Commit graph

348 commits

Author SHA1 Message Date
Bo Wang c073ed7601 Fix typo in comments and code (#10233)
Summary:
Fix typo in comments and code.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10233

Test Plan: Existing unit tests should pass.

Reviewed By: jay-zhuang, anand1976

Differential Revision: D37356702

Pulled By: gitbw95

fbshipit-source-id: 32c019adcc6dcc95a9882b38147a310091368e51
2022-06-22 15:45:21 -07:00
Peter Dillinger 84210c9489 Add data block hash index to crash test, fix MultiGet issue (#10220)
Summary:
There was a bug in the MultiGet enhancement in https://github.com/facebook/rocksdb/issues/9899 with data
block hash index, which was not caught because data block hash index was
never added to stress tests. This change fixes both issues.

Fixes https://github.com/facebook/rocksdb/issues/10186

I intend to pick this into the 7.4.0 release candidate

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10220

Test Plan:
Failure quickly reproduces in crash test with
kDataBlockBinaryAndHash, and does not seem to with the fix. Reproducing
the failure with a unit test I believe would be too tricky and fragile
to be worthwhile.

Reviewed By: anand1976

Differential Revision: D37315647

Pulled By: pdillinger

fbshipit-source-id: 9f648265bba867275edc752f7a56611a59401cba
2022-06-21 16:23:58 -07:00
Peter Dillinger fff302d989 More testing w/prefix extractor, small refactor (#10122)
Summary:
There was an interesting code path not covered by testing that
is difficult to replicate in a unit test, which is now covered using a
sync point. Specifically, the case of table_prefix_extractor == null and
!need_upper_bound_check in `BlockBasedTable::PrefixMayMatch`, which
can happen if table reader is open before extractor is registered with global
object registry, but is later registered and re-set with SetOptions. (We
don't have sufficient testing control over object registry to set that up
repeatedly.)

Also, this function has been renamed to `PrefixRangeMayMatch` for clarity
vs. other functions that are not the same.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10122

Test Plan: unit tests expanded

Reviewed By: siying

Differential Revision: D36944834

Pulled By: pdillinger

fbshipit-source-id: 9e52d9da1929a3e42bbc230fcdc3599949de7bdb
2022-06-16 16:41:25 -07:00
Peter Dillinger 126c223714 Remove deprecated block-based filter (#10184)
Summary:
In https://github.com/facebook/rocksdb/issues/9535, release 7.0, we hid the old block-based filter from being created using
the public API, because of its inefficiency. Although we normally maintain read compatibility
on old DBs forever, filters are not required for reading a DB, only for optimizing read
performance. Thus, it should be acceptable to remove this code and the substantial
maintenance burden it carries as useful features are developed and validated (such
as user timestamp).

This change completely removes the code for reading and writing the old block-based
filters, net removing about 1370 lines of code no longer needed. Options removed from
testing / benchmarking tools. The prior existence is only evident in a couple of places:
* `CacheEntryRole::kDeprecatedFilterBlock` - We can update this public API enum in
a major release to minimize source code incompatibilities.
* A warning is logged when an old table file is opened that used the old block-based
filter. This is provided as a courtesy, and would be a pain to unit test, so manual testing
should suffice. Unfortunately, sst_dump does not tell you whether a file uses
block-based filter, and the structure of the code makes it very difficult to fix.
* To detect that case, `kObsoleteFilterBlockPrefix` (renamed from `kFilterBlockPrefix`)
for metaindex is maintained (for now).

Other notes:
* In some cases where numbers are associated with filter configurations, we have had to
update the assigned numbers so that they all correspond to something that exists.
* Fixed potential stat counting bug by assuming `filter_checked = false` for cases
like `filter == nullptr` rather than assuming `filter_checked = true`
* Removed obsolete `block_offset` and `prefix_extractor` parameters from several
functions.
* Removed some unnecessary checks `if (!table_prefix_extractor() && !prefix_extractor)`
because the caller guarantees the prefix extractor exists and is compatible

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10184

Test Plan:
tests updated, manually test new warning in LOG using base version to
generate a DB

Reviewed By: riversand963

Differential Revision: D37212647

Pulled By: pdillinger

fbshipit-source-id: 06ee020d8de3b81260ffc36ad0c1202cbf463a80
2022-06-16 15:51:33 -07:00
anand76 a6691d0f65 Update stats to help users estimate MultiGet async IO impact (#10182)
Summary:
Add a couple of stats to help users estimate the impact of potential MultiGet perf improvements -
1. NUM_LEVEL_READ_PER_MULTIGET - A histogram stat for number of levels that required MultiGet to read from a file
2. MULTIGET_COROUTINE_COUNT - A ticker stat to count the number of times the coroutine version of MultiGetFromSST was used

The NUM_DATA_BLOCKS_READ_PER_LEVEL stat is obsoleted as it doesn't provide useful information for MultiGet optimization.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10182

Reviewed By: akankshamahajan15

Differential Revision: D37213296

Pulled By: anand1976

fbshipit-source-id: 5d2b7708017c0e278578ae4bffac3926f6530efb
2022-06-16 12:12:43 -07:00
Akanksha Mahajan 8353ae8b27 Add few optimizations in async_io for short scans (#10140)
Summary:
This PR adds few optimizations for async_io for shorter scans.
1.  If async_io is enabled, seek would create FilePrefetchBuffer object to fetch the data asynchronously. However `FilePrefetchbuffer::num_file_reads_` wasn't taken into consideration if it calls Next after Seek and would go for Prefetching.  This PR fixes that and Next will go for prefetching only if `FilePrefetchbuffer::num_file_reads_` is greater than 2 along with if blocks are sequential. This scenario is only for implicit auto readahead.
2. For seek, when it calls TryReadFromCacheAsync to poll it makes async call as well because TryReadFromCacheAsync flow wasn't changed. So I updated to return after poll instead of further prefetching any data.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10140

Test Plan:
1. Added a unit test
                  2. Ran crash_test with async_io = 1 to make sure nothing crashes.

Reviewed By: anand1976

Differential Revision: D37042242

Pulled By: akankshamahajan15

fbshipit-source-id: b8e6b7cb2ee0886f37a8f53951948b9084e8ffda
2022-06-15 20:17:35 -07:00
Gang Liao cba398df8a Add blob cache option in the column family options (#10155)
Summary:
There is currently no caching mechanism for blobs, which is not ideal especially when the database resides on remote storage (where we cannot rely on the OS page cache). As part of this task, we would like to make it possible for the application to configure a blob cache.
This PR is a part of https://github.com/facebook/rocksdb/issues/10156

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10155

Reviewed By: ltamasi

Differential Revision: D37150819

Pulled By: gangliao

fbshipit-source-id: b807c7916ea5d411588128f8e22a49f171388fe2
2022-06-14 14:19:26 -07:00
Hui Xiao d665afdbf3 Account memory of FileMetaData in global memory limit (#9924)
Summary:
**Context/Summary:**
As revealed by heap profiling, allocation of `FileMetaData` for [newly created file added to a Version](https://github.com/facebook/rocksdb/pull/9924/files#diff-a6aa385940793f95a2c5b39cc670bd440c4547fa54fd44622f756382d5e47e43R774) can consume significant heap memory. This PR is to account that toward our global memory limit based on block cache capacity.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9924

Test Plan:
- Previous `make check` verified there are only 2 places where the memory of  the allocated `FileMetaData` can be released
- New unit test `TEST_P(ChargeFileMetadataTestWithParam, Basic)`
- db bench (CPU cost of `charge_file_metadata` in write and compact)
   - **write micros/op: -0.24%** : `TEST_TMPDIR=/dev/shm/testdb ./db_bench -benchmarks=fillseq -db=$TEST_TMPDIR -charge_file_metadata=1 (remove this option for pre-PR) -disable_auto_compactions=1 -write_buffer_size=100000 -num=4000000 | egrep 'fillseq'`
   - **compact micros/op -0.87%** : `TEST_TMPDIR=/dev/shm/testdb ./db_bench -benchmarks=fillseq -db=$TEST_TMPDIR -charge_file_metadata=1 -disable_auto_compactions=1 -write_buffer_size=100000 -num=4000000 -numdistinct=1000 && ./db_bench -benchmarks=compact -db=$TEST_TMPDIR -use_existing_db=1 -charge_file_metadata=1 -disable_auto_compactions=1 | egrep 'compact'`

table 1 - write

#-run | (pre-PR) avg micros/op | std micros/op | (post-PR)  micros/op | std micros/op | change (%)
-- | -- | -- | -- | -- | --
10 | 3.9711 | 0.264408 | 3.9914 | 0.254563 | 0.5111933721
20 | 3.83905 | 0.0664488 | 3.8251 | 0.0695456 | -0.3633711465
40 | 3.86625 | 0.136669 | 3.8867 | 0.143765 | 0.5289363078
80 | 3.87828 | 0.119007 | 3.86791 | 0.115674 | **-0.2673865734**
160 | 3.87677 | 0.162231 | 3.86739 | 0.16663 | **-0.2419539978**

table 2 - compact

#-run | (pre-PR) avg micros/op | std micros/op | (post-PR)  micros/op | std micros/op | change (%)
-- | -- | -- | -- | -- | --
10 | 2,399,650.00 | 96,375.80 | 2,359,537.00 | 53,243.60 | -1.67
20 | 2,410,480.00 | 89,988.00 | 2,433,580.00 | 91,121.20 | 0.96
40 | 2.41E+06 | 121811 | 2.39E+06 | 131525 | **-0.96**
80 | 2.40E+06 | 134503 | 2.39E+06 | 108799 | **-0.78**

- stress test: `python3 tools/db_crashtest.py blackbox --charge_file_metadata=1  --cache_size=1` killed as normal

Reviewed By: ajkr

Differential Revision: D36055583

Pulled By: hx235

fbshipit-source-id: b60eab94707103cb1322cf815f05810ef0232625
2022-06-14 13:06:40 -07:00
Peter Dillinger d3a3b02134 Fix bug with kHashSearch and changing prefix_extractor with SetOptions (#10128)
Summary:
When opening an SST file created using index_type=kHashSearch,
the *current* prefix_extractor would be saved, and used with hash index
if the *new current* prefix_extractor at query time is compatible with
the SST file. This is a problem if the prefix_extractor at SST open time
is not compatible but SetOptions later changes (back) to one that is
compatible.

This change fixes that by using the known compatible (or missing) prefix
extractor we save for use with prefix filtering. Detail: I have moved the
InternalKeySliceTransform wrapper to avoid some indirection and remove
unnecessary fields.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10128

Test Plan:
expanded unit test (using some logic from https://github.com/facebook/rocksdb/issues/10122) that fails
before fix and probably covers some other previously uncovered cases.

Reviewed By: siying

Differential Revision: D36955738

Pulled By: pdillinger

fbshipit-source-id: 0c78a6b0d24054ef2f3cb237bf010c1c5589fb10
2022-06-10 08:51:45 -07:00
Peter Dillinger 4f78f9699b Refactor: Add BlockTypes to make them imply C++ type in block cache (#10098)
Summary:
We have three related concepts:
* BlockType: an internal enum conceptually indicating a type of SST file
block
* CacheEntryRole: a user-facing enum for categorizing block cache entries,
which is also involved in associated cache entries with an appropriate
deleter. Can include categories for non-block cache entries (e.g. memory
reservations).
* TBlocklike: a C++ type for the actual type behind a void* cache entry.

We had some existing code ugliness because BlockType did not imply
TBlocklike, because of various kinds of "filter" block. This refactoring
fixes that with new BlockTypes.

More clean-up can come in later work.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10098

Test Plan: existing tests

Reviewed By: akankshamahajan15

Differential Revision: D36897945

Pulled By: pdillinger

fbshipit-source-id: 3ae496b5caa81e0a0ed85e873eb5b525e2d9a295
2022-06-06 11:16:12 -07:00
Hui Xiao 4bdcc80192 Increase ChargeTableReaderTest/ChargeTableReaderTest.Basic error tolerance rate from 1% to 5% (#10113)
Summary:
**Context:**
https://github.com/facebook/rocksdb/pull/9748 added support to charge table reader memory to block cache. In the test `ChargeTableReaderTest/ChargeTableReaderTest.Basic`, it estimated the table reader memory, calculated the expected number of table reader opened based on this estimation and asserted this number with actual number. The expected number of table reader opened calculated based on estimated table reader memory will not be 100% accurate and should have tolerance for error. It was previously set to 1% and recently encountered an assertion failure that `(opened_table_reader_num) <= (max_table_reader_num_capped_upper_bound), actual: 375 or 376 vs 374` where `opened_table_reader_num` is the actual opened one and `max_table_reader_num_capped_upper_bound` is the estimated opened one (=371 * 1.01). I believe it's safe to increase error tolerance from 1% to 5% hence there is this PR.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10113

Test Plan: - CI again succeeds.

Reviewed By: ajkr

Differential Revision: D36911556

Pulled By: hx235

fbshipit-source-id: 259687dd77b450fea0f5658a5b567a1d31d4b1f7
2022-06-03 19:42:22 -07:00
Akanksha Mahajan 2db6a4a1d6 Seek parallelization (#9994)
Summary:
The RocksDB iterator is a hierarchy of iterators. MergingIterator maintains a heap of LevelIterators, one for each L0 file and for each non-zero level. The Seek() operation naturally lends itself to parallelization, as it involves positioning every LevelIterator on the correct data block in the correct SST file. It lookups a level for a target key, to find the first key that's >= the target key. This typically involves reading one data block that is likely to contain the target key, and scan forward to find the first valid key. The forward scan may read more data blocks. In order to find the right data block, the iterator may read some metadata blocks (required for opening a file and searching the index).
This flow can be parallelized.

Design: Seek will be called two times under async_io option. First seek will send asynchronous request to prefetch the data blocks at each level and second seek will follow the normal flow and in FilePrefetchBuffer::TryReadFromCacheAsync it will wait for the Poll() to get the results and add the iterator to min_heap.
- Status::TryAgain is passed down from FilePrefetchBuffer::PrefetchAsync to block_iter_.Status indicating asynchronous request has been submitted.
- If for some reason asynchronous request returns error in submitting the request, it will fallback to sequential reading of blocks in one pass.
- If the data already exists in prefetch_buffer, it will return the data without prefetching further and it will be treated as single pass of seek.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9994

Test Plan:
- **Run Regressions.**
```
./db_bench -db=/tmp/prefix_scan_prefetch_main -benchmarks="fillseq" -key_size=32 -value_size=512 -num=5000000 -use_direct_io_for_flush_and_compaction=true -target_file_size_base=16777216
```
i) Previous release 7.0 run for normal prefetching with async_io disabled:
```
./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 7.0
Date:       Thu Mar 17 13:11:34 2022
CPU:        24 * Intel Core Processor (Broadwell)
CPUCache:   16384 KB
Keys:       32 bytes each (+ 0 bytes user-defined timestamp)
Values:     512 bytes each (256 bytes after compression)
Entries:    5000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    2594.0 MB (estimated)
FileSize:   1373.3 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: Snappy
Compression sampling rate: 0
Memtablerep: SkipListFactory
Perf Level: 1
------------------------------------------------
DB path: [/tmp/prefix_scan_prefetch_main]
seekrandom   :  483618.390 micros/op 2 ops/sec;  338.9 MB/s (249 of 249 found)
```

ii) normal prefetching after changes with async_io disable:
```
./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1
Set seed to 1652922591315307 because --seed was 0
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 7.3
Date:       Wed May 18 18:09:51 2022
CPU:        32 * Intel Xeon Processor (Skylake)
CPUCache:   16384 KB
Keys:       32 bytes each (+ 0 bytes user-defined timestamp)
Values:     512 bytes each (256 bytes after compression)
Entries:    5000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    2594.0 MB (estimated)
FileSize:   1373.3 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: Snappy
Compression sampling rate: 0
Memtablerep: SkipListFactory
Perf Level: 1
------------------------------------------------
DB path: [/tmp/prefix_scan_prefetch_main]
seekrandom   :  483080.466 micros/op 2 ops/sec 120.287 seconds 249 operations;  340.8 MB/s (249 of 249 found)
```
iii) db_bench with async_io enabled completed succesfully

```
./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1 -async_io=1 -adaptive_readahead=1
Set seed to 1652924062021732 because --seed was 0
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 7.3
Date:       Wed May 18 18:34:22 2022
CPU:        32 * Intel Xeon Processor (Skylake)
CPUCache:   16384 KB
Keys:       32 bytes each (+ 0 bytes user-defined timestamp)
Values:     512 bytes each (256 bytes after compression)
Entries:    5000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    2594.0 MB (estimated)
FileSize:   1373.3 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: Snappy
Compression sampling rate: 0
Memtablerep: SkipListFactory
Perf Level: 1
------------------------------------------------
DB path: [/tmp/prefix_scan_prefetch_main]
seekrandom   :  553913.576 micros/op 1 ops/sec 120.199 seconds 217 operations;  293.6 MB/s (217 of 217 found)
```

- db_stress with async_io disabled completed succesfully
```
 export CRASH_TEST_EXT_ARGS=" --async_io=0"
 make crash_test -j
```

I**n Progress**: db_stress with async_io is failing and working on debugging/fixing it.

Reviewed By: anand1976

Differential Revision: D36459323

Pulled By: akankshamahajan15

fbshipit-source-id: abb1cd944abe712bae3986ae5b16704b3338917c
2022-05-20 16:09:33 -07:00
anand76 e015206dd6 Fix crash due to MultiGet async IO and direct IO (#10024)
Summary:
MultiGet with async IO is not officially supported with Posix yet. Avoid a crash by using synchronous MultiRead when direct IO is enabled.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10024

Test Plan: Run db_crashtest.py manually

Reviewed By: akankshamahajan15

Differential Revision: D36551053

Pulled By: anand1976

fbshipit-source-id: 72190418fa92dd0397e87825df618b12c9bdecda
2022-05-20 12:38:21 -07:00
Changyu Bi cc23b46da1 Support using ZDICT_finalizeDictionary to generate zstd dictionary (#9857)
Summary:
An untrained dictionary is currently simply the concatenation of several samples. The ZSTD API, ZDICT_finalizeDictionary(), can improve such a dictionary's effectiveness at low cost. This PR changes how dictionary is created by calling the ZSTD ZDICT_finalizeDictionary() API instead of creating raw content dictionary (when max_dict_buffer_bytes > 0), and pass in all buffered uncompressed data blocks as samples.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9857

Test Plan:
#### db_bench test for cpu/memory of compression+decompression and space saving on synthetic data:
Set up: change the parameter [here](fb9a167a55/tools/db_bench_tool.cc (L1766)) to 16384 to make synthetic data more compressible.
```
# linked local ZSTD with version 1.5.2
# DEBUG_LEVEL=0 ROCKSDB_NO_FBCODE=1 ROCKSDB_DISABLE_ZSTD=1  EXTRA_CXXFLAGS="-DZSTD_STATIC_LINKING_ONLY -DZSTD -I/data/users/changyubi/install/include/" EXTRA_LDFLAGS="-L/data/users/changyubi/install/lib/ -l:libzstd.a" make -j32 db_bench

dict_bytes=16384
train_bytes=1048576
echo "========== No Dictionary =========="
TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=filluniquerandom,compact -num=10000000 -compression_type=zstd -compression_max_dict_bytes=0 -block_size=4096 -max_background_jobs=24 -memtablerep=vector -allow_concurrent_memtable_write=false -disable_wal=true -max_write_buffer_number=8 >/dev/null 2>&1
TEST_TMPDIR=/dev/shm /usr/bin/time ./db_bench -use_existing_db=true -benchmarks=compact -compression_type=zstd -compression_max_dict_bytes=0 -block_size=4096 2>&1 | grep elapsed
du -hc /dev/shm/dbbench/*sst | grep total

echo "========== Raw Content Dictionary =========="
TEST_TMPDIR=/dev/shm ./db_bench_main -benchmarks=filluniquerandom,compact -num=10000000 -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -block_size=4096 -max_background_jobs=24 -memtablerep=vector -allow_concurrent_memtable_write=false -disable_wal=true -max_write_buffer_number=8 >/dev/null 2>&1
TEST_TMPDIR=/dev/shm /usr/bin/time ./db_bench_main -use_existing_db=true -benchmarks=compact -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -block_size=4096 2>&1 | grep elapsed
du -hc /dev/shm/dbbench/*sst | grep total

echo "========== FinalizeDictionary =========="
TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=filluniquerandom,compact -num=10000000 -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes -compression_use_zstd_dict_trainer=false -block_size=4096 -max_background_jobs=24 -memtablerep=vector -allow_concurrent_memtable_write=false -disable_wal=true -max_write_buffer_number=8 >/dev/null 2>&1
TEST_TMPDIR=/dev/shm /usr/bin/time ./db_bench -use_existing_db=true -benchmarks=compact -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes -compression_use_zstd_dict_trainer=false -block_size=4096 2>&1 | grep elapsed
du -hc /dev/shm/dbbench/*sst | grep total

echo "========== TrainDictionary =========="
TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=filluniquerandom,compact -num=10000000 -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes -block_size=4096 -max_background_jobs=24 -memtablerep=vector -allow_concurrent_memtable_write=false -disable_wal=true -max_write_buffer_number=8 >/dev/null 2>&1
TEST_TMPDIR=/dev/shm /usr/bin/time ./db_bench -use_existing_db=true -benchmarks=compact -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes -block_size=4096 2>&1 | grep elapsed
du -hc /dev/shm/dbbench/*sst | grep total

# Result: TrainDictionary is much better on space saving, but FinalizeDictionary seems to use less memory.
# before compression data size: 1.2GB
dict_bytes=16384
max_dict_buffer_bytes =  1048576
                    space   cpu/memory
No Dictionary       468M    14.93user 1.00system 0:15.92elapsed 100%CPU (0avgtext+0avgdata 23904maxresident)k
Raw Dictionary      251M    15.81user 0.80system 0:16.56elapsed 100%CPU (0avgtext+0avgdata 156808maxresident)k
FinalizeDictionary  236M    11.93user 0.64system 0:12.56elapsed 100%CPU (0avgtext+0avgdata 89548maxresident)k
TrainDictionary     84M     7.29user 0.45system 0:07.75elapsed 100%CPU (0avgtext+0avgdata 97288maxresident)k
```

#### Benchmark on 10 sample SST files for spacing saving and CPU time on compression:
FinalizeDictionary is comparable to TrainDictionary in terms of space saving, and takes less time in compression.
```
dict_bytes=16384
train_bytes=1048576

for sst_file in `ls ../temp/myrock-sst/`
do
  echo "********** $sst_file **********"
  echo "========== No Dictionary =========="
  ./sst_dump --file="../temp/myrock-sst/$sst_file" --command=recompress --compression_level_from=6 --compression_level_to=6 --compression_types=kZSTD

  echo "========== Raw Content Dictionary =========="
  ./sst_dump --file="../temp/myrock-sst/$sst_file" --command=recompress --compression_level_from=6 --compression_level_to=6 --compression_types=kZSTD --compression_max_dict_bytes=$dict_bytes

  echo "========== FinalizeDictionary =========="
  ./sst_dump --file="../temp/myrock-sst/$sst_file" --command=recompress --compression_level_from=6 --compression_level_to=6 --compression_types=kZSTD --compression_max_dict_bytes=$dict_bytes --compression_zstd_max_train_bytes=$train_bytes --compression_use_zstd_finalize_dict

  echo "========== TrainDictionary =========="
  ./sst_dump --file="../temp/myrock-sst/$sst_file" --command=recompress --compression_level_from=6 --compression_level_to=6 --compression_types=kZSTD --compression_max_dict_bytes=$dict_bytes --compression_zstd_max_train_bytes=$train_bytes
done

                         010240.sst (Size/Time) 011029.sst              013184.sst              021552.sst              185054.sst              185137.sst              191666.sst              7560381.sst             7604174.sst             7635312.sst
No Dictionary           28165569 / 2614419      32899411 / 2976832      32977848 / 3055542      31966329 / 2004590      33614351 / 1755877      33429029 / 1717042      33611933 / 1776936      33634045 / 2771417      33789721 / 2205414      33592194 / 388254
Raw Content Dictionary  28019950 / 2697961      33748665 / 3572422      33896373 / 3534701      26418431 / 2259658      28560825 / 1839168      28455030 / 1846039      28494319 / 1861349      32391599 / 3095649      33772142 / 2407843      33592230 / 474523
FinalizeDictionary      27896012 / 2650029      33763886 / 3719427      33904283 / 3552793      26008225 / 2198033      28111872 / 1869530      28014374 / 1789771      28047706 / 1848300      32296254 / 3204027      33698698 / 2381468      33592344 / 517433
TrainDictionary         28046089 / 2740037      33706480 / 3679019      33885741 / 3629351      25087123 / 2204558      27194353 / 1970207      27234229 / 1896811      27166710 / 1903119      32011041 / 3322315      32730692 / 2406146      33608631 / 570593
```

#### Decompression/Read test:
With FinalizeDictionary/TrainDictionary, some data structure used for decompression are in stored in dictionary, so they are expected to be faster in terms of decompression/reads.
```
dict_bytes=16384
train_bytes=1048576
echo "No Dictionary"
TEST_TMPDIR=/dev/shm/ ./db_bench -benchmarks=filluniquerandom,compact -compression_type=zstd -compression_max_dict_bytes=0 > /dev/null 2>&1
TEST_TMPDIR=/dev/shm/ ./db_bench -use_existing_db=true -benchmarks=readrandom -cache_size=0 -compression_type=zstd -compression_max_dict_bytes=0 2>&1 | grep MB/s

echo "Raw Dictionary"
TEST_TMPDIR=/dev/shm/ ./db_bench -benchmarks=filluniquerandom,compact -compression_type=zstd -compression_max_dict_bytes=$dict_bytes > /dev/null 2>&1
TEST_TMPDIR=/dev/shm/ ./db_bench -use_existing_db=true -benchmarks=readrandom -cache_size=0 -compression_type=zstd  -compression_max_dict_bytes=$dict_bytes 2>&1 | grep MB/s

echo "FinalizeDict"
TEST_TMPDIR=/dev/shm/ ./db_bench -benchmarks=filluniquerandom,compact -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes -compression_use_zstd_dict_trainer=false  > /dev/null 2>&1
TEST_TMPDIR=/dev/shm/ ./db_bench -use_existing_db=true -benchmarks=readrandom -cache_size=0 -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes -compression_use_zstd_dict_trainer=false 2>&1 | grep MB/s

echo "Train Dictionary"
TEST_TMPDIR=/dev/shm/ ./db_bench -benchmarks=filluniquerandom,compact -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes > /dev/null 2>&1
TEST_TMPDIR=/dev/shm/ ./db_bench -use_existing_db=true -benchmarks=readrandom -cache_size=0 -compression_type=zstd -compression_max_dict_bytes=$dict_bytes -compression_zstd_max_train_bytes=$train_bytes 2>&1 | grep MB/s

No Dictionary
readrandom   :      12.183 micros/op 82082 ops/sec 12.183 seconds 1000000 operations;    9.1 MB/s (1000000 of 1000000 found)
Raw Dictionary
readrandom   :      12.314 micros/op 81205 ops/sec 12.314 seconds 1000000 operations;    9.0 MB/s (1000000 of 1000000 found)
FinalizeDict
readrandom   :       9.787 micros/op 102180 ops/sec 9.787 seconds 1000000 operations;   11.3 MB/s (1000000 of 1000000 found)
Train Dictionary
readrandom   :       9.698 micros/op 103108 ops/sec 9.699 seconds 1000000 operations;   11.4 MB/s (1000000 of 1000000 found)
```

Reviewed By: ajkr

Differential Revision: D35720026

Pulled By: cbi42

fbshipit-source-id: 24d230fdff0fd28a1bb650658798f00dfcfb2a1f
2022-05-20 12:09:09 -07:00
anand76 57997ddaaf Multi file concurrency in MultiGet using coroutines and async IO (#9968)
Summary:
This PR implements a coroutine version of batched MultiGet in order to concurrently read from multiple SST files in a level using async IO, thus reducing the latency of the MultiGet. The API from the user perspective is still synchronous and single threaded, with the RocksDB part of the processing happening in the context of the caller's thread. In Version::MultiGet, the decision is made whether to call synchronous or coroutine code.

A good way to review this PR is to review the first 4 commits in order - de773b3, 70c2f70, 10b50e1, and 377a597 - before reviewing the rest.

TODO:
1. Figure out how to build it in CircleCI (requires some dependencies to be installed)
2. Do some stress testing with coroutines enabled

No regression in synchronous MultiGet between this branch and main -
```
./db_bench -use_existing_db=true --db=/data/mysql/rocksdb/prefix_scan -benchmarks="readseq,multireadrandom" -key_size=32 -value_size=512 -num=5000000 -batch_size=64 -multiread_batched=true -use_direct_reads=false -duration=60 -ops_between_duration_checks=1 -readonly=true -adaptive_readahead=true -threads=16 -cache_size=10485760000 -async_io=false -multiread_stride=40000 -statistics
```
Branch - ```multireadrandom :       4.025 micros/op 3975111 ops/sec 60.001 seconds 238509056 operations; 2062.3 MB/s (14767808 of 14767808 found)```

Main - ```multireadrandom :       3.987 micros/op 4013216 ops/sec 60.001 seconds 240795392 operations; 2082.1 MB/s (15231040 of 15231040 found)```

More benchmarks in various scenarios are given below. The measurements were taken with ```async_io=false``` (no coroutines) and ```async_io=true``` (use coroutines). For an IO bound workload (with every key requiring an IO), the coroutines version shows a clear benefit, being ~2.6X faster. For CPU bound workloads, the coroutines version has ~6-15% higher CPU utilization, depending on how many keys overlap an SST file.

1. Single thread IO bound workload on remote storage with sparse MultiGet batch keys (~1 key overlap/file) -
No coroutines - ```multireadrandom :     831.774 micros/op 1202 ops/sec 60.001 seconds 72136 operations;    0.6 MB/s (72136 of 72136 found)```
Using coroutines - ```multireadrandom :     318.742 micros/op 3137 ops/sec 60.003 seconds 188248 operations;    1.6 MB/s (188248 of 188248 found)```

2. Single thread CPU bound workload (all data cached) with ~1 key overlap/file -
No coroutines - ```multireadrandom :       4.127 micros/op 242322 ops/sec 60.000 seconds 14539384 operations;  125.7 MB/s (14539384 of 14539384 found)```
Using coroutines - ```multireadrandom :       4.741 micros/op 210935 ops/sec 60.000 seconds 12656176 operations;  109.4 MB/s (12656176 of 12656176 found)```

3. Single thread CPU bound workload with ~2 key overlap/file -
No coroutines - ```multireadrandom :       3.717 micros/op 269000 ops/sec 60.000 seconds 16140024 operations;  139.6 MB/s (16140024 of 16140024 found)```
Using coroutines - ```multireadrandom :       4.146 micros/op 241204 ops/sec 60.000 seconds 14472296 operations;  125.1 MB/s (14472296 of 14472296 found)```

4. CPU bound multi-threaded (16 threads) with ~4 key overlap/file -
No coroutines - ```multireadrandom :       4.534 micros/op 3528792 ops/sec 60.000 seconds 211728728 operations; 1830.7 MB/s (12737024 of 12737024 found) ```
Using coroutines - ```multireadrandom :       4.872 micros/op 3283812 ops/sec 60.000 seconds 197030096 operations; 1703.6 MB/s (12548032 of 12548032 found) ```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9968

Reviewed By: akankshamahajan15

Differential Revision: D36348563

Pulled By: anand1976

fbshipit-source-id: c0ce85a505fd26ebfbb09786cbd7f25202038696
2022-05-19 15:36:27 -07:00
Peter Dillinger 280b9f371a Fix auto_prefix_mode performance with partitioned filters (#10012)
Summary:
Essentially refactored the RangeMayExist implementation in
FullFilterBlockReader to FilterBlockReaderCommon so that it applies to
partitioned filters as well. (The function is not called for the
block-based filter case.) RangeMayExist is essentially a series of checks
around a possible PrefixMayExist, and I'm confident those checks should
be the same for partitioned as for full filters. (I think it's likely
that bugs remain in those checks, but this change is overall a simplifying
one.)

Added auto_prefix_mode support to db_bench

Other small fixes as well

Fixes https://github.com/facebook/rocksdb/issues/10003

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10012

Test Plan:
Expanded unit test that uses statistics to check for filter
optimization, fails without the production code changes here

Performance: populate two DBs with
```
TEST_TMPDIR=/dev/shm/rocksdb_nonpartitioned ./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 -prefix_size=8
TEST_TMPDIR=/dev/shm/rocksdb_partitioned ./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 -prefix_size=8 -partition_index_and_filters
```

Observe no measurable change in non-partitioned performance
```
TEST_TMPDIR=/dev/shm/rocksdb_nonpartitioned ./db_bench -benchmarks=seekrandom[-X1000] -num=10000000 -readonly -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=8 -auto_prefix_mode -cache_index_and_filter_blocks=1 -cache_size=1000000000 -duration 20
```
Before: seekrandom [AVG 15 runs] : 11798 (± 331) ops/sec
After: seekrandom [AVG 15 runs] : 11724 (± 315) ops/sec

Observe big improvement with partitioned (also supported by bloom use statistics)
```
TEST_TMPDIR=/dev/shm/rocksdb_partitioned ./db_bench -benchmarks=seekrandom[-X1000] -num=10000000 -readonly -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=8 -partition_index_and_filters -auto_prefix_mode -cache_index_and_filter_blocks=1 -cache_size=1000000000 -duration 20
```
Before: seekrandom [AVG 12 runs] : 2942 (± 57) ops/sec
After: seekrandom [AVG 12 runs] : 7489 (± 184) ops/sec

Reviewed By: siying

Differential Revision: D36469796

Pulled By: pdillinger

fbshipit-source-id: bcf1e2a68d347b32adb2b27384f945434e7a266d
2022-05-19 13:09:03 -07:00
Hui Xiao dde774db64 Mark old reserve* option deprecated (#10016)
Summary:
**Context/Summary:**
https://github.com/facebook/rocksdb/pull/9926 removed inefficient `reserve*` option API but forgot to mark them deprecated in `block_based_table_type_info` for compatible table format.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10016

Test Plan: build-format-compatible

Reviewed By: pdillinger

Differential Revision: D36484247

Pulled By: hx235

fbshipit-source-id: c41b90cc99fb7ab7098934052f0af7290b221f98
2022-05-18 22:25:54 -07:00
gitbw95 4da34b97ee Set Read rate limiter priority dynamically and pass it to FS (#9996)
Summary:
### Context:
Background compactions and flush generate large reads and writes, and can be long running, especially for universal compaction. In some cases, this can impact foreground reads and writes by users.

### Solution
User, Flush, and Compaction reads share some code path. For this task, we update the rate_limiter_priority in ReadOptions for code paths (e.g. FindTable (mainly in BlockBasedTable::Open()) and various iterators), and eventually update the rate_limiter_priority in IOOptions for FSRandomAccessFile.

**This PR is for the Read path.** The **Read:** dynamic priority for different state are listed as follows:

| State | Normal | Delayed | Stalled |
| ----- | ------ | ------- | ------- |
|  Flush (verification read in BuildTable()) | IO_USER | IO_USER | IO_USER |
|  Compaction | IO_LOW  | IO_USER | IO_USER |
|  User | User provided | User provided | User provided |

We will respect the read_options that the user provided and will not set it.
The only sst read for Flush is the verification read in BuildTable(). It claims to be "regard as user read".

**Details**
1. Set read_options.rate_limiter_priority dynamically:
- User: Do not update the read_options. Use the read_options that the user provided.
- Compaction: Update read_options in CompactionJob::ProcessKeyValueCompaction().
- Flush: Update read_options in BuildTable().

2. Pass the rate limiter priority to FSRandomAccessFile functions:
- After calling the FindTable(), read_options is passed through GetTableReader(table_cache.cc), BlockBasedTableFactory::NewTableReader(block_based_table_factory.cc), and BlockBasedTable::Open(). The Open() needs some updates for the ReadOptions variable and the updates are also needed for the called functions,  including PrefetchTail(), PrepareIOOptions(), ReadFooterFromFile(), ReadMetaIndexblock(), ReadPropertiesBlock(), PrefetchIndexAndFilterBlocks(), and ReadRangeDelBlock().
- In RandomAccessFileReader, the functions to be updated include Read(), MultiRead(), ReadAsync(), and Prefetch().
- Update the downstream functions of NewIndexIterator(), NewDataBlockIterator(), and BlockBasedTableIterator().

### Test Plans
Add unit tests.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9996

Reviewed By: anand1976

Differential Revision: D36452483

Pulled By: gitbw95

fbshipit-source-id: 60978204a4f849bb9261cb78d9bc1cb56d6008cf
2022-05-18 19:41:44 -07:00
Hui Xiao 3573558ec5 Rewrite memory-charging feature's option API (#9926)
Summary:
**Context:**
Previous PR https://github.com/facebook/rocksdb/pull/9748, https://github.com/facebook/rocksdb/pull/9073, https://github.com/facebook/rocksdb/pull/8428 added separate flag for each charged memory area. Such API design is not scalable as we charge more and more memory areas. Also, we foresee an opportunity to consolidate this feature with other cache usage related features such as `cache_index_and_filter_blocks` using `CacheEntryRole`.

Therefore we decided to consolidate all these flags with `CacheUsageOptions cache_usage_options` and this PR serves as the first step by consolidating memory-charging related flags.

**Summary:**
- Replaced old API reference with new ones, including making `kCompressionDictionaryBuildingBuffer` opt-out and added a unit test for that
- Added missing db bench/stress test for some memory charging features
- Renamed related test suite to indicate they are under the same theme of memory charging
- Refactored a commonly used mocked cache component in memory charging related tests to reduce code duplication
- Replaced the phrases "memory tracking" / "cache reservation" (other than CacheReservationManager-related ones) with "memory charging" for standard description of this feature.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9926

Test Plan:
- New unit test for opt-out `kCompressionDictionaryBuildingBuffer` `TEST_F(ChargeCompressionDictionaryBuildingBufferTest, Basic)`
- New unit test for option validation/sanitization `TEST_F(CacheUsageOptionsOverridesTest, SanitizeAndValidateOptions)`
- CI
- db bench (in case querying new options introduces regression) **+0.5% micros/op**: `TEST_TMPDIR=/dev/shm/testdb ./db_bench -benchmarks=fillseq -db=$TEST_TMPDIR  -charge_compression_dictionary_building_buffer=1(remove this for comparison)  -compression_max_dict_bytes=10000 -disable_auto_compactions=1 -write_buffer_size=100000 -num=4000000 | egrep 'fillseq'`

#-run | (pre-PR) avg micros/op | std micros/op | (post-PR)  micros/op | std micros/op | change (%)
-- | -- | -- | -- | -- | --
10 | 3.9711 | 0.264408 | 3.9914 | 0.254563 | 0.5111933721
20 | 3.83905 | 0.0664488 | 3.8251 | 0.0695456 | **-0.3633711465**
40 | 3.86625 | 0.136669 | 3.8867 | 0.143765 | **0.5289363078**

- db_stress: `python3 tools/db_crashtest.py blackbox  -charge_compression_dictionary_building_buffer=1 -charge_filter_construction=1 -charge_table_reader=1 -cache_size=1` killed as normal

Reviewed By: ajkr

Differential Revision: D36054712

Pulled By: hx235

fbshipit-source-id: d406e90f5e0c5ea4dbcb585a484ad9302d4302af
2022-05-17 15:01:51 -07:00
sdong c4cd8e1acc Fix a bug handling multiget index I/O error. (#9993)
Summary:
In one path of BlockBasedTable::MultiGet(), Next() is directly called after calling Seek() against the index iterator. This might cause crash if an I/O error happens in Seek().
The bug is discovered in crash test.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9993

Test Plan: See existing CI tests pass.

Reviewed By: anand1976

Differential Revision: D36381758

fbshipit-source-id: a11e0aa48dcee168c2554c33b532646ffdb68877
2022-05-13 13:15:10 -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
sdong 49628c9a83 Use std::numeric_limits<> (#9954)
Summary:
Right now we still don't fully use std::numeric_limits but use a macro, mainly for supporting VS 2013. Right now we only support VS 2017 and up so it is not a problem. The code comment claims that MinGW still needs it. We don't have a CI running MinGW so it's hard to validate. since we now require C++17, it's hard to imagine MinGW would still build RocksDB but doesn't support std::numeric_limits<>.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9954

Test Plan: See CI Runs.

Reviewed By: riversand963

Differential Revision: D36173954

fbshipit-source-id: a35a73af17cdcae20e258cdef57fcf29a50b49e0
2022-05-05 13:08:21 -07:00
Xinyu Zeng 8b74cea7fe Reduce comparator objects init cost in BlockIter (#9611)
Summary:
This PR solves the problem discussed in https://github.com/facebook/rocksdb/issues/7149. By storing the pointer of InternalKeyComparator as icmp_ in BlockIter, the object size remains the same. And for each call to CompareCurrentKey, there is no need to create Comparator objects. One can use icmp_ directly or use the "user_comparator" from the icmp_.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9611

Test Plan:
with https://github.com/facebook/rocksdb/issues/9903,

```
$ TEST_TMPDIR=/dev/shm python3.6 ../benchmark/tools/compare.py benchmarks ./db_basic_bench ../rocksdb-pr9611/db_basic_bench --benchmark_filter=DBGet/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:0/negative_query:0/enable_filter:0/mmap:1/iterations:262144/threads:1 --benchmark_repetitions=50
...
Comparing ./db_basic_bench to ../rocksdb-pr9611/db_basic_bench
Benchmark                                                                                                                                                               Time             CPU      Time Old      Time New       CPU Old       CPU New
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
...
DBGet/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:0/negative_query:0/enable_filter:0/mmap:1/iterations:262144/threads:1_pvalue                 0.0001          0.0001      U Test, Repetitions: 50 vs 50
DBGet/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:0/negative_query:0/enable_filter:0/mmap:1/iterations:262144/threads:1_mean                  -0.0483         -0.0483          3924          3734          3924          3734
DBGet/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:0/negative_query:0/enable_filter:0/mmap:1/iterations:262144/threads:1_median                -0.0713         -0.0713          3971          3687          3970          3687
DBGet/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:0/negative_query:0/enable_filter:0/mmap:1/iterations:262144/threads:1_stddev                -0.0342         -0.0344           225           217           225           217
DBGet/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:0/negative_query:0/enable_filter:0/mmap:1/iterations:262144/threads:1_cv                    +0.0148         +0.0146             0             0             0             0
OVERALL_GEOMEAN                                                                                                                                                      -0.0483         -0.0483             0             0             0             0
```

Reviewed By: akankshamahajan15

Differential Revision: D35882037

Pulled By: ajkr

fbshipit-source-id: 9e5337bbad8f1239dff7aa9f6549020d599bfcdf
2022-05-03 17:37:19 -07:00
Peter Dillinger 9d0cae7104 Eliminate unnecessary (slow) block cache Ref()ing in MultiGet (#9899)
Summary:
When MultiGet() determines that multiple query keys can be
served by examining the same data block in block cache (one Lookup()),
each PinnableSlice referring to data in that data block needs to hold
on to the block in cache so that they can be released at arbitrary
times by the API user. Historically this is accomplished with extra
calls to Ref() on the Handle from Lookup(), with each PinnableSlice
cleanup calling Release() on the Handle, but this creates extra
contention on the block cache for the extra Ref()s and Release()es,
especially because they hit the same cache shard repeatedly.

In the case of merge operands (possibly more cases?), the problem was
compounded by doing an extra Ref()+eventual Release() for each merge
operand for a key reusing a block (which could be the same key!), rather
than one Ref() per key. (Note: the non-shared case with `biter` was
already one per key.)

This change optimizes MultiGet not to rely on these extra, contentious
Ref()+Release() calls by instead, in the shared block case, wrapping
the cache Release() cleanup in a refcounted object referenced by the
PinnableSlices, such that after the last wrapped reference is released,
the cache entry is Release()ed. Relaxed atomic refcounts should be
much faster than mutex-guarded Ref() and Release(), and much less prone
to a performance cliff when MultiGet() does a lot of block sharing.

Note that I did not use std::shared_ptr, because that would require an
extra indirection object (shared_ptr itself new/delete) in order to
associate a ref increment/decrement with a Cleanable cleanup entry. (If
I assumed it was the size of two pointers, I could do some hackery to
make it work without the extra indirection, but that's too fragile.)

Some details:
* Fixed (removed) extra block cache tracing entries in cases of cache
entry reuse in MultiGet, but it's likely that in some other cases traces
are missing (XXX comment inserted)
* Moved existing implementations for cleanable.h from iterator.cc to
new cleanable.cc
* Improved API comments on Cleanable
* Added a public SharedCleanablePtr class to cleanable.h in case others
could benefit from the same pattern (potentially many Cleanables and/or
smart pointers referencing a shared Cleanable)
* Add a typedef for MultiGetContext::Mask
* Some variable renaming for clarity

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9899

Test Plan:
Added unit tests for SharedCleanablePtr.

Greatly enhanced ability of existing tests to detect cache use-after-free.
* Release PinnableSlices from MultiGet as they are read rather than in
bulk (in db_test_util wrapper).
* In ASAN build, default to using a trivially small LRUCache for block_cache
so that entries are immediately erased when unreferenced. (Updated two
tests that depend on caching.) New ASAN testsuite running time seems
OK to me.

If I introduce a bug into my implementation where we skip the shared
cleanups on block reuse, ASAN detects the bug in
`db_basic_test *MultiGet*`. If I remove either of the above testing
enhancements, the bug is not detected.

Consider for follow-up work: manipulate or randomize ordering of
PinnableSlice use and release from MultiGet db_test_util wrapper. But in
typical cases, natural ordering gives pretty good functional coverage.

Performance test:
In the extreme (but possible) case of MultiGetting the same or adjacent keys
in a batch, throughput can improve by an order of magnitude.
`./db_bench -benchmarks=multireadrandom -db=/dev/shm/testdb -readonly -num=5 -duration=10 -threads=20 -multiread_batched -batch_size=200`
Before ops/sec, num=5: 1,384,394
Before ops/sec, num=500: 6,423,720
After ops/sec, num=500: 10,658,794
After ops/sec, num=5: 16,027,257

Also note that previously, with high parallelism, having query keys
concentrated in a single block was worse than spreading them out a bit. Now
concentrated in a single block is faster than spread out, which is hopefully
consistent with natural expectation.

Random query performance: with num=1000000, over 999 x 10s runs running before & after simultaneously (each -threads=12):
Before: multireadrandom [AVG    999 runs] : 1088699 (± 7344) ops/sec;  120.4 (± 0.8 ) MB/sec
After: multireadrandom [AVG    999 runs] : 1090402 (± 7230) ops/sec;  120.6 (± 0.8 ) MB/sec
Possibly better, possibly in the noise.

Reviewed By: anand1976

Differential Revision: D35907003

Pulled By: pdillinger

fbshipit-source-id: bbd244d703649a8ca12d476f2d03853ed9d1a17e
2022-04-26 21:59:24 -07:00
Akanksha Mahajan 3653029dda Add stats related to async prefetching (#9845)
Summary:
Add stats PREFETCHED_BYTES_DISCARDED and POLL_WAIT_MICROS.
PREFETCHED_BYTES_DISCARDED records number of prefetched bytes discarded by
FilePrefetchBuffer. POLL_WAIT_MICROS records the time taken by underling
file_system Poll API.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9845

Test Plan: Update existing tests

Reviewed By: anand1976

Differential Revision: D35909694

Pulled By: akankshamahajan15

fbshipit-source-id: e009ef940bb9ed72c9446f5529095caabb8a1e36
2022-04-25 21:58:22 -07:00
Hui Xiao a5063c8931 Fix issue of opening too many files in BlockBasedTableReaderCapMemoryTest.CapMemoryUsageUnderCacheCapacity (#9869)
Summary:
**Context:**
Unit test for https://github.com/facebook/rocksdb/pull/9748 keeps opening new files to see whether the new feature is able to correctly constrain the opening based on block cache capacity.

However, the unit test has two places written inefficiently that can lead to opening too many new files relative to underlying operating system/file system constraint, even before hitting the block cache capacity:
(1) [opened_table_reader_num < 2 * max_table_reader_num](https://github.com/facebook/rocksdb/pull/9748/files?show-viewed-files=true&file-filters%5B%5D=#diff-ec9f5353e317df71093094734ba29193b94a998f0f9c9af924e4c99692195eeaR438), which can leads to 1200 + open files because of (2) below
(2) NewLRUCache(6 * CacheReservationManagerImpl<CacheEntryRole::kBlockBasedTableReader>::GetDummyEntrySize()) in [here](https://github.com/facebook/rocksdb/pull/9748/files?show-viewed-files=true&file-filters%5B%5D=#diff-ec9f5353e317df71093094734ba29193b94a998f0f9c9af924e4c99692195eeaR364)

Therefore we see CI failures like this on machine with a strict open file limit ~1000 (see the "table_1021" naming in following error msg)
https://app.circleci.com/pipelines/github/facebook/rocksdb/12886/workflows/75524682-3fa4-41ee-9a61-81827b51d99b/jobs/345270
```
fs_->NewWritableFile(path, foptions, &file, nullptr)
IO error: While open a file for appending: /dev/shm/rocksdb.Jedwt/run-block_based_table_reader_test-CapMemoryUsageUnderCacheCapacity-BlockBasedTableReaderCapMemoryTest.CapMemoryUsageUnderCacheCapacity-0/block_based_table_reader_test_1668910_829492452552920927/**table_1021**: Too many open files
```

**Summary:**
- Revised the test more efficiently on the above 2 places,  including using 1.1 instead 2 in the threshold and lowering down the block cache capacity a bit
- Renamed some variables for clarity

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9869

Test Plan:
- Manual inspection of max opened table reader in all test case, which is around ~389
- Circle CI to see if error is gone

Reviewed By: ajkr

Differential Revision: D35752655

Pulled By: hx235

fbshipit-source-id: 8a0953d39d561babfa4257b8ed8550bb21b04839
2022-04-19 19:02:00 -07:00
Akanksha Mahajan 0c7f455f85 Make initial auto readahead_size configurable (#9836)
Summary:
Make initial auto readahead_size configurable

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9836

Test Plan:
Added new unit test
Ran regression:
Without change:

```
./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 7.0
Date:       Thu Mar 17 13:11:34 2022
CPU:        24 * Intel Core Processor (Broadwell)
CPUCache:   16384 KB
Keys:       32 bytes each (+ 0 bytes user-defined timestamp)
Values:     512 bytes each (256 bytes after compression)
Entries:    5000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    2594.0 MB (estimated)
FileSize:   1373.3 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: Snappy
Compression sampling rate: 0
Memtablerep: SkipListFactory
Perf Level: 1
------------------------------------------------
DB path: [/tmp/prefix_scan_prefetch_main]
seekrandom   :  483618.390 micros/op 2 ops/sec;  338.9 MB/s (249 of 249 found)
```

With this change:
```
 ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1
Set seed to 1649895440554504 because --seed was 0
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 7.2
Date:       Wed Apr 13 17:17:20 2022
CPU:        24 * Intel Core Processor (Broadwell)
CPUCache:   16384 KB
Keys:       32 bytes each (+ 0 bytes user-defined timestamp)
Values:     512 bytes each (256 bytes after compression)
Entries:    5000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    2594.0 MB (estimated)
FileSize:   1373.3 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: Snappy
Compression sampling rate: 0
Memtablerep: SkipListFactory
Perf Level: 1
------------------------------------------------
DB path: [/tmp/prefix_scan_prefetch_main]
... finished 100 ops
seekrandom   :  476892.488 micros/op 2 ops/sec;  344.6 MB/s (252 of 252 found)
```

Reviewed By: anand1976

Differential Revision: D35632815

Pulled By: akankshamahajan15

fbshipit-source-id: c8057a88f9294c9d03b1d434b03affe02f74d796
2022-04-15 17:28:09 -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
Akanksha Mahajan 63e68a4e77 Enable async prefetching for ReadOptions.readahead_size (#9827)
Summary:
Currently async prefetching is enabled for implicit internal auto readahead in FilePrefetchBuffer if `ReadOptions.async_io` is set. This PR enables async prefetching for `ReadOptions.readahead_size` when `ReadOptions.async_io` is set true.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9827

Test Plan: Update unit test

Reviewed By: anand1976

Differential Revision: D35552129

Pulled By: akankshamahajan15

fbshipit-source-id: d9f9a96672852a591375a21eef15355cf3289f5c
2022-04-11 13:46:57 -07:00
Hui Xiao 49623f9c8e Account memory of big memory users in BlockBasedTable in global memory limit (#9748)
Summary:
**Context:**
Through heap profiling, we discovered that `BlockBasedTableReader` objects can accumulate and lead to high memory usage (e.g, `max_open_file = -1`). These memories are currently not saved, not tracked, not constrained and not cache evict-able. As a first step to improve this, similar to https://github.com/facebook/rocksdb/pull/8428,  this PR is to track an estimate of `BlockBasedTableReader` object's memory in block cache and fail future creation if the memory usage exceeds the available space of cache at the time of creation.

**Summary:**
- Approximate big memory users  (`BlockBasedTable::Rep` and `TableProperties` )' memory usage in addition to the existing estimated ones (filter block/index block/un-compression dictionary)
- Charge all of these memory usages to block cache on `BlockBasedTable::Open()` and release them on `~BlockBasedTable()` as there is no memory usage fluctuation of concern in between
- Refactor on CacheReservationManager (and its call-sites) to add concurrent support for BlockBasedTable  used in this PR.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9748

Test Plan:
- New unit tests
- db bench: `OpenDb` : **-0.52% in ms**
  - Setup `./db_bench -benchmarks=fillseq -db=/dev/shm/testdb -disable_auto_compactions=1 -write_buffer_size=1048576`
  - Repeated run with pre-change w/o feature and post-change with feature, benchmark `OpenDb`:  `./db_bench -benchmarks=readrandom -use_existing_db=1 -db=/dev/shm/testdb -reserve_table_reader_memory=true (remove this when running w/o feature) -file_opening_threads=3 -open_files=-1 -report_open_timing=true| egrep 'OpenDb:'`

#-run | (feature-off) avg milliseconds | std milliseconds | (feature-on) avg milliseconds | std milliseconds | change (%)
-- | -- | -- | -- | -- | --
10 | 11.4018 | 5.95173 | 9.47788 | 1.57538 | -16.87382694
20 | 9.23746 | 0.841053 | 9.32377 | 1.14074 | 0.9343477536
40 | 9.0876 | 0.671129 | 9.35053 | 1.11713 | 2.893283155
80 | 9.72514 | 2.28459 | 9.52013 | 1.0894 | -2.108041632
160 | 9.74677 | 0.991234 | 9.84743 | 1.73396 | 1.032752389
320 | 10.7297 | 5.11555 | 10.547 | 1.97692 | **-1.70275031**
640 | 11.7092 | 2.36565 | 11.7869 | 2.69377 | **0.6635807741**

-  db bench on write with cost to cache in WriteBufferManager (just in case this PR's CRM refactoring accidentally slows down anything in WBM) : `fillseq` : **+0.54% in micros/op**
`./db_bench -benchmarks=fillseq -db=/dev/shm/testdb -disable_auto_compactions=1 -cost_write_buffer_to_cache=true -write_buffer_size=10000000000 | egrep 'fillseq'`

#-run | (pre-PR) avg micros/op | std micros/op | (post-PR)  avg micros/op | std micros/op | change (%)
-- | -- | -- | -- | -- | --
10 | 6.15 | 0.260187 | 6.289 | 0.371192 | 2.260162602
20 | 7.28025 | 0.465402 | 7.37255 | 0.451256 | 1.267813605
40 | 7.06312 | 0.490654 | 7.13803 | 0.478676 | **1.060579461**
80 | 7.14035 | 0.972831 | 7.14196 | 0.92971 | **0.02254791432**

-  filter bench: `bloom filter`: **-0.78% in ms/key**
    - ` ./filter_bench -impl=2 -quick -reserve_table_builder_memory=true | grep 'Build avg'`

#-run | (pre-PR) avg ns/key | std ns/key | (post-PR)  ns/key | std ns/key | change (%)
-- | -- | -- | -- | -- | --
10 | 26.4369 | 0.442182 | 26.3273 | 0.422919 | **-0.4145720565**
20 | 26.4451 | 0.592787 | 26.1419 | 0.62451 | **-1.1465262**

- Crash test `python3 tools/db_crashtest.py blackbox --reserve_table_reader_memory=1 --cache_size=1` killed as normal

Reviewed By: ajkr

Differential Revision: D35136549

Pulled By: hx235

fbshipit-source-id: 146978858d0f900f43f4eb09bfd3e83195e3be28
2022-04-06 10:33:00 -07:00
Akanksha Mahajan 36bc3da97f Fix segfault in FilePrefetchBuffer with async_io enabled (#9777)
Summary:
If FilePrefetchBuffer object is destroyed and then later Poll() calls callback on object which has been destroyed, it gives segfault on accessing destroyed object. It was caught after adding unit tests that tests Posix implementation of ReadAsync and Poll APIs.
This PR also updates and fixes existing IOURing tests which were not running locally because RocksDbIOUringEnable function wasn't defined and IOUring was disabled for those tests

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9777

Test Plan: Added new unit test

Reviewed By: anand1976

Differential Revision: D35254002

Pulled By: akankshamahajan15

fbshipit-source-id: 68e80054ffb14ae25c255920ebc6548ca5f130a1
2022-04-04 15:35:43 -07:00
Alan Paxton b6ad0d958f Fb 9718 verify checksums is ignored (#9767)
Summary:
Fixes https://github.com/facebook/rocksdb/issues/9718

The verify_checksums flag of read_options should be passed to the read options used by the BlockFetcher in a couple of cases where it is not at present. It will now happen (but did not, previously) on iteration and on [multi]get, where a fetcher is created as part of the iterate/get call.

This may result in much better performance in a few workloads where the client chooses to remove verification.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9767

Reviewed By: mrambacher

Differential Revision: D35218986

Pulled By: jay-zhuang

fbshipit-source-id: 329d29764bb70fbc7f2673440bc46c107a813bc8
2022-03-29 11:54:54 -07:00
myasuka 98130c5a26 Enable READ_BLOCK_COMPACTION_MICROS to track stats (#9722)
Summary:
After commit [d642c60](d642c60bdc), the stats `READ_BLOCK_COMPACTION_MICROS` cannot record any compaction read duration, and it always report zero.

This PR targets to distinguish `READ_BLOCK_COMPACTION_MICROS` with `READ_BLOCK_GET_MICROS` so that `READ_BLOCK_COMPACTION_MICROS` could record the correct stats.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9722

Reviewed By: ajkr

Differential Revision: D35021870

Pulled By: jay-zhuang

fbshipit-source-id: f1a804994265e51465de64c2a08f2e0eeb6fc5a3
2022-03-24 15:06:24 -07:00
Peter Dillinger 91687d70ea Fix a major performance bug in 7.0 re: filter compatibility (#9736)
Summary:
Bloom filters generated by pre-7.0 releases are not read by
7.0.x releases (and vice-versa) due to changes to FilterPolicy::Name()
in https://github.com/facebook/rocksdb/issues/9590. This can severely impact read performance and read I/O on
upgrade or downgrade with existing DB, but not data correctness.

To fix, we go back using the old, unified name in SST metadata but (for
a while anyway) recognize the aliases that could be generated by early
7.0.x releases. This unfortunately requires a public API change to avoid
interfering with all the good changes from https://github.com/facebook/rocksdb/issues/9590, but the API change
only affects users with custom FilterPolicy, which should be very few.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9736

Test Plan:
manual

Generate DBs with
```
./db_bench.7.0 -db=/dev/shm/rocksdb.7.0 -bloom_bits=10 -cache_index_and_filter_blocks=1 -benchmarks=fillrandom -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0
```
and similar. Compare with
```
for IMPL in 6.29 7.0 fixed; do for DB in 6.29 7.0 fixed; do echo "Testing $IMPL on $DB:"; ./db_bench.$IMPL -db=/dev/shm/rocksdb.$DB -use_existing_db -readonly -bloom_bits=10 -benchmarks=readrandom -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -duration=10 2>&1 | grep micros/op; done; done
```

Results:
```
Testing 6.29 on 6.29:
readrandom   :      34.381 micros/op 29085 ops/sec;    3.2 MB/s (291999 of 291999 found)
Testing 6.29 on 7.0:
readrandom   :     190.443 micros/op 5249 ops/sec;    0.6 MB/s (52999 of 52999 found)
Testing 6.29 on fixed:
readrandom   :      40.148 micros/op 24907 ops/sec;    2.8 MB/s (249999 of 249999 found)
Testing 7.0 on 6.29:
readrandom   :     229.430 micros/op 4357 ops/sec;    0.5 MB/s (43999 of 43999 found)
Testing 7.0 on 7.0:
readrandom   :      33.348 micros/op 29986 ops/sec;    3.3 MB/s (299999 of 299999 found)
Testing 7.0 on fixed:
readrandom   :     152.734 micros/op 6546 ops/sec;    0.7 MB/s (65999 of 65999 found)
Testing fixed on 6.29:
readrandom   :      32.024 micros/op 31224 ops/sec;    3.5 MB/s (312999 of 312999 found)
Testing fixed on 7.0:
readrandom   :      33.990 micros/op 29390 ops/sec;    3.3 MB/s (294999 of 294999 found)
Testing fixed on fixed:
readrandom   :      28.714 micros/op 34825 ops/sec;    3.9 MB/s (348999 of 348999 found)
```

Just paying attention to order of magnitude of ops/sec (short test
durations, lots of noise), it's clear that with the fix we can read <= 6.29
& >= 7.0 at full speed, where neither 6.29 nor 7.0 can on both. And 6.29
release can properly read fixed DB at full speed.

Reviewed By: siying, ajkr

Differential Revision: D35057844

Pulled By: pdillinger

fbshipit-source-id: a46893a6af4bf084375ebe4728066d00eb08f050
2022-03-23 10:00:54 -07:00
gitbw95 8102690a52 Update Cache::Release param from force_erase to erase_if_last_ref (#9728)
Summary:
The param name force_erase may be misleading, since the handle is erased only if it has last reference even if the param is set true.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9728

Reviewed By: pdillinger

Differential Revision: D35038673

Pulled By: gitbw95

fbshipit-source-id: 0d16d1e8fed17b97eba7fb53207119332f659a5f
2022-03-22 10:22:18 -07:00
Akanksha Mahajan 49a10feb21 Provide implementation to prefetch data asynchronously in FilePrefetchBuffer (#9674)
Summary:
In FilePrefetchBuffer if reads are sequential, after prefetching call ReadAsync API to prefetch data asynchronously so that in next prefetching data will be available. Data prefetched asynchronously will be readahead_size/2. It uses two buffers, one for synchronous prefetching and one for asynchronous. In case, the data is overlapping, the data is copied from both buffers to third buffer to make it continuous.
This feature is under ReadOptions::async_io and is under experimental.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9674

Test Plan:
1. Add new unit tests
2. Run **db_stress** to make sure nothing crashes.

    -   Normal prefetch without `async_io` ran successfully:
```
export CRASH_TEST_EXT_ARGS=" --async_io=0"
 make crash_test -j
 ```

3. **Run Regressions**.
   i) Main branch without any change for normal prefetching with async_io disabled:

 ```
 ./db_bench -db=/tmp/prefix_scan_prefetch_main -benchmarks="fillseq" -key_size=32 -value_size=512 -num=5000000 -
           use_direct_io_for_flush_and_compaction=true -target_file_size_base=16777216
 ```

```
./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 7.0
Date:       Thu Mar 17 13:11:34 2022
CPU:        24 * Intel Core Processor (Broadwell)
CPUCache:   16384 KB
Keys:       32 bytes each (+ 0 bytes user-defined timestamp)
Values:     512 bytes each (256 bytes after compression)
Entries:    5000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    2594.0 MB (estimated)
FileSize:   1373.3 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: Snappy
Compression sampling rate: 0
Memtablerep: SkipListFactory
Perf Level: 1
------------------------------------------------
DB path: [/tmp/prefix_scan_prefetch_main]
seekrandom   :  483618.390 micros/op 2 ops/sec;  338.9 MB/s (249 of 249 found)
```

  ii) normal prefetching after changes with async_io disable:

```
./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_withchange -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680 -duration=120 -ops_between_duration_checks=1
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 7.0
Date:       Thu Mar 17 14:11:31 2022
CPU:        24 * Intel Core Processor (Broadwell)
CPUCache:   16384 KB
Keys:       32 bytes each (+ 0 bytes user-defined timestamp)
Values:     512 bytes each (256 bytes after compression)
Entries:    5000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    2594.0 MB (estimated)
FileSize:   1373.3 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: Snappy
Compression sampling rate: 0
Memtablerep: SkipListFactory
Perf Level: 1
------------------------------------------------
DB path: [/tmp/prefix_scan_prefetch_withchange]
seekrandom   :  471347.227 micros/op 2 ops/sec;  348.1 MB/s (255 of 255 found)
```

Reviewed By: anand1976

Differential Revision: D34731543

Pulled By: akankshamahajan15

fbshipit-source-id: 8e23aa93453d5fe3c672b9231ad582f60207937f
2022-03-21 07:12:43 -07:00
Hui Xiao 4a776d81cc Dynamic toggling of BlockBasedTableOptions::detect_filter_construct_corruption (#9654)
Summary:
**Context/Summary:**
As requested, `BlockBasedTableOptions::detect_filter_construct_corruption` can now be dynamically configured using `DB::SetOptions` after this PR

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9654

Test Plan: - New unit test

Reviewed By: pdillinger

Differential Revision: D34622609

Pulled By: hx235

fbshipit-source-id: c06773ef3d029e6bf1724d3a72dffd37a8ec66d9
2022-03-04 10:35:08 -08:00
sdong 33742c2a9f Remove BlockBasedTableOptions.hash_index_allow_collision (#9454)
Summary:
BlockBasedTableOptions.hash_index_allow_collision is already deprecated and has no effect. Delete it for preparing 7.0 release.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9454

Test Plan: Run all existing tests.

Reviewed By: ajkr

Differential Revision: D33805827

fbshipit-source-id: ed8a436d1d083173ec6aef2a762ba02e1eefdc9d
2022-03-01 13:58:02 -08:00
Andrew Kryczka 0a89cea5f5 Handle failures in block-based table size/offset approximation (#9615)
Summary:
In crash test with fault injection, we were seeing stack traces like the following:

```
https://github.com/facebook/rocksdb/issues/3 0x00007f75f763c533 in __GI___assert_fail (assertion=assertion@entry=0x1c5b2a0 "end_offset >= start_offset", file=file@entry=0x1c580a0 "table/block_based/block_based_table_reader.cc", line=line@entry=3245,
function=function@entry=0x1c60e60 "virtual uint64_t rocksdb::BlockBasedTable::ApproximateSize(const rocksdb::Slice&, const rocksdb::Slice&, rocksdb::TableReaderCaller)") at assert.c:101
https://github.com/facebook/rocksdb/issues/4 0x00000000010ea9b4 in rocksdb::BlockBasedTable::ApproximateSize (this=<optimized out>, start=..., end=..., caller=<optimized out>) at table/block_based/block_based_table_reader.cc:3224
https://github.com/facebook/rocksdb/issues/5 0x0000000000be61fb in rocksdb::TableCache::ApproximateSize (this=0x60f0000161b0, start=..., end=..., fd=..., caller=caller@entry=rocksdb::kCompaction, internal_comparator=..., prefix_extractor=...) at db/table_cache.cc:719
https://github.com/facebook/rocksdb/issues/6 0x0000000000c3eaec in rocksdb::VersionSet::ApproximateSize (this=<optimized out>, v=<optimized out>, f=..., start=..., end=..., caller=<optimized out>) at ./db/version_set.h:850
https://github.com/facebook/rocksdb/issues/7 0x0000000000c6ebc3 in rocksdb::VersionSet::ApproximateSize (this=<optimized out>, options=..., v=v@entry=0x621000047500, start=..., end=..., start_level=start_level@entry=0, end_level=<optimized out>, caller=<optimized out>)
at db/version_set.cc:5657
https://github.com/facebook/rocksdb/issues/8 0x000000000166e894 in rocksdb::CompactionJob::GenSubcompactionBoundaries (this=<optimized out>) at ./include/rocksdb/options.h:1869
https://github.com/facebook/rocksdb/issues/9 0x000000000168c526 in rocksdb::CompactionJob::Prepare (this=this@entry=0x7f75f3ffcf00) at db/compaction/compaction_job.cc:546
```

The problem occurred in `ApproximateSize()` when the index `Seek()` for the first `ApproximateDataOffsetOf()` encountered an I/O error, while the second `Seek()` did not. In the old code that scenario caused `start_offset == data_size` , thus it was easy to trip the assertion that `end_offset >= start_offset`.

The fix is to set `start_offset == 0` when the first index `Seek()` fails, and `end_offset == data_size` when the second index `Seek()` fails. I doubt these give an "on average correct" answer for how this function is used, but I/O errors in index seeks are hopefully rare, it looked consistent with what was already there, and it was easier to calculate.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9615

Test Plan:
run the repro command for a while and stopped seeing coredumps -

```
$ while !  ./db_stress --block_size=128 --cache_size=32768 --clear_column_family_one_in=0 --column_families=1 --continuous_verification_interval=0 --db=/dev/shm/rocksdb_crashtest --delpercent=4 --delrangepercent=1 --destroy_db_initially=0 --expected_values_dir=/dev/shm/rocksdb_crashtest_expected --index_type=2 --iterpercent=10  --kill_random_test=18887 --max_key=1000000 --max_bytes_for_level_base=2048576 --nooverwritepercent=1 --open_files=-1 --open_read_fault_one_in=32 --ops_per_thread=1000000 --prefixpercent=5 --read_fault_one_in=0 --readpercent=45 --reopen=0 --skip_verifydb=1 --subcompactions=2 --target_file_size_base=524288 --test_batches_snapshots=0 --value_size_mult=32 --write_buffer_size=524288 --writepercent=35  ; do : ; done
```

Reviewed By: pdillinger

Differential Revision: D34383069

Pulled By: ajkr

fbshipit-source-id: fac26c3b20ea962e75387515ba5f2724dc48719f
2022-02-28 23:45:08 -08:00
mrambacher 30b08878d8 Make FilterPolicy Customizable (#9590)
Summary:
Make FilterPolicy into a Customizable class.  Allow new FilterPolicy to be discovered through the ObjectRegistry

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9590

Reviewed By: pdillinger

Differential Revision: D34327367

Pulled By: mrambacher

fbshipit-source-id: 37e7edac90ec9457422b72f359ab8ef48829c190
2022-02-18 13:22:31 -08:00
Andrew Kryczka 54fb2a8975 Change type of cache buffer passed to Cache::CreateCallback() to const void* (#9595)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/9595

Reviewed By: riversand963

Differential Revision: D34329906

Pulled By: ajkr

fbshipit-source-id: 508601856fa9bee4d40f4a68d14d333ef2143d40
2022-02-17 21:09:56 -08:00
Peter Dillinger 725833a424 Hide FilterBits{Builder,Reader} from public API (#9592)
Summary:
We don't have any evidence of people using these to build custom
filters. The recommended way of customizing filter handling is to
defer to various built-in policies based on FilterBuildingContext
(e.g. to build Monkey filtering policy). With old API, we have
evidence of people modifying keys going into filter, but most cases
of that can be handled with prefix_extractor.

Having FilterBitsBuilder+Reader in the public API is an ogoing
hinderance to code evolution (e.g. recent new Finish and
MaybePostVerify), and so this change removes them from the public API
for 7.0. Maybe they will come back in some form later, but lacking
evidence of them providing value in the public API, we want to take back
more freedom to evolve these.

With this moved to internal-only, there is no rush to clean up the
complex Finish signatures, or add memory allocator support, but doing so
is much easier with them out of public API, for example to use
CacheAllocationPtr without exposing it in the public API.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9592

Test Plan: cosmetic changes only

Reviewed By: hx235

Differential Revision: D34315470

Pulled By: pdillinger

fbshipit-source-id: 03e03bb66a72c73df2c464d2dbbbae906dd8f99b
2022-02-17 16:34:46 -08:00
Andrew Kryczka babe56ddba Add rate limiter priority to ReadOptions (#9424)
Summary:
Users can set the priority for file reads associated with their operation by setting `ReadOptions::rate_limiter_priority` to something other than `Env::IO_TOTAL`. Rate limiting `VerifyChecksum()` and `VerifyFileChecksums()` is the motivation for this PR, so it also includes benchmarks and minor bug fixes to get that working.

`RandomAccessFileReader::Read()` already had support for rate limiting compaction reads. I changed that rate limiting to be non-specific to compaction, but rather performed according to the passed in `Env::IOPriority`. Now the compaction read rate limiting is supported by setting `rate_limiter_priority = Env::IO_LOW` on its `ReadOptions`.

There is no default value for the new `Env::IOPriority` parameter to `RandomAccessFileReader::Read()`. That means this PR goes through all callers (in some cases multiple layers up the call stack) to find a `ReadOptions` to provide the priority. There are TODOs for cases I believe it would be good to let user control the priority some day (e.g., file footer reads), and no TODO in cases I believe it doesn't matter (e.g., trace file reads).

The API doc only lists the missing cases where a file read associated with a provided `ReadOptions` cannot be rate limited. For cases like file ingestion checksum calculation, there is no API to provide `ReadOptions` or `Env::IOPriority`, so I didn't count that as missing.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9424

Test Plan:
- new unit tests
- new benchmarks on ~50MB database with 1MB/s read rate limit and 100ms refill interval; verified with strace reads are chunked (at 0.1MB per chunk) and spaced roughly 100ms apart.
  - setup command: `./db_bench -benchmarks=fillrandom,compact -db=/tmp/testdb -target_file_size_base=1048576 -disable_auto_compactions=true -file_checksum=true`
  - benchmarks command: `strace -ttfe pread64 ./db_bench -benchmarks=verifychecksum,verifyfilechecksums -use_existing_db=true -db=/tmp/testdb -rate_limiter_bytes_per_sec=1048576 -rate_limit_bg_reads=1 -rate_limit_user_ops=true -file_checksum=true`
- crash test using IO_USER priority on non-validation reads with https://github.com/facebook/rocksdb/issues/9567 reverted: `python3 tools/db_crashtest.py blackbox --max_key=1000000 --write_buffer_size=524288 --target_file_size_base=524288 --level_compaction_dynamic_level_bytes=true --duration=3600 --rate_limit_bg_reads=true --rate_limit_user_ops=true --rate_limiter_bytes_per_sec=10485760 --interval=10`

Reviewed By: hx235

Differential Revision: D33747386

Pulled By: ajkr

fbshipit-source-id: a2d985e97912fba8c54763798e04f006ccc56e0c
2022-02-16 23:18:14 -08:00
Peter Dillinger 1e403a0c6c Fix assertion failure in FastLocalBloomBitsBuilder (#9585)
Summary:
As in

```
db_stress: table/block_based/filter_policy.cc:316: rocksdb::{anonymous}::FastLocalBloomBitsBuilder::FastLocalBloomBitsBuilder(int, std::atomic<long int>*, std::shared_ptr<rocksdb::CacheReservationManager>, bool): Assertion `millibits_per_key >= 1000' failed.
```

This assertion failure was actually happening with our RibbonFilterPolicy
which falls back to Bloom for some cases, often for flush, but was
missing new special logic to skip generating filter for 0 bits per key
case. Fixed by adding the logic in other builtin FilterPolicy
implementations.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9585

Test Plan:
Updated db_bloom_filter_test to do more integration testing
of the RibbonFilterPolicy ("auto Ribbon") class, incl regression test
this with SkipFilterOnEssentiallyZeroBpk

Reviewed By: ajkr

Differential Revision: D34295101

Pulled By: pdillinger

fbshipit-source-id: 3488eb207fc1d67bbbd1301313714aa1b6406e6e
2022-02-16 22:43:34 -08:00
Peter Dillinger 8c681087c7 Refactor FilterPolicies toward Customizable (#9567)
Summary:
Some changes to make it easier to make FilterPolicy
customizable. Especially, create distinct classes for the different
testing-only and user-facing built-in FilterPolicy modes.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9567

Test Plan:
tests updated, with no intended difference in functionality
tested. No difference in test performance seen as a result of moving to
string-based filter type configuration.

Reviewed By: mrambacher

Differential Revision: D34234694

Pulled By: pdillinger

fbshipit-source-id: 8a94931a9e04c3bcca863a4f524cfd064aaf0122
2022-02-16 08:30:03 -08:00
Peter Dillinger 479eb1aad6 Hide deprecated, inefficient block-based filter from public API (#9535)
Summary:
This change removes the ability to configure the deprecated,
inefficient block-based filter in the public API. Options that would
have enabled it now use "full" (and optionally partitioned) filters.
Existing block-based filters can still be read and used, and a "back
door" way to build them still exists, for testing and in case of trouble.

About the only way this removal would cause an issue for users is if
temporary memory for filter construction greatly increases. In
HISTORY.md we suggest a few possible mitigations: partitioned filters,
smaller SST files, or setting reserve_table_builder_memory=true.

Or users who have customized a FilterPolicy using the
CreateFilter/KeyMayMatch mechanism removed in https://github.com/facebook/rocksdb/issues/9501 will have to upgrade
their code. (It's long past time for people to move to the new
builder/reader customization interface.)

This change also introduces some internal-use-only configuration strings
for testing specific filter implementations while bypassing some
compatibility / intelligence logic. This is intended to hint at a path
toward making FilterPolicy Customizable, but it also gives us a "back
door" way to configure block-based filter.

Aside: updated db_bench so that -readonly implies -use_existing_db

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9535

Test Plan:
Unit tests updated. Specifically,

* BlockBasedTableTest.BlockReadCountTest is tweaked to validate the back
door configuration interface and ignoring of `use_block_based_builder`.
* BlockBasedTableTest.TracingGetTest is migrated from testing
block-based filter access pattern to full filter access patter, by
re-ordering some things.
* Options test (pretty self-explanatory)

Performance test - create with `./db_bench -db=/dev/shm/rocksdb1 -bloom_bits=10 -cache_index_and_filter_blocks=1 -benchmarks=fillrandom -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0` with and without `-use_block_based_filter`, which creates a DB with 21 SST files in L0. Read with `./db_bench -db=/dev/shm/rocksdb1 -readonly -bloom_bits=10 -cache_index_and_filter_blocks=1 -benchmarks=readrandom -num=10000000 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -duration=30`

Without -use_block_based_filter: readrandom 464 ops/sec, 689280 KB DB
With -use_block_based_filter: readrandom 169 ops/sec, 690996 KB DB
No consistent difference with fillrandom

Reviewed By: jay-zhuang

Differential Revision: D34153871

Pulled By: pdillinger

fbshipit-source-id: 31f4a933c542f8f09aca47fa64aec67832a69738
2022-02-12 07:05:57 -08:00
Peter Dillinger 68a9c186d0 FilterPolicy API changes for 7.0 (#9501)
Summary:
* Inefficient block-based filter is no longer customizable in the public
API, though (for now) can still be enabled.
  * Removed deprecated FilterPolicy::CreateFilter() and
  FilterPolicy::KeyMayMatch()
  * Removed `rocksdb_filterpolicy_create()` from C API
* Change meaning of nullptr return from GetBuilderWithContext() from "use
block-based filter" to "generate no filter in this case." This is a
cleaner solution to the proposal in https://github.com/facebook/rocksdb/issues/8250.
  * Also, when user specifies bits_per_key < 0.5, we now round this down
  to "no filter" because we expect a filter with >= 80% FP rate is
  unlikely to be worth the CPU cost of accessing it (esp with
  cache_index_and_filter_blocks=1 or partition_filters=1).
  * bits_per_key >= 0.5 and < 1.0 is still rounded up to 1.0 (for 62% FP
  rate)
  * This also gives us some support for configuring filters from OPTIONS
  file as currently saved: `filter_policy=rocksdb.BuiltinBloomFilter`.
  Opening from such an options file will enable reading filters (an
  improvement) but not writing new ones. (See Customizable follow-up
  below.)
* Also removed deprecated functions
  * FilterBitsBuilder::CalculateNumEntry()
  * FilterPolicy::GetFilterBitsBuilder()
  * NewExperimentalRibbonFilterPolicy()
* Remove default implementations of
  * FilterBitsBuilder::EstimateEntriesAdded()
  * FilterBitsBuilder::ApproximateNumEntries()
  * FilterPolicy::GetBuilderWithContext()
* Remove support for "filter_policy=experimental_ribbon" configuration
string.
* Allow "filter_policy=bloomfilter:n" without bool to discourage use of
block-based filter.

Some pieces for https://github.com/facebook/rocksdb/issues/9389

Likely follow-up (later PRs):
* Refactoring toward FilterPolicy Customizable, so that we can generate
filters with same configuration as before when configuring from options
file.
* Remove support for user enabling block-based filter (ignore `bool
use_block_based_builder`)
  * Some months after this change, we could even remove read support for
  block-based filter, because it is not critical to DB data
  preservation.
* Make FilterBitsBuilder::FinishV2 to avoid `using
FilterBitsBuilder::Finish` mess and add support for specifying a
MemoryAllocator (for cache warming)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9501

Test Plan:
A number of obsolete tests deleted and new tests or test
cases added or updated.

Reviewed By: hx235

Differential Revision: D34008011

Pulled By: pdillinger

fbshipit-source-id: a39a720457c354e00d5b59166b686f7f59e392aa
2022-02-08 13:56:46 -08:00
Hui Xiao 920386f2b7 Detect (new) Bloom/Ribbon Filter construction corruption (#9342)
Summary:
Note: rebase on and merge after https://github.com/facebook/rocksdb/pull/9349, https://github.com/facebook/rocksdb/pull/9345, (optional) https://github.com/facebook/rocksdb/pull/9393
**Context:**
(Quoted from pdillinger) Layers of information during new Bloom/Ribbon Filter construction in building block-based tables includes the following:
a) set of keys to add to filter
b) set of hashes to add to filter (64-bit hash applied to each key)
c) set of Bloom indices to set in filter, with duplicates
d) set of Bloom indices to set in filter, deduplicated
e) final filter and its checksum

This PR aims to detect corruption (e.g, unexpected hardware/software corruption on data structures residing in the memory for a long time) from b) to e) and leave a) as future works for application level.
- b)'s corruption is detected by verifying the xor checksum of the hash entries calculated as the entries accumulate before being added to the filter. (i.e, `XXPH3FilterBitsBuilder::MaybeVerifyHashEntriesChecksum()`)
- c) - e)'s corruption is detected by verifying the hash entries indeed exists in the constructed filter by re-querying these hash entries in the filter (i.e, `FilterBitsBuilder::MaybePostVerify()`) after computing the block checksum (except for PartitionFilter, which is done right after each `FilterBitsBuilder::Finish` for impl simplicity - see code comment for more). For this stage of detection, we assume hash entries are not corrupted after checking on b) since the time interval from b) to c) is relatively short IMO.

Option to enable this feature of detection is `BlockBasedTableOptions::detect_filter_construct_corruption` which is false by default.

**Summary:**
- Implemented new functions `XXPH3FilterBitsBuilder::MaybeVerifyHashEntriesChecksum()` and `FilterBitsBuilder::MaybePostVerify()`
- Ensured hash entries, final filter and banding and their [cache reservation ](https://github.com/facebook/rocksdb/issues/9073) are released properly despite corruption
   - See [Filter.construction.artifacts.release.point.pdf ](https://github.com/facebook/rocksdb/files/7923487/Design.Filter.construction.artifacts.release.point.pdf) for high-level design
   -  Bundled and refactored hash entries's related artifact in XXPH3FilterBitsBuilder into `HashEntriesInfo` for better control on lifetime of these artifact during `SwapEntires`, `ResetEntries`
- Ensured RocksDB block-based table builder calls `FilterBitsBuilder::MaybePostVerify()` after constructing the filter by `FilterBitsBuilder::Finish()`
- When encountering such filter construction corruption, stop writing the filter content to files and mark such a block-based table building non-ok by storing the corruption status in the builder.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9342

Test Plan:
- Added new unit test `DBFilterConstructionCorruptionTestWithParam.DetectCorruption`
- Included this new feature in `DBFilterConstructionReserveMemoryTestWithParam.ReserveMemory` as this feature heavily touch ReserveMemory's impl
   - For fallback case, I run `./filter_bench -impl=3 -detect_filter_construct_corruption=true -reserve_table_builder_memory=true -strict_capacity_limit=true  -quick -runs 10 | grep 'Build avg'` to make sure nothing break.
- Added to `filter_bench`: increased filter construction time by **30%**, mostly by `MaybePostVerify()`
   -  FastLocalBloom
       - Before change: `./filter_bench -impl=2 -quick -runs 10 | grep 'Build avg'`: **28.86643s**
       - After change:
          -  `./filter_bench -impl=2 -detect_filter_construct_corruption=false -quick -runs 10 | grep 'Build avg'` (expect a tiny increase due to MaybePostVerify is always called regardless): **27.6644s (-4% perf improvement might be due to now we don't drop bloom hash entry in `AddAllEntries` along iteration but in bulk later, same with the bypassing-MaybePostVerify case below)**
          - `./filter_bench -impl=2 -detect_filter_construct_corruption=true -quick -runs 10 | grep 'Build avg'` (expect acceptable increase): **34.41159s (+20%)**
          - `./filter_bench -impl=2 -detect_filter_construct_corruption=true -quick -runs 10 | grep 'Build avg'` (by-passing MaybePostVerify, expect minor increase): **27.13431s (-6%)**
    -  Standard128Ribbon
       - Before change: `./filter_bench -impl=3 -quick -runs 10 | grep 'Build avg'`: **122.5384s**
       - After change:
          - `./filter_bench -impl=3 -detect_filter_construct_corruption=false -quick -runs 10 | grep 'Build avg'` (expect a tiny increase due to MaybePostVerify is always called regardless - verified by removing MaybePostVerify under this case and found only +-1ns difference): **124.3588s (+2%)**
          - `./filter_bench -impl=3 -detect_filter_construct_corruption=true -quick -runs 10 | grep 'Build avg'`(expect acceptable increase): **159.4946s (+30%)**
          - `./filter_bench -impl=3 -detect_filter_construct_corruption=true -quick -runs 10 | grep 'Build avg'`(by-passing MaybePostVerify, expect minor increase) : **125.258s (+2%)**
- Added to `db_stress`: `make crash_test`, `./db_stress --detect_filter_construct_corruption=true`
- Manually smoke-tested: manually corrupted the filter construction in some db level tests with basic PUT and background flush. As expected, the error did get returned to users in subsequent PUT and Flush status.

Reviewed By: pdillinger

Differential Revision: D33746928

Pulled By: hx235

fbshipit-source-id: cb056426be5a7debc1cd16f23bc250f36a08ca57
2022-02-01 17:42:35 -08:00
Peter Dillinger f6d7ec1d02 Ignore total_order_seek in DB::Get (#9427)
Summary:
Apparently setting total_order_seek=true for DB::Get was
intended to allow accurate read semantics if the current prefix
extractor doesn't match what was used to generate SST files on
disk. But since prefix_extractor was made a mutable option in 5.14.0, we
have been able to detect this case and provide the correct semantics
regardless of the total_order_seek option. Since that time, the option
has only made Get() slower in a reasonably common case: prefix_extractor
unchanged and whole_key_filtering=false.

So this change primarily removes unnecessary effect of
total_order_seek on Get. Also cleans up some related comments.

Also adds a -total_order_seek option to db_bench and canonicalizes
handling of ReadOptions in db_bench so that command line options have
the expected association with library features. (There is potential
for change in regression test behavior, but the old behavior is likely
indefensible, or some other inconsistency would need to be fixed.)

TODO in follow-up work: there should be no reason for Get() to depend on
current prefix extractor at all.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9427

Test Plan:
Unit tests updated.

Performance (using db_bench update)

Create DB with `TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -benchmarks=fillrandom -num=10000000 -disable_wal=1 -write_buffer_size=10000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=12 -whole_key_filtering=0`

Test with and without `-total_order_seek` on `TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -use_existing_db -readonly -benchmarks=readrandom -num=10000000 -duration=40 -disable_wal=1 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=12`

Before this change, total_order_seek=false: 25188 ops/sec
Before this change, total_order_seek=true:   1222 ops/sec (~20x slower)

After this change, total_order_seek=false: 24570 ops/sec
After this change, total_order_seek=true:  25012 ops/sec (indistinguishable)

Reviewed By: siying

Differential Revision: D33753458

Pulled By: pdillinger

fbshipit-source-id: bf892f34907a5e407d9c40bd4d42f0adbcbe0014
2022-01-31 19:46:42 -08:00
Hui Xiao 11d7329503 Clarify status-handling logic in BlockBasedTableBuilder::WriteRawBlock (#9393)
Summary:
**Context:**
Inside `BlockBasedTableBuilder::WriteRawBlock`, there are multiple places that change local variables `io_s` and `s` while
depend on them. This PR attempts to clarify the relevant logics so that it's easier to read and add places of changing these local variables later (like https://github.com/facebook/rocksdb/pull/9342.) without changing the current behavior.

**Summary:**
- Shorten the lifetime of local var `io_s` and `s` as much as possible to avoid if-else branches by early return

**Test**
- Reasoned against original behavior to verify new changes do not break existing behaviors.
- Rely on CI tests since we are not changing current behavior.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9393

Reviewed By: pdillinger

Differential Revision: D33626095

Pulled By: hx235

fbshipit-source-id: 6184d1e1d85d2650d16617c449971988d062ed3f
2022-01-26 10:24:16 -08:00