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286 commits

Author SHA1 Message Date
Andrew Kryczka 8e29f243c9 No filesystem reads during Merge() writes (#12365)
Summary:
This occasional filesystem read in the write path has caused user pain. It doesn't seem very useful considering it only limits one component's merge chain length, and only helps merge uncached (i.e., infrequently read) values. This PR proposes allowing `max_successive_merges` to be exceeded when the value cannot be read from in-memory components. I included a rollback flag (`strict_max_successive_merges`) just in case.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12365

Test Plan:
"rocksdb.block.cache.data.add" is number of data blocks read from filesystem. Since the benchmark is write-only, compaction is disabled, and flush doesn't read data blocks, any nonzero value means the user write issued the read.

```
$ for s in false true; do echo -n "strict_max_successive_merges=$s: " && ./db_bench -value_size=64 -write_buffer_size=131072 -writes=128 -num=1 -benchmarks=mergerandom,flush,mergerandom -merge_operator=stringappend -disable_auto_compactions=true -compression_type=none -strict_max_successive_merges=$s -max_successive_merges=100 -statistics=true |& grep 'block.cache.data.add COUNT' ; done
strict_max_successive_merges=false: rocksdb.block.cache.data.add COUNT : 0
strict_max_successive_merges=true: rocksdb.block.cache.data.add COUNT : 1
```

Reviewed By: hx235

Differential Revision: D53982520

Pulled By: ajkr

fbshipit-source-id: e40f761a60bd601f232417ac0058e4a33ee9c0f4
2024-02-21 13:15:27 -08:00
Peter Dillinger 54cb9c77d9 Prefer static_cast in place of most reinterpret_cast (#12308)
Summary:
The following are risks associated with pointer-to-pointer reinterpret_cast:
* Can produce the "wrong result" (crash or memory corruption). IIRC, in theory this can happen for any up-cast or down-cast for a non-standard-layout type, though in practice would only happen for multiple inheritance cases (where the base class pointer might be "inside" the derived object). We don't use multiple inheritance a lot, but we do.
* Can mask useful compiler errors upon code change, including converting between unrelated pointer types that you are expecting to be related, and converting between pointer and scalar types unintentionally.

I can only think of some obscure cases where static_cast could be troublesome when it compiles as a replacement:
* Going through `void*` could plausibly cause unnecessary or broken pointer arithmetic. Suppose we have
`struct Derived: public Base1, public Base2`.  If we have `Derived*` -> `void*` -> `Base2*` -> `Derived*` through reinterpret casts, this could plausibly work (though technical UB) assuming the `Base2*` is not dereferenced. Changing to static cast could introduce breaking pointer arithmetic.
* Unnecessary (but safe) pointer arithmetic could arise in a case like `Derived*` -> `Base2*` -> `Derived*` where before the Base2 pointer might not have been dereferenced. This could potentially affect performance.

With some light scripting, I tried replacing pointer-to-pointer reinterpret_casts with static_cast and kept the cases that still compile. Most occurrences of reinterpret_cast have successfully been changed (except for java/ and third-party/). 294 changed, 257 remain.

A couple of related interventions included here:
* Previously Cache::Handle was not actually derived from in the implementations and just used as a `void*` stand-in with reinterpret_cast. Now there is a relationship to allow static_cast. In theory, this could introduce pointer arithmetic (as described above) but is unlikely without multiple inheritance AND non-empty Cache::Handle.
* Remove some unnecessary casts to void* as this is allowed to be implicit (for better or worse).

Most of the remaining reinterpret_casts are for converting to/from raw bytes of objects. We could consider better idioms for these patterns in follow-up work.

I wish there were a way to implement a template variant of static_cast that would only compile if no pointer arithmetic is generated, but best I can tell, this is not possible. AFAIK the best you could do is a dynamic check that the void* conversion after the static cast is unchanged.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12308

Test Plan: existing tests, CI

Reviewed By: ltamasi

Differential Revision: D53204947

Pulled By: pdillinger

fbshipit-source-id: 9de23e618263b0d5b9820f4e15966876888a16e2
2024-02-07 10:44:11 -08:00
Hui Xiao 06e593376c Group SST write in flush, compaction and db open with new stats (#11910)
Summary:
## Context/Summary
Similar to https://github.com/facebook/rocksdb/pull/11288, https://github.com/facebook/rocksdb/pull/11444, categorizing SST/blob file write according to different io activities allows more insight into the activity.

For that, this PR does the following:
- Tag different write IOs by passing down and converting WriteOptions to IOOptions
- Add new SST_WRITE_MICROS histogram in WritableFileWriter::Append() and breakdown FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS

Some related code refactory to make implementation cleaner:
- Blob stats
   - Replace high-level write measurement with low-level WritableFileWriter::Append() measurement for BLOB_DB_BLOB_FILE_WRITE_MICROS. This is to make FILE_WRITE_{FLUSH|COMPACTION|DB_OPEN}_MICROS  include blob file. As a consequence, this introduces some behavioral changes on it, see HISTORY and db bench test plan below for more info.
   - Fix bugs where BLOB_DB_BLOB_FILE_SYNCED/BLOB_DB_BLOB_FILE_BYTES_WRITTEN include file failed to sync and bytes failed to write.
- Refactor WriteOptions constructor for easier construction with io_activity and rate_limiter_priority
- Refactor DBImpl::~DBImpl()/BlobDBImpl::Close() to bypass thread op verification
- Build table
   - TableBuilderOptions now includes Read/WriteOpitons so BuildTable() do not need to take these two variables
   - Replace the io_priority passed into BuildTable() with TableBuilderOptions::WriteOpitons::rate_limiter_priority. Similar for BlobFileBuilder.
This parameter is used for dynamically changing file io priority for flush, see  https://github.com/facebook/rocksdb/pull/9988?fbclid=IwAR1DtKel6c-bRJAdesGo0jsbztRtciByNlvokbxkV6h_L-AE9MACzqRTT5s for more
   - Update ThreadStatus::FLUSH_BYTES_WRITTEN to use io_activity to track flush IO in flush job and db open instead of io_priority

## Test
### db bench

Flush
```
./db_bench --statistics=1 --benchmarks=fillseq --num=100000 --write_buffer_size=100

rocksdb.sst.write.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377
rocksdb.file.write.flush.micros P50 : 1.830863 P95 : 4.094720 P99 : 6.578947 P100 : 26.000000 COUNT : 7875 SUM : 20377
rocksdb.file.write.compaction.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0
rocksdb.file.write.db.open.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0
```

compaction, db oopen
```
Setup: ./db_bench --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench

Run:./db_bench --statistics=1 --benchmarks=compact  --db=../db_bench --use_existing_db=1

rocksdb.sst.write.micros P50 : 2.675325 P95 : 9.578788 P99 : 18.780000 P100 : 314.000000 COUNT : 638 SUM : 3279
rocksdb.file.write.flush.micros P50 : 0.000000 P95 : 0.000000 P99 : 0.000000 P100 : 0.000000 COUNT : 0 SUM : 0
rocksdb.file.write.compaction.micros P50 : 2.757353 P95 : 9.610687 P99 : 19.316667 P100 : 314.000000 COUNT : 615 SUM : 3213
rocksdb.file.write.db.open.micros P50 : 2.055556 P95 : 3.925000 P99 : 9.000000 P100 : 9.000000 COUNT : 23 SUM : 66
```

blob stats - just to make sure they aren't broken by this PR
```
Integrated Blob DB

Setup: ./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench

Run:./db_bench --enable_blob_files=1 --statistics=1 --benchmarks=compact  --db=../db_bench --use_existing_db=1

pre-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 7.298246 P95 : 9.771930 P99 : 9.991813 P100 : 16.000000 COUNT : 235 SUM : 1600
rocksdb.blobdb.blob.file.synced COUNT : 1
rocksdb.blobdb.blob.file.bytes.written COUNT : 34842

post-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 2.000000 P95 : 2.829360 P99 : 2.993779 P100 : 9.000000 COUNT : 707 SUM : 1614
- COUNT is higher and values are smaller as it includes header and footer write
- COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164

rocksdb.blobdb.blob.file.synced COUNT : 1 (stay the same)
rocksdb.blobdb.blob.file.bytes.written COUNT : 34842 (stay the same)
```

```
Stacked Blob DB

Run: ./db_bench --use_blob_db=1 --statistics=1 --benchmarks=fillseq --num=10000 --disable_auto_compactions=1 -write_buffer_size=100 --db=../db_bench

pre-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 12.808042 P95 : 19.674497 P99 : 28.539683 P100 : 51.000000 COUNT : 10000 SUM : 140876
rocksdb.blobdb.blob.file.synced COUNT : 8
rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445

post-PR:
rocksdb.blobdb.blob.file.write.micros P50 : 1.657370 P95 : 2.952175 P99 : 3.877519 P100 : 24.000000 COUNT : 30001 SUM : 67924
- COUNT is higher and values are smaller as it includes header and footer write
- COUNT is 3X higher due to each Append() count as one post-PR, while in pre-PR, 3 Append()s counts as one. See https://github.com/facebook/rocksdb/pull/11910/files#diff-32b811c0a1c000768cfb2532052b44dc0b3bf82253f3eab078e15ff201a0dabfL157-L164

rocksdb.blobdb.blob.file.synced COUNT : 8 (stay the same)
rocksdb.blobdb.blob.file.bytes.written COUNT : 1043445 (stay the same)
```

###  Rehearsal CI stress test
Trigger 3 full runs of all our CI stress tests

###  Performance

Flush
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=ManualFlush/key_num:524288/per_key_size:256 --benchmark_repetitions=1000
-- default: 1 thread is used to run benchmark; enable_statistics = true

Pre-pr: avg 507515519.3 ns
497686074,499444327,500862543,501389862,502994471,503744435,504142123,504224056,505724198,506610393,506837742,506955122,507695561,507929036,508307733,508312691,508999120,509963561,510142147,510698091,510743096,510769317,510957074,511053311,511371367,511409911,511432960,511642385,511691964,511730908,

Post-pr: avg 511971266.5 ns, regressed 0.88%
502744835,506502498,507735420,507929724,508313335,509548582,509994942,510107257,510715603,511046955,511352639,511458478,512117521,512317380,512766303,512972652,513059586,513804934,513808980,514059409,514187369,514389494,514447762,514616464,514622882,514641763,514666265,514716377,514990179,515502408,
```

Compaction
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_{pre|post}_pr --benchmark_filter=ManualCompaction/comp_style:0/max_data:134217728/per_key_size:256/enable_statistics:1  --benchmark_repetitions=1000
-- default: 1 thread is used to run benchmark

Pre-pr: avg 495346098.30 ns
492118301,493203526,494201411,494336607,495269217,495404950,496402598,497012157,497358370,498153846

Post-pr: avg 504528077.20, regressed 1.85%. "ManualCompaction" include flush so the isolated regression for compaction should be around 1.85-0.88 = 0.97%
502465338,502485945,502541789,502909283,503438601,504143885,506113087,506629423,507160414,507393007
```

Put with WAL (in case passing WriteOptions slows down this path even without collecting SST write stats)
```
TEST_TMPDIR=/dev/shm ./db_basic_bench_pre_pr --benchmark_filter=DBPut/comp_style:0/max_data:107374182400/per_key_size:256/enable_statistics:1/wal:1  --benchmark_repetitions=1000
-- default: 1 thread is used to run benchmark

Pre-pr: avg 3848.10 ns
3814,3838,3839,3848,3854,3854,3854,3860,3860,3860

Post-pr: avg 3874.20 ns, regressed 0.68%
3863,3867,3871,3874,3875,3877,3877,3877,3880,3881
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11910

Reviewed By: ajkr

Differential Revision: D49788060

Pulled By: hx235

fbshipit-source-id: 79e73699cda5be3b66461687e5147c2484fc5eff
2023-12-29 15:29:23 -08:00
Levi Tamasi 0ebe1614cb Eliminate some code duplication in MergeHelper (#12121)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12121

The patch eliminates some code duplication by unifying the two sets of `MergeHelper::TimedFullMerge` overloads using variadic templates. It also brings the order of parameters into sync when it comes to the various `TimedFullMerge*` methods.

Reviewed By: jaykorean

Differential Revision: D51862483

fbshipit-source-id: e3f832a6ff89ba34591451655cf11025d0a0d018
2023-12-05 14:07:42 -08:00
Yu Zhang ba8fa0f546 internal_repo_rocksdb (4372117296613874540) (#12117)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/12117

Reviewed By: ajkr

Differential Revision: D51745846

Pulled By: jowlyzhang

fbshipit-source-id: 51c806a484b3b43d174b06d2cfe9499191d09914
2023-12-04 11:17:32 -08:00
Levi Tamasi f42e70bf56 Integrate FullMergeV3 into the query and compaction paths (#11858)
Summary:
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11858

The patch builds on https://github.com/facebook/rocksdb/pull/11807 and integrates the `FullMergeV3` API into the read and compaction code paths by updating and extending the logic in `MergeHelper`.

In particular, when it comes to merge inputs, the existing `TimedFullMergeWithEntity` is folded into `TimedFullMerge`, since wide-column base values are now handled the same way as plain base values (or no base values for that matter), e.g. they are passed directly to the `MergeOperator`. On the other hand, there is some new differentiation on the output side. Namely, there are now two sets of `TimedFullMerge` variants: one set for contexts where the complete merge result and its value type are needed (used by iterators and compactions), and another set where the merge result is needed in a form determined by the client (used by the point lookup APIs, where e.g. for `Get` we have to extract the value of the default column of any wide-column results).

Implementation-wise, the two sets of overloads use different visitors to process the `std::variant` produced by `FullMergeV3`. This has the benefit of eliminating some repeated code e.g. in the point lookup paths, since `TimedFullMerge` now populates the application's result object (`PinnableSlice`/`string` or `PinnableWideColumns`) directly. Moreover, within each set of variants, there is a separate overload for the no base value/plain base value/wide-column base value cases, which eliminates some repeated branching w/r/t to the type of the base value if any.

Reviewed By: jaykorean

Differential Revision: D49352562

fbshipit-source-id: c2fb9853dba3fbbc6918665bde4195c4ea150a0c
2023-09-19 17:27:04 -07:00
Vardhan 87a21d08fe Add an option to trigger flush when the number of range deletions reach a threshold (#11358)
Summary:
Add a mutable column family option `memtable_max_range_deletions`. When non-zero, RocksDB will try to flush the current memtable after it has at least `memtable_max_range_deletions` range deletions. Java API is added and crash test is updated accordingly to randomly enable this option.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11358

Test Plan:
* New unit test: `DBRangeDelTest.MemtableMaxRangeDeletions`
* Ran crash test `python3 ./tools/db_crashtest.py whitebox --simple --memtable_max_range_deletions=20` and saw logs showing flushed memtables usually with 20 range deletions.

Reviewed By: ajkr

Differential Revision: D46582680

Pulled By: cbi42

fbshipit-source-id: f23d6fa8d8264ecf0a18d55c113ba03f5e2504da
2023-08-02 19:58:56 -07:00
Yu Zhang 4ea7b796b7 Respect cutoff timestamp during flush (#11599)
Summary:
Make flush respect the cutoff timestamp `full_history_ts_low` as much as possible for the user-defined timestamps in Memtables only feature. We achieve this by not proceeding with the actual flushing but instead reschedule the same `FlushRequest` so a follow up flush job can continue with the check after some interval.

This approach doesn't work well for atomic flush, so this feature currently is not supported in combination with atomic flush. Furthermore, this approach also requires a customized method to get the next immediately bigger user-defined timestamp. So currently it's limited to comparator that use uint64_t as the user-defined timestamp format. This support can be extended when we add such a customized method to `AdvancedColumnFamilyOptions`.

For non atomic flush request, at any single time, a column family can only have as many as one FlushRequest for it in the `flush_queue_`. There is deduplication done at `FlushRequest` enqueueing(`SchedulePendingFlush`) and dequeueing time (`PopFirstFromFlushQueue`). We hold the db mutex between when a `FlushRequest` is popped from the queue and the same FlushRequest get rescheduled, so no other `FlushRequest` with a higher `max_memtable_id` can be added to the `flush_queue_` blocking us from re-enqueueing the same `FlushRequest`.

Flush is continued nevertheless if there is risk of entering write stall mode had the flush being postponed, e.g. due to accumulation of write buffers, exceeding the `max_write_buffer_number` setting. When this happens, the newest user-defined timestamp in the involved Memtables need to be tracked and we use it to increase the `full_history_ts_low`, which is an inclusive cutoff timestamp for which RocksDB promises to keep all user-defined timestamps equal to and newer than it.

Tet plan:
```
./column_family_test --gtest_filter="*RetainUDT*"
./memtable_list_test --gtest_filter="*WithTimestamp*"
./flush_job_test --gtest_filter="*WithTimestamp*"
```

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11599

Reviewed By: ajkr

Differential Revision: D47561586

Pulled By: jowlyzhang

fbshipit-source-id: 9400445f983dd6eac489e9dd0fb5d9b99637fe89
2023-07-26 16:25:06 -07:00
leipeng 25b08eb438 MemTable::Add: first_seqno_.compare_exchange_weak to earliest_seqno_ (#11398)
Summary:
This should be a benign bug caused by a long lived typo, this PR fix this issue.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11398

Reviewed By: ajkr

Differential Revision: D47163379

Pulled By: cbi42

fbshipit-source-id: 531728cae496fd7ac1371bbbd64fc103c3a90dcf
2023-07-03 15:05:38 -07:00
Peter Dillinger 206fdea3d9 Change internal headers with duplicate names (#11408)
Summary:
In IDE navigation I find it annoying that there are two statistics.h files (etc.) and often land on the wrong one. Here I migrate several headers to use the blah.h <- blah_impl.h <- blah.cc idiom. Although clang-format wants "blah.h" to be the top include for "blah.cc", I think overall this is an improvement.

No public API changes.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11408

Test Plan: existing tests

Reviewed By: ltamasi

Differential Revision: D45456696

Pulled By: pdillinger

fbshipit-source-id: 809d931253f3272c908cf5facf7e1d32fc507373
2023-05-17 11:27:09 -07:00
Changyu Bi 62fc15f009 Block per key-value checksum (#11287)
Summary:
add option `block_protection_bytes_per_key` and implementation for block per key-value checksum. The main changes are
1. checksum construction and verification in block.cc/h
2. pass the option `block_protection_bytes_per_key` around (mainly for methods defined in table_cache.h)
3. unit tests/crash test updates

Tests:
* Added unit tests
* Crash test: `python3 tools/db_crashtest.py blackbox --simple --block_protection_bytes_per_key=1 --write_buffer_size=1048576`

Follow up (maybe as a separate PR): make sure corruption status returned from BlockIters are correctly handled.

Performance:
Turning on block per KV protection has a non-trivial negative impact on read performance and costs additional memory.
For memory, each block includes additional 24 bytes for checksum-related states beside checksum itself. For CPU, I set up a DB of size ~1.2GB with 5M keys (32 bytes key and 200 bytes value) which compacts to ~5 SST files (target file size 256 MB) in L6 without compression. I tested readrandom performance with various block cache size (to mimic various cache hit rates):

```
SETUP
make OPTIMIZE_LEVEL="-O3" USE_LTO=1 DEBUG_LEVEL=0 -j32 db_bench
./db_bench -benchmarks=fillseq,compact0,waitforcompaction,compact,waitforcompaction -write_buffer_size=33554432 -level_compaction_dynamic_level_bytes=true -max_background_jobs=8 -target_file_size_base=268435456 --num=5000000 --key_size=32 --value_size=200 --compression_type=none

BENCHMARK
./db_bench --use_existing_db -benchmarks=readtocache,readrandom[-X10] --num=5000000 --key_size=32 --disable_auto_compactions --reads=1000000 --block_protection_bytes_per_key=[0|1] --cache_size=$CACHESIZE

The readrandom ops/sec looks like the following:
Block cache size:  2GB        1.2GB * 0.9    1.2GB * 0.8     1.2GB * 0.5   8MB
Main              240805     223604         198176           161653       139040
PR prot_bytes=0   238691     226693         200127           161082       141153
PR prot_bytes=1   214983     193199         178532           137013       108211
prot_bytes=1 vs    -10%        -15%          -10.8%          -15%        -23%
prot_bytes=0
```

The benchmark has a lot of variance, but there was a 5% to 25% regression in this benchmark with different cache hit rates.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11287

Reviewed By: ajkr

Differential Revision: D43970708

Pulled By: cbi42

fbshipit-source-id: ef98d898b71779846fa74212b9ec9e08b7183940
2023-04-25 12:08:23 -07:00
Hui Xiao 151242ce46 Group rocksdb.sst.read.micros stat by IOActivity flush and compaction (#11288)
Summary:
**Context:**
The existing stat rocksdb.sst.read.micros does not reflect each of compaction and flush cases but aggregate them, which is not so helpful for us to understand IO read behavior of each of them.

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

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

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

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

**Read**

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

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

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

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

Reviewed By: ajkr

Differential Revision: D44007011

Pulled By: hx235

fbshipit-source-id: a54c89e4846dfc9a135389edf3f3eedfea257132
2023-04-21 09:07:18 -07:00
Levi Tamasi 49881921cd Rename a recently added PerfContext counter (#11294)
Summary:
The patch renames the counter added in https://github.com/facebook/rocksdb/issues/11284 for better consistency with the existing naming scheme.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11294

Test Plan: `make check`

Reviewed By: jowlyzhang

Differential Revision: D44035964

Pulled By: ltamasi

fbshipit-source-id: 8b1a2a03ee728148365367e0ecc1fcf462f62191
2023-03-13 18:43:27 -07:00
Levi Tamasi 1d52438504 Add a PerfContext counter for merge operands applied in point lookups (#11284)
Summary:
The existing PerfContext counter `internal_merge_count` only tracks the
Merge operands applied during range scans. The patch adds a new counter
called `internal_merge_count_point_lookups` to track the same metric
for point lookups (`Get` / `MultiGet` / `GetEntity` / `MultiGetEntity`), and
also fixes a couple of cases in the iterator where the existing counter wasn't
updated.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11284

Test Plan: `make check`

Reviewed By: jowlyzhang

Differential Revision: D43926082

Pulled By: ltamasi

fbshipit-source-id: 321566d8b4cf0a3b6c9b73b7a5c984fb9bb492e9
2023-03-08 18:22:11 -08:00
Levi Tamasi 3c9eed688e Enable moving a string or PinnableSlice into PinnableWideColumns (#11248)
Summary:
This makes it possible to eliminate some copies in `GetEntity` / `MultiGetEntity`,
in particular when `Merge`s or blobs are involved.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11248

Test Plan: `make check`

Reviewed By: akankshamahajan15

Differential Revision: D43544215

Pulled By: ltamasi

fbshipit-source-id: bc4c8955a24bbd8bc4ab098e72133ead757f9707
2023-02-24 10:33:00 -08:00
Levi Tamasi 9794acb597 Add a new MultiGetEntity API (#11222)
Summary:
The new `MultiGetEntity` API can be used to get a consistent view of
a batch of keys, with the results presented as wide-column entities.
Similarly to `GetEntity` and the iterator's `columns` API, if the entry
corresponding to the key is a wide-column entity to start with, it is
returned as-is, and if it is a plain key-value, it is wrapped into an entity
with a single default column.

Implementation-wise, the new API shares the logic of the batched `MultiGet`
API (via the `MultiGetCommon` methods). Both single-CF and multi-CF
`MultiGetEntity` APIs are provided, and blobs are also supported.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11222

Test Plan: `make check`

Reviewed By: akankshamahajan15

Differential Revision: D43256950

Pulled By: ltamasi

fbshipit-source-id: 47fb2cb7e2d0470e3580f43fdb2fe9e51f0e7005
2023-02-15 09:34:17 -08:00
sdong 4720ba4391 Remove RocksDB LITE (#11147)
Summary:
We haven't been actively mantaining RocksDB LITE recently and the size must have been gone up significantly. We are removing the support.

Most of changes were done through following comments:

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

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

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

Test Plan: See CI

Reviewed By: pdillinger

Differential Revision: D42796341

fbshipit-source-id: 4920e15fc2060c2cd2221330a6d0e5e65d4b7fe2
2023-01-27 13:14:19 -08:00
Andrew Kryczka b44cbbf709 Fix GetMergeOperands() returning MergeInProgress (#11136)
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/11136

Test Plan: the provided unit test used to fail due to `GetMergeOperands()` returning `Status::MergeInProgress()`; it passes now because the `GetMergeOperands()` call returns `Status::OK()`

Reviewed By: pdillinger

Differential Revision: D42759198

Pulled By: ajkr

fbshipit-source-id: 878f9f40ccc1d7e2fe7b1352814bae3a49c19939
2023-01-26 15:11:19 -08:00
Andrew Kryczka b7fbcefda8 Add API to limit blast radius of merge operator failure (#11092)
Summary:
Prior to this PR, `FullMergeV2()` can only return `false` to indicate failure, which causes any operation invoking it to fail. During a compaction, such a failure causes the compaction to fail and causes the DB to irreversibly enter read-only mode. Some users asked for a way to allow the merge operator to fail without such widespread damage.

To limit the blast radius of merge operator failures, this PR introduces the `MergeOperationOutput::op_failure_scope` API. When unpopulated (`kDefault`) or set to `kTryMerge`, the merge operator failure handling is the same as before. When set to `kMustMerge`, merge operator failure still causes failure to operations that must merge (`Get()`, iterator, `MultiGet()`, etc.). However, under `kMustMerge`, flushes/compactions can survive merge operator failures by outputting the unmerged input operands.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11092

Reviewed By: siying

Differential Revision: D42525673

Pulled By: ajkr

fbshipit-source-id: 951dc3bf190f86347dccf3381be967565cda52ee
2023-01-20 14:40:30 -08:00
Levi Tamasi 2ea109521f Revisit the interface of MergeHelper::TimedFullMerge(WithEntity) (#10932)
Summary:
The patch refines/reworks `MergeHelper::TimedFullMerge(WithEntity)`
a bit in two ways. First, it eliminates the recently introduced `TimedFullMerge`
overload, which makes the responsibilities clearer by making sure the query
result (`value` for `Get`, `columns` for `GetEntity`) is set uniformly in
`SaveValue` and `GetContext`. Second, it changes the interface of
`TimedFullMergeWithEntity` so it exposes its result in a serialized form; this
is a more decoupled design which will come in handy when adding support
for `Merge` with wide-column entities to `DBIter`.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10932

Test Plan: `make check`

Reviewed By: akankshamahajan15

Differential Revision: D41129399

Pulled By: ltamasi

fbshipit-source-id: 69d8da358c77d4fc7e8c40f4dafc2c129a710677
2022-11-09 12:54:05 -08:00
Levi Tamasi fbd9077d66 Fix a bug where GetContext does not update READ_NUM_MERGE_OPERANDS (#10925)
Summary:
The patch fixes a bug where `GetContext::Merge` (and `MergeEntity`) does not update the ticker `READ_NUM_MERGE_OPERANDS` because it implicitly uses the default parameter value of `update_num_ops_stats=false` when calling `MergeHelper::TimedFullMerge`. Also, to prevent such issues going forward, the PR removes the default parameter values from the `TimedFullMerge` methods. In addition, it removes an unused/unnecessary parameter from `TimedFullMergeWithEntity`, and does some cleanup at the call sites of these methods.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10925

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D41096453

Pulled By: ltamasi

fbshipit-source-id: fc60646d32b4d516b8fe81e265c3f020a32fd7f8
2022-11-07 15:42:10 -08:00
Levi Tamasi 941d834739 Support Merge for wide-column entities during point lookups (#10916)
Summary:
The patch adds `Merge` support for wide-column entities to the point lookup
APIs, i.e. `Get`, `MultiGet`, `GetEntity`, and `GetMergeOperands`. (I plan to
update the iterator and compaction logic in separate PRs.) In terms of semantics,
the `Merge` operation is applied to the default (anonymous) column; any other
columns in the entity are unaffected.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10916

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D40962311

Pulled By: ltamasi

fbshipit-source-id: 244bc9d172be1af2f204796b2f89104e4d2fa373
2022-11-03 08:35:42 -07:00
Andrew Kryczka 5cf6ab6f31 Ran clang-format on db/ directory (#10910)
Summary:
Ran `find ./db/ -type f | xargs clang-format -i`. Excluded minor changes it tried to make on db/db_impl/. Everything else it changed was directly under db/ directory. Included minor manual touchups mentioned in PR commit history.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10910

Reviewed By: riversand963

Differential Revision: D40880683

Pulled By: ajkr

fbshipit-source-id: cfe26cda05b3fb9a72e3cb82c286e21d8c5c4174
2022-11-02 14:34:24 -07:00
Yanqin Jin 7d26e4c5a3 Basic Support for Merge with user-defined timestamp (#10819)
Summary:
This PR implements the originally disabled `Merge()` APIs when user-defined timestamp is enabled.

Simplest usage:
```cpp
// assume string append merge op is used with '.' as delimiter.
// ts1 < ts2
db->Put(WriteOptions(), "key", ts1, "v0");
db->Merge(WriteOptions(), "key", ts2, "1");
ReadOptions ro;
ro.timestamp = &ts2;
db->Get(ro, "key", &value);
ASSERT_EQ("v0.1", value);
```

Some code comments are added for clarity.

Note: support for timestamp in `DB::GetMergeOperands()` will be done in a follow-up PR.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10819

Test Plan: make check

Reviewed By: ltamasi

Differential Revision: D40603195

Pulled By: riversand963

fbshipit-source-id: f96d6f183258f3392d80377025529f7660503013
2022-10-31 22:28:58 -07:00
Yanqin Jin 9079895aae Fix deletion counting in memtable stats (#10886)
Summary:
Currently, a memtable's stats `num_deletes_` is incremented only if the entry is a regular delete (kTypeDeletion). We need to fix it by accounting for kTypeSingleDeletion and kTypeDeletionWithTimestamp.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10886

Test Plan: make check

Reviewed By: ltamasi

Differential Revision: D40740754

Pulled By: riversand963

fbshipit-source-id: 7bde62cd6df136585bc5bfb1c426c7a8276c08e1
2022-10-28 17:03:44 -07:00
Levi Tamasi 7867a1112b Handle Merges correctly in GetEntity (#10894)
Summary:
The PR fixes the handling of `Merge`s in `GetEntity`. Note that `Merge` is not yet
supported for wide-column entities written using `PutEntity`; this change is
about returning correct (i.e. consistent with `Get`) results in cases like when the
base value is a plain old key-value written using `Put` or when there is no real base
value because we hit either a tombstone or the beginning of history.

Implementation-wise, the patch introduces a new wrapper around the existing
`MergeHelper::TimedFullMerge` that can store the merge result in either a string
(for the purposes of `Get`) or a `PinnableWideColumns` instance (for `GetEntity`).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10894

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D40782708

Pulled By: ltamasi

fbshipit-source-id: 3d700d56b2ef81f02ba1e2d93f6481bf13abcc90
2022-10-28 10:48:51 -07:00
Changyu Bi 7a95938899 Improve FragmentTombstones() speed by lazily initializing seq_set_ (#10848)
Summary:
FragmentedRangeTombstoneList has a member variable `seq_set_` that contains the sequence numbers of all range tombstones in a set. The set is constructed in `FragmentTombstones()` and is used only in `FragmentedRangeTombstoneList::ContainsRange()` which only happens during compaction. This PR moves the initialization of `seq_set_` to `FragmentedRangeTombstoneList::ContainsRange()`. This should speed up `FragmentTombstones()` when the range tombstone list is used for read/scan requests. Microbench shows the speed improvement to be ~45%.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10848

Test Plan:
- Existing tests and stress test: `python3 tools/db_crashtest.py whitebox --simple  --verify_iterator_with_expected_state_one_in=5`.
- Microbench: update `range_del_aggregator_bench` to benchmark speed of `FragmentTombstones()`:
```
./range_del_aggregator_bench --num_range_tombstones=1000 --tombstone_start_upper_bound=50000000 --num_runs=10000 --tombstone_width_mean=200 --should_deletes_per_run=100 --use_compaction_range_del_aggregator=true

Before this PR:
=========================
Fragment Tombstones:     270.286 us
AddTombstones:           1.28933 us
ShouldDelete (first):    0.525528 us
ShouldDelete (rest):     0.0797519 us

After this PR: time to fragment tombstones is pushed to AddTombstones() which only happen during compaction.
=========================
Fragment Tombstones:     149.879 us
AddTombstones:           102.131 us
ShouldDelete (first):    0.565871 us
ShouldDelete (rest):     0.0729444 us
```
- db_bench: this should improve speed for fragmenting range tombstones for mutable memtable:
```
./db_bench --benchmarks=readwhilewriting --writes_per_range_tombstone=100 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=500000 --reads=250000 --disable_auto_compactions --max_num_range_tombstones=100000 --finish_after_writes --write_buffer_size=1073741824 --threads=25

Before this PR:
readwhilewriting :      18.301 micros/op 1310445 ops/sec 4.769 seconds 6250000 operations;   28.1 MB/s (41001 of 250000 found)
After this PR:
readwhilewriting :      16.943 micros/op 1439376 ops/sec 4.342 seconds 6250000 operations;   23.8 MB/s (28977 of 250000 found)
```

Reviewed By: ajkr

Differential Revision: D40646227

Pulled By: cbi42

fbshipit-source-id: ea471667edb258f67d01cfd828588e80a89e4083
2022-10-25 11:33:04 -07:00
Levi Tamasi 8dd4bf6cff Separate the handling of value types in SaveValue (#10840)
Summary:
Currently, the code in `SaveValue` that handles `kTypeValue` and
`kTypeBlobIndex` (and more recently, `kTypeWideColumnEntity`) is
mostly shared. This made sense originally; however, by now the
handling of these three value types has diverged significantly. The
patch makes the logic cleaner and also eliminates quite a bit of branching
by giving each value type its own `case` and removing a fall-through.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10840

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D40568420

Pulled By: ltamasi

fbshipit-source-id: 2e614606afd1c3d9c76d9b5f1efa0959fc174103
2022-10-21 10:05:46 -07:00
Peter Dillinger 8367f0d2d7 Improve / refactor anonymous mmap capabilities (#10810)
Summary:
The motivation for this change is a planned feature (related to HyperClockCache) that will depend on a large array that can essentially grow automatically, up to some bound, without the pointer address changing and with guaranteed zero-initialization of the data. Anonymous mmaps provide such functionality, and this change provides an internal API for that.

The other existing use of anonymous mmap in RocksDB is for allocating in huge pages. That code and other related Arena code used some awkward non-RAII and pre-C++11 idioms, so I cleaned up much of that as well, with RAII, move semantics, constexpr, etc.

More specifcs:
* Minimize conditional compilation
* Add Windows support for anonymous mmaps
* Use std::deque instead of std::vector for more efficient bag

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10810

Test Plan: unit test added for new functionality

Reviewed By: riversand963

Differential Revision: D40347204

Pulled By: pdillinger

fbshipit-source-id: ca83fcc47e50fabf7595069380edd2954f4f879c
2022-10-17 17:10:16 -07:00
Changyu Bi 9f2363f4c4 User-defined timestamp support for DeleteRange() (#10661)
Summary:
Add user-defined timestamp support for range deletion. The new API is `DeleteRange(opt, cf, begin_key, end_key, ts)`. Most of the change is to update the comparator to compare without timestamp. Other than that, major changes are
- internal range tombstone data structures (`FragmentedRangeTombstoneList`, `RangeTombstone`, etc.) to store timestamps.
- Garbage collection of range tombstones and range tombstone covered keys during compaction.
- Get()/MultiGet() to return the timestamp of a range tombstone when needed.
- Get/Iterator with range tombstones bounded by readoptions.timestamp.
- timestamp crash test now issues DeleteRange by default.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10661

Test Plan:
- Added unit test: `make check`
- Stress test: `python3 tools/db_crashtest.py --enable_ts whitebox --readpercent=57 --prefixpercent=4 --writepercent=25 -delpercent=5 --iterpercent=5 --delrangepercent=4`
- Ran `db_bench` to measure regression when timestamp is not enabled. The tests are for write (with some range deletion) and iterate with DB fitting in memory: `./db_bench--benchmarks=fillrandom,seekrandom --writes_per_range_tombstone=200 --max_write_buffer_number=100 --min_write_buffer_number_to_merge=100 --writes=500000 --reads=500000 --seek_nexts=10 --disable_auto_compactions -disable_wal=true --max_num_range_tombstones=1000`.  Did not see consistent regression in no timestamp case.

| micros/op | fillrandom | seekrandom |
| --- | --- | --- |
|main| 2.58 |10.96|
|PR 10661| 2.68 |10.63|

Reviewed By: riversand963

Differential Revision: D39441192

Pulled By: cbi42

fbshipit-source-id: f05aca3c41605caf110daf0ff405919f300ddec2
2022-09-30 16:13:03 -07:00
Yanqin Jin 07249fea8f Fix DBImpl::GetLatestSequenceForKey() for Merge (#10724)
Summary:
Currently, without this fix, DBImpl::GetLatestSequenceForKey() may not return the latest sequence number for merge operands of the key. This can cause conflict checking during optimistic transaction commit phase to fail. Fix it by always returning the latest sequence number of the key, also considering range tombstones.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10724

Test Plan: make check

Reviewed By: cbi42

Differential Revision: D39756847

Pulled By: riversand963

fbshipit-source-id: 0764c3dd4cb24960b37e18adccc6e7feed0e6876
2022-09-23 17:29:05 -07:00
Changyu Bi be04a3b6cd Fix data race in accessing cached_range_tombstone_ (#10680)
Summary:
fix a data race introduced in https://github.com/facebook/rocksdb/issues/10547 (P5295241720), first reported by pdillinger. The race is between the `std::atomic_load_explicit` in NewRangeTombstoneIteratorInternal and the `std::atomic_store_explicit` in MemTable::Add() that operate on `cached_range_tombstone_`. P5295241720 shows that `atomic_store_explicit` initializes some mutex which `atomic_load_explicit` could be trying to call `lock()` on at the same time. This fix moves the initialization to memtable constructor.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10680

Test Plan: `USE_CLANG=1 COMPILE_WITH_TSAN=1 make -j24 whitebox_crash_test`

Reviewed By: ajkr

Differential Revision: D39528696

Pulled By: cbi42

fbshipit-source-id: ee740841044438e18ad2b8ea567444dd542dd8e2
2022-09-14 20:50:10 -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
Levi Tamasi 81388b36e0 Add support for wide-column point lookups (#10540)
Summary:
The patch adds a new API `GetEntity` that can be used to perform
wide-column point lookups. It also extends the `Get` code path and
the `MemTable` / `MemTableList` and `Version` / `GetContext` logic
accordingly so that wide-column entities can be served from both
memtables and SSTs. If the result of a lookup is a wide-column entity
(`kTypeWideColumnEntity`), it is passed to the application in deserialized
form; if it is a plain old key-value (`kTypeValue`), it is presented as a
wide-column entity with a single default (anonymous) column.
(In contrast, regular `Get` returns plain old key-values as-is, and
returns the value of the default column for wide-column entities, see
https://github.com/facebook/rocksdb/issues/10483 .)

The result of `GetEntity` is a self-contained `PinnableWideColumns` object.
`PinnableWideColumns` contains a `PinnableSlice`, which either stores the
underlying data in its own buffer or holds on to a cache handle. It also contains
a `WideColumns` instance, which indexes the contents of the `PinnableSlice`,
so applications can access the values of columns efficiently.

There are several pieces of functionality which are currently not supported
for wide-column entities: there is currently no `MultiGetEntity` or wide-column
iterator; also, `Merge` and `GetMergeOperands` are not supported, and there
is no `GetEntity` implementation for read-only and secondary instances.
We plan to implement these in future PRs.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10540

Test Plan: `make check`

Reviewed By: akankshamahajan15

Differential Revision: D38847474

Pulled By: ltamasi

fbshipit-source-id: 42311a34ccdfe88b3775e847a5e2a5296e002b5b
2022-08-19 11:51:12 -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
Levi Tamasi 24bcab7d5d Make queries return the value of the default column for wide-column entities (#10483)
Summary:
The patch adds support for wide-column entities to the existing query
APIs (`Get`, `MultiGet`, and iterator). Namely, when during a query a
wide-column entity is encountered, we will return the value of the default
(anonymous) column as the result. Later, we plan to add wide-column
specific query APIs which will enable retrieving entire wide-column entities
or a subset of their columns.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10483

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D38441881

Pulled By: ltamasi

fbshipit-source-id: 6444e79a31aff2470e866698e3a97985bc2b3543
2022-08-08 16:10:08 -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
Levi Tamasi 0d1e0722ef Fix in-place updates for value types other than kTypeValue (#10254)
Summary:
The patch fixes a couple of issues related to in-place updates: 1) the value type was not passed from
`MemTableInserter::PutCFImpl` to `MemTable::Update` and 2) `MemTable::UpdateCallback` was called
for any value type (with the callee's logic assuming `kTypeValue`) even though the callback mechanism
is only safe for plain values.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10254

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D37463644

Pulled By: ltamasi

fbshipit-source-id: 33802477dac0691681f416ae84c4d9742c6fe41a
2022-06-27 16:37:09 -07:00
Levi Tamasi c73d2a9d18 Add API for writing wide-column entities (#10242)
Summary:
The patch builds on https://github.com/facebook/rocksdb/pull/9915 and adds
a new API called `PutEntity` that can be used to write a wide-column entity
to the database. The new API is added to both `DB` and `WriteBatch`. Note
that currently there is no way to retrieve these entities; more precisely, all
read APIs (`Get`, `MultiGet`, and iterator) return `NotSupported` when they
encounter a wide-column entity that is required to answer a query. Read-side
support (as well as other missing functionality like `Merge`, compaction filter,
and timestamp support) will be added in later PRs.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10242

Test Plan: `make check`

Reviewed By: riversand963

Differential Revision: D37369748

Pulled By: ltamasi

fbshipit-source-id: 7f5e412359ed7a400fd80b897dae5599dbcd685d
2022-06-25 15:30:47 -07:00
Peter Dillinger f81ea75df7 Don't count no prefix as Bloom hit (#10244)
Summary:
When a key is "out of domain" for the prefix_extractor (no
prefix assigned) then the Bloom filter is not queried. PerfContext
was counting this as a Bloom "hit" while Statistics doesn't count this
as a prefix Bloom checked. I think it's more accurate to call it neither
hit nor miss, so changing the counting to make it PerfContext coounting
more like Statistics.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10244

Test Plan:
tests updates and expanded (Get and MultiGet). Iterator test
coverage of the change will come in next PR

Reviewed By: bjlemaire

Differential Revision: D37371297

Pulled By: pdillinger

fbshipit-source-id: fed132fba6a92b2314ab898d449fce2d1586c157
2022-06-23 11:00:27 -07:00
Andrew Kryczka 5d6005c780 Add WriteOptions::protection_bytes_per_key (#10037)
Summary:
Added an option, `WriteOptions::protection_bytes_per_key`, that controls how many bytes per key we use for integrity protection in `WriteBatch`. It takes effect when `WriteBatch::GetProtectionBytesPerKey() == 0`.

Currently the only supported value is eight. Invoking a user API with it set to any other nonzero value will result in `Status::NotSupported` returned to the user.

There is also a bug fix for integrity protection with `inplace_callback`, where we forgot to take into account the possible change in varint length when calculating KV checksum for the final encoded buffer.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10037

Test Plan:
- Manual
  - Set default value of `WriteOptions::protection_bytes_per_key` to eight and ran `make check -j24`
  - Enabled in MyShadow for 1+ week
- Automated
  - Unit tests have a `WriteMode` that enables the integrity protection via `WriteOptions`
  - Crash test - in most cases, use `WriteOptions::protection_bytes_per_key` to enable integrity protection

Reviewed By: cbi42

Differential Revision: D36614569

Pulled By: ajkr

fbshipit-source-id: 8650087ceac9b61b560f1e5fafe5e1baf9c725fb
2022-06-16 23:10:07 -07:00
Yanqin Jin 3e02c6e05a Point-lookup returns timestamps of Delete and SingleDelete (#10056)
Summary:
If caller specifies a non-null `timestamp` argument in `DB::Get()` or a non-null `timestamps` in `DB::MultiGet()`,
RocksDB will return the timestamps of the point tombstones.

Note: DeleteRange is still unsupported.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/10056

Test Plan: make check

Reviewed By: ltamasi

Differential Revision: D36677956

Pulled By: riversand963

fbshipit-source-id: 2d7af02cc7237b1829cd269086ea895a49d501ae
2022-06-03 20:00:42 -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
Peter Dillinger ea89c77f27 Fix major bug with MultiGet, DeleteRange, and memtable Bloom (#9453)
Summary:
MemTable::MultiGet was not considering range tombstones before
querying Bloom filter. This means range tombstones would be skipped for
keys (or prefixes) with no other entries in the memtable. This could cause
old values for a key (in SST files) to still show up until the range tombstone
covering it has been flushed.

This is fixed by essentially disabling the memtable Bloom filter when there
are any range tombstones. (This could be better optimized in the future, but
good enough for now.)

Did some other cleanup/optimization in the same code to (more than) offset
the cost of checking on range tombstones in more cases. There is now
notable improvement when memtable_whole_key_filtering and prefix_extractor
are used together (unusual), and this makes MultiGet closer to the Get
implementation.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9453

Test Plan:
new unit test added. Added memtable Bloom to crash test.

Performance testing
--------------------

Build WAL-only DB (recovers to memtable):
```
TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -benchmarks=fillrandom -num=1000000 -write_buffer_size=250000000
```

Query test command, to maximize sensitivity to the changed code:
```
TEST_TMPDIR=/dev/shm/rocksdb ./db_bench -use_existing_db -readonly -benchmarks=multireadrandom -num=10000000 -write_buffer_size=250000000 -memtable_bloom_size_ratio=0.015 -multiread_batched -batch_size=24 -threads=8 -memtable_whole_key_filtering=$MWKF -prefix_size=$PXS
```
(Note -num here is 10x larger for mostly memtable misses)

Before & after run simultaneously, average over 10 iterations per data point, ops/sec.

MWKF=0 PXS=0 (Bloom disabled)
Before: 5724844
After: 6722066

MWKF=0 PXS=7 (prefixes hardly unique; Bloom not useful)
Before: 9981319
After: 10237990

MWKF=0 PXS=8 (prefixes unique; Bloom useful)
Before:  12081715
After: 12117603

MWKF=1 PXS=0 (whole key Bloom useful)
Before: 11944354
After: 12096085

MWKF=1 PXS=7 (whole key Bloom useful in new version; prefixes not useful in old version)
Before: 9444299
After: 11826029

MWKF=1 PXS=7 (whole key Bloom useful in new version; prefixes useful in old version)
Before: 11784465
After: 11778591

Only in this last case is the 'before' *slightly* faster, perhaps because hashing prefixes is slightly faster than hashing whole keys. Otherwise, 'after' is faster.

Reviewed By: ajkr

Differential Revision: D33805025

Pulled By: pdillinger

fbshipit-source-id: 597523cae4f4eafdf6ae6bb2bc6cb46f83b017bf
2022-01-27 14:55:04 -08:00
mrambacher 13ae16c315 Cleanup includes in dbformat.h (#8930)
Summary:
This header file was including everything and the kitchen sink when it did not need to.  This resulted in many places including this header when they needed other pieces instead.

Cleaned up this header to only include what was needed and fixed up the remaining code to include what was now missing.

Hopefully, this sort of code hygiene cleanup will speed up the builds...

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8930

Reviewed By: pdillinger

Differential Revision: D31142788

Pulled By: mrambacher

fbshipit-source-id: 6b45de3f300750c79f751f6227dece9cfd44085d
2021-09-29 04:04:40 -07:00
Andrew Kryczka d648cb47b9 Adapt key-value checksum for timestamp-suffixed keys (#8914)
Summary:
After https://github.com/facebook/rocksdb/issues/8725, keys added to `WriteBatch` may be timestamp-suffixed, while `WriteBatch` has no awareness of the timestamp size. Therefore, `WriteBatch` can no longer calculate timestamp checksum separately from the rest of the key's checksum in all cases.

This PR changes the definition of key in KV checksum to include the timestamp suffix. That way we do not need to worry about where the timestamp begins within the key. I believe the only practical effect of this change is now `AssignTimestamp()` requires recomputing the whole key checksum (`UpdateK()`) rather than just the timestamp portion (`UpdateT()`).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8914

Test Plan:
run stress command that used to fail

```
$ ./db_stress --batch_protection_bytes_per_key=8 -clear_column_family_one_in=0 -test_batches_snapshots=1
```

Reviewed By: riversand963

Differential Revision: D30925715

Pulled By: ajkr

fbshipit-source-id: c143f7ccb46c0efb390ad57ef415c250d754deff
2021-09-14 13:14:39 -07:00
Baptiste Lemaire c521a9ab2b Retire superfluous functions introduced in earlier mempurge PRs. (#8558)
Summary:
The main challenge to make the memtable garbage collection prototype (nicknamed `mempurge`) was to not get rid of WAL files that contain unflushed (but mempurged) data. That was successfully guaranteed by not writing the VersionEdit to the MANIFEST file after a successful mempurge.
By not writing VersionEdits to the `MANIFEST` file after a succesful mempurge operation, we do not change the earliest log file number that contains unflushed data: `cfd->GetLogNumber()` (`cfd->SetLogNumber()` is only called in `VersionSet::ProcessManifestWrites`). As a result, a number of functions introduced earlier just for the mempurge operation are not obscolete/redundant. (e.g.: `FlushJob::ExtractEarliestLogFileNumber`), and this PR aims at cleaning up all these now-unnecessary functions. In particular, we no longer need to store the earliest log file number in the `MemTable` struct itself. This PR therefore also reverts the `MemTable` struct to its original form.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8558

Test Plan: Already included in `db_flush_test.cc`.

Reviewed By: anand1976

Differential Revision: D29764351

Pulled By: bjlemaire

fbshipit-source-id: 0f43b260fa270251862512f397d3f24ee62e8437
2021-07-22 18:29:13 -07:00
Baptiste Lemaire 206845c057 Mempurge support for wal (#8528)
Summary:
In this PR, `mempurge` is made compatible with the Write Ahead Log: in case of recovery, the DB is now capable of recovering the data that was "mempurged" and kept in the `imm()` list of immutable memtables.
The twist was to add a uint64_t to the `memtable` struct to store the number of the earliest log file containing entries from the `memtable`. When a `Flush` operation is replaced with a `MemPurge`, the `VersionEdit` (which usually contains the new min log file number to pick up for recovery and the level 0 file path of the newly created SST file) is no longer appended to the manifest log, and every time the `deleteWal` method is called, a check is made on the list of immutable memtables.
This PR also includes a unit test that verifies that no data is lost upon Reopening of the database when the mempurge feature is activated. This extensive unit test includes two column families, with valid data contained in the imm() at time of "crash"/reopening (recovery).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8528

Reviewed By: pdillinger

Differential Revision: D29701097

Pulled By: bjlemaire

fbshipit-source-id: 072a900fb6ccc1edcf5eef6caf88f3060238edf9
2021-07-15 17:49:13 -07:00
mrambacher 8948dc8524 Make ImmutableOptions struct that inherits from ImmutableCFOptions and ImmutableDBOptions (#8262)
Summary:
The ImmutableCFOptions contained a bunch of fields that belonged to the ImmutableDBOptions.  This change cleans that up by introducing an ImmutableOptions struct.  Following the pattern of Options struct, this class inherits from the DB and CFOption structs (of the Immutable form).

Only one structural change (the ImmutableCFOptions::fs was changed to a shared_ptr from a raw one) is in this PR.  All of the other changes involve moving the member variables from the ImmutableCFOptions into the ImmutableOptions and changing member variables or function parameters as required for compilation purposes.

Follow-on PRs may do a further clean-up of the code, such as renaming variables (such as "ImmutableOptions cf_options") and potentially eliminating un-needed function parameters (there is no longer a need to pass both an ImmutableDBOptions and an ImmutableOptions to a function).

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8262

Reviewed By: pdillinger

Differential Revision: D28226540

Pulled By: mrambacher

fbshipit-source-id: 18ae71eadc879dedbe38b1eb8e6f9ff5c7147dbf
2021-05-05 14:00:17 -07:00
mrambacher 0ca6d6297f Rename variables in ImmutableCFOptions to avoid conflicts with ImmutableDBOptions (#8227)
Summary:
Renaming ImmutableCFOptions::info_log and statistics to logger and stats.  This is stage 2 in creating an ImmutableOptions class.  It is necessary because the names match those in ImmutableOptions and have different types.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8227

Reviewed By: jay-zhuang

Differential Revision: D28000967

Pulled By: mrambacher

fbshipit-source-id: 3bf2aa04e8f1e8724d825b7deacf41080c14420b
2021-04-26 12:43:45 -07:00