Commit Graph

177 Commits

Author SHA1 Message Date
sdong 911c0208b9 WritableFileWriter tries to skip operations after failure (#10489)
Summary:
A flag in WritableFileWriter is introduced to remember error has happened. Subsequent operations will fail with an assertion. Those operations, except Close() are not supposed to be called anyway. This change will help catch bug in tests and stress tests and limit damage of a potential bug of continue writing to a file after a failure.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10489

Test Plan: Fix existing unit tests and watch crash tests for a while.

Reviewed By: anand1976

Differential Revision: D38473277

fbshipit-source-id: 09aafb971e56cfd7f9ef92ad15b883f54acf1366
2022-08-10 10:19:20 -07:00
Akanksha Mahajan 2acbf386a3 Provide support for direct_reads with async_io (#10197)
Summary:
Provide support for use_direct_reads with async_io.

TestPlan:
-  Updated unit tests
-  db_bench: Results in https://github.com/facebook/rocksdb/pull/10197#issuecomment-1159239420
- db_stress
```
export CRASH_TEST_EXT_ARGS=" --async_io=1 --use_direct_reads=1"
make crash_test -j
```
- Ran db_bench on previous RocksDB version before any async_io implementation (as there have many changes in different PRs in this area) https://github.com/facebook/rocksdb/pull/10197#issuecomment-1160781563.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10197

Reviewed By: anand1976

Differential Revision: D37255646

Pulled By: akankshamahajan15

fbshipit-source-id: fec61ae15bf4d625f79dea56e4f86e0e307ba920
2022-07-06 11:42:59 -07:00
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
Andrew Kryczka d5d8920f2c Fix race condition with WAL tracking and `FlushWAL(true /* sync */)` (#10185)
Summary:
`FlushWAL(true /* sync */)` is used internally and for manual WAL sync. It had a bug when used together with `track_and_verify_wals_in_manifest` where the synced size tracked in MANIFEST was larger than the number of bytes actually synced.

The bug could be repro'd almost immediately with the following crash test command: `python3 tools/db_crashtest.py blackbox --simple --write_buffer_size=524288 --max_bytes_for_level_base=2097152 --target_file_size_base=524288 --duration=3600 --interval=10 --sync_fault_injection=1 --disable_wal=0 --checkpoint_one_in=1000 --max_key=10000 --value_size_mult=33`.

An example error message produced by the above command is shown below. The error sometimes arose from the checkpoint and other times arose from the main stress test DB.

```
Corruption: Size mismatch: WAL (log number: 119) in MANIFEST is 27938 bytes , but actually is 27859 bytes on disk.
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10185

Test Plan:
- repro unit test
- the above crash test command no longer finds the error. It does find a different error after a while longer such as "Corruption: WAL file 481 required by manifest but not in directory list"

Reviewed By: riversand963

Differential Revision: D37200993

Pulled By: ajkr

fbshipit-source-id: 98e0071c1a89f4d009888512ed89f9219779ae5f
2022-06-17 16:45:28 -07:00
Hui Xiao a5d773e077 Add rate-limiting support to batched MultiGet() (#10159)
Summary:
**Context/Summary:**
https://github.com/facebook/rocksdb/pull/9424 added rate-limiting support for user reads, which does not include batched `MultiGet()`s that call `RandomAccessFileReader::MultiRead()`. The reason is that it's harder (compared with RandomAccessFileReader::Read()) to implement the ideal rate-limiting where we first call `RateLimiter::RequestToken()` for allowed bytes to multi-read and then consume those bytes by satisfying as many requests in `MultiRead()` as possible. For example, it can be tricky to decide whether we want partially fulfilled requests within one `MultiRead()` or not.

However, due to a recent urgent user request, we decide to pursue an elementary (but a conditionally ineffective) solution where we accumulate enough rate limiter requests toward the total bytes needed by one `MultiRead()` before doing that `MultiRead()`. This is not ideal when the total bytes are huge as we will actually consume a huge bandwidth from rate-limiter causing a burst on disk. This is not what we ultimately want with rate limiter. Therefore a follow-up work is noted through TODO comments.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10159

Test Plan:
- Modified existing unit test `DBRateLimiterOnReadTest/DBRateLimiterOnReadTest.NewMultiGet`
- Traced the underlying system calls `io_uring_enter` and verified they are 10 seconds apart from each other correctly under the setting of  `strace -ftt -e trace=io_uring_enter ./db_bench -benchmarks=multireadrandom -db=/dev/shm/testdb2 -readonly -num=50 -threads=1 -multiread_batched=1 -batch_size=100 -duration=10 -rate_limiter_bytes_per_sec=200 -rate_limiter_refill_period_us=1000000 -rate_limit_bg_reads=1 -disable_auto_compactions=1 -rate_limit_user_ops=1` where each `MultiRead()` read about 2000 bytes (inspected by debugger) and the rate limiter grants 200 bytes per seconds.
- Stress test:
   - Verified `./db_stress (-test_cf_consistency=1/test_batches_snapshots=1) -use_multiget=1 -cache_size=1048576 -rate_limiter_bytes_per_sec=10241024 -rate_limit_bg_reads=1 -rate_limit_user_ops=1` work

Reviewed By: ajkr, anand1976

Differential Revision: D37135172

Pulled By: hx235

fbshipit-source-id: 73b8e8f14761e5d4b77235dfe5d41f4eea968bcd
2022-06-17 16:40:47 -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
zczhu b6de139df5 Handle "NotSupported" status by default implementation of Close() in … (#10127)
Summary:
The default implementation of Close() function in Directory/FSDirectory classes returns `NotSupported` status. However, we don't want operations that worked in older versions to begin failing after upgrading when run on FileSystems that have not implemented Directory::Close() yet. So we require the upper level that calls Close() function should properly handle "NotSupported" status instead of treating it as an error status.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10127

Reviewed By: ajkr

Differential Revision: D36971112

Pulled By: littlepig2013

fbshipit-source-id: 100f0e6ad1191e1acc1ba6458c566a11724cf466
2022-06-07 09:49:31 -07:00
Yanqin Jin d739de63e5 Fix a bug in WAL tracking (#10087)
Summary:
Closing https://github.com/facebook/rocksdb/issues/10080

When `SyncWAL()` calls `MarkLogsSynced()`, even if there is only one active WAL file,
this event should still be added to the MANIFEST.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10087

Test Plan: make check

Reviewed By: ajkr

Differential Revision: D36797580

Pulled By: riversand963

fbshipit-source-id: 24184c9dd606b3939a454ed41de6e868d1519999
2022-06-03 16:33:00 -07:00
Zichen Zhu 65893ad959 Explicitly closing all directory file descriptors (#10049)
Summary:
Currently, the DB directory file descriptor is left open until the deconstruction process (`DB::Close()` does not close the file descriptor). To verify this, comment out the lines between `db_ = nullptr` and `db_->Close()` (line 512, 513, 514, 515 in ldb_cmd.cc) to leak the ``db_'' object, build `ldb` tool and run
```
strace --trace=open,openat,close ./ldb --db=$TEST_TMPDIR --ignore_unknown_options put K1 V1 --create_if_missing
```
There is one directory file descriptor that is not closed in the strace log.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10049

Test Plan: Add a new unit test DBBasicTest.DBCloseAllDirectoryFDs: Open a database with different WAL directory and three different data directories, and all directory file descriptors should be closed after calling Close(). Explicitly call Close() after a directory file descriptor is not used so that the counter of directory open and close should be equivalent.

Reviewed By: ajkr, hx235

Differential Revision: D36722135

Pulled By: littlepig2013

fbshipit-source-id: 07bdc2abc417c6b30997b9bbef1f79aa757b21ff
2022-06-01 18:03:34 -07:00
Akanksha Mahajan 28ea1fb44a Provide support for IOTracing for ReadAsync API (#9833)
Summary:
Same as title

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9833

Test Plan:
Add unit test and manually check the output of tracing logs
For fixed readahead_size it logs as:
```
Access Time : 193352113447923     , File Name: 000026.sst          , File Operation: ReadAsync         , Latency: 15075     , IO Status: OK, Length: 12288, Offset: 659456
Access Time : 193352113465232     , File Name: 000026.sst          , File Operation: ReadAsync         , Latency: 14425     , IO Status: OK, Length: 12288, Offset: 671744
Access Time : 193352113481539     , File Name: 000026.sst          , File Operation: ReadAsync         , Latency: 13062     , IO Status: OK, Length: 12288, Offset: 684032
Access Time : 193352113497692     , File Name: 000026.sst          , File Operation: ReadAsync         , Latency: 13649     , IO Status: OK, Length: 12288, Offset: 696320
Access Time : 193352113520043     , File Name: 000026.sst          , File Operation: ReadAsync         , Latency: 19384     , IO Status: OK, Length: 12288, Offset: 708608
Access Time : 193352113538401     , File Name: 000026.sst          , File Operation: ReadAsync         , Latency: 15406     , IO Status: OK, Length: 12288, Offset: 720896
Access Time : 193352113554855     , File Name: 000026.sst          , File Operation: ReadAsync         , Latency: 13670     , IO Status: OK, Length: 12288, Offset: 733184
Access Time : 193352113571624     , File Name: 000026.sst          , File Operation: ReadAsync         , Latency: 13855     , IO Status: OK, Length: 12288, Offset: 745472
Access Time : 193352113587924     , File Name: 000026.sst          , File Operation: ReadAsync         , Latency: 13953     , IO Status: OK, Length: 12288, Offset: 757760
Access Time : 193352113603285     , File Name: 000026.sst          , File Operation: Prefetch          , Latency: 59        , IO Status: Not implemented: Prefetch not supported, Length: 8868, Offset: 898349
```

For implicit readahead:
```
Access Time : 193351865156587     , File Name: 000026.sst          , File Operation: Prefetch          , Latency: 48        , IO Status: Not implemented: Prefetch not supported, Length: 12266, Offset: 391174
Access Time : 193351865160354     , File Name: 000026.sst          , File Operation: Prefetch          , Latency: 51        , IO Status: Not implemented: Prefetch not supported, Length: 12266, Offset: 395248
Access Time : 193351865164253     , File Name: 000026.sst          , File Operation: Prefetch          , Latency: 49        , IO Status: Not implemented: Prefetch not supported, Length: 12266, Offset: 399322
Access Time : 193351865165461     , File Name: 000026.sst          , File Operation: ReadAsync         , Latency: 222871    , IO Status: OK, Length: 135168, Offset: 401408
```

Reviewed By: anand1976

Differential Revision: D35601634

Pulled By: akankshamahajan15

fbshipit-source-id: 5a4f32a850af878efa0767bd5706380152a1f26e
2022-05-25 19:47:03 -07:00
Changyu Bi 8515bd50c9 Support read rate-limiting in SequentialFileReader (#9973)
Summary:
Added rate limiter and read rate-limiting support to SequentialFileReader. I've updated call sites to SequentialFileReader::Read with appropriate IO priority (or left a TODO and specified IO_TOTAL for now).

The PR is separated into four commits: the first one added the rate-limiting support, but with some fixes in the unit test since the number of request bytes from rate limiter in SequentialFileReader are not accurate (there is overcharge at EOF). The second commit fixed this by allowing SequentialFileReader to check file size and determine how many bytes are left in the file to read. The third commit added benchmark related code. The fourth commit moved the logic of using file size to avoid overcharging the rate limiter into backup engine (the main user of SequentialFileReader).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9973

Test Plan:
- `make check`, backup_engine_test covers usage of SequentialFileReader with rate limiter.
- Run db_bench to check if rate limiting is throttling as expected: Verified that reads and writes are together throttled at 2MB/s, and at 0.2MB chunks that are 100ms apart.
  - Set up: `./db_bench --benchmarks=fillrandom -db=/dev/shm/test_rocksdb`
  - Benchmark:
```
strace -ttfe read,write ./db_bench --benchmarks=backup -db=/dev/shm/test_rocksdb --backup_rate_limit=2097152 --use_existing_db
strace -ttfe read,write ./db_bench --benchmarks=restore -db=/dev/shm/test_rocksdb --restore_rate_limit=2097152 --use_existing_db
```
- db bench on backup and restore to ensure no performance regression.
  - backup (avg over 50 runs): pre-change: 1.90443e+06 micros/op; post-change: 1.8993e+06 micros/op (improve by 0.2%)
  - restore (avg over 50 runs): pre-change: 1.79105e+06 micros/op; post-change: 1.78192e+06 micros/op (improve by 0.5%)

```
# Set up
./db_bench --benchmarks=fillrandom -db=/tmp/test_rocksdb -num=10000000

# benchmark
TEST_TMPDIR=/tmp/test_rocksdb
NUM_RUN=50
for ((j=0;j<$NUM_RUN;j++))
do
   ./db_bench -db=$TEST_TMPDIR -num=10000000 -benchmarks=backup -use_existing_db | egrep 'backup'
  # Restore
  #./db_bench -db=$TEST_TMPDIR -num=10000000 -benchmarks=restore -use_existing_db
done > rate_limit.txt && awk -v NUM_RUN=$NUM_RUN '{sum+=$3;sum_sqrt+=$3^2}END{print sum/NUM_RUN, sqrt(sum_sqrt/NUM_RUN-(sum/NUM_RUN)^2)}' rate_limit.txt >> rate_limit_2.txt
```

Reviewed By: hx235

Differential Revision: D36327418

Pulled By: cbi42

fbshipit-source-id: e75d4307cff815945482df5ba630c1e88d064691
2022-05-24 10:28:57 -07:00
Akanksha Mahajan a479c2c2b2 Fix stress test failure "Corruption: checksum mismatch" or "Iterator Diverged" with async_io enabled (#10032)
Summary:
In case of non sequential reads with `async_io`, `FilePRefetchBuffer::TryReadFromCacheAsync` can be called for previous blocks with `offset < bufs_[curr_].offset_` which wasn't handled correctly resulting wrong data being returned from buffer.

Since `FilePRefetchBuffer::PrefetchAsync` can be called for any data block, it sets `prev_len_` to 0  indicating `FilePRefetchBuffer::TryReadFromCacheAsync` to go for the prefetching even though offset < bufs_[curr_].offset_  This is because async prefetching is always done in second buffer (to avoid mutex) even though curr_ is empty leading to  offset < bufs_[curr_].offset_ in some cases.
If prev_len_ is non zero then `TryReadFromCacheAsync` returns false if `offset < bufs_[curr_].offset_ && prev_len != 0` indicating reads are not sequential and previous call wasn't PrefetchAsync.

-  This PR also simplifies `FilePRefetchBuffer::TryReadFromCacheAsync` as it was getting complicated covering different scenarios based on `async_io` enabled/disabled. If `for_compaction` is set true, it now calls `FilePRefetchBufferTryReadFromCache` following synchronous flow as before. Its decided in BlockFetcher.cc

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10032

Test Plan:
1.  export CRASH_TEST_EXT_ARGS=" --async_io=1"
     make crash_test -j completed successfully locally
2. make crash_test -j completed successfully locally
3. Reran CircleCi mini crashtest job 4 - 5 times.
4. Updated prefetch_test for more coverage.

Reviewed By: anand1976

Differential Revision: D36579858

Pulled By: akankshamahajan15

fbshipit-source-id: 0c428d62b45e12e082a83acf533a5e37a584bedf
2022-05-23 12:15:26 -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
Bo Wang 5be1579ead Address comments for PR #9988 and #9996 (#10020)
Summary:
1. The latest change of DecideRateLimiterPriority in https://github.com/facebook/rocksdb/pull/9988 is reverted.
2. For https://github.com/facebook/rocksdb/blob/main/db/builder.cc#L345-L349
  2.1. Remove `we will regrad this verification as user reads` from the comments.
  2.2. `Do not set` the read_options.rate_limiter_priority to Env::IO_USER . Flush should be a background job.
  2.3. Update db_rate_limiter_test.cc.
3. In IOOptions, mark `prio` as deprecated for future removal.
4. In `file_system.h`, mark `IOPriority` as deprecated for future removal.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10020

Test Plan: Unit tests.

Reviewed By: ajkr

Differential Revision: D36525317

Pulled By: gitbw95

fbshipit-source-id: 011ba421822f8a124e6d25a2661c4e242df6ad36
2022-05-19 15:23:53 -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
gitbw95 05c678e135 Set Write rate limiter priority dynamically and pass it to FS (#9988)
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.

From the RocksDB perspective, there can be two kinds of rate limiters, the internal (native) one and the external one.
- The internal (native) rate limiter is introduced in [the wiki](https://github.com/facebook/rocksdb/wiki/Rate-Limiter). Currently, only IO_LOW and IO_HIGH are used and they are set statically.
- For the external rate limiter, in FSWritableFile functions,  IOOptions is open for end users to set and get rate_limiter_priority for their own rate limiter. Currently, RocksDB doesn’t pass the rate_limiter_priority through IOOptions to the file system.

### Solution
During the User Read, Flush write, Compaction read/write, the WriteController is used to determine whether DB writes are stalled or slowed down. The rate limiter priority (Env::IOPriority) can be determined accordingly. We decided to always pass the priority in IOOptions. What the file system does with it should be a contract between the user and the file system. We would like to set the rate limiter priority at file level, since the Flush/Compaction job level may be too coarse with multiple files and block IO level is too granular.

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

| State | Normal | Delayed | Stalled |
| ----- | ------ | ------- | ------- |
|  Flush | IO_HIGH | IO_USER | IO_USER |
|  Compaction | IO_LOW | IO_USER | IO_USER |

Flush and Compaction writes share the same call path through BlockBaseTableWriter, WritableFileWriter, and FSWritableFile. When a new FSWritableFile object is created, its io_priority_ can be set dynamically based on the state of the WriteController. In WritableFileWriter, before the call sites of FSWritableFile functions, WritableFileWriter::DecideRateLimiterPriority() determines the rate_limiter_priority. The options (IOOptions) argument of FSWritableFile functions will be updated with the rate_limiter_priority.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9988

Test Plan: Add unit tests.

Reviewed By: anand1976

Differential Revision: D36395159

Pulled By: gitbw95

fbshipit-source-id: a7c82fc29759139a1a07ec46c37dbf7e753474cf
2022-05-18 00:41:41 -07:00
Hui Xiao f6339de0d2 Clarify some SequentialFileReader::Read logic (#10002)
Summary:
**Context/Summary:**
The logic related to PositionedRead in SequentialFileReader::Read confused me a bit as discussed here https://github.com/facebook/rocksdb/pull/9973#discussion_r872869256. Therefore I added a drawing with help from cbi42.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10002

Test Plan: - no code change

Reviewed By: anand1976, cbi42

Differential Revision: D36422632

Pulled By: hx235

fbshipit-source-id: 9a8311d2365564f90d216c430f542fc11b2d9cde
2022-05-17 10:24:04 -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
Akanksha Mahajan fce65e7e4f Fix bug in async_io path which reads incorrect length (#9916)
Summary:
In FilePrefetchBuffer, in case data is overlapping between two
buffers and more data is required to read and copy that to third buffer,
incorrect length was updated resulting in
```
Iterator diverged from control iterator which has value 00000000000310C3000000000000012B0000000000000274 total_order_seek: 1 auto_prefix_mode: 0 S 000000000002C37F000000000000012B000000000000001C NNNPPPPPNN; total_order_seek: 1 auto_prefix_mode: 0 S 000000000002F10B00000000000000BF78787878787878 NNNPNNNNPN; total_order_seek: 1 auto_prefix_mode: 0 S 00000000000310C3000000000000012B000000000000026B
iterator is not valid
Control CF default
db_stress: db_stress_tool/db_stress_test_base.cc:1388: void rocksdb::StressTest::VerifyIterator(rocksdb::ThreadState*, rocksdb::ColumnFamilyHandle*, const rocksdb::ReadOptions&, rocksdb::Iterator*, rocksdb::Iterator*, rocksdb::StressTest::LastIterateOp, const rocksdb::Slice&, const string&, bool*): Assertion `false' failed.
Aborted (core dumped)
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9916

Test Plan:
```
- CircleCI jobs
- Ran db_stress with OPTIONS file which caught the bug
 ./db_stress --acquire_snapshot_one_in=10000 --adaptive_readahead=0 --async_io=1 --avoid_flush_during_recovery=0 --avoid_unnecessary_blocking_io=1 --backup_max_size=104857600 --backup_one_in=0 --batch_protection_bytes_per_key=0 --block_size=16384 --bloom_bits=42.26248932628998 --bottommost_compression_type=disable --cache_index_and_filter_blocks=0 --cache_size=8388608 --checkpoint_one_in=0 --checksum_type=kxxHash --clear_column_family_one_in=0 --compact_files_one_in=1000000 --compact_range_one_in=1000000 --compaction_ttl=0 --compression_max_dict_buffer_bytes=1073741823 --compression_max_dict_bytes=16384 --compression_parallel_threads=1 --compression_type=zstd --compression_zstd_max_train_bytes=65536 --continuous_verification_interval=0 --db=/dev/shm/rocksdb/ --db_write_buffer_size=134217728 --delpercent=5 --delrangepercent=0 --destroy_db_initially=0 --detect_filter_construct_corruption=0 --disable_wal=0 --enable_blob_files=0 --enable_compaction_filter=0 --enable_pipelined_write=0 --fail_if_options_file_error=0 --file_checksum_impl=none --flush_one_in=1000000 --format_version=4 --get_current_wal_file_one_in=0 --get_live_files_one_in=1000000 --get_property_one_in=1000000 --get_sorted_wal_files_one_in=0 --index_block_restart_interval=12 --index_type=2 --ingest_external_file_one_in=0 --iterpercent=10 --key_len_percent_dist=1,30,69 --level_compaction_dynamic_level_bytes=True --long_running_snapshots=0 --mark_for_compaction_one_file_in=0 --max_background_compactions=20 --max_bytes_for_level_base=10485760 --max_key=25000000 --max_key_len=3 --max_manifest_file_size=1073741824 --max_write_batch_group_size_bytes=1048576 --max_write_buffer_number=3 --max_write_buffer_size_to_maintain=8388608 --memtable_prefix_bloom_size_ratio=0.001 --memtable_whole_key_filtering=1 --memtablerep=skip_list --mmap_read=0 --mock_direct_io=False --nooverwritepercent=1 --open_files=100 --open_metadata_write_fault_one_in=0 --open_read_fault_one_in=0 --open_write_fault_one_in=16 --ops_per_thread=100000000 --optimize_filters_for_memory=0 --paranoid_file_checks=1 --partition_filters=0 --partition_pinning=1 --pause_background_one_in=1000000 --periodic_compaction_seconds=0 --prefix_size=-1 --prefixpercent=0 --prepopulate_block_cache=0 --progress_reports=0 --read_fault_one_in=0 --read_only=0 --readpercent=50 --recycle_log_file_num=1 --reopen=0 --reserve_table_reader_memory=0 --ribbon_starting_level=999 --secondary_cache_fault_one_in=0 --secondary_catch_up_one_in=0 --set_options_one_in=10000 --snapshot_hold_ops=100000 --sst_file_manager_bytes_per_sec=104857600 --sst_file_manager_bytes_per_truncate=0 --subcompactions=2 --sync=0 --sync_fault_injection=False --target_file_size_base=2097152 --target_file_size_multiplier=2 --test_batches_snapshots=0 --test_cf_consistency=0 --top_level_index_pinning=3 --unpartitioned_pinning=3 --use_blob_db=0 --use_block_based_filter=0 --use_clock_cache=0 --use_direct_io_for_flush_and_compaction=1 --use_direct_reads=0 --use_full_merge_v1=0 --use_merge=0 --use_multiget=0 --use_txn=0 --user_timestamp_size=0 --value_size_mult=32 --verify_checksum=1 --verify_checksum_one_in=1000000 --verify_db_one_in=100000 --wal_compression=zstd --write_buffer_size=4194304 --write_dbid_to_manifest=0 --writepercent=35 --options_file=/home/akankshamahajan/OPTIONS.orig -column_families=1

db_bench with async_io enabled to make sure db_bench completes successfully without any failure.
- ./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
```

crash_test in progress

Reviewed By: anand1976

Differential Revision: D35985789

Pulled By: akankshamahajan15

fbshipit-source-id: 5abe185f34caa99ca587d4bdc8954bd0802b1bf9
2022-04-27 22:33:29 -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
Akanksha Mahajan 5bd374b392 Add experimental new FS API AbortIO to cancel read request (#9901)
Summary:
Add experimental new API AbortIO in FileSystem to abort the
read requests submitted asynchronously through ReadAsync API.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9901

Test Plan: Existing tests

Reviewed By: anand1976

Differential Revision: D35885591

Pulled By: akankshamahajan15

fbshipit-source-id: df3944e6e9e6e487af1fa688376b4abb6837fb02
2022-04-25 14:20:03 -07:00
Hui Xiao e83c55439a Conditionally declare and define variable that is unused in LITE mode (#9854)
Summary:
Context:
As mentioned in https://github.com/facebook/rocksdb/issues/9701, we have the following in LITE=1 make static_lib for v7.0.2
```
  CC       file/sequence_file_reader.o
  CC       file/sst_file_manager_impl.o
  CC       file/writable_file_writer.o
In file included from file/writable_file_writer.cc:10:
./file/writable_file_writer.h:163:15: error: private field 'temperature_' is not used [-Werror,-Wunused-private-field]
  Temperature temperature_;
              ^
1 error generated.
make: *** [file/writable_file_writer.o] Error 1
```

 as titled

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9854

Test Plan:
- Local `LITE=1 make static_lib` reveals the same error and error is gone after this fix
- CI

Reviewed By: ajkr, jay-zhuang

Differential Revision: D35706585

Pulled By: hx235

fbshipit-source-id: 7743310298231ad6866304ffa2225c8abdc91d9a
2022-04-18 14:16:35 -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
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
Akanksha Mahajan f3bcac39a6 Fix stress test failure in ReadAsync. (#9824)
Summary:
Fix stress test failure in ReadAsync by ignoring errors
injected during async read by FaultInjectionFS.
Failure:
```
 WARNING: prefix_size is non-zero but memtablerep != prefix_hash
Didn't get expected error from MultiGet.
num_keys 14 Expected 1 errors, seen 0
Callstack that injected the fault
Injected error type = 32538
Message: error;
#0   ./db_stress() [0x6f7dd4] rocksdb::port::SaveStack(int*, int)	/data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/port/stack_trace.cc:152
https://github.com/facebook/rocksdb/issues/1   ./db_stress() [0x7f2bda] rocksdb::FaultInjectionTestFS::InjectThreadSpecificReadError(rocksdb::FaultInjectionTestFS::ErrorOperation, rocksdb::Slice*, bool, char*, bool, bool*)	/data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/utilities/fault_injection_fs.cc:891
https://github.com/facebook/rocksdb/issues/2   ./db_stress() [0x7f2e78] rocksdb::TestFSRandomAccessFile::Read(unsigned long, unsigned long, rocksdb::IOOptions const&, rocksdb::Slice*, char*, rocksdb::IODebugContext*) const	/data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/utilities/fault_injection_fs.cc:367
https://github.com/facebook/rocksdb/issues/3   ./db_stress() [0x6483d7] rocksdb::(anonymous namespace)::CompositeRandomAccessFileWrapper::Read(unsigned long, unsigned long, rocksdb::Slice*, char*) const	/data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/env/composite_env.cc:61
https://github.com/facebook/rocksdb/issues/4   ./db_stress() [0x654564] rocksdb::(anonymous namespace)::LegacyRandomAccessFileWrapper::Read(unsigned long, unsigned long, rocksdb::IOOptions const&, rocksdb::Slice*, char*, rocksdb::IODebugContext*) const	/data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/env/env.cc:152
https://github.com/facebook/rocksdb/issues/5   ./db_stress() [0x659b3b] rocksdb::FSRandomAccessFile::ReadAsync(rocksdb::FSReadRequest&, rocksdb::IOOptions const&, std::function<void (rocksdb::FSReadRequest const&, void*)>, void*, void**, std::function<void (void*)>*, rocksdb::IODebugContext*)	/data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/./include/rocksdb/file_system.h:896
https://github.com/facebook/rocksdb/issues/6   ./db_stress() [0x8b8bab] rocksdb::RandomAccessFileReader::ReadAsync(rocksdb::FSReadRequest&, rocksdb::IOOptions const&, std::function<void (rocksdb::FSReadRequest const&, void*)>, void*, void**, std::function<void (void*)>*, rocksdb::Env::IOPriority)	/data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/file/random_access_file_reader.cc:459
https://github.com/facebook/rocksdb/issues/7   ./db_stress() [0x8b501f] rocksdb::FilePrefetchBuffer::ReadAsync(rocksdb::IOOptions const&, rocksdb::RandomAccessFileReader*, rocksdb::Env::IOPriority, unsigned long, unsigned long, unsigned long, unsigned int)	/data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/file/file_prefetch_buffer.cc:124
https://github.com/facebook/rocksdb/issues/8   ./db_stress() [0x8b55fc] rocksdb::FilePrefetchBuffer::PrefetchAsync(rocksdb::IOOptions const&, rocksdb::RandomAccessFileReader*, unsigned long, unsigned long, unsigned long, rocksdb::Env::IOPriority, bool&)	/data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/file/file_prefetch_buffer.cc:363
https://github.com/facebook/rocksdb/issues/9   ./db_stress() [0x8b61f8] rocksdb::FilePrefetchBuffer::TryReadFromCacheAsync(rocksdb::IOOptions const&, rocksdb::RandomAccessFileReader*, unsigned long, unsigned long, rocksdb::Slice*, rocksdb::Status*, rocksdb::Env::IOPriority, bool)	/data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/file/file_prefetch_buffer.cc:482
https://github.com/facebook/rocksdb/issues/10  ./db_stress() [0x745e04] rocksdb::BlockFetcher::TryGetFromPrefetchBuffer()	/data/sandcastle/boxes/trunk-hg-fbcode-fbsource/fbcode/internal_repo_rocksdb/repo/table/block_fetcher.cc:76
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9824

Test Plan:
```
./db_stress --acquire_snapshot_one_in=10000 --adaptive_readahead=1 --allow_concurrent_memtable_write=0 --async_io=1 --atomic_flush=1 --avoid_flush_during_recovery=0 --avoid_unnecessary_blocking_io=0 -- backup_max_size=104857600 --backup_one_in=100000 --batch_protection_bytes_per_key=0 --block_size=16384 --bloom_bits=5.037629726741734 --bottommost_compression_type=lz4hc --cache_index_and_filter_blocks=0 --cache_size=8388608 --checkpoint_one_in=1000000 --checksum_type=kxxHash --clear_column_family_one_in=0 --column_families=1 --compact_files_one_in=1000000 --compact_range_one_in=1000000 --compaction_ttl=100 --compression_max_dict_buffer_bytes=1073741823 --compression_max_dict_bytes=16384 --compression_parallel_threads=1 --compression_type=zstd --compression_zstd_max_train_bytes=0 --continuous_verification_interval=0 --db=/home/akankshamahajan/dev/shm/rocksdb/rocksdb_crashtest_blackbox --db_write_buffer_size=8388608 --delpercent=0 --delrangepercent=0 --destroy_db_initially=0 - detect_filter_construct_corruption=1 --disable_wal=1 --enable_compaction_filter=0 --enable_pipelined_write=0 --expected_values_dir=/home/akankshamahajan/dev/shm/rocksdb/rocksdb_crashtest_expected --experimental_mempurge_threshold=8.772789063014715 --fail_if_options_file_error=0 --file_checksum_impl=crc32c --flush_one_in=1000000 --format_version=3 --get_current_wal_file_one_in=0 --get_live_files_one_in=1000000 --get_property_one_in=1000000 --get_sorted_wal_files_one_in=0 --index_block_restart_interval=15 --index_type=3 --iterpercent=0 --key_len_percent_dist=1,30,69 --level_compaction_dynamic_level_bytes=False --long_running_snapshots=0 --mark_for_compaction_one_file_in=0 --max_background_compactions=1 --max_bytes_for_level_base=67108864 --max_key=25000000 --max_key_len=3 --max_manifest_file_size=1073741824 --max_write_batch_group_size_bytes=16777216 --max_write_buffer_number=3 --max_write_buffer_size_to_maintain=2097152 --memtable_prefix_bloom_size_ratio=0.001 --memtable_whole_key_filtering=1 --memtablerep=skip_list --mmap_read=0 --mock_direct_io=True --nooverwritepercent=1 --open_files=-1 --open_metadata_write_fault_one_in=0 --open_read_fault_one_in=0 --open_write_fault_one_in=0 --ops_per_thread=100000000 --optimize_filters_for_memory=0 --paranoid_file_checks=1 --partition_filters=0 --partition_pinning=2 --pause_background_one_in=1000000 --periodic_compaction_seconds=1000 --prefix_size=-1 --prefixpercent=0 --prepopulate_block_cache=0 --progress_reports=0 --read_fault_one_in=32 --readpercent=100 --recycle_log_file_num=1 --reopen=0 --reserve_table_reader_memory=1 --ribbon_starting_level=999 --secondary_cache_fault_one_in=0 --set_options_one_in=0 --snapshot_hold_ops=100000 --sst_file_manager_bytes_per_sec=0 --sst_file_manager_bytes_per_truncate=0 --subcompactions=2 --sync=0 --sync_fault_injection=False --target_file_size_base=16777216 --target_file_size_multiplier=1 --test_batches_snapshots=0 --top_level_index_pinning=3 --unpartitioned_pinning=2 --use_block_based_filter=0 --use_clock_cache=0 --use_direct_io_for_flush_and_compaction=1 --use_direct_reads=0 --use_full_merge_v1=0 --use_merge=1 --use_multiget=1 --user_timestamp_size=0 --value_size_mult=32 --verify_checksum=1 --verify_checksum_one_in=1000000 --verify_db_one_in=100000 --wal_compression=none --write_buffer_size=33554432 --write_dbid_to_manifest=1 --write_fault_one_in=0 --writepercent=0
```

Reviewed By: anand1976

Differential Revision: D35514566

Pulled By: akankshamahajan15

fbshipit-source-id: e2a868fdd7422604774c1419738f9926a21e92a4
2022-04-11 10:56:11 -07:00
Akanksha Mahajan 3fc2eaf561 Fix valgrind test failure for async read (#9819)
Summary:
Since all plaftorms don't support io_uring. So updated the unit
test to take that into consideration when testing async reads in unit tests.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9819

Test Plan:
valgrind --error-exitcode=2 --leak-check=full ./prefetch_test
--gtest_filter=PrefetchTest2.ReadAsyncWithPosixFS
CircleCI jobs

Reviewed By: pdillinger

Differential Revision: D35469959

Pulled By: akankshamahajan15

fbshipit-source-id: b170459ec816487fc0a13b1d55dbbe4f754b2eba
2022-04-07 10:31:50 -07:00
Akanksha Mahajan 7ea26abb8b Fix reseting of async_read_in_progress_ variable in FilePrefetchBuffer to call Poll API (#9815)
Summary:
Currently RocksDB reset async_read_in_progress_ in callback
due to which underlying filesystem relying on Poll API won't be called
leading to stale memory access.
In order to fix it, async_read_in_progress_ will be reset after Poll API
is called to make sure underlying file_system waiting on Poll can clear
its state or take appropriate action.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9815

Test Plan: CircleCI tests

Reviewed By: anand1976

Differential Revision: D35451534

Pulled By: akankshamahajan15

fbshipit-source-id: b70ef6251a7aa9ed4876ba5e5100baa33d7d474c
2022-04-06 18:36:23 -07:00
Akanksha Mahajan 0b8f885939 Update stats for Read and ReadAsync in random_access_file_reader for async prefetching (#9810)
Summary:
Update stats in random_access_file_reader for Read and
ReadAsync API to take into account the read latency for async
prefetching.

It also fixes ERROR_HANDLER_AUTORESUME_RETRY_COUNT stat whose value was
incorrect in portal.h

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9810

Test Plan: Update unit test

Reviewed By: anand1976

Differential Revision: D35433081

Pulled By: akankshamahajan15

fbshipit-source-id: aeec3901270e58a003ce6b5214bd25ddcb3a12a9
2022-04-06 14:26:53 -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
SGZW f68706409d Fix typo about file/sst_file_manager_impl.h (#9799)
Summary:
Fix typo deletition-> deletion

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9799

Reviewed By: ajkr

Differential Revision: D35341617

Pulled By: jay-zhuang

fbshipit-source-id: 32bc384b99e5564f6a673076c6a4f160ee6c2e46
2022-04-04 09:57:33 -07:00
bbkot e55018a8ce fixing issue #8345 RocksDB does not work when using UNC network paths (#9384)
Summary:
Fix https://github.com/facebook/rocksdb/issues/8345
RocksDB does not work with network filesystem paths on Windows, e.g. "\\hostname\folder\..."

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9384

Reviewed By: mrambacher

Differential Revision: D33830622

Pulled By: riversand963

fbshipit-source-id: 2a99dc3c94415eb1460e110784b97d71600218f1
2022-03-30 15:55:31 -07:00
Akanksha Mahajan 33f8a08af2 Fix some errors in async prefetching in FilePrefetchBuffer (#9734)
Summary:
In ReadOption `async_io` which prefetches the data asynchronously, db_bench and db_stress runs were failing  because wrong data was prefetched which resulted in Error: Checksum mismatched. Wrong data was copied because capacity was less than actual size needed. It has been fixed in this PR.

Since there are two separate methods for async and sync prefetching, these changes are in async prefetching methods and any changes would not effect normal prefetching. I ran the regressions to make sure normal prefetching is fine.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9734

Test Plan:
1. CircleCI jobs

2.  Ran db_bench
```
. /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

```
3. Ran db_stress test
```
export CRASH_TEST_EXT_ARGS=" --async_io=1 --adaptive_readahead=1"
make crash_test -j
```

4. Run regressions for async_io disabled.

Old flow without any async changes:
```
./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 async prefetching changes and async_io disabled to make sure in normal prefetching there is no regression.
 ```
 ./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=0
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 7.1
Date:       Wed Mar 23 15:56:37 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   :  481819.816 micros/op 2 ops/sec;  340.2 MB/s (250 of 250 found)
```

Reviewed By: riversand963

Differential Revision: D35058471

Pulled By: akankshamahajan15

fbshipit-source-id: 9233a1e6d97cea0c7a8111bfb9e8ac3251c341ce
2022-03-25 18:26:22 -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
Jay Zhuang f0fca81fc6 Deflake DeleteSchedulerTest.StartBGEmptyTrashMultipleTimes (#9706)
Summary:
The designed sync point may not be hit if trash file is generated faster
than deleting. Then the file will be deleted directly instead of waiting
for background trash empty thread to do it.
Increase SstFileManager Trash/DB ratio to avoid that.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9706

Test Plan:
`gtest-parallel ./delete_scheduler_test
--gtest_filter=DeleteSchedulerTest.StartBGEmptyTrashMultipleTimes -r
10000 -w 100`
It was likely to happen on one of the host.

Reviewed By: riversand963

Differential Revision: D34964735

Pulled By: jay-zhuang

fbshipit-source-id: bb78015489b5f6b3f11783aae7e5853ea197702c
2022-03-17 13:30:28 -07:00
Hui Xiao ca0ef54f16 Rate-limit automatic WAL flush after each user write (#9607)
Summary:
**Context:**
WAL flush is currently not rate-limited by `Options::rate_limiter`. This PR is to provide rate-limiting to auto WAL flush, the one that automatically happen after each user write operation (i.e, `Options::manual_wal_flush == false`), by adding `WriteOptions::rate_limiter_options`.

Note that we are NOT rate-limiting WAL flush that do NOT automatically happen after each user write, such as  `Options::manual_wal_flush == true + manual FlushWAL()` (rate-limiting multiple WAL flushes),  for the benefits of:
- being consistent with [ReadOptions::rate_limiter_priority](https://github.com/facebook/rocksdb/blob/7.0.fb/include/rocksdb/options.h#L515)
- being able to turn off some WAL flush's rate-limiting but not all (e.g, turn off specific the WAL flush of a critical user write like a service's heartbeat)

`WriteOptions::rate_limiter_options` only accept `Env::IO_USER` and `Env::IO_TOTAL` currently due to an implementation constraint.
- The constraint is that we currently queue parallel writes (including WAL writes) based on FIFO policy which does not factor rate limiter priority into this layer's scheduling. If we allow lower priorities such as `Env::IO_HIGH/MID/LOW` and such writes specified with lower priorities occurs before ones specified with higher priorities (even just by a tiny bit in arrival time), the former would have blocked the latter, leading to a "priority inversion" issue and contradictory to what we promise for rate-limiting priority. Therefore we only allow `Env::IO_USER` and `Env::IO_TOTAL`  right now before improving that scheduling.

A pre-requisite to this feature is to support operation-level rate limiting in `WritableFileWriter`, which is also included in this PR.

**Summary:**
- Renamed test suite `DBRateLimiterTest to DBRateLimiterOnReadTest` for adding a new test suite
- Accept `rate_limiter_priority` in `WritableFileWriter`'s private and public write functions
- Passed `WriteOptions::rate_limiter_options` to `WritableFileWriter` in the path of automatic WAL flush.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9607

Test Plan:
- Added new unit test to verify existing flush/compaction rate-limiting does not break, since `DBTest, RateLimitingTest` is disabled and current db-level rate-limiting tests focus on read only (e.g, `db_rate_limiter_test`, `DBTest2, RateLimitedCompactionReads`).
- Added new unit test `DBRateLimiterOnWriteWALTest, AutoWalFlush`
- `strace -ftt -e trace=write ./db_bench -benchmarks=fillseq -db=/dev/shm/testdb -rate_limit_auto_wal_flush=1 -rate_limiter_bytes_per_sec=15 -rate_limiter_refill_period_us=1000000 -write_buffer_size=100000000 -disable_auto_compactions=1 -num=100`
   - verified that WAL flush(i.e, system-call _write_) were chunked into 15 bytes and each _write_ was roughly 1 second apart
   - verified the chunking disappeared when `-rate_limit_auto_wal_flush=0`
- crash test: `python3 tools/db_crashtest.py blackbox --disable_wal=0  --rate_limit_auto_wal_flush=1 --rate_limiter_bytes_per_sec=10485760 --interval=10` killed as normal

**Benchmarked on flush/compaction to ensure no performance regression:**
- compaction with rate-limiting  (see table 1, avg over 1280-run):  pre-change: **915635 micros/op**; post-change:
   **907350 micros/op (improved by 0.106%)**
```
#!/bin/bash
TEST_TMPDIR=/dev/shm/testdb
START=1
NUM_DATA_ENTRY=8
N=10

rm -f compact_bmk_output.txt compact_bmk_output_2.txt dont_care_output.txt
for i in $(eval echo "{$START..$NUM_DATA_ENTRY}")
do
    NUM_RUN=$(($N*(2**($i-1))))
    for j in $(eval echo "{$START..$NUM_RUN}")
    do
       ./db_bench --benchmarks=fillrandom -db=$TEST_TMPDIR -disable_auto_compactions=1 -write_buffer_size=6710886 > dont_care_output.txt && ./db_bench --benchmarks=compact -use_existing_db=1 -db=$TEST_TMPDIR -level0_file_num_compaction_trigger=1 -rate_limiter_bytes_per_sec=100000000 | egrep 'compact'
    done > compact_bmk_output.txt && awk -v NUM_RUN=$NUM_RUN '{sum+=$3;sum_sqrt+=$3^2}END{print sum/NUM_RUN, sqrt(sum_sqrt/NUM_RUN-(sum/NUM_RUN)^2)}' compact_bmk_output.txt >> compact_bmk_output_2.txt
done
```
- compaction w/o rate-limiting  (see table 2, avg over 640-run):  pre-change: **822197 micros/op**; post-change: **823148 micros/op (regressed by 0.12%)**
```
Same as above script, except that -rate_limiter_bytes_per_sec=0
```
- flush with rate-limiting (see table 3, avg over 320-run, run on the [patch](ee5c6023a9) to augment current db_bench ): pre-change: **745752 micros/op**; post-change: **745331 micros/op (regressed by 0.06 %)**
```
 #!/bin/bash
TEST_TMPDIR=/dev/shm/testdb
START=1
NUM_DATA_ENTRY=8
N=10

rm -f flush_bmk_output.txt flush_bmk_output_2.txt

for i in $(eval echo "{$START..$NUM_DATA_ENTRY}")
do
    NUM_RUN=$(($N*(2**($i-1))))
    for j in $(eval echo "{$START..$NUM_RUN}")
    do
       ./db_bench -db=$TEST_TMPDIR -write_buffer_size=1048576000 -num=1000000 -rate_limiter_bytes_per_sec=100000000 -benchmarks=fillseq,flush | egrep 'flush'
    done > flush_bmk_output.txt && awk -v NUM_RUN=$NUM_RUN '{sum+=$3;sum_sqrt+=$3^2}END{print sum/NUM_RUN, sqrt(sum_sqrt/NUM_RUN-(sum/NUM_RUN)^2)}' flush_bmk_output.txt >> flush_bmk_output_2.txt
done

```
- flush w/o rate-limiting (see table 4, avg over 320-run, run on the [patch](ee5c6023a9) to augment current db_bench): pre-change: **487512 micros/op**, post-change: **485856 micors/ops (improved by 0.34%)**
```
Same as above script, except that -rate_limiter_bytes_per_sec=0
```

| table 1 - compact with rate-limiting|
#-run | (pre-change) avg micros/op | std micros/op | (post-change)  avg micros/op | std micros/op | change in avg micros/op  (%)
-- | -- | -- | -- | -- | --
10 | 896978 | 16046.9 | 901242 | 15670.9 | 0.475373978
20 | 893718 | 15813 | 886505 | 17544.7 | -0.8070778478
40 | 900426 | 23882.2 | 894958 | 15104.5 | -0.6072681153
80 | 906635 | 21761.5 | 903332 | 23948.3 | -0.3643141948
160 | 898632 | 21098.9 | 907583 | 21145 | 0.9960695813
3.20E+02 | 905252 | 22785.5 | 908106 | 25325.5 | 0.3152713278
6.40E+02 | 905213 | 23598.6 | 906741 | 21370.5 | 0.1688000504
**1.28E+03** | **908316** | **23533.1** | **907350** | **24626.8** | **-0.1063506533**
average over #-run | 901896.25 | 21064.9625 | 901977.125 | 20592.025 | 0.008967217682

| table 2 - compact w/o rate-limiting|
#-run | (pre-change) avg micros/op | std micros/op | (post-change)  avg micros/op | std micros/op | change in avg micros/op  (%)
-- | -- | -- | -- | -- | --
10 | 811211 | 26996.7 | 807586 | 28456.4 | -0.4468627768
20 | 815465 | 14803.7 | 814608 | 28719.7 | -0.105093413
40 | 809203 | 26187.1 | 797835 | 25492.1 | -1.404839082
80 | 822088 | 28765.3 | 822192 | 32840.4 | 0.01265071379
160 | 821719 | 36344.7 | 821664 | 29544.9 | -0.006693285661
3.20E+02 | 820921 | 27756.4 | 821403 | 28347.7 | 0.05871454135
**6.40E+02** | **822197** | **28960.6** | **823148** | **30055.1** | **0.1156657103**
average over #-run | 8.18E+05 | 2.71E+04 | 8.15E+05 | 2.91E+04 |  -0.25

| table 3 - flush with rate-limiting|
#-run | (pre-change) avg micros/op | std micros/op | (post-change)  avg micros/op | std micros/op | change in avg micros/op  (%)
-- | -- | -- | -- | -- | --
10 | 741721 | 11770.8 | 740345 | 5949.76 | -0.1855144994
20 | 735169 | 3561.83 | 743199 | 9755.77 | 1.09226586
40 | 743368 | 8891.03 | 742102 | 8683.22 | -0.1703059588
80 | 742129 | 8148.51 | 743417 | 9631.58| 0.1735547324
160 | 749045 | 9757.21 | 746256 | 9191.86 | -0.3723407806
**3.20E+02** | **745752** | **9819.65** | **745331** | **9840.62** | **-0.0564530836**
6.40E+02 | 749006 | 11080.5 | 748173 | 10578.7 | -0.1112140624
average over #-run | 743741.4286 | 9004.218571 | 744117.5714 | 9090.215714 | 0.05057441238

| table 4 - flush w/o rate-limiting|
#-run | (pre-change) avg micros/op | std micros/op | (post-change)  avg micros/op | std micros/op | change in avg micros/op (%)
-- | -- | -- | -- | -- | --
10 | 477283 | 24719.6 | 473864 | 12379 | -0.7163464863
20 | 486743 | 20175.2 | 502296 | 23931.3 | 3.195320734
40 | 482846 | 15309.2 | 489820 | 22259.5 | 1.444352858
80 | 491490 | 21883.1 | 490071 | 23085.7 | -0.2887139108
160 | 493347 | 28074.3 | 483609 | 21211.7 | -1.973864238
**3.20E+02** | **487512** | **21401.5** | **485856** | **22195.2** | **-0.3396839462**
6.40E+02 | 490307 | 25418.6 | 485435 | 22405.2 | -0.9936631539
average over #-run | 4.87E+05 | 2.24E+04 | 4.87E+05 | 2.11E+04 | 0.00E+00

Reviewed By: ajkr

Differential Revision: D34442441

Pulled By: hx235

fbshipit-source-id: 4790f13e1e5c0a95ae1d1cc93ffcf69dc6e78bdd
2022-03-08 13:19:39 -08:00
anand76 3362a730dc Avoid usage of ReopenWritableFile in db_stress (#9649)
Summary:
The UniqueIdVerifier constructor currently calls ReopenWritableFile on
the FileSystem, which might not be supported. Instead of relying on
reopening the unique IDs file for writing, create a new file and copy
the original contents.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9649

Test Plan: Run db_stress

Reviewed By: pdillinger

Differential Revision: D34572307

Pulled By: anand1976

fbshipit-source-id: 3a777908582d79dae57488d4278bad126774f698
2022-03-04 10:30:10 -08:00
Jay Zhuang d3a2f284d9 Add Temperature info in `NewSequentialFile()` (#9499)
Summary:
Add Temperature hints information from RocksDB in API
`NewSequentialFile()`. backup and checkpoint operations need to open the
source files with `NewSequentialFile()`, which will have the temperature
hints. Other operations are not covered.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9499

Test Plan: Added unittest

Reviewed By: pdillinger

Differential Revision: D34006115

Pulled By: jay-zhuang

fbshipit-source-id: 568b34602b76520e53128672bd07e9d886786a2f
2022-02-18 18:23:07 -08:00
Jay Zhuang f4b2500e12 Add last level and non-last level read statistics (#9519)
Summary:
Add last level and non-last level read statistics:
```
LAST_LEVEL_READ_BYTES,
LAST_LEVEL_READ_COUNT,
NON_LAST_LEVEL_READ_BYTES,
NON_LAST_LEVEL_READ_COUNT,
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9519

Test Plan: added unittest

Reviewed By: siying

Differential Revision: D34062539

Pulled By: jay-zhuang

fbshipit-source-id: 908644c3050878b4234febdc72e3e19d89af38cd
2022-02-18 14:23:07 -08:00
Jay Zhuang 2fbc672732 Add temperature information to the event listener callbacks (#9591)
Summary:
RocksDB try to provide temperature information in the event
listener callbacks. The information is not guaranteed, as some operation
like backup won't have these information.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9591

Test Plan: Added unittest

Reviewed By: siying, pdillinger

Differential Revision: D34309339

Pulled By: jay-zhuang

fbshipit-source-id: 4aca4f270f99fa49186d85d300da42594663d6d7
2022-02-18 11:23:18 -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
Yanqin Jin dd203ed604 Disallow a combination of options (#9348)
Summary:
Disallow `immutable_db_opts.use_direct_io_for_flush_and_compaction == true` and
`mutable_db_opts.writable_file_max_buffer_size == 0`, since it causes `WritableFileWriter::Append()`
to loop forever and does not make much sense in direct IO.

This combination of options itself does not make much sense: asking RocksDB to do direct IO but not allowing
RocksDB to allocate a buffer. We should detect this false combination and warn user early, no matter whether
the application is running on a platform that supports direct IO or not. In the case of platform **not** supporting
direct IO, it's ok if the user learns about this and then finds that direct IO is not supported.

One tricky thing: the constructor of `WritableFileWriter` is being used in our unit tests, and it's impossible
to return status code from constructor. Since we do not throw, I put an assertion for now. Fortunately,
the constructor is not exposed to external applications.

Closing https://github.com/facebook/rocksdb/issues/7109

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9348

Test Plan: make check

Reviewed By: ajkr

Differential Revision: D33371924

Pulled By: riversand963

fbshipit-source-id: 2a3701ab541cee23bffda8a36cdf37b2d235edfa
2022-01-27 19:30:24 -08:00
anand76 beb86addeb Fix race condition in SstFileManagerImpl error recovery code (#9435)
Summary:
There is a race in SstFileManagerImpl between the ClearError() function
and CancelErrorRecovery(). The race can cause ClearError() to deref the
file system pointer after it has been freed. This is likely to occur
during process shutdown, when the order of destruction of the
DB/Env/FileSystem and SstFileManagerImpl is not deterministic.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9435

Test Plan:
Reproduce the crash in a TSAN build by introducing sleeps in the code, and verify with
the fix.

Reviewed By: siying

Differential Revision: D33774696

Pulled By: anand1976

fbshipit-source-id: 643d3da31b8d2ee6d9b6db5d33327e0053ce3b83
2022-01-25 23:22:58 -08:00
Yanqin Jin 08721293ea Fix a bug causing duplicate trailing entries in WritableFile (buffered IO) (#9236)
Summary:
`db_stress` is a user of `FaultInjectionTestFS`. After injecting a write error, `db_stress` probabilistically determins
data drop (https://github.com/facebook/rocksdb/blob/6.27.fb/db_stress_tool/db_stress_test_base.cc#L2615:L2619).

In some of our recent runs of `db_stress`, we found duplicate trailing entries corresponding to file trivial move in
the MANIFEST, causing the recovery to fail, because the file move operation is not idempotent: you cannot delete a
file from a given level twice.

Investigation suggests that data buffering in both `WritableFileWriter` and `FaultInjectionTestFS` may be the root cause.

WritableFileWriter buffers data to write in a memory buffer, `WritableFileWriter::buf_`. After each
`WriteBuffered()`/`WriteBufferedWithChecksum()` succeeds, the `buf_` is cleared.

If the underlying file `WritableFileWriter::writable_file_` is opened in buffered IO mode, then `FaultInjectionTestFS`
buffers data written for each file until next file sync. After an injected error, user of `FaultInjectionFS` can
choose to drop some or none of previously buffered data. If `db_stress` does not drop any unsynced data, then
such data will still exist in the `FaultInjectionTestFS`'s buffer.

Existing implementation of `WritableileWriter::WriteBuffered()` does not clear `buf_` if there is an error. This may lead
to the data being buffered two copies: one in `WritableFileWriter`, and another in `FaultInjectionTestFS`.
We also know that the `WritableFileWriter` of MANIFEST file will close upon an error.  During `Close()`, it will flush the
content in `buf_`. If no write error is injected to `FaultInjectionTestFS` this time, then we end up with two copies of the
data appended to the file.

To fix, we clear the `WritableFileWriter::buf_` upon failure as well. We focus this PR on files opened in non-direct mode.

This PR includes a unit test to reproduce a case when write error injection
to `WritableFile` can cause duplicate trailing entries.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9236

Test Plan: make check

Reviewed By: zhichao-cao

Differential Revision: D33033984

Pulled By: riversand963

fbshipit-source-id: ebfa5a0db8cbf1ed73100528b34fcba543c5db31
2021-12-13 09:00:36 -08:00
Akanksha Mahajan 04b2c16f9b Fix bug in rocksdb internal automatic prefetching (#9234)
Summary:
After introducing adaptive_readahead, the original flow got
broken. Readahead size was set to 0 because of which rocksdb wasn't be
able to do automatic prefetching which it enables after seeing
sequential reads. This PR fixes it.

----------------------------------------------------------------------------------------------------

Before this patch:
b_bench -use_existing_db=true -db=/tmp/prefix_scan -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 6.27
Date:       Tue Nov 30 11:56:50 2021
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
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
DB path: [/tmp/prefix_scan]

seekrandom   : 5356367.174 micros/op 0 ops/sec;   29.4 MB/s (23 of 23 found)

----------------------------------------------------------------------------------------------------

After the patch:
./db_bench -use_existing_db=true -db=/tmp/prefix_scan -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 6.27
Date:       Tue Nov 30 14:38:33 2021
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
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
DB path: [/tmp/prefix_scan]
seekrandom   :  456504.277 micros/op 2 ops/sec;  359.8 MB/s (264 of 264 found)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9234

Test Plan:
Ran ./db_bench -db=/data/mysql/rocksdb/prefix_scan
-benchmarks="fillseq" -key_size=32 -value_size=512 -num=5000000 -use_d
irect_io_for_flush_and_compaction=true -target_file_size_base=16777216
and then ./db_bench -use_existing_db=true
-db=/data/mysql/rocksdb/prefix_scan -benchmarks="seekrandom"
-key_size=32 -value_siz
e=512 -num=5000000 -use_direct_reads=true -seek_nexts=327680
-duration=120 -ops_between_duration_checks=1
 and compared the results.

Reviewed By: anand1976

Differential Revision: D32743965

Pulled By: akankshamahajan15

fbshipit-source-id: b950fba68c91963b7deb5c20acdf471bc60251f5
2021-11-30 22:53:10 -08:00
Levi Tamasi dc5de45af8 Support readahead during compaction for blob files (#9187)
Summary:
The patch adds a new BlobDB configuration option `blob_compaction_readahead_size`
that can be used to enable prefetching data from blob files during compaction.
This is important when using storage with higher latencies like HDDs or remote filesystems.
If enabled, prefetching is used for all cases when blobs are read during compaction,
namely garbage collection, compaction filters (when the existing value has to be read from
a blob file), and `Merge` (when the value of the base `Put` is stored in a blob file).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9187

Test Plan: Ran `make check` and the stress/crash test.

Reviewed By: riversand963

Differential Revision: D32565512

Pulled By: ltamasi

fbshipit-source-id: 87be9cebc3aa01cc227bec6b5f64d827b8164f5d
2021-11-19 17:53:47 -08:00
Akanksha Mahajan 4a7c1dc375 Add listener API that notifies on IOError (#9177)
Summary:
Add a new API in listener.h that notifies about IOErrors on
Read/Write/Append/Flush etc. The API reports about IOStatus, filename, Operation
name, offset and length.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9177

Test Plan: Added new unit tests

Reviewed By: anand1976

Differential Revision: D32470627

Pulled By: akankshamahajan15

fbshipit-source-id: 189a717033590ae227b3beae8b1e7e185e4cdc12
2021-11-18 17:11:19 -08:00
Zhichao Cao b694cd0e0d Add tiered storage related read bytes stats to Statistic (#9123)
Summary:
Add the 3 read bytes counter to the Statistic, which will be used by storage tiering and get the information for files with different temperature.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9123

Test Plan: added new testing cases.

Reviewed By: siying

Differential Revision: D32154745

Pulled By: zhichao-cao

fbshipit-source-id: b7905d6dae469a72428742364ec07b634b6f15da
2021-11-16 15:17:17 -08:00
Akanksha Mahajan 17ce1ca48b Reuse internal auto readhead_size at each Level (expect L0) for Iterations (#9056)
Summary:
RocksDB does auto-readahead for iterators on noticing more than two sequential reads for a table file if user doesn't provide readahead_size. The readahead starts at 8KB and doubles on every additional read up to max_auto_readahead_size. However at each level, if iterator moves over next file, readahead_size starts again from 8KB.

This PR introduces a new ReadOption "adaptive_readahead" which when set true will maintain readahead_size  at each level. So when iterator moves from one file to another, new file's readahead_size will continue from previous file's readahead_size instead of scratch. However if reads are not sequential it will fall back to 8KB (default) with no prefetching for that block.

1. If block is found in cache but it was eligible for prefetch (block wasn't in Rocksdb's prefetch buffer),  readahead_size will decrease by 8KB.
2. It maintains readahead_size for L1 - Ln levels.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9056

Test Plan:
Added new unit tests
Ran db_bench for "readseq, seekrandom, seekrandomwhilewriting, readrandom" with --adaptive_readahead=true and there was no regression if new feature is enabled.

Reviewed By: anand1976

Differential Revision: D31773640

Pulled By: akankshamahajan15

fbshipit-source-id: 7332d16258b846ae5cea773009195a5af58f8f98
2021-11-10 16:20:04 -08:00
Jay Zhuang 29102641dd Skip directory fsync for filesystem btrfs (#8903)
Summary:
Directory fsync might be expensive on btrfs and it may not be needed.
Here are 4 directory fsync cases:
1. creating a new file: dir-fsync is not needed on btrfs, as long as the
   new file itself is synced.
2. renaming a file: dir-fsync is not needed if the renamed file is
   synced. So an API `FsyncAfterFileRename(filename, ...)` is provided
   to sync the file on btrfs. By default, it just calls dir-fsync.
3. deleting files: dir-fsync is forced by set
   `IOOptions.force_dir_fsync = true`
4. renaming multiple files (like backup and checkpoint): dir-fsync is
   forced, the same as above.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8903

Test Plan: run tests on btrfs and non btrfs

Reviewed By: ajkr

Differential Revision: D30885059

Pulled By: jay-zhuang

fbshipit-source-id: dd2730b31580b0bcaedffc318a762d7dbf25de4a
2021-11-03 12:21:27 -07:00