Commit Graph

1390 Commits

Author SHA1 Message Date
Changyu Bi df492791b6 Fix segfault in Iterator::Refresh() (#10739)
Summary:
when a new internal iterator is constructed during iterator refresh, pointer to the previous memtable range tombstone iterator was not cleared. This could cause segfault for future `Refresh()` calls when they try to free the memtable range tombstones. This PR fixes this issue.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10739

Test Plan: added a unit test in db_range_del_test.cc to reproduce this issue.

Reviewed By: ajkr, riversand963

Differential Revision: D39825283

Pulled By: cbi42

fbshipit-source-id: 3b59a2b73865aed39e28cdd5c1b57eed7991b94c
2022-09-26 18:57:23 -07:00
Yanqin Jin 52f2411722 Update HISTORY to mention PR #10724 (#10737)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10737

Reviewed By: cbi42

Differential Revision: D39825386

Pulled By: riversand963

fbshipit-source-id: a3c55f2777e034d6ae6ff44ef0219d9fbbf1cc96
2022-09-26 15:59:30 -07:00
Changyu Bi 93f46da1fa Mention in HISTORY.md the fix in #10705 (#10720)
Summary:
Mention in HISTORY.md the fix in https://github.com/facebook/rocksdb/issues/10705.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10720

Reviewed By: riversand963

Differential Revision: D39709455

Pulled By: cbi42

fbshipit-source-id: 1a2c9dd8425c73f7095ddb1d0b1cca8ed35b7ef2
2022-09-21 15:08:43 -07:00
Akanksha Mahajan 0f4978d34f Fix sqe->addr passed in cancel request in io_uring (#10644)
Summary:
Update io_uring_prep_cancel as it is now backward compatible.
Also, io_uring_prep_cancel expects sqe->addr to match with read
request submitted. It's being set wrong which is now fixed in this PR.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10644

Test Plan:
- Ran internally with lastest liburing package and on RocksDB
github repo with older version.
- Ran seekrandom regression to confirm there is no regression.

Reviewed By: anand1976

Differential Revision: D39284229

Pulled By: akankshamahajan15

fbshipit-source-id: fd52cdf23d676da114896163626b75c8ae09c980
2022-09-21 14:21:59 -07:00
Yanqin Jin 2b6f3510c2 Update version number and HISTORY in main branch (#10694)
Summary:
This PR bumps up version number from 7.7 to 7.8 in main branch, indicating that next release will be 7.8. We are going to release 7.7 soon. Since 7.7.fb branch has been created, we can land this to main.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10694

Reviewed By: gitbw95

Differential Revision: D39581577

Pulled By: riversand963

fbshipit-source-id: 84f3fecf25fd9ac96e46b4cd6d50ddb6edc89427
2022-09-19 12:25:44 -07:00
gitbw95 2cc5b39560 Add enable_split_merge option for CompressedSecondaryCache (#10690)
Summary:
`enable_custom_split_merge` is added for enabling the custom split and merge feature, which split the compressed value into chunks so that they may better fit jemalloc bins.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10690

Test Plan:
Unit Tests
Stress Tests

Reviewed By: anand1976

Differential Revision: D39567604

Pulled By: gitbw95

fbshipit-source-id: f6d1d46200f365220055f793514601dcb0edc4b7
2022-09-16 15:41:49 -07:00
Peter Dillinger 0f91c72adc Call experimental new clock cache HyperClockCache (#10684)
Summary:
This change establishes a distinctive name for the experimental new lock-free clock cache (originally developed by guidotag and revamped in PR https://github.com/facebook/rocksdb/issues/10626). A few reasons:
* We want to make it clear that this is a fundamentally different implementation vs. the old clock cache, to avoid people saying "I already tried clock cache."
* We want to highlight the key feature: it's fast (especially under parallel load)
* Because it requires an estimated charge per entry, it is not drop-in API compatible with old clock cache. This estimate might always be required for highest performance, and giving it a distinct name should reduce confusion about the distinct API requirements.
* We might develop a variant requiring the same estimate parameter but with LRU eviction. In that case, using the name HyperLRUCache should make things more clear. (FastLRUCache is just a prototype that might soon be removed.)

Some API detail:
* To reduce copy-pasting parameter lists, etc. as in LRUCache construction, I have a `MakeSharedCache()` function on `HyperClockCacheOptions` instead of `NewHyperClockCache()`.
* Changes -cache_type=clock_cache to -cache_type=hyper_clock_cache for applicable tools. I think this is more consistent / sustainable for reasons already stated.

For performance tests see https://github.com/facebook/rocksdb/pull/10626

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10684

Test Plan: no interesting functional changes; tests updated

Reviewed By: anand1976

Differential Revision: D39547800

Pulled By: pdillinger

fbshipit-source-id: 5c0fe1b5cf3cb680ab369b928c8569682b9795bf
2022-09-16 12:47:29 -07:00
anand76 37b75e1364 Fix some MultiGet stats (#10673)
Summary:
The stats were not accurate for the coroutine version of MultiGet. This PR fixes it.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10673

Reviewed By: akankshamahajan15

Differential Revision: D39492615

Pulled By: anand1976

fbshipit-source-id: b46c04e15ea27e66f4c31f00c66497aa283bf9d3
2022-09-15 22:48:06 -07:00
anand76 7b11d48444 Change MultiGet multi-level optimization to default on (#10671)
Summary:
Change the ```ReadOptions.optimize_multiget_for_io``` flag to default on. It doesn't impact regular MultiGet users as its only applicable when ```ReadOptions.async_io``` is also set to true.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10671

Reviewed By: akankshamahajan15

Differential Revision: D39477439

Pulled By: anand1976

fbshipit-source-id: 47abcdbfa69f9bc60422ab68a238b232e085d4ba
2022-09-14 08:51:16 -07:00
Changyu Bi f291eefb02 Cache fragmented range tombstone list for mutable memtables (#10547)
Summary:
Each read from memtable used to read and fragment all the range tombstones into a `FragmentedRangeTombstoneList`. https://github.com/facebook/rocksdb/issues/10380 improved the inefficient here by caching a `FragmentedRangeTombstoneList` with each immutable memtable. This PR extends the caching to mutable memtables. The fragmented range tombstone can be constructed in either read (This PR) or write path (https://github.com/facebook/rocksdb/issues/10584). With both implementation, each `DeleteRange()` will invalidate the cache, and the difference is where the cache is re-constructed.`CoreLocalArray` is used to store the cache with each memtable so that multi-threaded reads can be efficient. More specifically, each core will have a shared_ptr to a shared_ptr pointing to the current cache. Each read thread will only update the reference count in its core-local shared_ptr, and this is only needed when reading from mutable memtables.

The choice between write path and read path is not an easy one: they are both improvement compared to no caching in the current implementation, but they favor different operations and could cause regression in the other operation (read vs write). The write path caching in (https://github.com/facebook/rocksdb/issues/10584) leads to a cleaner implementation, but I chose the read path caching here to avoid significant regression in write performance when there is a considerable amount of range tombstones in a single memtable (the number from the benchmark below suggests >1000 with concurrent writers). Note that even though the fragmented range tombstone list is only constructed in `DeleteRange()` operations, it could block other writes from proceeding, and hence affects overall write performance.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10547

Test Plan:
- TestGet() in stress test is updated in https://github.com/facebook/rocksdb/issues/10553 to compare Get() result against expected state: `./db_stress_branch --readpercent=57 --prefixpercent=4 --writepercent=25 -delpercent=5 --iterpercent=5 --delrangepercent=4`
- Perf benchmark: tested read and write performance where a memtable has 0, 1, 10, 100 and 1000 range tombstones.
```
./db_bench --benchmarks=fillrandom,readrandom --writes_per_range_tombstone=200 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=200000 --reads=100000 --disable_auto_compactions --max_num_range_tombstones=1000
```
Write perf regressed since the cost of constructing fragmented range tombstone list is shifted from every read to a single write. 6cbe5d8e172dc5f1ef65c9d0a6eedbd9987b2c72 is included in the last column as a reference to see performance impact on multi-thread reads if `CoreLocalArray` is not used.

micros/op averaged over 5 runs: first 4 columns are for fillrandom, last 4 columns are for readrandom.
|   |fillrandom main           | write path caching          | read path caching          |memtable V3 (https://github.com/facebook/rocksdb/issues/10308)     | readrandom main            | write path caching           | read path caching            |memtable V3      |
|---   |---  |---   |---   |---   | ---   |           ---   |  ---   |  ---   |
| 0                    |6.35                           |6.15                           |5.82                           |6.12                           |2.24                           |2.26                           |2.03                           |2.07                           |
| 1                    |5.99                           |5.88                           |5.77                           |6.28                           |2.65                           |2.27                           |2.24                           |2.5                            |
| 10                   |6.15                           |6.02                           |5.92                           |5.95                           |5.15                           |2.61                           |2.31                           |2.53                           |
| 100                  |5.95                           |5.78                           |5.88                           |6.23                           |28.31                          |2.34                           |2.45                           |2.94                           |
| 100 25 threads       |52.01                          |45.85                          |46.18                          |47.52                          |35.97                          |3.34                           |3.34                           |3.56                           |
| 1000                 |6.0                            |7.07                           |5.98                           |6.08                           |333.18                         |2.86                           |2.7                            |3.6                            |
| 1000 25 threads      |52.6                           |148.86                         |79.06                          |45.52                          |473.49                         |3.66                           |3.48                           |4.38                           |

  - Benchmark performance of`readwhilewriting` from https://github.com/facebook/rocksdb/issues/10552, 100 range tombstones are written: `./db_bench --benchmarks=readwhilewriting --writes_per_range_tombstone=500 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=100000 --reads=500000 --disable_auto_compactions --max_num_range_tombstones=10000 --finish_after_writes`

readrandom micros/op:
|  |main            |write path caching           |read path caching            |memtable V3      |
|---|---|---|---|---|
| single thread        |48.28                          |1.55                           |1.52                           |1.96                           |
| 25 threads           |64.3                           |2.55                           |2.67                           |2.64                           |

Reviewed By: ajkr

Differential Revision: D38895410

Pulled By: cbi42

fbshipit-source-id: 930bfc309dd1b2f4e8e9042f5126785bba577559
2022-09-13 20:07:28 -07:00
Akanksha Mahajan 03fc43976d Async optimization in scan path (#10602)
Summary:
Optimizations
1. In FilePrefetchBuffer, when data is overlapping between two buffers, it copies the data from first to third buffer, then from
second to third buffer to return continuous buffer. This optimization will call ReadAsync on first buffer as soon as buffer is empty instead of getting blocked by second buffer to copy the data.
2. For fixed size readahead_size, FilePrefetchBuffer will issues two async read calls. One with length + readahead_size_/2 on first buffer(if buffer is empty) and readahead_size_/2 on second buffer during seek.

- Add readahead_size to db_stress for stress testing these changes in https://github.com/facebook/rocksdb/pull/10632

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10602

Test Plan:
- CircleCI tests
- stress_test completed successfully
export CRASH_TEST_EXT_ARGS="--async_io=1"
make crash_test -j32
- db_bench showed no regression
   With this PR:
```
 ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main1 -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=50000000 -use_direct_reads=false -seek_nexts=327680 -duration=30 -ops_between_duration_checks=1 -async_io=1
Set seed to 1661876074584472 because --seed was 0
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
Integrated BlobDB: blob cache disabled
RocksDB:    version 7.7.0
Date:       Tue Aug 30 09:14:34 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:    50000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    25939.9 MB (estimated)
FileSize:   13732.9 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_main1]
seekrandom   :  270878.018 micros/op 3 ops/sec 30.068 seconds 111 operations;  618.7 MB/s (111 of 111 found)

 ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main1 -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=50000000 -use_direct_reads=true -seek_nexts=327680 -duration=30 -ops_between_duration_checks=1 -async_io=1
Set seed to 1661875332862922 because --seed was 0
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
Integrated BlobDB: blob cache disabled
RocksDB:    version 7.7.0
Date:       Tue Aug 30 09:02:12 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:    50000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    25939.9 MB (estimated)
FileSize:   13732.9 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_prefetch_main1]
seekrandom   :  358352.488 micros/op 2 ops/sec 30.102 seconds 84 operations;  474.4 MB/s (84 of 84 found)
```

Without PR in main:
```
./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main1 -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=50000000 -use_direct_reads=false -seek_nexts=327680 -duration=30 -ops_between_duration_checks=1 -async_io=1
Set seed to 1661876425983045 because --seed was 0
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
Integrated BlobDB: blob cache disabled
RocksDB:    version 7.7.0
Date:       Tue Aug 30 09:20:26 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:    50000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    25939.9 MB (estimated)
FileSize:   13732.9 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_main1]
seekrandom   :  280881.953 micros/op 3 ops/sec 30.054 seconds 107 operations;  605.2 MB/s (107 of 107 found)

 ./db_bench -use_existing_db=true -db=/tmp/prefix_scan_prefetch_main1 -benchmarks="seekrandom" -key_size=32 -value_size=512 -num=50000000 -use_direct_reads=false -seek_nexts=327680 -duration=30 -ops_between_duration_checks=1 -async_io=0
Set seed to 1661876475267771 because --seed was 0
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
Integrated BlobDB: blob cache disabled
RocksDB:    version 7.7.0
Date:       Tue Aug 30 09:21:15 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:    50000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    25939.9 MB (estimated)
FileSize:   13732.9 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_main1]
seekrandom   :  363155.084 micros/op 2 ops/sec 30.142 seconds 83 operations;  468.1 MB/s (83 of 83 found)
```

Reviewed By: anand1976

Differential Revision: D39141328

Pulled By: akankshamahajan15

fbshipit-source-id: 560655922c1a437a8569c228abb31b8c0b413120
2022-09-12 17:42:01 -07:00
ltamasi dc7d155438 Mention some recent blob caching related changes in HISTORY.md (#10653)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10653

Reviewed By: riversand963

Differential Revision: D39368165

Pulled By: ltamasi

fbshipit-source-id: 06cfd3c87ca90b9d07c082d5e307c0dc6a16840c
2022-09-09 09:56:10 -07:00
gitbw95 0148c4934d Add PerfContext counters for CompressedSecondaryCache (#10650)
Summary:
Add PerfContext counters for CompressedSecondaryCache.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10650

Test Plan: Unit Tests.

Reviewed By: anand1976

Differential Revision: D39354712

Pulled By: gitbw95

fbshipit-source-id: 1b90d3df99d08ddecd351edfd48d1e3723fdbc15
2022-09-08 16:35:57 -07:00
Yanqin Jin 3d67d79154 Fix overlapping check by excluding timestamp (#10615)
Summary:
With user-defined timestamp, checking overlapping should exclude
timestamp part from key. This has already been done for range checking
for files in sstableKeyCompare(), but not yet done when checking with
concurrent compactions.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10615

Test Plan:
(Will add more tests)

make check
(Repro seems easier with this commit sha: git checkout 78bbdef530)
rm -rf /dev/shm/rocksdb/* &&
mkdir /dev/shm/rocksdb/rocksdb_crashtest_expected &&
./db_stress
--allow_data_in_errors=True --clear_column_family_one_in=0
--continuous_verification_interval=0 --data_block_index_type=1
--db=/dev/shm/rocksdb//rocksdb_crashtest_blackbox --delpercent=5
--delrangepercent=0
--expected_values_dir=/dev/shm/rocksdb//rocksdb_crashtest_expected
--iterpercent=0 --max_background_compactions=20
--max_bytes_for_level_base=10485760 --max_key=25000000
--max_write_batch_group_size_bytes=1048576 --nooverwritepercent=1
--ops_per_thread=1000000 --paranoid_file_checks=1 --partition_filters=0
--prefix_size=8 --prefixpercent=5 --readpercent=30 --reopen=0
--snapshot_hold_ops=100000 --subcompactions=1 --compaction_pri=3
--target_file_size_base=65536 --target_file_size_multiplier=2
--test_batches_snapshots=0 --test_cf_consistency=0 --use_multiget=1
--user_timestamp_size=8 --value_size_mult=32 --verify_checksum=1
--write_buffer_size=65536 --writepercent=60 -disable_wal=1

Reviewed By: akankshamahajan15

Differential Revision: D39146797

Pulled By: riversand963

fbshipit-source-id: 7fca800026ca6219220100b8b6cf84d907828163
2022-09-08 13:03:07 -07:00
Peter Dillinger 6de7081cf3 Always verify SST unique IDs on SST file open (#10532)
Summary:
Although we've been tracking SST unique IDs in the DB manifest
unconditionally, checking has been opt-in and with an extra pass at DB::Open
time. This changes the behavior of `verify_sst_unique_id_in_manifest` to
check unique ID against manifest every time an SST file is opened through
table cache (normal DB operations), replacing the explicit pass over files
at DB::Open time. This change also enables the option by default and
removes the "EXPERIMENTAL" designation.

One possible criticism is that the option no longer ensures the integrity
of a DB at Open time. This is far from an all-or-nothing issue. Verifying
the IDs of all SST files hardly ensures all the data in the DB is readable.
(VerifyChecksum is supposed to do that.) Also, with
max_open_files=-1 (default, extremely common), all SST files are
opened at DB::Open time anyway.

Implementation details:
* `VerifySstUniqueIdInManifest()` functions are the extra/explicit pass
that is now removed.
* Unit tests that manipulate/corrupt table properties have to opt out of
this check, because that corrupts the "actual" unique id. (And even for
testing we don't currently have a mechanism to set "no unique id"
in the in-memory file metadata for new files.)
* A lot of other unit test churn relates to (a) default checking on, and
(b) checking on SST open even without DB::Open (e.g. on flush)
* Use `FileMetaData` for more `TableCache` operations (in place of
`FileDescriptor`) so that we have access to the unique_id whenever
we might need to open an SST file. **There is the possibility of
performance impact because we can no longer use the more
localized `fd` part of an `FdWithKeyRange` but instead follow the
`file_metadata` pointer. However, this change (possible regression)
is only done for `GetMemoryUsageByTableReaders`.**
* Removed a completely unnecessary constructor overload of
`TableReaderOptions`

Possible follow-up:
* Verification only happens when opening through table cache. Are there
more places where this should happen?
* Improve error message when there is a file size mismatch vs. manifest
(FIXME added in the appropriate place).
* I'm not sure there's a justification for `FileDescriptor` to be distinct from
`FileMetaData`.
* I'm skeptical that `FdWithKeyRange` really still makes sense for
optimizing some data locality by duplicating some data in memory, but I
could be wrong.
* An unnecessary overload of NewTableReader was recently added, in
the public API nonetheless (though unusable there). It should be cleaned
up to put most things under `TableReaderOptions`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10532

Test Plan:
updated unit tests

Performance test showing no significant difference (just noise I think):
`./db_bench -benchmarks=readwhilewriting[-X10] -num=3000000 -disable_wal=1 -bloom_bits=8 -write_buffer_size=1000000 -target_file_size_base=1000000`
Before: readwhilewriting [AVG 10 runs] : 68702 (± 6932) ops/sec
After: readwhilewriting [AVG 10 runs] : 68239 (± 7198) ops/sec

Reviewed By: jay-zhuang

Differential Revision: D38765551

Pulled By: pdillinger

fbshipit-source-id: a827a708155f12344ab2a5c16e7701c7636da4c2
2022-09-07 22:52:42 -07:00
Bo Wang d490bfcdb6 Avoid recompressing cold block in CompressedSecondaryCache (#10527)
Summary:
**Summary:**
When a block is firstly `Lookup` from the secondary cache, we just insert a dummy block in the primary cache (charging the actual size of the block) and don’t erase the block from the secondary cache. A standalone handle is returned from `Lookup`. Only if the block is hit again, we erase it from the secondary cache and add it into the primary cache.

When a block is firstly evicted from the primary cache to the secondary cache, we just insert a dummy block (size 0) in the secondary cache. When the block is evicted again, it is treated as a hot block and is inserted into the secondary cache.

**Implementation Details**
Add a new state of LRUHandle: The handle is never inserted into the LRUCache (both hash table and LRU list) and it doesn't experience the above three states. The entry can be freed when refs becomes 0.  (refs >= 1 && in_cache == false && IS_STANDALONE == true)

The behaviors of  `LRUCacheShard::Lookup()` are updated if the secondary_cache is CompressedSecondaryCache:
1. If a handle is found in primary cache:
  1.1. If the handle's value is not nullptr, it is returned immediately.
  1.2. If the handle's value is nullptr, this means the handle is a dummy one. For a dummy handle, if it was retrieved from secondary cache, it may still exist in secondary cache.
    - 1.2.1. If no valid handle can be `Lookup` from secondary cache, return nullptr.
    - 1.2.2. If the handle from secondary cache is valid, erase it from the secondary cache and add it into the primary cache.
2. If a handle is not found in primary cache:
  2.1. If no valid handle can be `Lookup` from secondary cache, return nullptr.
  2.2.  If the handle from secondary cache is valid, insert a dummy block in the primary cache (charging the actual size of the block)  and return a standalone handle.

The behaviors of `LRUCacheShard::Promote()` are updated as follows:
1. If `e->sec_handle` has value, one of the following steps can happen:
  1.1. Insert a dummy handle and return a standalone handle to caller when `secondary_cache_` is `CompressedSecondaryCache` and e is a standalone handle.
  1.2. Insert the item into the primary cache and return the handle to caller.
  1.3. Exception handling.
3. If `e->sec_handle` has no value, mark the item as not in cache and charge the cache as its only metadata that'll shortly be released.

The behavior of  `CompressedSecondaryCache::Insert()` is updated:
1. If a block is evicted from the primary cache for the first time, a dummy item is inserted.
4. If a dummy item is found for a block, the block is inserted into the secondary cache.

The behavior of  `CompressedSecondaryCache:::Lookup()` is updated:
1. If a handle is not found or it is a dummy item, a nullptr is returned.
2. If `erase_handle` is true, the handle is erased.

The behaviors of  `LRUCacheShard::Release()` are adjusted for the standalone handles.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10527

Test Plan:
1. stress tests.
5. unit tests.
6. CPU profiling for db_bench.

Reviewed By: siying

Differential Revision: D38747613

Pulled By: gitbw95

fbshipit-source-id: 74a1eba7e1957c9affb2bd2ae3e0194584fa6eca
2022-09-07 19:00:27 -07:00
Changyu Bi 30bc495c03 Skip swaths of range tombstone covered keys in merging iterator (2022 edition) (#10449)
Summary:
Delete range logic is moved from `DBIter` to `MergingIterator`, and `MergingIterator` will seek to the end of a range deletion if possible instead of scanning through each key and check with `RangeDelAggregator`.

With the invariant that a key in level L (consider memtable as the first level, each immutable and L0 as a separate level) has a larger sequence number than all keys in any level >L, a range tombstone `[start, end)` from level L covers all keys in its range in any level >L. This property motivates optimizations in iterator:
- in `Seek(target)`, if level L has a range tombstone `[start, end)` that covers `target.UserKey`, then for all levels > L, we can do Seek() on `end` instead of `target` to skip some range tombstone covered keys.
- in `Next()/Prev()`, if the current key is covered by a range tombstone `[start, end)` from level L, we can do `Seek` to `end` for all levels > L.

This PR implements the above optimizations in `MergingIterator`. As all range tombstone covered keys are now skipped in `MergingIterator`, the range tombstone logic is removed from `DBIter`. The idea in this PR is similar to https://github.com/facebook/rocksdb/issues/7317, but this PR leaves `InternalIterator` interface mostly unchanged. **Credit**: the cascading seek optimization and the sentinel key (discussed below) are inspired by [Pebble](https://github.com/cockroachdb/pebble/blob/master/merging_iter.go) and suggested by ajkr in https://github.com/facebook/rocksdb/issues/7317. The two optimizations are mostly implemented in `SeekImpl()/SeekForPrevImpl()` and `IsNextDeleted()/IsPrevDeleted()` in `merging_iterator.cc`. See comments for each method for more detail.

One notable change is that the minHeap/maxHeap used by `MergingIterator` now contains range tombstone end keys besides point key iterators. This helps to reduce the number of key comparisons. For example, for a range tombstone `[start, end)`, a `start` and an `end` `HeapItem` are inserted into the heap. When a `HeapItem` for range tombstone start key is popped from the minHeap, we know this range tombstone becomes "active" in the sense that, before the range tombstone's end key is popped from the minHeap, all the keys popped from this heap is covered by the range tombstone's internal key range `[start, end)`.

Another major change, *delete range sentinel key*, is made to `LevelIterator`. Before this PR, when all point keys in an SST file are iterated through in `MergingIterator`, a level iterator would advance to the next SST file in its level. In the case when an SST file has a range tombstone that covers keys beyond the SST file's last point key, advancing to the next SST file would lose this range tombstone. Consequently, `MergingIterator` could return keys that should have been deleted by some range tombstone. We prevent this by pretending that file boundaries in each SST file are sentinel keys. A `LevelIterator` now only advance the file iterator once the sentinel key is processed.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10449

Test Plan:
- Added many unit tests in db_range_del_test
- Stress test: `./db_stress --readpercent=5 --prefixpercent=19 --writepercent=20 -delpercent=10 --iterpercent=44 --delrangepercent=2`
- Additional iterator stress test is added to verify against iterators against expected state: https://github.com/facebook/rocksdb/issues/10538. This is based on ajkr's previous attempt https://github.com/facebook/rocksdb/pull/5506#issuecomment-506021913.

```
python3 ./tools/db_crashtest.py blackbox --simple --write_buffer_size=524288 --target_file_size_base=524288 --max_bytes_for_level_base=2097152 --compression_type=none --max_background_compactions=8 --value_size_mult=33 --max_key=5000000 --interval=10 --duration=7200 --delrangepercent=3 --delpercent=9 --iterpercent=25 --writepercent=60 --readpercent=3 --prefixpercent=0 --num_iterations=1000 --range_deletion_width=100 --verify_iterator_with_expected_state_one_in=1
```

- Performance benchmark: I used a similar setup as in the blog [post](http://rocksdb.org/blog/2018/11/21/delete-range.html) that introduced DeleteRange, "a database with 5 million data keys, and 10000 range tombstones (ignoring those dropped during compaction) that were written in regular intervals after 4.5 million data keys were written".  As expected, the performance with this PR depends on the range tombstone width.
```
# Setup:
TEST_TMPDIR=/dev/shm ./db_bench_main --benchmarks=fillrandom --writes=4500000 --num=5000000
TEST_TMPDIR=/dev/shm ./db_bench_main --benchmarks=overwrite --writes=500000 --num=5000000 --use_existing_db=true --writes_per_range_tombstone=50

# Scan entire DB
TEST_TMPDIR=/dev/shm ./db_bench_main --benchmarks=readseq[-X5] --use_existing_db=true --num=5000000 --disable_auto_compactions=true

# Short range scan (10 Next())
TEST_TMPDIR=/dev/shm/width-100/ ./db_bench_main --benchmarks=seekrandom[-X5] --use_existing_db=true --num=500000 --reads=100000 --seek_nexts=10 --disable_auto_compactions=true

# Long range scan(1000 Next())
TEST_TMPDIR=/dev/shm/width-100/ ./db_bench_main --benchmarks=seekrandom[-X5] --use_existing_db=true --num=500000 --reads=2500 --seek_nexts=1000 --disable_auto_compactions=true
```
Avg over of 10 runs (some slower tests had fews runs):

For the first column (tombstone), 0 means no range tombstone, 100-10000 means width of the 10k range tombstones, and 1 means there is a single range tombstone in the entire DB (width is 1000). The 1 tombstone case is to test regression when there's very few range tombstones in the DB, as no range tombstone is likely to take a different code path than with range tombstones.

- Scan entire DB

| tombstone width | Pre-PR ops/sec | Post-PR ops/sec | ±% |
| ------------- | ------------- | ------------- |  ------------- |
| 0 range tombstone    |2525600 (± 43564)    |2486917 (± 33698)    |-1.53%               |
| 100   |1853835 (± 24736)    |2073884 (± 32176)    |+11.87%              |
| 1000  |422415 (± 7466)      |1115801 (± 22781)    |+164.15%             |
| 10000 |22384 (± 227)        |227919 (± 6647)      |+918.22%             |
| 1 range tombstone      |2176540 (± 39050)    |2434954 (± 24563)    |+11.87%              |
- Short range scan

| tombstone width | Pre-PR ops/sec | Post-PR ops/sec | ±% |
| ------------- | ------------- | ------------- |  ------------- |
| 0  range tombstone   |35398 (± 533)        |35338 (± 569)        |-0.17%               |
| 100   |28276 (± 664)        |31684 (± 331)        |+12.05%              |
| 1000  |7637 (± 77)          |25422 (± 277)        |+232.88%             |
| 10000 |1367                 |28667                |+1997.07%            |
| 1 range tombstone      |32618 (± 581)        |32748 (± 506)        |+0.4%                |

- Long range scan

| tombstone width | Pre-PR ops/sec | Post-PR ops/sec | ±% |
| ------------- | ------------- | ------------- |  ------------- |
| 0 range tombstone     |2262 (± 33)          |2353 (± 20)          |+4.02%               |
| 100   |1696 (± 26)          |1926 (± 18)          |+13.56%              |
| 1000  |410 (± 6)            |1255 (± 29)          |+206.1%              |
| 10000 |25                   |414                  |+1556.0%             |
| 1 range tombstone   |1957 (± 30)          |2185 (± 44)          |+11.65%              |

- Microbench does not show significant regression: https://gist.github.com/cbi42/59f280f85a59b678e7e5d8561e693b61

Reviewed By: ajkr

Differential Revision: D38450331

Pulled By: cbi42

fbshipit-source-id: b5ef12e8d8c289ed2e163ccdf277f5039b511fca
2022-09-02 09:51:19 -07:00
Akanksha Mahajan 4cd16d65ae Add new option num_file_reads_for_auto_readahead in BlockBasedTableOptions (#10556)
Summary:
RocksDB does auto-readahead for iterators on noticing more
than two reads for a table file if user doesn't provide readahead_size and reads are sequential.
A new option num_file_reads_for_auto_readahead is added which can be
configured and indicates after how many sequential reads prefetching should
be start.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10556

Test Plan: Existing and new unit test

Reviewed By: anand1976

Differential Revision: D38947147

Pulled By: akankshamahajan15

fbshipit-source-id: c9eeab495f84a8df7f701c42f04894e46440ad97
2022-09-01 11:56:00 -07:00
anand76 5fbcc8c54d Update MULTIGET_IO_BATCH_SIZE for non-async MultiGet (#10622)
Summary:
This stat was only getting updated in the async (coroutine) version of MultiGet.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10622

Reviewed By: akankshamahajan15

Differential Revision: D39188790

Pulled By: anand1976

fbshipit-source-id: 7e231507f65fc94c8a006c38f79dfba182a2c24a
2022-08-31 21:03:52 -07:00
sdong 9509003503 Option migration tool to break down files for FIFO compaction (#10600)
Summary:
Right now, when the option migration tool migrates to FIFO compaction, it compacts all the data into one single SST file and move to L0. Although it creates a valid LSM-tree for FIFO, for any data to be deleted for FIFO, the giant file will be deleted, which might make the DB almost empty. There is not good solution for it, because usually we don't have enough information to reconstruct the FIFO LSM-tree. This change changes to a solution that compromises the FIFO condition. We hope the solution is more useable.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10600

Test Plan: Add unit tests for that.

Reviewed By: jay-zhuang

Differential Revision: D39106424

fbshipit-source-id: bdfd852c3b343373765b8d9716fefc08fd27145c
2022-08-31 12:08:23 -07:00
Hui Xiao e484b81eee Sync dir containing CURRENT after RenameFile on CURRENT as much as possible (#10573)
Summary:
**Context:**
Below crash test revealed a bug that directory containing CURRENT file (short for `dir_contains_current_file` below) was not always get synced after a new CURRENT is created and being called with `RenameFile` as part of the creation.

This bug exposes a risk that such un-synced directory containing the updated CURRENT can’t survive a host crash (e.g, power loss) hence get corrupted. This then will be followed by a recovery from a corrupted CURRENT that we don't want.

The root-cause is that a nullptr `FSDirectory* dir_contains_current_file` sometimes gets passed-down to `SetCurrentFile()` hence in those case `dir_contains_current_file->FSDirectory::FsyncWithDirOptions()` will be skipped  (which otherwise will internally call`Env/FS::SyncDic()` )
```
./db_stress --acquire_snapshot_one_in=10000 --adaptive_readahead=1 --allow_data_in_errors=True --avoid_unnecessary_blocking_io=0 --backup_max_size=104857600 --backup_one_in=100000 --batch_protection_bytes_per_key=8 --block_size=16384 --bloom_bits=134.8015470676662 --bottommost_compression_type=disable --cache_size=8388608 --checkpoint_one_in=1000000 --checksum_type=kCRC32c --clear_column_family_one_in=0 --compact_files_one_in=1000000 --compact_range_one_in=1000000 --compaction_pri=2 --compaction_ttl=100 --compression_max_dict_buffer_bytes=511 --compression_max_dict_bytes=16384 --compression_type=zstd --compression_use_zstd_dict_trainer=1 --compression_zstd_max_train_bytes=65536 --continuous_verification_interval=0 --data_block_index_type=0 --db=$db --db_write_buffer_size=1048576 --delpercent=5 --delrangepercent=0 --destroy_db_initially=0 --disable_wal=0 --enable_compaction_filter=0 --enable_pipelined_write=1 --expected_values_dir=$exp --fail_if_options_file_error=1 --file_checksum_impl=none --flush_one_in=1000000 --get_current_wal_file_one_in=0 --get_live_files_one_in=1000000 --get_property_one_in=1000000 --get_sorted_wal_files_one_in=0 --index_block_restart_interval=4 --ingest_external_file_one_in=0 --iterpercent=10 --key_len_percent_dist=1,30,69 --level_compaction_dynamic_level_bytes=True --mark_for_compaction_one_file_in=10 --max_background_compactions=20 --max_bytes_for_level_base=10485760 --max_key=10000 --max_key_len=3 --max_manifest_file_size=16384 --max_write_batch_group_size_bytes=64 --max_write_buffer_number=3 --max_write_buffer_size_to_maintain=0 --memtable_prefix_bloom_size_ratio=0.001 --memtable_protection_bytes_per_key=1 --memtable_whole_key_filtering=1 --mmap_read=1 --nooverwritepercent=1 --open_metadata_write_fault_one_in=0 --open_read_fault_one_in=0 --open_write_fault_one_in=0 --ops_per_thread=100000000 --optimize_filters_for_memory=1 --paranoid_file_checks=1 --partition_pinning=2 --pause_background_one_in=1000000 --periodic_compaction_seconds=0 --prefix_size=5 --prefixpercent=5 --prepopulate_block_cache=1 --progress_reports=0 --read_fault_one_in=1000 --readpercent=45 --recycle_log_file_num=0 --reopen=0 --ribbon_starting_level=999 --secondary_cache_fault_one_in=32 --secondary_cache_uri=compressed_secondary_cache://capacity=8388608 --set_options_one_in=10000 --snapshot_hold_ops=100000 --sst_file_manager_bytes_per_sec=0 --sst_file_manager_bytes_per_truncate=0 --subcompactions=3 --sync_fault_injection=1 --target_file_size_base=2097 --target_file_size_multiplier=2 --test_batches_snapshots=1 --top_level_index_pinning=1 --use_full_merge_v1=1 --use_merge=1 --value_size_mult=32 --verify_checksum=1 --verify_checksum_one_in=1000000 --verify_db_one_in=100000 --verify_sst_unique_id_in_manifest=1 --wal_bytes_per_sync=524288 --write_buffer_size=4194 --writepercent=35
```

```
stderr:
WARNING: prefix_size is non-zero but memtablerep != prefix_hash
db_stress: utilities/fault_injection_fs.cc:748: virtual rocksdb::IOStatus rocksdb::FaultInjectionTestFS::RenameFile(const std::string &, const std::string &, const rocksdb::IOOptions &, rocksdb::IODebugContext *): Assertion `tlist.find(tdn.second) == tlist.end()' failed.`
```

**Summary:**
The PR ensured the non-test path pass down a non-null dir containing CURRENT (which is by current RocksDB assumption just db_dir) by doing the following:
- Renamed `directory_to_fsync` as `dir_contains_current_file` in `SetCurrentFile()` to tighten the association between this directory and CURRENT file
- Changed `SetCurrentFile()` API to require `dir_contains_current_file` being passed-in, instead of making it by default nullptr.
    -  Because `SetCurrentFile()`'s `dir_contains_current_file` is passed down from `VersionSet::LogAndApply()` then `VersionSet::ProcessManifestWrites()` (i.e, think about this as a chain of 3 functions related to MANIFEST update), these 2 functions also got refactored to require `dir_contains_current_file`
- Updated the non-test-path callers of these 3 functions to obtain and pass in non-nullptr `dir_contains_current_file`, which by current assumption of RocksDB, is the `FSDirectory* db_dir`.
    - `db_impl` path will obtain `DBImpl::directories_.getDbDir()` while others with no access to such `directories_` are obtained on the fly by creating such object `FileSystem::NewDirectory(..)` and manage it by unique pointers to ensure short life time.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10573

Test Plan:
- `make check`
- Passed the repro db_stress command
- For future improvement, since we currently don't assert dir containing CURRENT to be non-nullptr due to https://github.com/facebook/rocksdb/pull/10573#pullrequestreview-1087698899, there is still chances that future developers mistakenly pass down nullptr dir containing CURRENT thus resulting skipped sync dir and cause the bug again. Therefore a smarter test (e.g, such as quoted from ajkr  "(make) unsynced data loss to be dropping files corresponding to unsynced directory entries") is still needed.

Reviewed By: ajkr

Differential Revision: D39005886

Pulled By: hx235

fbshipit-source-id: 336fb9090d0cfa6ca3dd580db86268007dde7f5a
2022-08-29 17:35:21 -07:00
anand76 72a3fb3424 Update statistics for async scan readaheads (#10585)
Summary:
Imported a fix to "rocksdb.prefetched.bytes.discarded" stat from https://github.com/facebook/rocksdb/issues/10561, and added a new stat "rocksdb.async.prefetch.abort.micros" to measure time spent waiting for async reads to abort.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10585

Reviewed By: akankshamahajan15

Differential Revision: D39067000

Pulled By: anand1976

fbshipit-source-id: d7cda71abb48017239bd5fd832345a16c7024faf
2022-08-29 14:37:44 -07:00
Peter Dillinger c5afbbfe4b Don't wait for indirect flush in read-only DB (#10569)
Summary:
Some APIs for getting live files, which are used by Checkpoint
and BackupEngine, can optionally trigger and wait for a flush. These
would deadlock when used on a read-only DB. Here we fix that by assuming
the user wants the overall operation to succeed and is OK without
flushing (because the DB is read-only).

Follow-up work: the same or other issues can be hit by directly invoking
some DB functions that are clearly not appropriate for read-only
instance, but are not covered by overrides in DBImplReadOnly and
CompactedDBImpl. These should be fixed to avoid similar problems on
accidental misuse. (Long term, it would be nice to have a DBReadOnly
class without those members, like BackupEngineReadOnly.)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10569

Test Plan: tests updated to catch regression (hang before the fix)

Reviewed By: riversand963

Differential Revision: D38995759

Pulled By: pdillinger

fbshipit-source-id: f5f8bc7123e13cb45bd393dd974d7d6eda20bc68
2022-08-29 13:36:23 -07:00
Levi Tamasi 64e74723f7 Use the default metadata charge policy when creating an LRU cache via the Java API (#10577)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10577

Reviewed By: akankshamahajan15

Differential Revision: D39035884

Pulled By: ltamasi

fbshipit-source-id: 48f116f8ca172b7eb5eb3651f39ddb891a7ffade
2022-08-29 09:42:04 -07:00
Jay Zhuang d9e71fb2c5 Fix periodic_task unable to re-register the same task type (#10379)
Summary:
Timer has a limitation that it cannot re-register a task with the same name,
because the cancel only mark the task as invalid and wait for the Timer thread
to clean it up later, before the task is cleaned up, the same task name cannot
be added. Which makes the task option update likely to fail, which basically
cancel and re-register the same task name. Change the periodic task name to a
random unique id and store it in periodic_task_scheduler.

Also refactor the `periodic_work` to `periodic_task` to make each job function
as a `task`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10379

Test Plan: unittests

Reviewed By: ajkr

Differential Revision: D38000615

Pulled By: jay-zhuang

fbshipit-source-id: e4135f9422e3b53aaec8eda54f4e18ce633a279e
2022-08-25 18:52:37 -07:00
Brendan MacDonell 418b36a9bc Support CompactionPri::kRoundRobin in RocksJava (#10572)
Summary:
Pretty trivial — this PR just adds the new compaction priority to the Java API.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10572

Reviewed By: hx235

Differential Revision: D39006523

Pulled By: ajkr

fbshipit-source-id: ea8d665817e7b05826c397afa41c3abcda81484e
2022-08-25 13:32:03 -07:00
Andrew Kryczka 7ad4b38617 Ensure writes to WAL tail during `FlushWAL(true /* sync */)` will be synced (#10560)
Summary:
WAL append and switch can both happen between `FlushWAL(true /* sync */)`'s sync operations and its call to `MarkLogsSynced()`. We permit this since locks need to be released for the sync operations. Such an appended/switched WAL is both inactive and incompletely synced at the time `MarkLogsSynced()` processes it.

Prior to this PR, `MarkLogsSynced()` assumed all inactive WALs were fully synced and removed them from consideration for future syncs. That was wrong in the scenario described above and led to the latest append(s) never being synced. This PR changes `MarkLogsSynced()` to only remove inactive WALs from consideration for which all flushed data has been synced.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10560

Test Plan: repro unit test for the scenario described above. Without this PR, it fails on "key2" not found

Reviewed By: riversand963

Differential Revision: D38957391

Pulled By: ajkr

fbshipit-source-id: da77175eba97ff251a4219b227b3bb2d4843ed26
2022-08-25 12:53:46 -07:00
Changyu Bi d140fbfd7d Add Iterator test against expected state to stress test (#10538)
Summary:
As mentioned in https://github.com/facebook/rocksdb/pull/5506#issuecomment-506021913,
`db_stress` does not have much verification for iterator correctness.
It has a `TestIterate()` function, but that is mainly for comparing results
between two iterators, one with `total_order_seek` and the other optionally
sets auto_prefix, upper/lower bounds. Commit 49a0581ad2462e31aa3f768afa769e0d33390f33
added a new `TestIterateAgainstExpected()` function that compares iterator against
expected state. It locks a range of keys, creates an iterator, does
a random sequence of `Next/Prev` and compares against expected state.
This PR is based on that commit, the main changes include some logs
(for easier debugging if a test fails), a forward and backward scan to
cover the entire locked key range, and a flag for optionally turning on
this version of Iterator testing.

Added constraint that the checks against expected state in
`TestIterateAgainstExpected()` and in `TestGet()` are only turned on
when `--skip_verifydb` flag is not set.
Remove the change log introduced in https://github.com/facebook/rocksdb/issues/10553.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10538

Test Plan:
Run `db_stress` with `--verify_iterator_with_expected_state_one_in=1`,
and a large `--iterpercent` and `--num_iterations`. Checked `op_logs`
manually to ensure expected coverage. Tweaked part of the code in
https://github.com/facebook/rocksdb/issues/10449 and stress test was able to catch it.
- internally run various flavor of crash test

Reviewed By: ajkr

Differential Revision: D38847269

Pulled By: cbi42

fbshipit-source-id: 8b4402a9bba9f6cfa08051943cd672579d489599
2022-08-24 14:59:50 -07:00
muthukrishnan.s 79ed4be80f Add get_name, get_id for column family handle in C API (#10499)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10499

Reviewed By: hx235

Differential Revision: D38523859

Pulled By: ajkr

fbshipit-source-id: 268bba1fcce4a3e20c51e498a79d7b476f663aea
2022-08-24 13:49:02 -07:00
Changyu Bi 198e5d8ee9 Update `TestGet()` to verify against expected state (#10553)
Summary:
updated `TestGet()` in `no_batched_op_stress` to check the result of `Get()` operations against expected state (`expected_state_manager_`). More specifically, if `Get()` finds a key, expected state should not have `DELETION_SENTINEL` for the same key, and if `Get()` returns NotFound for a key, expected state should not have the key. One intention for this change it to verify correctness of code path change regarding range tombstones.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10553

Test Plan: run db_stress with nonzero readpercent: `./db_stress_branch --readpercent=57 --prefixpercent=4 --writepercent=25 -delpercent=5 --iterpercent=5 --delrangepercent=4`. When I initially used wrong column family in `thread->shared->Get`, the test reported inconsistencies.

Reviewed By: ajkr

Differential Revision: D38927007

Pulled By: cbi42

fbshipit-source-id: f9f61b312ad0b4c21a799329609ba8526169b048
2022-08-23 17:08:14 -07:00
Peter Dillinger db7606a41a Fix "Behavior Changes" in 7.6 HISTORY.md (#10557)
Summary:
see diff

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10557

Test Plan: no functional change

Reviewed By: gitbw95

Differential Revision: D38950531

Pulled By: pdillinger

fbshipit-source-id: af72e80a31d7df38f6e633fa7115984c2274ed60
2022-08-23 13:03:41 -07:00
gitbw95 a9c2c7778d Update HISTORY.md for the upcoming 7.6 release (#10543)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10543

Reviewed By: anand1976

Differential Revision: D38877168

Pulled By: gitbw95

fbshipit-source-id: d6888f7dbb1f2a5bef144ad2443429a61663c1e8
2022-08-20 20:56:40 -07:00
anand76 35cdd3e71e MultiGet async IO across multiple levels (#10535)
Summary:
This PR exploits parallelism in MultiGet across levels. It applies only to the coroutine version of MultiGet. Previously, MultiGet file reads from SST files in the same level were parallelized. With this PR, MultiGet batches with keys distributed across multiple levels are read in parallel. This is accomplished by splitting the keys not present in a level (determined by bloom filtering) into a separate batch, and processing the new batch in parallel with the original batch.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10535

Test Plan:
1. Ensure existing MultiGet unit tests pass, updating them as necessary
2. New unit tests - TODO
3. Run stress test - TODO

No noticeable regression (<1%) without async IO -
Without PR: `multireadrandom :       7.261 micros/op 1101724 ops/sec 60.007 seconds 66110936 operations;  571.6 MB/s (8168992 of 8168992 found)`
With PR: `multireadrandom :       7.305 micros/op 1095167 ops/sec 60.007 seconds 65717936 operations;  568.2 MB/s (8271992 of 8271992 found)`

For a fully cached DB, but with async IO option on, no regression observed (<1%) -
Without PR: `multireadrandom :       5.201 micros/op 1538027 ops/sec 60.005 seconds 92288936 operations;  797.9 MB/s (11540992 of 11540992 found) `
With PR: `multireadrandom :       5.249 micros/op 1524097 ops/sec 60.005 seconds 91452936 operations;  790.7 MB/s (11649992 of 11649992 found) `

Reviewed By: akankshamahajan15

Differential Revision: D38774009

Pulled By: anand1976

fbshipit-source-id: c955e259749f1c091590ade73105b3ee46cd0007
2022-08-19 16:52:52 -07:00
anand76 2553d1efa1 Revert "Avoid dynamic memory allocation on read path (#10453)" (#10541)
Summary:
This reverts commit 0d885e80d4. The original commit causes a ASAN stack-use-after-return failure due to the `CreateCallback` being allocated on stack and then used in another thread when a secondary cache object is promoted to the primary cache.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10541

Reviewed By: gitbw95

Differential Revision: D38850039

Pulled By: anand1976

fbshipit-source-id: 810c592b7de2523693f5bb267159b23b0ee9132c
2022-08-19 11:02:54 -07:00
Bo Wang 13cb7a84b6 Fix the memory leak in db_stress tests that are caused by `FaultInjectionSecondaryCache` and add `CompressedSecondaryCache` into stress tests. (#10523)
Summary:
1. Fix the memory leak in db_stress tests that are caused by `FaultInjectionSecondaryCache`. To address the test requirements for both CompressedSecondaryCache and CachlibWrapper, a new class variable `base_is_compressed_sec_cache_` is added to determine the different behaviors in `Lookup()` and `WaitAll()`.
2. Add `CompressedSecondaryCache` into stress tests.

Before this PR, memory leak is reported during crash tests if  `CompressedSecondaryCache` is in stress tests. One example is shown as follows:
```
==70722==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 6648240 byte(s) in 83103 object(s) allocated from:
    #0 0x13de9d7 in operator new(unsigned long) (/data/sandcastle/boxes/eden-trunk-hg-fbcode-fbsource/fbcode/buck-out/dbgo/gen/aab7ed39/internal_repo_rocksdb/repo/db_stress+0x13de9d7)
    https://github.com/facebook/rocksdb/issues/1 0x9084c7 in rocksdb::BlocklikeTraits<rocksdb::Block>::Create(rocksdb::BlockContents&&, unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*) internal_repo_rocksdb/repo/table/block_based/block_like_traits.h:128
    https://github.com/facebook/rocksdb/issues/2 0x9084c7 in std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)::operator()(void const*, unsigned long, void**, unsigned long*) const internal_repo_rocksdb/repo/table/block_based/block_like_traits.h:34
    https://github.com/facebook/rocksdb/issues/3 0x9082c9 in rocksdb::Block std::__invoke_impl<rocksdb::Status, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)&, void const*, unsigned long, void**, unsigned long*>(std::__invoke_other, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)&, void const*&&, unsigned long&&, void**&&, unsigned long*&&) third-party-buck/platform010/build/libgcc/include/c++/trunk/bits/invoke.h:61
    https://github.com/facebook/rocksdb/issues/4 0x90825d in std::enable_if<is_invocable_r_v<rocksdb::Block, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)&, void const*, unsigned long, void**, unsigned long*>, rocksdb::Block>::type std::__invoke_r<rocksdb::Status, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)&, void const*, unsigned long, void**, unsigned long*>(std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)&, void const*&&, unsigned long&&, void**&&, unsigned long*&&) third-party-buck/platform010/build/libgcc/include/c++/trunk/bits/invoke.h:114
    https://github.com/facebook/rocksdb/issues/5 0x9081b0 in std::_Function_handler<rocksdb::Status (void const*, unsigned long, void**, unsigned long*), std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> rocksdb::GetCreateCallback<rocksdb::Block>(unsigned long, rocksdb::Statistics*, bool, rocksdb::FilterPolicy const*)::'lambda'(void const*, unsigned long, void**, unsigned long*)>::_M_invoke(std::_Any_data const&, void const*&&, unsigned long&&, void**&&, unsigned long*&&) third-party-buck/platform010/build/libgcc/include/c++/trunk/bits/std_function.h:291
    https://github.com/facebook/rocksdb/issues/6 0x991f2c in std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)>::operator()(void const*, unsigned long, void**, unsigned long*) const third-party-buck/platform010/build/libgcc/include/c++/trunk/bits/std_function.h:560
    https://github.com/facebook/rocksdb/issues/7 0x990277 in rocksdb::CompressedSecondaryCache::Lookup(rocksdb::Slice const&, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> const&, bool, bool&) internal_repo_rocksdb/repo/cache/compressed_secondary_cache.cc:77
    https://github.com/facebook/rocksdb/issues/8 0xd3aa4d in rocksdb::FaultInjectionSecondaryCache::Lookup(rocksdb::Slice const&, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> const&, bool, bool&) internal_repo_rocksdb/repo/utilities/fault_injection_secondary_cache.cc:92
    https://github.com/facebook/rocksdb/issues/9 0xeadaab in rocksdb::lru_cache::LRUCacheShard::Lookup(rocksdb::Slice const&, unsigned int, rocksdb::Cache::CacheItemHelper const*, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> const&, rocksdb::Cache::Priority, bool, rocksdb::Statistics*) internal_repo_rocksdb/repo/cache/lru_cache.cc:445
    https://github.com/facebook/rocksdb/issues/10 0x1064573 in rocksdb::ShardedCache::Lookup(rocksdb::Slice const&, rocksdb::Cache::CacheItemHelper const*, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> const&, rocksdb::Cache::Priority, bool, rocksdb::Statistics*) internal_repo_rocksdb/repo/cache/sharded_cache.cc:89
    https://github.com/facebook/rocksdb/issues/11 0x8be0df in rocksdb::BlockBasedTable::GetEntryFromCache(rocksdb::CacheTier const&, rocksdb::Cache*, rocksdb::Slice const&, rocksdb::BlockType, bool, rocksdb::GetContext*, rocksdb::Cache::CacheItemHelper const*, std::function<rocksdb::Status (void const*, unsigned long, void**, unsigned long*)> const&, rocksdb::Cache::Priority) const internal_repo_rocksdb/repo/table/block_based/block_based_table_reader.cc:389
    https://github.com/facebook/rocksdb/issues/12 0x905790 in rocksdb::Status rocksdb::BlockBasedTable::GetDataBlockFromCache<rocksdb::Block>(rocksdb::Slice const&, rocksdb::Cache*, rocksdb::Cache*, rocksdb::ReadOptions const&, rocksdb::CachableEntry<rocksdb::Block>*, rocksdb::UncompressionDict const&, rocksdb::BlockType, bool, rocksdb::GetContext*) const internal_repo_rocksdb/repo/table/block_based/block_based_table_reader.cc:1263
    https://github.com/facebook/rocksdb/issues/13 0x8b9259 in rocksdb::Status rocksdb::BlockBasedTable::MaybeReadBlockAndLoadToCache<rocksdb::Block>(rocksdb::FilePrefetchBuffer*, rocksdb::ReadOptions const&, rocksdb::BlockHandle const&, rocksdb::UncompressionDict const&, bool, bool, rocksdb::CachableEntry<rocksdb::Block>*, rocksdb::BlockType, rocksdb::GetContext*, rocksdb::BlockCacheLookupContext*, rocksdb::BlockContents*, bool) const internal_repo_rocksdb/repo/table/block_based/block_based_table_reader.cc:1559
    https://github.com/facebook/rocksdb/issues/14 0x8b710c in rocksdb::Status rocksdb::BlockBasedTable::RetrieveBlock<rocksdb::Block>(rocksdb::FilePrefetchBuffer*, rocksdb::ReadOptions const&, rocksdb::BlockHandle const&, rocksdb::UncompressionDict const&, rocksdb::CachableEntry<rocksdb::Block>*, rocksdb::BlockType, rocksdb::GetContext*, rocksdb::BlockCacheLookupContext*, bool, bool, bool, bool) const internal_repo_rocksdb/repo/table/block_based/block_based_table_reader.cc:1726
    https://github.com/facebook/rocksdb/issues/15 0x8c329f in rocksdb::DataBlockIter* rocksdb::BlockBasedTable::NewDataBlockIterator<rocksdb::DataBlockIter>(rocksdb::ReadOptions const&, rocksdb::BlockHandle const&, rocksdb::DataBlockIter*, rocksdb::BlockType, rocksdb::GetContext*, rocksdb::BlockCacheLookupContext*, rocksdb::FilePrefetchBuffer*, bool, bool, rocksdb::Status&) const internal_repo_rocksdb/repo/table/block_based/block_based_table_reader_impl.h:58
    https://github.com/facebook/rocksdb/issues/16 0x920117 in rocksdb::BlockBasedTableIterator::InitDataBlock() internal_repo_rocksdb/repo/table/block_based/block_based_table_iterator.cc:262
    https://github.com/facebook/rocksdb/issues/17 0x920d42 in rocksdb::BlockBasedTableIterator::MaterializeCurrentBlock() internal_repo_rocksdb/repo/table/block_based/block_based_table_iterator.cc:332
    https://github.com/facebook/rocksdb/issues/18 0xc6a201 in rocksdb::IteratorWrapperBase<rocksdb::Slice>::PrepareValue() internal_repo_rocksdb/repo/table/iterator_wrapper.h:78
    https://github.com/facebook/rocksdb/issues/19 0xc6a201 in rocksdb::IteratorWrapperBase<rocksdb::Slice>::PrepareValue() internal_repo_rocksdb/repo/table/iterator_wrapper.h:78
    https://github.com/facebook/rocksdb/issues/20 0xef9f6c in rocksdb::MergingIterator::PrepareValue() internal_repo_rocksdb/repo/table/merging_iterator.cc:260
    https://github.com/facebook/rocksdb/issues/21 0xc6a201 in rocksdb::IteratorWrapperBase<rocksdb::Slice>::PrepareValue() internal_repo_rocksdb/repo/table/iterator_wrapper.h:78
    https://github.com/facebook/rocksdb/issues/22 0xc67bcd in rocksdb::DBIter::FindNextUserEntryInternal(bool, rocksdb::Slice const*) internal_repo_rocksdb/repo/db/db_iter.cc:326
    https://github.com/facebook/rocksdb/issues/23 0xc66d36 in rocksdb::DBIter::FindNextUserEntry(bool, rocksdb::Slice const*) internal_repo_rocksdb/repo/db/db_iter.cc:234
    https://github.com/facebook/rocksdb/issues/24 0xc7ab47 in rocksdb::DBIter::Next() internal_repo_rocksdb/repo/db/db_iter.cc:161
    https://github.com/facebook/rocksdb/issues/25 0x70d938 in rocksdb::BatchedOpsStressTest::TestPrefixScan(rocksdb::ThreadState*, rocksdb::ReadOptions const&, std::vector<int, std::allocator<int> > const&, std::vector<long, std::allocator<long> > const&) internal_repo_rocksdb/repo/db_stress_tool/batched_ops_stress.cc:320
    https://github.com/facebook/rocksdb/issues/26 0x6dc6a8 in rocksdb::StressTest::OperateDb(rocksdb::ThreadState*) internal_repo_rocksdb/repo/db_stress_tool/db_stress_test_base.cc:907
    https://github.com/facebook/rocksdb/issues/27 0x6867de in rocksdb::ThreadBody(void*) internal_repo_rocksdb/repo/db_stress_tool/db_stress_driver.cc:33
    https://github.com/facebook/rocksdb/issues/28 0xce4cc2 in rocksdb::(anonymous namespace)::StartThreadWrapper(void*) internal_repo_rocksdb/repo/env/env_posix.cc:461
    https://github.com/facebook/rocksdb/issues/29 0x7f23f9068c0e in start_thread /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/nptl/pthread_create.c:434:8
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10523

Test Plan:
```
$COMPILE_WITH_ASAN=1  make -j 24
$db_stress J=40 crash_test_with_txn
```

Reviewed By: anand1976

Differential Revision: D38646839

Pulled By: gitbw95

fbshipit-source-id: 9452895c7dc95481a9d7afe83b15193cf5b1c43e
2022-08-18 21:53:27 -07:00
Andrew Kryczka 91166012c8 Prevent a case of WriteBufferManager flush thrashing (#6364)
Summary:
Previously, the flushes triggered by `WriteBufferManager` could affect
the same CF repeatedly if it happens to get consecutive writes. Such
flushes are not particularly useful for reducing memory usage since
they switch nearly-empty memtables to immutable while they've just begun
filling their first arena block. In fact they may not even reduce the
mutable memory count if they involve replacing one mutable memtable containing
one arena block with a new mutable memtable containing one arena block.
Further, if such switches happen even a few times before a flush finishes,
the immutable memtable limit will be reached and writes will stall.

This PR adds a heuristic to not switch memtables to immutable for CFs
that already have one or more immutable memtables awaiting flush. There
is a memory usage regression if the user continues writing to the same
CF, that DB does not have any CFs eligible for switching, flushes
are not finishing, and the `WriteBufferManager` was constructed with
`allow_stall=false`. Before, it would grow by switching nearly empty
memtables until writes stall. Now, it would grow by filling memtables
until writes stall. This feels like an acceptable behavior change because
users who prefer to stall over violate the memory limit should be using
`allow_stall=true`, which is unaffected by this PR.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/6364

Test Plan:
- Command:

`rm -rf /dev/shm/dbbench/ && TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num_multi_db=8 -num_column_families=2 -write_buffer_size=4194304 -db_write_buffer_size=16777216 -compression_type=none -statistics=true -target_file_size_base=4194304 -max_bytes_for_level_base=16777216`

- `rocksdb.db.write.stall` count before this PR: 175
- `rocksdb.db.write.stall` count after this PR: 0

Reviewed By: jay-zhuang

Differential Revision: D20167197

Pulled By: ajkr

fbshipit-source-id: 4a64064e9bc33d57c0a35f15547542d0191d0cb7
2022-08-17 15:53:40 -07:00
Gang Liao 275cd80cdb Add a blob-specific cache priority (#10461)
Summary:
RocksDB's `Cache` abstraction currently supports two priority levels for items: high (used for frequently accessed/highly valuable SST metablocks like index/filter blocks) and low (used for SST data blocks). Blobs are typically lower-value targets for caching than data blocks, since 1) with BlobDB, data blocks containing blob references conceptually form an index structure which has to be consulted before we can read the blob value, and 2) cached blobs represent only a single key-value, while cached data blocks generally contain multiple KVs. Since we would like to make it possible to use the same backing cache for the block cache and the blob cache, it would make sense to add a new, lower-than-low cache priority level (bottom level) for blobs so data blocks are prioritized over them.

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

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10461

Reviewed By: siying

Differential Revision: D38672823

Pulled By: ltamasi

fbshipit-source-id: 90cf7362036563d79891f47be2cc24b827482743
2022-08-12 17:59:06 -07:00
Changyu Bi fd165c869d Add memtable per key-value checksum (#10281)
Summary:
Append per key-value checksum to internal key. These checksums are verified on read paths including Get, Iterator and during Flush. Get and Iterator will return `Corruption` status if there is a checksum verification failure. Flush will make DB become read-only upon memtable entry checksum verification failure.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10281

Test Plan:
- Added new unit test cases: `make check`
- Benchmark on memtable insert
```
TEST_TMPDIR=/dev/shm/memtable_write ./db_bench -benchmarks=fillseq -disable_wal=true -max_write_buffer_number=100 -num=10000000 -min_write_buffer_number_to_merge=100

# avg over 10 runs
Baseline: 1166936 ops/sec
memtable 2 bytes kv checksum : 1.11674e+06 ops/sec (-4%)
memtable 2 bytes kv checksum + write batch 8 bytes kv checksum: 1.08579e+06 ops/sec (-6.95%)
write batch 8 bytes kv checksum: 1.17979e+06 ops/sec (+1.1%)
```
-  Benchmark on only memtable read: ops/sec dropped 31% for `readseq` due to time spend on verifying checksum.
ops/sec for `readrandom` dropped ~6.8%.
```
# Readseq
sudo TEST_TMPDIR=/dev/shm/memtable_read ./db_bench -benchmarks=fillseq,readseq"[-X20]" -disable_wal=true -max_write_buffer_number=100 -num=10000000 -min_write_buffer_number_to_merge=100

readseq [AVG    20 runs] : 7432840 (± 212005) ops/sec;  822.3 (± 23.5) MB/sec
readseq [MEDIAN 20 runs] : 7573878 ops/sec;  837.9 MB/sec

With -memtable_protection_bytes_per_key=2:

readseq [AVG    20 runs] : 5134607 (± 119596) ops/sec;  568.0 (± 13.2) MB/sec
readseq [MEDIAN 20 runs] : 5232946 ops/sec;  578.9 MB/sec

# Readrandom
sudo TEST_TMPDIR=/dev/shm/memtable_read ./db_bench -benchmarks=fillrandom,readrandom"[-X10]" -disable_wal=true -max_write_buffer_number=100 -num=1000000 -min_write_buffer_number_to_merge=100
readrandom [AVG    10 runs] : 140236 (± 3938) ops/sec;    9.8 (± 0.3) MB/sec
readrandom [MEDIAN 10 runs] : 140545 ops/sec;    9.8 MB/sec

With -memtable_protection_bytes_per_key=2:
readrandom [AVG    10 runs] : 130632 (± 2738) ops/sec;    9.1 (± 0.2) MB/sec
readrandom [MEDIAN 10 runs] : 130341 ops/sec;    9.1 MB/sec
```

- Stress test: `python3 -u tools/db_crashtest.py whitebox --duration=1800`

Reviewed By: ajkr

Differential Revision: D37607896

Pulled By: cbi42

fbshipit-source-id: fdaefb475629d2471780d4a5f5bf81b44ee56113
2022-08-12 13:51:32 -07:00
Peter Dillinger 86a1e3e0e7 Derive cache keys from SST unique IDs (#10394)
Summary:
... so that cache keys can be derived from DB manifest data
before reading the file from storage--so that every part of the file
can potentially go in a persistent cache.

See updated comments in cache_key.cc for technical details. Importantly,
the new cache key encoding uses some fancy but efficient math to pack
data into the cache key without depending on the sizes of the various
pieces. This simplifies some existing code creating cache keys, like
cache warming before the file size is known.

This should provide us an essentially permanent mapping between SST
unique IDs and base cache keys, with the ability to "upgrade" SST
unique IDs (and thus cache keys) with new SST format_versions.

These cache keys are of similar, perhaps indistinguishable quality to
the previous generation. Before this change (see "corrected" days
between collision):

```
./cache_bench -stress_cache_key -sck_keep_bits=43
18 collisions after 2 x 90 days, est 10 days between (1.15292e+19 corrected)
```

After this change (keep 43 bits, up through 50, to validate "trajectory"
is ok on "corrected" days between collision):
```
19 collisions after 3 x 90 days, est 14.2105 days between (1.63836e+19 corrected)
16 collisions after 5 x 90 days, est 28.125 days between (1.6213e+19 corrected)
15 collisions after 7 x 90 days, est 42 days between (1.21057e+19 corrected)
15 collisions after 17 x 90 days, est 102 days between (1.46997e+19 corrected)
15 collisions after 49 x 90 days, est 294 days between (2.11849e+19 corrected)
15 collisions after 62 x 90 days, est 372 days between (1.34027e+19 corrected)
15 collisions after 53 x 90 days, est 318 days between (5.72858e+18 corrected)
15 collisions after 309 x 90 days, est 1854 days between (1.66994e+19 corrected)
```

However, the change does modify (probably weaken) the "guaranteed unique" promise from this

> SST files generated in a single process are guaranteed to have unique cache keys, unless/until number session ids * max file number = 2**86

to this (see https://github.com/facebook/rocksdb/issues/10388)

> With the DB id limitation, we only have nice guaranteed unique cache keys for files generated in a single process until biggest session_id_counter and offset_in_file reach combined 64 bits

I don't think this is a practical concern, though.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10394

Test Plan: unit tests updated, see simulation results above

Reviewed By: jay-zhuang

Differential Revision: D38667529

Pulled By: pdillinger

fbshipit-source-id: 49af3fe7f47e5b61162809a78b76c769fd519fba
2022-08-12 13:49:49 -07:00
Levi Tamasi f3ddbe66bd Mention PR 10391 in HISTORY.md (#10522)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10522

Reviewed By: riversand963

Differential Revision: D38639429

Pulled By: ltamasi

fbshipit-source-id: 14d7ed4df76a78ba6882e0474048a720afb907d4
2022-08-11 15:51:11 -07:00
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
gitbw95 f060b47ee8 Fix the segdefault bug in CompressedSecondaryCache and its tests (#10507)
Summary:
This fix is to replace `AllocateBlock()` with `new`. Once I figure out why `AllocateBlock()` might cause the segfault, I will update the implementation.

Fix the bug that causes ./compressed_secondary_cache_test output following test failures:

```
Note: Google Test filter = CompressedSecondaryCacheTest.MergeChunksIntoValueTest
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from CompressedSecondaryCacheTest
[ RUN      ] CompressedSecondaryCacheTest.MergeChunksIntoValueTest
[       OK ] CompressedSecondaryCacheTest.MergeChunksIntoValueTest (1 ms)
[----------] 1 test from CompressedSecondaryCacheTest (1 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (9 ms total)
[  PASSED  ] 1 test.
t/run-compressed_secondary_cache_test-CompressedSecondaryCacheTest.MergeChunksIntoValueTest: line 4: 1091086 Segmentation fault      (core dumped) TEST_TMPDIR=$d ./compressed_secondary_cache_test --gtest_filter=CompressedSecondaryCacheTest.MergeChunksIntoValueTest
Note: Google Test filter = CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from CompressedSecondaryCacheTest
[ RUN      ] CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression
[       OK ] CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression (1 ms)
[----------] 1 test from CompressedSecondaryCacheTest (1 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (2 ms total)
[  PASSED  ] 1 test.
t/run-compressed_secondary_cache_test-CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression: line 4: 1090883 Segmentation fault      (core dumped) TEST_TMPDIR=$d ./compressed_secondary_cache_test --gtest_filter=CompressedSecondaryCacheTest.BasicTestWithMemoryAllocatorAndCompression

```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10507

Test Plan:
Test 1:
```
$make -j 24
$./compressed_secondary_cache_test
```
Test 2:
```
$COMPILE_WITH_ASAN=1  make -j 24
$./compressed_secondary_cache_test
```
Test 3:
```
$COMPILE_WITH_TSAN=1 make -j 24
$./compressed_secondary_cache_test
```

Reviewed By: anand1976

Differential Revision: D38529885

Pulled By: gitbw95

fbshipit-source-id: d903fa3fadbd4d29f9528728c63a4f61c4396890
2022-08-09 15:34:50 -07:00
Levi Tamasi 06b04127a8 Reset blob value as soon as it's not needed in DBIter (#10490)
Summary:
We have recently added caching support to BlobDB, and separately,
implemented an optimization where reading blobs from the cache
results in the cache handle being transferred to the target `PinnableSlice`
(as opposed to the contents getting copied). With these changes,
it makes sense to reset the `PinnableSlice` storing the blob value in
`DBIter` as soon as we move to a different iterator position to prevent
us from holding on to the cache handle any longer than necessary.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10490

Test Plan: `make check`

Reviewed By: akankshamahajan15

Differential Revision: D38473630

Pulled By: ltamasi

fbshipit-source-id: 84c045ffac76436c6152fd0f5775b007f4051386
2022-08-09 11:39:57 -07:00
Levi Tamasi a85443c001 Update HISTORY.md for PR 10492 (#10504)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/10504

Reviewed By: akankshamahajan15

Differential Revision: D38514813

Pulled By: ltamasi

fbshipit-source-id: 3c0c157740a6680b6f91216adcc2553c3a327b94
2022-08-08 15:54:13 -07:00
Jay Zhuang 3f763763aa Change `bottommost_temperture` to `last_level_temperture` (#10471)
Summary:
Change tiered compaction feature from `bottommost_temperture` to
`last_level_temperture`. The old option is kept for migration purpose only,
which is behaving the same as `last_level_temperture` and it will be removed in
the next release.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10471

Test Plan: CI

Reviewed By: siying

Differential Revision: D38450621

Pulled By: jay-zhuang

fbshipit-source-id: cc1cdf8bad409376fec0152abc0a64fb72a91527
2022-08-08 14:36:34 -07:00
Jay Zhuang 375534752a Improve universal compaction picker for tiered compaction (#10467)
Summary:
Current universal compaction picker may cause extra size amplification
compaction if there're more hot data on penultimate level. Improve the picker
to skip the last level for size amp calculation if tiered compaction is
enabled, which can
1. avoid extra unnecessary size amp compaction;
2. typically cold tier (the last level) is not size constrained, so skip size
   amp for cold tier is intended;

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10467

Test Plan: CI and added unittest

Reviewed By: siying

Differential Revision: D38391350

Pulled By: jay-zhuang

fbshipit-source-id: 103c0731c05e0a7e8f267e9e829d022328be25d2
2022-08-08 14:34:36 -07:00
Jay Zhuang 0d885e80d4 Avoid dynamic memory allocation on read path (#10453)
Summary:
lambda function dynamicly allocates memory from heap if it needs to
capture multiple values, which could be expensive.
Switch to explictly use local functor from stack.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10453

Test Plan:
CI
db_bench shows ~2-3% read improvement:
```
# before the change
TEST_TMPDIR=/tmp/dbbench4 ./db_bench_main --benchmarks=filluniquerandom,readrandom -compression_type=none -max_background_jobs=12 -num=10000000
readrandom   :       8.528 micros/op 117265 ops/sec 85.277 seconds 10000000 operations;   13.0 MB/s (10000000 of 10000000 found)
# after the change
TEST_TMPDIR=/tmp/dbbench5 ./db_bench_new --benchmarks=filluniquerandom,readrandom -compression_type=none -max_background_jobs=12 -num=10000000
readrandom   :       8.263 micros/op 121015 ops/sec 82.634 seconds 10000000 operations;   13.4 MB/s (10000000 of 10000000 found)
```
details: https://gist.github.com/jay-zhuang/5ac0628db8fc9cbcb499e056d4cb5918

Micro-benchmark shows a similar improvement ~1-2%:
before the change:
https://gist.github.com/jay-zhuang/9dc0ebf51bbfbf4af82f6193d43cf75b
after the change:
https://gist.github.com/jay-zhuang/fc061f1813cd8f441109ad0b0fe7c185

Reviewed By: ajkr

Differential Revision: D38345056

Pulled By: jay-zhuang

fbshipit-source-id: f3597aeeee338a804d37bf2e81386d5a100665e0
2022-08-08 12:59:31 -07:00
Changyu Bi 9d77bf8f7b Fragment memtable range tombstone in the write path (#10380)
Summary:
- Right now each read fragments the memtable range tombstones https://github.com/facebook/rocksdb/issues/4808. This PR explores the idea of fragmenting memtable range tombstones in the write path and reads can just read this cached fragmented tombstone without any fragmenting cost. This PR only does the caching for immutable memtable, and does so right before a memtable is added to an immutable memtable list. The fragmentation is done without holding mutex to minimize its performance impact.
- db_bench is updated to print out the number of range deletions executed if there is any.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10380

Test Plan:
- CI, added asserts in various places to check whether a fragmented range tombstone list should have been constructed.
- Benchmark: as this PR only optimizes immutable memtable path, the number of writes in the benchmark is chosen such  an immutable memtable is created and range tombstones are in that memtable.

```
single thread:
./db_bench --benchmarks=fillrandom,readrandom --writes_per_range_tombstone=1 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=500000 --reads=100000 --max_num_range_tombstones=100

multi_thread
./db_bench --benchmarks=fillrandom,readrandom --writes_per_range_tombstone=1 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=15000 --reads=20000 --threads=32 --max_num_range_tombstones=100
```
Commit 99cdf16464 is included in benchmark result. It was an earlier attempt where tombstones are fragmented for each write operation. Reader threads share it using a shared_ptr which would slow down multi-thread read performance as seen in benchmark results.
Results are averaged over 5 runs.

Single thread result:
| Max # tombstones  | main fillrandom micros/op | 99cdf16464 | Post PR | main readrandom micros/op |  99cdf16464 | Post PR |
| ------------- | ------------- |------------- |------------- |------------- |------------- |------------- |
| 0    |6.68     |6.57     |6.72     |4.72     |4.79     |4.54     |
| 1    |6.67     |6.58     |6.62     |5.41     |4.74     |4.72     |
| 10   |6.59     |6.5      |6.56     |7.83     |4.69     |4.59     |
| 100  |6.62     |6.75     |6.58     |29.57    |5.04     |5.09     |
| 1000 |6.54     |6.82     |6.61     |320.33   |5.22     |5.21     |

32-thread result: note that "Max # tombstones" is per thread.
| Max # tombstones  | main fillrandom micros/op | 99cdf16464 | Post PR | main readrandom micros/op |  99cdf16464 | Post PR |
| ------------- | ------------- |------------- |------------- |------------- |------------- |------------- |
| 0    |234.52   |260.25   |239.42   |5.06     |5.38     |5.09     |
| 1    |236.46   |262.0    |231.1    |19.57    |22.14    |5.45     |
| 10   |236.95   |263.84   |251.49   |151.73   |21.61    |5.73     |
| 100  |268.16   |296.8    |280.13   |2308.52  |22.27    |6.57     |

Reviewed By: ajkr

Differential Revision: D37916564

Pulled By: cbi42

fbshipit-source-id: 05d6d2e16df26c374c57ddcca13a5bfe9d5b731e
2022-08-05 12:02:33 -07:00
Bo Wang f28d0c2020 Fix data race reported on SetIsInSecondaryCache in LRUCache (#10472)
Summary:
Currently, `SetIsInSecondaryCache` is after `Promote`. After `Promote`, a handle can be accessed and its flags can be set. This causes data race.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10472

Test Plan:
unit tests
stress tests

Reviewed By: pdillinger

Differential Revision: D38403991

Pulled By: gitbw95

fbshipit-source-id: 0aaa2d2edeaf5bc799fcce605648fe49eb7119c2
2022-08-04 13:52:11 -07:00
Bo Wang 87b82f28a1 Split cache to minimize internal fragmentation (#10287)
Summary:
### **Summary:**
To minimize the internal fragmentation caused by the variable size of the compressed blocks, the original block is split according to the jemalloc bin size in `Insert()` and then merged back in `Lookup()`.  Based on the analysis of the results of the following tests, from the overall internal fragmentation perspective, this PR does mitigate the internal fragmentation issue.

_Do more myshadow tests with the latest commit. I finished several myshadow AB Testing and the results are promising. For the config of 4GB primary cache and 3GB secondary cache, Jemalloc resident stats shows consistently ~0.15GB memory saving; the allocated and active stats show similar memory savings. The CPU usage is almost the same before and after this PR._

To evaluate the issue of memory fragmentations and the benefits of this PR, I conducted two sets of local tests as follows.

**T1**
Keys:       16 bytes each (+ 0 bytes user-defined timestamp)
Values:     100 bytes each (50 bytes after compression)
Entries:    90000000
RawSize:    9956.4 MB (estimated)
FileSize:   5664.8 MB (estimated)

| Test Name | Primary Cache Size (MB) | Compressed Secondary Cache Size (MB) |
| - | - | - |
| T1_3 | 4000 | 4000 |
| T1_4 | 2000 | 3000 |

Populate the DB:
./db_bench --benchmarks=fillrandom --num=90000000 -db=/mem_fragmentation/db_bench_1
Overwrite it to a stable state:
./db_bench --benchmarks=overwrite --num=90000000 -use_existing_db -db=/mem_fragmentation/db_bench_1

Run read tests with differnt cache setting:
T1_3:
MALLOC_CONF="prof:true,prof_stats:true" ../rocksdb/db_bench --benchmarks=seekrandom  --threads=16 --num=90000000 -use_existing_db --benchmark_write_rate_limit=52000000 -use_direct_reads --cache_size=4000000000 -compressed_secondary_cache_size=4000000000 -use_compressed_secondary_cache -db=/mem_fragmentation/db_bench_1 --print_malloc_stats=true > ~/temp/mem_frag/20220710/jemalloc_stats_json_T1_3_20220710 -duration=1800 &

T1_4:
MALLOC_CONF="prof:true,prof_stats:true" ../rocksdb/db_bench --benchmarks=seekrandom  --threads=16 --num=90000000 -use_existing_db --benchmark_write_rate_limit=52000000 -use_direct_reads --cache_size=2000000000 -compressed_secondary_cache_size=3000000000 -use_compressed_secondary_cache -db=/mem_fragmentation/db_bench_1 --print_malloc_stats=true > ~/temp/mem_frag/20220710/jemalloc_stats_json_T1_4_20220710 -duration=1800 &

For T1_3 and T1_4, I also conducted the tests before and after this PR. The following table show the important jemalloc stats.

| Test Name | T1_3 | T1_3 after mem defrag | T1_4 | T1_4 after mem defrag |
| - | - | - | - | - |
| allocated (MB)  | 8728 | 8076 | 5518 | 5043 |
| available (MB)  | 8753 | 8092 | 5536 | 5051 |
| external fragmentation rate  | 0.003 | 0.002 | 0.003 | 0.0016 |
| resident (MB)  | 8956 | 8365 | 5655 | 5235 |

**T2**
Keys:       32 bytes each (+ 0 bytes user-defined timestamp)
Values:     256 bytes each (128 bytes after compression)
Entries:    40000000
RawSize:    10986.3 MB (estimated)
FileSize:   6103.5 MB (estimated)

| Test Name | Primary Cache Size (MB) | Compressed Secondary Cache Size (MB) |
| - | - | - |
| T2_3 | 4000 | 4000 |
| T2_4 | 2000 | 3000 |

Create DB (10GB):
./db_bench -benchmarks=fillrandom -use_direct_reads=true -num=40000000 -key_size=32 -value_size=256 -db=/mem_fragmentation/db_bench_2
Overwrite it to a stable state:
./db_bench --benchmarks=overwrite --num=40000000 -use_existing_db -key_size=32 -value_size=256 -db=/mem_fragmentation/db_bench_2

Run read tests with differnt cache setting:
T2_3:
MALLOC_CONF="prof:true,prof_stats:true" ./db_bench  --benchmarks="mixgraph" -use_direct_io_for_flush_and_compaction=true -use_direct_reads=true -cache_size=4000000000 -compressed_secondary_cache_size=4000000000 -use_compressed_secondary_cache -keyrange_dist_a=14.18 -keyrange_dist_b=-2.917 -keyrange_dist_c=0.0164 -keyrange_dist_d=-0.08082 -keyrange_num=30 -value_k=0.2615 -value_sigma=25.45 -iter_k=2.517 -iter_sigma=14.236 -mix_get_ratio=0.85 -mix_put_ratio=0.14 -mix_seek_ratio=0.01 -sine_mix_rate_interval_milliseconds=5000 -sine_a=1000 -sine_b=0.000073 -sine_d=400000 -reads=80000000 -num=40000000 -key_size=32 -value_size=256 -use_existing_db=true -db=/mem_fragmentation/db_bench_2 --print_malloc_stats=true > ~/temp/mem_frag/jemalloc_stats_T2_3 -duration=1800  &

T2_4:
MALLOC_CONF="prof:true,prof_stats:true" ./db_bench  --benchmarks="mixgraph" -use_direct_io_for_flush_and_compaction=true -use_direct_reads=true -cache_size=2000000000 -compressed_secondary_cache_size=3000000000 -use_compressed_secondary_cache -keyrange_dist_a=14.18 -keyrange_dist_b=-2.917 -keyrange_dist_c=0.0164 -keyrange_dist_d=-0.08082 -keyrange_num=30 -value_k=0.2615 -value_sigma=25.45 -iter_k=2.517 -iter_sigma=14.236 -mix_get_ratio=0.85 -mix_put_ratio=0.14 -mix_seek_ratio=0.01 -sine_mix_rate_interval_milliseconds=5000 -sine_a=1000 -sine_b=0.000073 -sine_d=400000 -reads=80000000 -num=40000000 -key_size=32 -value_size=256 -use_existing_db=true -db=/mem_fragmentation/db_bench_2 --print_malloc_stats=true > ~/temp/mem_frag/jemalloc_stats_T2_4 -duration=1800  &

For T2_3 and T2_4, I also conducted the tests before and after this PR. The following table show the important jemalloc stats.

| Test Name |  T2_3 | T2_3 after mem defrag | T2_4 | T2_4 after mem defrag |
| -  | - | - | - | - |
| allocated (MB)  | 8425 | 8093 | 5426 | 5149 |
| available (MB)  | 8489 | 8138 | 5435 | 5158 |
| external fragmentation rate  | 0.008 | 0.0055 | 0.0017 | 0.0017 |
| resident (MB)  | 8676 | 8392 | 5541 | 5321 |

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10287

Test Plan: Unit tests.

Reviewed By: anand1976

Differential Revision: D37743362

Pulled By: gitbw95

fbshipit-source-id: 0010c5af08addeacc5ebbc4ffe5be882fb1d38ad
2022-08-02 15:28:11 -07:00