead, which returns a
cached value backed by an atomic variable. Two test cases had to be updated
for this change. `MemoryTest.MemTableAndTableReadersTotal` was fixed by
increasing the value size used so each value ends up in its own memtable,
which was the original intention (note: the test has been broken in the sense
that the test code didn't consider that memtable sizes below 64 KB get
increased to 64 KB by `SanitizeOptions`, and has been passing only by
accident). `DBTest.MemoryUsageWithMaxWriteBufferSizeToMaintain` relies on
completely up-to-date values and thus was changed to use `ApproximateMemoryUsage`
directly instead of going through the DB properties. Note: this should be safe in this case
since there's only a single thread involved.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8206

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D27866811

Pulled By: ltamasi

fbshipit-source-id: 7bd754d0565e0a65f1f7f0e78ffc093beef79394
2021-04-19 16:38:02 -07:00
Levi Tamasi cb25bc1128 Update compaction statistics to include the amount of data read from blob files (#8022)
Summary:
The patch does the following:
1) Exposes the amount of data (number of bytes) read from blob files from
`BlobFileReader::GetBlob` / `Version::GetBlob`.
2) Tracks the total number and size of blobs read from blob files during a
compaction (due to garbage collection or compaction filter usage) in
`CompactionIterationStats` and propagates this data to
`InternalStats::CompactionStats` / `CompactionJobStats`.
3) Updates the formulae for write amplification calculations to include the
amount of data read from blob files.
4) Extends the compaction stats dump with a new column `Rblob(GB)` and
a new line containing the total number and size of blob files in the current
`Version` to complement the information about the shape and size of the LSM tree
that's already there.
5) Updates `CompactionJobStats` so that the number of files and amount of data
written by a compaction are broken down per file type (i.e. table/blob file).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8022

Test Plan: Ran `make check` and `db_bench`.

Reviewed By: riversand963

Differential Revision: D26801199

Pulled By: ltamasi

fbshipit-source-id: 28a5f072048a702643b28cb5971b4099acabbfb2
2021-03-04 00:43:48 -08:00
Levi Tamasi a46f080cce Break down the amount of data written during flushes/compactions per file type (#8013)
Summary:
The patch breaks down the "bytes written" (as well as the "number of output files")
compaction statistics into two, so the values are logged separately for table files
and blob files in the info log, and are shown in separate columns (`Write(GB)` for table
files, `Wblob(GB)` for blob files) when the compaction statistics are dumped.
This will also come in handy for fixing the write amplification statistics, which currently
do not consider the amount of data read from blob files during compaction. (This will
be fixed by an upcoming patch.)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8013

Test Plan: Ran `make check` and `db_bench`.

Reviewed By: riversand963

Differential Revision: D26742156

Pulled By: ltamasi

fbshipit-source-id: 31d18ee8f90438b438ca7ed1ea8cbd92114442d5
2021-03-02 09:48:00 -08:00
mrambacher 12f1137355 Add a SystemClock class to capture the time functions of an Env (#7858)
Summary:
Introduces and uses a SystemClock class to RocksDB.  This class contains the time-related functions of an Env and these functions can be redirected from the Env to the SystemClock.

Many of the places that used an Env (Timer, PerfStepTimer, RepeatableThread, RateLimiter, WriteController) for time-related functions have been changed to use SystemClock instead.  There are likely more places that can be changed, but this is a start to show what can/should be done.  Over time it would be nice to migrate most (if not all) of the uses of the time functions from the Env to the SystemClock.

There are several Env classes that implement these functions.  Most of these have not been converted yet to SystemClock implementations; that will come in a subsequent PR.  It would be good to unify many of the Mock Timer implementations, so that they behave similarly and be tested similarly (some override Sleep, some use a MockSleep, etc).

Additionally, this change will allow new methods to be introduced to the SystemClock (like https://github.com/facebook/rocksdb/issues/7101 WaitFor) in a consistent manner across a smaller number of classes.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7858

Reviewed By: pdillinger

Differential Revision: D26006406

Pulled By: mrambacher

fbshipit-source-id: ed10a8abbdab7ff2e23d69d85bd25b3e7e899e90
2021-01-25 22:09:11 -08:00
Peter Dillinger 4d1ac19e3d aggregated-table-properties with GetMapProperty (#7779)
Summary:
So that we can more easily get aggregate live table data such
as total filter, index, and data sizes.

Also adds ldb support for getting properties

Also fixed some missing/inaccurate related comments in db.h

For example:

    $ ./ldb --db=testdb get_property rocksdb.aggregated-table-properties
    rocksdb.aggregated-table-properties.data_size: 102871
    rocksdb.aggregated-table-properties.filter_size: 0
    rocksdb.aggregated-table-properties.index_partitions: 0
    rocksdb.aggregated-table-properties.index_size: 2232
    rocksdb.aggregated-table-properties.num_data_blocks: 100
    rocksdb.aggregated-table-properties.num_deletions: 0
    rocksdb.aggregated-table-properties.num_entries: 15000
    rocksdb.aggregated-table-properties.num_merge_operands: 0
    rocksdb.aggregated-table-properties.num_range_deletions: 0
    rocksdb.aggregated-table-properties.raw_key_size: 288890
    rocksdb.aggregated-table-properties.raw_value_size: 198890
    rocksdb.aggregated-table-properties.top_level_index_size: 0
    $ ./ldb --db=testdb get_property rocksdb.aggregated-table-properties-at-level1
    rocksdb.aggregated-table-properties-at-level1.data_size: 80909
    rocksdb.aggregated-table-properties-at-level1.filter_size: 0
    rocksdb.aggregated-table-properties-at-level1.index_partitions: 0
    rocksdb.aggregated-table-properties-at-level1.index_size: 1787
    rocksdb.aggregated-table-properties-at-level1.num_data_blocks: 81
    rocksdb.aggregated-table-properties-at-level1.num_deletions: 0
    rocksdb.aggregated-table-properties-at-level1.num_entries: 12466
    rocksdb.aggregated-table-properties-at-level1.num_merge_operands: 0
    rocksdb.aggregated-table-properties-at-level1.num_range_deletions: 0
    rocksdb.aggregated-table-properties-at-level1.raw_key_size: 238210
    rocksdb.aggregated-table-properties-at-level1.raw_value_size: 163414
    rocksdb.aggregated-table-properties-at-level1.top_level_index_size: 0
    $

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7779

Test Plan: Added a test to ldb_test.py

Reviewed By: jay-zhuang

Differential Revision: D25653103

Pulled By: pdillinger

fbshipit-source-id: 2905469a08a64dd6b5510cbd7be2e64d3234d6d3
2020-12-19 08:00:14 -08:00
Akanksha Mahajan 20c7d7c58a Handling misuse of snprintf return value (#7686)
Summary:
Handle misuse of snprintf return value to avoid Out of bound
read/write.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7686

Test Plan: make check -j64

Reviewed By: riversand963

Differential Revision: D25030831

Pulled By: akankshamahajan15

fbshipit-source-id: 1a1d181c067c78b94d720323ae00b79566b57cfa
2020-12-07 13:43:55 -08:00
Levi Tamasi bb69b4ce7f Fix InternalStats::DumpCFStats (#7666)
Summary:
https://github.com/facebook/rocksdb/pull/7461 accidentally broke
`InternalStats::DumpCFStats` by making `DumpCFFileHistogram` overwrite
the output of `DumpCFStatsNoFileHistogram` instead of appending to it,
resulting in only the file histogram related information getting logged.
The patch fixes this by reverting to appending in `DumpCFFileHistogram`.

Fixes https://github.com/facebook/rocksdb/issues/7664 .

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7666

Test Plan: Ran `make check` and checked the info log of `db_bench`.

Reviewed By: riversand963

Differential Revision: D24929051

Pulled By: ltamasi

fbshipit-source-id: 636a3d5ebb5ce23de4f3fe4f03ad3f16cb2858f8
2020-11-12 17:33:04 -08:00
Levi Tamasi 22655a398b Introduce a blob file reader class (#7461)
Summary:
The patch adds a class called `BlobFileReader` that can be used to retrieve blobs
using the information available in blob references (e.g. blob file number, offset, and
size). This will come in handy when implementing blob support for `Get`, `MultiGet`,
and iterators, and also for compaction/garbage collection.

When a `BlobFileReader` object is created (using the factory method `Create`),
it first checks whether the specified file is potentially valid by comparing the file
size against the combined size of the blob file header and footer (files smaller than
the threshold are considered malformed). Then, it opens the file, and reads and verifies
the header and footer. The verification involves magic number/CRC checks
as well as checking for unexpected header/footer fields, e.g. incorrect column family ID
or TTL blob files.

Blobs can be retrieved using `GetBlob`. `GetBlob` validates the offset and compression
type passed by the caller (because of the presence of the header and footer, the
specified offset cannot be too close to the start/end of the file; also, the compression type
has to match the one in the blob file header), and retrieves and potentially verifies and
uncompresses the blob. In particular, when `ReadOptions::verify_checksums` is set,
`BlobFileReader` reads the blob record header as well (as opposed to just the blob itself)
and verifies the key/value size, the key itself, as well as the CRC of the blob record header
and the key/value pair.

In addition, the patch exposes the compression type from `BlobIndex` (both using an
accessor and via `DebugString`), and adds a blob file read latency histogram to
`InternalStats` that can be used with `BlobFileReader`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7461

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D23999219

Pulled By: ltamasi

fbshipit-source-id: deb6b1160d251258b308d5156e2ec063c3e12e5e
2020-10-07 15:44:53 -07:00
mrambacher 7d472accdc Bring the Configurable options together (#5753)
Summary:
This PR merges the functionality of making the ColumnFamilyOptions, TableFactory, and DBOptions into Configurable into a single PR, resolving any merge conflicts

Pull Request resolved: https://github.com/facebook/rocksdb/pull/5753

Reviewed By: ajkr

Differential Revision: D23385030

Pulled By: zhichao-cao

fbshipit-source-id: 8b977a7731556230b9b8c5a081b98e49ee4f160a
2020-09-14 17:01:01 -07:00
Yanqin Jin e66199d848 First step towards handling MANIFEST write error (#6949)
Summary:
This PR provides preliminary support for handling IO error during MANIFEST write.
File write/sync is not guaranteed to be atomic. If we encounter an IOError while writing/syncing to the MANIFEST file, we cannot be sure about the state of the MANIFEST file. The version edits may or may not have reached the file. During cleanup, if we delete the newly-generated SST files referenced by the pending version edit(s), but the version edit(s) actually are persistent in the MANIFEST, then next recovery attempt will process the version edits(s) and then fail since the SST files have already been deleted.
One approach is to truncate the MANIFEST after write/sync error, so that it is safe to delete the SST files. However, file truncation may not be supported on certain file systems. Therefore, we take the following approach.
If an IOError is detected during MANIFEST write/sync, we disable file deletions for the faulty database. Depending on whether the IOError is retryable (set by underlying file system), either RocksDB or application can call `DB::Resume()`, or simply shutdown and restart. During `Resume()`, RocksDB will try to switch to a new MANIFEST and write all existing in-memory version storage in the new file. If this succeeds, then RocksDB may proceed. If all recovery is completed, then file deletions will be re-enabled.
Note that multiple threads can call `LogAndApply()` at the same time, though only one of them will be going through the process MANIFEST write, possibly batching the version edits of other threads. When the leading MANIFEST writer finishes, all of the MANIFEST writing threads in this batch will have the same IOError. They will all call `ErrorHandler::SetBGError()` in which file deletion will be disabled.

Possible future directions:
- Add an `ErrorContext` structure so that it is easier to pass more info to `ErrorHandler`. Currently, as in this example, a new `BackgroundErrorReason` has to be added.

Test plan (dev server):
make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6949

Reviewed By: anand1976

Differential Revision: D22026020

Pulled By: riversand963

fbshipit-source-id: f3c68a2ef45d9b505d0d625c7c5e0c88495b91c8
2020-06-24 19:07:08 -07:00
sdong fdf882ded2 Replace namespace name "rocksdb" with ROCKSDB_NAMESPACE (#6433)
Summary:
When dynamically linking two binaries together, different builds of RocksDB from two sources might cause errors. To provide a tool for user to solve the problem, the RocksDB namespace is changed to a flag which can be overridden in build time.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6433

Test Plan: Build release, all and jtest. Try to build with ROCKSDB_NAMESPACE with another flag.

Differential Revision: D19977691

fbshipit-source-id: aa7f2d0972e1c31d75339ac48478f34f6cfcfb3e
2020-02-20 12:09:57 -08:00
Yanqin Jin cfd9732f65 Remove inaccurate code comment (#6274)
Summary:
Remove a comment.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6274

Differential Revision: D19323151

Pulled By: riversand963

fbshipit-source-id: d0d804d6882edcd94e35544ef45578b32ff1caae
2020-01-08 17:51:42 -08:00
Connor1996 3e26a94ba1 Add oldest snapshot sequence property (#6228)
Summary:
Add oldest snapshot sequence property, so we can use `db.GetProperty("rocksdb.oldest-snapshot-sequence")` to get the sequence number of the oldest snapshot.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6228

Differential Revision: D19264145

Pulled By: maysamyabandeh

fbshipit-source-id: 67fbe5304d89cbc475bd404e30d1299f7b11c010
2020-01-07 08:36:44 -08:00
sdong e8263dbdaa Apply formatter to recent 200+ commits. (#5830)
Summary:
Further apply formatter to more recent commits.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5830

Test Plan: Run all existing tests.

Differential Revision: D17488031

fbshipit-source-id: 137458fd94d56dd271b8b40c522b03036943a2ab
2019-09-20 12:04:26 -07:00
sdong adbc25a4c8 Rename InternalDBStatsType enum names (#5779)
Summary:
When building with clang 9, warning is reported for InternalDBStatsType type names shadowed the one for statistics. Rename them.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5779

Test Plan: Build with clang 9 and see it passes.

Differential Revision: D17239378

fbshipit-source-id: af28fb42066c738cd1b841f9fe21ab4671dafd18
2019-09-06 17:31:10 -07:00
Zhongyi Xie d68f9f4580 simplify include directive involving inttypes (#5402)
Summary:
When using `PRIu64` type of printf specifier, current code base does the following:
```
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
```
However, this can be simplified to
```
#include <cinttypes>
```
as long as flag `-std=c++11` is used.
This should solve issues like https://github.com/facebook/rocksdb/issues/5159
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5402

Differential Revision: D15701195

Pulled By: miasantreble

fbshipit-source-id: 6dac0a05f52aadb55e9728038599d3d2e4b59d03
2019-06-06 13:56:07 -07:00
Vijay Nadimpalli 49c5a12dbe Organizing rocksdb/db directory
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5390

Differential Revision: D15579388

Pulled By: vjnadimpalli

fbshipit-source-id: 5bfc95e31554b8ff05b97b76d6534113f527f366
2019-05-31 11:57:01 -07:00