Summary:
With some new use cases onboarding to prefix extractors/seek/filters, one of the risks is existing iterator code, e.g. for maintenance tasks, being unintentionally subject to prefix seek semantics. This is a longstanding known design flaw with prefix seek, and `prefix_same_as_start` and `auto_prefix_mode` were steps in the direction of making that obsolete. However, we can't just immediately set `total_order_seek` to true by default, because that would impact so much code instantly.
Here we add a new DB option, `prefix_seek_opt_in_only` that basically allows users to transition to the future behavior when they are ready. When set to true, all iterators will be treated as if `total_order_seek=true` and then the only ways to get prefix seek semantics are with `prefix_same_as_start` or `auto_prefix_mode`.
Related fixes / changes:
* Make sure that `prefix_same_as_start` and `auto_prefix_mode` are compatible with (or override) `total_order_seek` (depending on your interpretation).
* Fix a bug in which a new iterator after dynamically changing the prefix extractor might mix different prefix semantics between memtable and SSTs. Both should use the latest extractor semantics, which means iterators ignoring memtable prefix filters with an old extractor. And that means passing the latest prefix extractor to new memtable iterators that might use prefix seek. (Without the fix, the test added for this fails in many ways.)
Suggested follow-up:
* Investigate a FIXME where a MergeIteratorBuilder is created in db_impl.cc. No unit test detects a change in value that should impact correctness.
* Make memtable prefix bloom compatible with `auto_prefix_mode`, which might require involving the memtablereps because we don't know at iterator creation time (only seek time) whether an auto_prefix_mode seek will be a prefix seek.
* Add `prefix_same_as_start` testing to db_stress
Pull Request resolved: https://github.com/facebook/rocksdb/pull/13026
Test Plan:
tests updated, added. Add combination of `total_order_seek=true` and `auto_prefix_mode=true` to stress test. Ran `make blackbox_crash_test` for a long while.
Manually ran tests with `prefix_seek_opt_in_only=true` as default, looking for unexpected issues. I inspected most of the results and migrated many tests to be ready for such a change (but not all).
Reviewed By: ltamasi
Differential Revision: D63147378
Pulled By: pdillinger
fbshipit-source-id: 1f4477b730683d43b4be7e933338583702d3c25e
Summary:
We have a request to use the cold tier as primary source of truth for the DB, and to best support such use cases and to complement the existing options controlling SST file temperatures, we add two new DB options:
* `metadata_write_temperature` for DB "small" files that don't contain much user data
* `wal_write_temperature` for WALs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12957
Test Plan: Unit test included, though it's hard to be sure we've covered all the places
Reviewed By: jowlyzhang
Differential Revision: D61664815
Pulled By: pdillinger
fbshipit-source-id: 8e19c9dd8fd2db059bb15f74938d6bc12002e82b
Summary:
These names are confusing with `Logger` etc. so moving to `WalFile` etc.
Other small, related name refactorings.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12695
Test Plan: Left most unit tests using old names as an API compatibility test. Non-test code compiles with deprecated names removed. No functional changes.
Reviewed By: ajkr
Differential Revision: D57747458
Pulled By: pdillinger
fbshipit-source-id: 7b77596b9c20d865d43b9dc66c30c8bd2b3b424f
Summary:
Thanks ltamasi for pointing out this bug.
We were incorrectly overwriting `Status::Incomplete` with `Status::OK` after a table cache miss failed to open the file due to the read being memory-only (`kBlockCacheTier`). The fix is to simply stop overwriting the status.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12443
Reviewed By: cbi42
Differential Revision: D54930128
Pulled By: ajkr
fbshipit-source-id: 52f912a2e93b46e71d79fc5968f8ca35b299213d
Summary:
Currently SST files that aren't applicable to last_level_temperature nor file_temperature_age_thresholds are written with temperature kUnknown, which is a little weird and doesn't support CF-based tiering. The default_temperature option only affects how kUnknown is interpreted for stats.
This change adds a new per-CF option default_write_temperature that determines the temperature of new SST files when those other options do not apply.
Also made a change to ignore last_level_temperature with FIFO compaction, because I found that could lead to an infinite loop in compaction.
Needed follow-up: Fix temperature handling with external file ingestion
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12388
Test Plan: unit tests extended appropriately. (Ignore whitespace changes when reviewing.)
Reviewed By: jowlyzhang
Differential Revision: D54266574
Pulled By: pdillinger
fbshipit-source-id: c9ec9a74dbf22be6e986f77f9689d05fea8ef0bb
Summary:
There is no strong reason for user to need this mode while on the other hand, its behavior is destructive.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12337
Reviewed By: hx235
Differential Revision: D53630393
Pulled By: jowlyzhang
fbshipit-source-id: ce94b537258102cd98f89aa4090025663664dd78
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
Summary:
**Context/Summary:**
We recently found out some code paths in flush and compaction aren't rate-limited when they should.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12290
Test Plan: existing UT**
Reviewed By: anand1976
Differential Revision: D53066103
Pulled By: hx235
fbshipit-source-id: 9dc4cab5f841230d18e5504dc480ac523e9d3950
Summary:
This PR significantly reduces the compaction pressure threshold introduced in https://github.com/facebook/rocksdb/issues/12130 by a factor of 64x. The original number was too high to trigger in scenarios where compaction parallelism was needed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12236
Reviewed By: cbi42
Differential Revision: D52765685
Pulled By: ajkr
fbshipit-source-id: 8298e966933b485de24f63165a00e672cb9db6c4
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
Summary:
Disabling file deletion can be critical for operations like making a backup, recovery from manifest IO error (for now). Ideally as long as there is one caller requesting file deletion disabled, it should be kept disabled until all callers agree to re-enable it. So this PR removes the default forcing behavior for the `EnableFileDeletion` API, and users need to explicitly pass the argument if they insisted on doing so knowing the consequence of what can be potentially disrupted.
This PR removes the API's default argument value so it will cause breakage for all users that are relying on the default value, regardless of whether the forcing behavior is critical for them. When fixing this breakage, it's good to check if the forcing behavior is indeed needed and potential disruption is OK.
This PR also makes unit test that do not need force behavior to do a regular enable file deletion.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12001
Reviewed By: ajkr
Differential Revision: D51214683
Pulled By: jowlyzhang
fbshipit-source-id: ca7b1ebf15c09eed00f954da2f75c00d2c6a97e4
Summary:
... when compiled with ASSERT_STATUS_CHECKED = 1.
The main change is in iterator_wrapper.h. The remaining changes are just fixing existing unit tests. Adding this check to IteratorWrapper gives a good coverage as the class is used in many places, including child iterators under merging iterator, merging iterator under DB iter, file_iter under level iterator, etc. This change can catch the bug fixed in https://github.com/facebook/rocksdb/issues/11782.
Future follow up: enable `ASSERT_STATUS_CHECKED=1` for stress test and for DEBUG_LEVEL=0.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11975
Test Plan:
* `ASSERT_STATUS_CHECKED=1 DEBUG_LEVEL=2 make -j32 J=32 check`
* I tried to run stress test with `ASSERT_STATUS_CHECKED=1`, but there are a lot of existing stress code that ignore status checking, and fail without the change in this PR. So defer that to a follow up task.
Reviewed By: ajkr
Differential Revision: D50383790
Pulled By: cbi42
fbshipit-source-id: 1a28ce0f5fdf1890f93400b26b3b1b3a287624ce
Summary:
This piggy back the existing last level file temperature statistics test to test the default temperature becoming effective.
While adding this unit test, I found that the approach to swap out and use default temperature in `VersionBuilder::LoadTableHandlers` will miss the L0 files created from flush, and only work for existing SST files, SST files created by compaction. So this PR moves that logic to `TableCache::GetTableReader`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11722
Test Plan:
```
./db_test2 --gtest_filter="*LastLevelStatistics*"
make all check
```
Reviewed By: pdillinger
Differential Revision: D48489171
Pulled By: jowlyzhang
fbshipit-source-id: ac29f7d484916f3218729594c5bb35c4f2979ac2
Summary:
It seems the flag `-fno-elide-constructors` is incorrectly overwritten in Makefile by 9c2ebcc2c3/Makefile (L243)
Applying the change in PR https://github.com/facebook/rocksdb/issues/11675 shows a lot of missing status checks. This PR adds the missing status checks.
Most of changes are just adding asserts in unit tests. I'll add pr comment around more interesting changes that need review.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11686
Test Plan: change Makefile as in https://github.com/facebook/rocksdb/issues/11675, and run `ASSERT_STATUS_CHECKED=1 TEST_UINT128_COMPAT=1 ROCKSDB_MODIFY_NPHASH=1 LIB_MODE=static OPT="-DROCKSDB_NAMESPACE=alternative_rocksdb_ns" make V=1 -j24 J=24 check`
Reviewed By: hx235
Differential Revision: D48176132
Pulled By: cbi42
fbshipit-source-id: 6758946cfb1c6ff84c4c1e0ca540d05e6fc390bd
Summary:
currently for leveled compaction, the max output level of a call to `CompactRange()` is pre-computed before compacting each level. This max output level is the max level whose key range overlaps with the manual compaction key range. However, during manual compaction, files in the max output level may be compacted down further by some background compaction. When this background compaction is a trivial move, there is a race condition and the manual compaction may not be able to compact all keys in the specified key range. This PR updates `CompactRange()` to always compact to the bottommost level to make this race condition more unlikely (it can still happen, see more in comment here: 796f58f42a/db/db_impl/db_impl_compaction_flush.cc (L1180C29-L1184)).
This PR also changes the behavior of CompactRange() when `bottommost_level_compaction=kIfHaveCompactionFilter` (the default option). The old behavior is that, if a compaction filter is provided, CompactRange() always does an intra-level compaction at the final output level for all files in the manual compaction key range. The only exception when `first_overlapped_level = 0` and `max_overlapped_level = 0`. It’s awkward to maintain the same behavior after this PR since we do not compute max_overlapped_level anymore. So the new behavior is similar to kForceOptimized: always does intra-level compaction at the bottommost level, but not including new files generated during this manual compaction.
Several unit tests are updated to work with this new manual compaction behavior.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11468
Test Plan: Add new unit tests `DBCompactionTest.ManualCompactionCompactAllKeysInRange*`
Reviewed By: ajkr
Differential Revision: D46079619
Pulled By: cbi42
fbshipit-source-id: 19d844ba4ec8dc1a0b8af5d2f36ff15820c6e76f
Summary:
We want to know more about opportunities for better range filters, and the effectiveness of our own range filters. Currently the stats are very limited, essentially logging just hits and misses against prefix filters for range scans in BLOOM_FILTER_PREFIX_* without tracking the false positive rate. Perhaps confusingly, when prefix filters are used for point queries, the stats are currently going into the non-PREFIX tickers.
This change does several things:
* Introduce new stat tickers for seeks and related filtering, \*LEVEL_SEEK\*
* Most importantly, allows us to see opportunities for range filtering. Specifically, we can count how many times a seek in an SST file accesses at least one data block, and how many times at least one value() is then accessed. If a data block was accessed but no value(), we can generally assume that the key(s) seen was(were) not of interest so could have been filtered with the right kind of filter, avoiding the data block access.
* We can get the same level of detail when a filter (for now, prefix Bloom/ribbon) is used, or not. Specifically, we can infer a false positive rate for prefix filters (not available before) from the seek "false positive" rate: when a data block is accessed but no value() is called. (There can be other explanations for a seek false positive, but in typical iterator usage it would indicate a filter false positive.)
* For efficiency, I wanted to avoid making additional calls to the prefix extractor (or key comparisons, etc.), which would be required if we wanted to more precisely detect filter false positives. I believe that instrumenting value() is the best balance of efficiency vs. accurately measuring what we are often interested in.
* The stats are divided between last level and non-last levels, to help understand potential tiered storage use cases.
* The old BLOOM_FILTER_PREFIX_* stats have a different meaning: no longer referring to iterators but to point queries using prefix filters. BLOOM_FILTER_PREFIX_TRUE_POSITIVE is added for computing the prefix false positive rate on point queries, which can be due to filter false positives as well as different keys with the same prefix.
* Similarly, the non-PREFIX BLOOM_FILTER stats are now for whole key filtering only.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11460
Test Plan:
unit tests updated, including updating many to pop the stat value since last read to improve test
readability and maintainability.
Performance test shows a consistent small improvement with these changes, both with clang and with gcc. CPU profile indicates that RecordTick is using less CPU, and this makes sense at least for a high filter miss rate. Before, we were recording two ticks per filter miss in iterators (CHECKED & USEFUL) and now recording just one (FILTERED).
Create DB with
```
TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num=10000000 -disable_wal=1 -write_buffer_size=30000000 -bloom_bits=8 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=8
```
And run simultaneous before&after with
```
TEST_TMPDIR=/dev/shm ./db_bench -readonly -benchmarks=seekrandom[-X1000] -num=10000000 -bloom_bits=8 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=8 -seek_nexts=1 -duration=20 -seed=43 -threads=8 -cache_size=1000000000 -statistics
```
Before: seekrandom [AVG 275 runs] : 189680 (± 222) ops/sec; 18.4 (± 0.0) MB/sec
After: seekrandom [AVG 275 runs] : 197110 (± 208) ops/sec; 19.1 (± 0.0) MB/sec
Reviewed By: ajkr
Differential Revision: D46029177
Pulled By: pdillinger
fbshipit-source-id: cdace79a2ea548d46c5900b068c5b7c3a02e5822
Summary:
Context:
In pull request https://github.com/facebook/rocksdb/issues/11436, we are introducing a new public API `waitForCompact(const WaitForCompactOptions& wait_for_compact_options)`. This API invokes the internal implementation `waitForCompact(bool wait_unscheduled=false)`. The unscheduled parameter indicates the compactions that are not yet scheduled but are required to process items in the queue.
In certain cases, we are unable to wait for compactions, such as during a shutdown or when background jobs are paused. It is important to return the appropriate status in these scenarios. For all other cases, we should wait for all compaction and flush jobs, including the unscheduled ones. The primary purpose of this new API is to wait until the system has resolved its compaction debt. Currently, the usage of `wait_unscheduled` is limited to test code.
This pull request eliminates the usage of wait_unscheduled. The internal `waitForCompact()` API now waits for unscheduled compactions unless the db is undergoing a shutdown. In the event of a shutdown, the API returns `Status::ShutdownInProgress()`.
Additionally, a new parameter, `abort_on_pause`, has been introduced with a default value of `false`. This parameter addresses the possibility of waiting indefinitely for unscheduled jobs if `PauseBackgroundWork()` was called before `waitForCompact()` is invoked. By setting `abort_on_pause` to `true`, the API will immediately return `Status::Aborted`.
Furthermore, all tests that previously called `waitForCompact(true)` have been fixed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11443
Test Plan:
Existing tests that involve a shutdown in progress:
- DBCompactionTest::CompactRangeShutdownWhileDelayed
- DBTestWithParam::PreShutdownMultipleCompaction
- DBTestWithParam::PreShutdownCompactionMiddle
Reviewed By: pdillinger
Differential Revision: D45923426
Pulled By: jaykorean
fbshipit-source-id: 7dc93fe6a6841a7d9d2d72866fa647090dba8eae
Summary:
**Context:**
We prefetch the tail part of a SST file (i.e, the blocks after data blocks till the end of the file) during each SST file open in hope to prefetch all the stuff at once ahead of time for later read e.g, footer, meta index, filter/index etc. The existing approach to estimate the tail size to prefetch is through `TailPrefetchStats` heuristics introduced in https://github.com/facebook/rocksdb/pull/4156, which has caused small reads in unlucky case (e.g, small read into the tail buffer during table open in thread 1 under the same BlockBasedTableFactory object can make thread 2's tail prefetching use a small size that it shouldn't) and is hard to debug. Therefore we decide to record the exact tail size and use it directly to prefetch tail of the SST instead of relying heuristics.
**Summary:**
- Obtain and record in manifest the tail size in `BlockBasedTableBuilder::Finish()`
- For backward compatibility, we fall back to TailPrefetchStats and last to simple heuristics that the tail size is a linear portion of the file size - see PR conversation for more.
- Make`tail_start_offset` part of the table properties and deduct tail size to record in manifest for external files (e.g, file ingestion, import CF) and db repair (with no access to manifest).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11406
Test Plan:
1. New UT
2. db bench
Note: db bench on /tmp/ where direct read is supported is too slow to finish and the default pinning setting in db bench is not helpful to profile # sst read of Get. Therefore I hacked the following to obtain the following comparison.
```
diff --git a/table/block_based/block_based_table_reader.cc b/table/block_based/block_based_table_reader.cc
index bd5669f0f..791484c1f 100644
--- a/table/block_based/block_based_table_reader.cc
+++ b/table/block_based/block_based_table_reader.cc
@@ -838,7 +838,7 @@ Status BlockBasedTable::PrefetchTail(
&tail_prefetch_size);
// Try file system prefetch
- if (!file->use_direct_io() && !force_direct_prefetch) {
+ if (false && !file->use_direct_io() && !force_direct_prefetch) {
if (!file->Prefetch(prefetch_off, prefetch_len, ro.rate_limiter_priority)
.IsNotSupported()) {
prefetch_buffer->reset(new FilePrefetchBuffer(
diff --git a/tools/db_bench_tool.cc b/tools/db_bench_tool.cc
index ea40f5fa0..39a0ac385 100644
--- a/tools/db_bench_tool.cc
+++ b/tools/db_bench_tool.cc
@@ -4191,6 +4191,8 @@ class Benchmark {
std::shared_ptr<TableFactory>(NewCuckooTableFactory(table_options));
} else {
BlockBasedTableOptions block_based_options;
+ block_based_options.metadata_cache_options.partition_pinning =
+ PinningTier::kAll;
block_based_options.checksum =
static_cast<ChecksumType>(FLAGS_checksum_type);
if (FLAGS_use_hash_search) {
```
Create DB
```
./db_bench --bloom_bits=3 --use_existing_db=1 --seed=1682546046158958 --partition_index_and_filters=1 --statistics=1 -db=/dev/shm/testdb/ -benchmarks=readrandom -key_size=3200 -value_size=512 -num=1000000 -write_buffer_size=6550000 -disable_auto_compactions=false -target_file_size_base=6550000 -compression_type=none
```
ReadRandom
```
./db_bench --bloom_bits=3 --use_existing_db=1 --seed=1682546046158958 --partition_index_and_filters=1 --statistics=1 -db=/dev/shm/testdb/ -benchmarks=readrandom -key_size=3200 -value_size=512 -num=1000000 -write_buffer_size=6550000 -disable_auto_compactions=false -target_file_size_base=6550000 -compression_type=none
```
(a) Existing (Use TailPrefetchStats for tail size + use seperate prefetch buffer in PartitionedFilter/IndexReader::CacheDependencies())
```
rocksdb.table.open.prefetch.tail.hit COUNT : 3395
rocksdb.sst.read.micros P50 : 5.655570 P95 : 9.931396 P99 : 14.845454 P100 : 585.000000 COUNT : 999905 SUM : 6590614
```
(b) This PR (Record tail size + use the same tail buffer in PartitionedFilter/IndexReader::CacheDependencies())
```
rocksdb.table.open.prefetch.tail.hit COUNT : 14257
rocksdb.sst.read.micros P50 : 5.173347 P95 : 9.015017 P99 : 12.912610 P100 : 228.000000 COUNT : 998547 SUM : 5976540
```
As we can see, we increase the prefetch tail hit count and decrease SST read count with this PR
3. Test backward compatibility by stepping through reading with post-PR code on a db generated pre-PR.
Reviewed By: pdillinger
Differential Revision: D45413346
Pulled By: hx235
fbshipit-source-id: 7d5e36a60a72477218f79905168d688452a4c064
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
Summary:
Compressed block cache is replaced by compressed secondary cache. Remove the feature.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11117
Test Plan: See CI passes
Reviewed By: pdillinger
Differential Revision: D42700164
fbshipit-source-id: 6cbb24e460da29311150865f60ecb98637f9f67d
Summary:
**Context:**
Sorting L0 files by `largest_seqno` has at least two inconvenience:
- File ingestion and compaction involving ingested files can create files of overlapping seqno range with the existing files. `force_consistency_check=true` will catch such overlap seqno range even those harmless overlap.
- For example, consider the following sequence of events ("key@n" indicates key at seqno "n")
- insert k1@1 to memtable m1
- ingest file s1 with k2@2, ingest file s2 with k3@3
- insert k4@4 to m1
- compact files s1, s2 and result in new file s3 of seqno range [2, 3]
- flush m1 and result in new file s4 of seqno range [1, 4]. And `force_consistency_check=true` will think s4 and s3 has file reordering corruption that might cause retuning an old value of k1
- However such caught corruption is a false positive since s1, s2 will not have overlapped keys with k1 or whatever inserted into m1 before ingest file s1 by the requirement of file ingestion (otherwise the m1 will be flushed first before any of the file ingestion completes). Therefore there in fact isn't any file reordering corruption.
- Single delete can decrease a file's largest seqno and ordering by `largest_seqno` can introduce a wrong ordering hence file reordering corruption
- For example, consider the following sequence of events ("key@n" indicates key at seqno "n", Credit to ajkr for this example)
- an existing SST s1 contains only k1@1
- insert k1@2 to memtable m1
- ingest file s2 with k3@3, ingest file s3 with k4@4
- insert single delete k5@5 in m1
- flush m1 and result in new file s4 of seqno range [2, 5]
- compact s1, s2, s3 and result in new file s5 of seqno range [1, 4]
- compact s4 and result in new file s6 of seqno range [2] due to single delete
- By the last step, we have file ordering by largest seqno (">" means "newer") : s5 > s6 while s6 contains a newer version of the k1's value (i.e, k1@2) than s5, which is a real reordering corruption. While this can be caught by `force_consistency_check=true`, there isn't a good way to prevent this from happening if ordering by `largest_seqno`
Therefore, we are redesigning the sorting criteria of L0 files and avoid above inconvenience. Credit to ajkr , we now introduce `epoch_num` which describes the order of a file being flushed or ingested/imported (compaction output file will has the minimum `epoch_num` among input files'). This will avoid the above inconvenience in the following ways:
- In the first case above, there will no longer be overlap seqno range check in `force_consistency_check=true` but `epoch_number` ordering check. This will result in file ordering s1 < s2 < s4 (pre-compaction) and s3 < s4 (post-compaction) which won't trigger false positive corruption. See test class `DBCompactionTestL0FilesMisorderCorruption*` for more.
- In the second case above, this will result in file ordering s1 < s2 < s3 < s4 (pre-compacting s1, s2, s3), s5 < s4 (post-compacting s1, s2, s3), s5 < s6 (post-compacting s4), which are correct file ordering without causing any corruption.
**Summary:**
- Introduce `epoch_number` stored per `ColumnFamilyData` and sort CF's L0 files by their assigned `epoch_number` instead of `largest_seqno`.
- `epoch_number` is increased and assigned upon `VersionEdit::AddFile()` for flush (or similarly for WriteLevel0TableForRecovery) and file ingestion (except for allow_behind_true, which will always get assigned as the `kReservedEpochNumberForFileIngestedBehind`)
- Compaction output file is assigned with the minimum `epoch_number` among input files'
- Refit level: reuse refitted file's epoch_number
- Other paths needing `epoch_number` treatment:
- Import column families: reuse file's epoch_number if exists. If not, assign one based on `NewestFirstBySeqNo`
- Repair: reuse file's epoch_number if exists. If not, assign one based on `NewestFirstBySeqNo`.
- Assigning new epoch_number to a file and adding this file to LSM tree should be atomic. This is guaranteed by us assigning epoch_number right upon `VersionEdit::AddFile()` where this version edit will be apply to LSM tree shape right after by holding the db mutex (e.g, flush, file ingestion, import column family) or by there is only 1 ongoing edit per CF (e.g, WriteLevel0TableForRecovery, Repair).
- Assigning the minimum input epoch number to compaction output file won't misorder L0 files (even through later `Refit(target_level=0)`). It's due to for every key "k" in the input range, a legit compaction will cover a continuous epoch number range of that key. As long as we assign the key "k" the minimum input epoch number, it won't become newer or older than the versions of this key that aren't included in this compaction hence no misorder.
- Persist `epoch_number` of each file in manifest and recover `epoch_number` on db recovery
- Backward compatibility with old db without `epoch_number` support is guaranteed by assigning `epoch_number` to recovered files by `NewestFirstBySeqno` order. See `VersionStorageInfo::RecoverEpochNumbers()` for more
- Forward compatibility with manifest is guaranteed by flexibility of `NewFileCustomTag`
- Replace `force_consistent_check` on L0 with `epoch_number` and remove false positive check like case 1 with `largest_seqno` above
- Due to backward compatibility issue, we might encounter files with missing epoch number at the beginning of db recovery. We will still use old L0 sorting mechanism (`NewestFirstBySeqno`) to check/sort them till we infer their epoch number. See usages of `EpochNumberRequirement`.
- Remove fix https://github.com/facebook/rocksdb/pull/5958#issue-511150930 and their outdated tests to file reordering corruption because such fix can be replaced by this PR.
- Misc:
- update existing tests with `epoch_number` so make check will pass
- update https://github.com/facebook/rocksdb/pull/5958#issue-511150930 tests to verify corruption is fixed using `epoch_number` and cover universal/fifo compaction/CompactRange/CompactFile cases
- assert db_mutex is held for a few places before calling ColumnFamilyData::NewEpochNumber()
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10922
Test Plan:
- `make check`
- New unit tests under `db/db_compaction_test.cc`, `db/db_test2.cc`, `db/version_builder_test.cc`, `db/repair_test.cc`
- Updated tests (i.e, `DBCompactionTestL0FilesMisorderCorruption*`) under https://github.com/facebook/rocksdb/pull/5958#issue-511150930
- [Ongoing] Compatibility test: manually run 36a5686ec0 (with file ingestion off for running the `.orig` binary to prevent this bug affecting upgrade/downgrade formality checking) for 1 hour on `simple black/white box`, `cf_consistency/txn/enable_ts with whitebox + test_best_efforts_recovery with blackbox`
- [Ongoing] normal db stress test
- [Ongoing] db stress test with aggressive value https://github.com/facebook/rocksdb/pull/10761
Reviewed By: ajkr
Differential Revision: D41063187
Pulled By: hx235
fbshipit-source-id: 826cb23455de7beaabe2d16c57682a82733a32a9
Summary:
The check for SST unique IDs added to best-efforts recovery (`Options::best_efforts_recovery` is true).
With best_efforts_recovery being true, RocksDB will recover to the latest point in
MANIFEST such that all valid SST files included up to this point pass unique ID checks as well.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10962
Test Plan: make check
Reviewed By: pdillinger
Differential Revision: D41378241
Pulled By: riversand963
fbshipit-source-id: a036064e2c17dec13d080a24ef2a9f85d607b16c
Summary:
Since the latency measurement uses real time it is possible for the operation to complete in zero microseconds and then fail these checks. We saw this with the operation that invokes Get() on an invalid CF. This PR relaxes the assertions to allow for operations completing in zero microseconds.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10979
Reviewed By: riversand963
Differential Revision: D41478300
Pulled By: ajkr
fbshipit-source-id: 50ef096bd8f0162b31adb46f54ae6ddc337d0a5e
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
Summary:
Allow the last level only compaction able to output result to penultimate level if the penultimate level is empty. Which will also block the other compaction output to the penultimate level.
(it includes the PR https://github.com/facebook/rocksdb/issues/10829)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10822
Reviewed By: siying
Differential Revision: D40389180
Pulled By: jay-zhuang
fbshipit-source-id: 4e5dcdce307795b5e07b5dd1fa29dd75bb093bad
Summary:
Try to align the compaction output file boundaries to the next level ones
(grandparent level), to reduce the level compaction write-amplification.
In level compaction, there are "wasted" data at the beginning and end of the
output level files. Align the file boundary can avoid such "wasted" compaction.
With this PR, it tries to align the non-bottommost level file boundaries to its
next level ones. It may cut file when the file size is large enough (at least
50% of target_file_size) and not too large (2x target_file_size).
db_bench shows about 12.56% compaction reduction:
```
TEST_TMPDIR=/data/dbbench2 ./db_bench --benchmarks=fillrandom,readrandom -max_background_jobs=12 -num=400000000 -target_file_size_base=33554432
# baseline:
Flush(GB): cumulative 25.882, interval 7.216
Cumulative compaction: 285.90 GB write, 162.36 MB/s write, 269.68 GB read, 153.15 MB/s read, 2926.7 seconds
# with this change:
Flush(GB): cumulative 25.882, interval 7.753
Cumulative compaction: 249.97 GB write, 141.96 MB/s write, 233.74 GB read, 132.74 MB/s read, 2534.9 seconds
```
The compaction simulator shows a similar result (14% with 100G random data).
As a side effect, with this PR, the SST file size can exceed the
target_file_size, but is capped at 2x target_file_size. And there will be
smaller files. Here are file size statistics when loading 100GB with the target
file size 32MB:
```
baseline this_PR
count 1.656000e+03 1.705000e+03
mean 3.116062e+07 3.028076e+07
std 7.145242e+06 8.046139e+06
```
The feature is enabled by default, to revert to the old behavior disable it
with `AdvancedColumnFamilyOptions.level_compaction_dynamic_file_size = false`
Also includes https://github.com/facebook/rocksdb/issues/1963 to cut file before skippable grandparent file. Which is for
use case like user adding 2 or more non-overlapping data range at the same
time, it can reduce the overlapping of 2 datasets in the lower levels.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10655
Reviewed By: cbi42
Differential Revision: D39552321
Pulled By: jay-zhuang
fbshipit-source-id: 640d15f159ab0cd973f2426cfc3af266fc8bdde2
Summary:
We have a lot of confusing code because of mixed, sometimes
completely opposite uses of of the term "raw block" or "raw contents",
sometimes within the same source file. For example, in `BlockBasedTableBuilder`,
`raw_block_contents` and `raw_size` generally referred to uncompressed block
contents and size, while `WriteRawBlock` referred to writing a block that
is already compressed if it is going to be. Meanwhile, in
`BlockBasedTable`, `raw_block_contents` either referred to a (maybe
compressed) block with trailer, or a maybe compressed block maybe
without trailer. (Note: left as follow-up work to use C++ typing to
better sort out the various kinds of BlockContents.)
This change primarily tries to apply some consistent terminology around
the kinds of block representations, avoiding the unclear "raw". (Any
meaning of "raw" assumes some bias toward the storage layer or toward
the logical data layer.) Preferred terminology:
* **Serialized block** - bytes that go into storage. For block-based table
(usually the case) this includes the block trailer. WART: block `size` may or
may not include the trailer; need to be clear about whether it does or not.
* **Maybe compressed block** - like a serialized block, but without the
trailer (or no promise of including a trailer). Must be accompanied by a
CompressionType.
* **Uncompressed block** - "payload" bytes that are either stored with no
compression, used as input to compression function, or result of
decompression function.
* **Parsed block** - an in-memory form of a block in block cache, as it is
used by the table reader. Different C++ types are used depending on the
block type (see block_like_traits.h).
Other refactorings:
* Misc corrections/improvements of internal API comments
* Remove a few misleading / unhelpful / redundant comments.
* Use move semantics in some places to simplify contracts
* Use better parameter names to indicate which parameters are used for
outputs
* Remove some extraneous `extern`
* Various clean-ups to `CacheDumperImpl` (mostly unnecessary code)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10408
Test Plan: existing tests
Reviewed By: akankshamahajan15
Differential Revision: D38172617
Pulled By: pdillinger
fbshipit-source-id: ccb99299f324ac5ca46996d34c5089621a4f260c
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
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
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
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/10309
Reviewed By: ltamasi
Differential Revision: D38211655
Pulled By: gangliao
fbshipit-source-id: 65ef33337db4d85277cc6f9782d67c421ad71dd5
Summary:
Using the Sequence number to time mapping to decide if a key is hot or not in
compaction and place it in the corresponding level.
Note: the feature is not complete, level compaction will run indefinitely until
all penultimate level data is cold and small enough to not trigger compaction.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10370
Test Plan:
CI
* Run basic db_bench for universal compaction manually
Reviewed By: siying
Differential Revision: D37892338
Pulled By: jay-zhuang
fbshipit-source-id: 792bbd91b1ccc2f62b5d14c53118434bcaac4bbe
Summary:
In leveled compaction, try to trivial move more than one files if possible, up to 4 files or max_compaction_bytes. This is to allow higher write throughput for some use cases where data is loaded in sequential order, where appying compaction results is the bottleneck.
When pick up a file to compact and it doesn't have overlapping files in the next level, try to expand to the next file if there is still no overlapping.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10190
Test Plan:
Add some unit tests.
For performance, Try to run
./db_bench_multi_move --benchmarks=fillseq --compression_type=lz4 --write_buffer_size=5000000 --num=100000000 --value_size=1000 -level_compaction_dynamic_level_bytes
Together with https://github.com/facebook/rocksdb/pull/10188 , stalling will be eliminated in this benchmark.
Reviewed By: jay-zhuang
Differential Revision: D37230647
fbshipit-source-id: 42b260f545c46abc5d90335ac2bbfcd09602b549
Summary:
auto_prefix_mode is designed to use prefix filtering in a
particular "safe" set of cases where the upper bound and the seek key
have different prefixes: where the upper bound is the "same length
immediate successor". These conditions are not sufficient to guarantee
the same iteration results as total_order_seek if the DB contains
"short" keys, less than the "full" (maximum) prefix length.
We are not simply disabling the optimization in these successor cases
because it is likely that users are essentially getting what they want
out of existing usage. Especially if users are constructing successor
bounds with the intention of doing a prefix-bounded seek, the existing
behavior is more expected than the total_order_seek behavior.
Consequently, for now we reconcile the bad specification of behavior by
documenting the existing mismatch with total_order_seek.
A closely related issue affects hypothetical comparators like
ReverseBytewiseComparator: if they "correctly" implement
IsSameLengthImmediateSuccessor, auto_prefix_mode could omit more
entries (other than "short" keys noted above). Luckily, the built-in
ReverseBytewiseComparator has an "incorrect" implementation of
IsSameLengthImmediateSuccessor that effectively prevents prefix
optimization and, thus, the bug. This is now documented as a new
constraint on IsSameLengthImmediateSuccessor, and the implementation
tweaked to be simply "safe" rather than "incorrect".
This change also includes unit test updates to demonstrate the above
issues. (Test was cleaned up for readability and simplicity.)
Intended follow-up:
* Tweak documented axioms for prefix_extractor (more details then)
* Consider some sort of fix for this case. I don't know what that would
look like without breaking the performance of existing code. Perhaps
if all keys in an SST file have prefixes that are "full length," we can track
that fact and use it to allow optimization with the "same length
immediate successor", but that would only apply to new files.
* Consider a better system of specifying prefix bounds
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10144
Test Plan: test updates included
Reviewed By: siying
Differential Revision: D37052710
Pulled By: pdillinger
fbshipit-source-id: 5f63b7d65f3f214e4b143e0f9aa1749527c587db
Summary:
As pointed out by [https://github.com/facebook/rocksdb/pull/8351#discussion_r645765422](https://github.com/facebook/rocksdb/pull/8351#discussion_r645765422), check `manual_compaction_paused` and `manual_compaction_canceled` can be reduced by setting `*canceled` to be true in `DisableManualCompaction()` and `*canceled` to be false in the last time calling `EnableManualCompaction()`.
Changed Tests: The origin `DBTest2.PausingManualCompaction1` uses a callback function to increase `manual_compaction_paused` and the origin CompactionJob/CompactionIterator with `manual_compaction_paused` can detect this. I changed the callback function so that it sets `*canceled` as true if `canceled` is not `nullptr` (to notify CompactionJob/CompactionIterator the compaction has been canceled).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10070
Test Plan: This change does not introduce new features, but some slight difference in compaction implementation. Run the same manual compaction unit tests as before (e.g., PausingManualCompaction[1-4], CancelManualCompaction[1-2], CancelManualCompactionWithListener in db_test2, and db_compaction_test).
Reviewed By: ajkr
Differential Revision: D36949133
Pulled By: littlepig2013
fbshipit-source-id: c5dc4c956fbf8f624003a0f5ad2690240063a821
Summary:
Only used as temperature high bound for current code, may
increase with more temperatures added.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10044
Test Plan: ci
Reviewed By: siying
Differential Revision: D36633410
Pulled By: jay-zhuang
fbshipit-source-id: eecdfa7623c31778c31d789902eacf78aad7b482
Summary:
For example, the default ZSTD version for ubuntu20 is 1.4.4, which will
fail the test `PresetCompressionDict`:
```
db/db_test_util.cc:607: Failure
Invalid argument: zstd finalizeDictionary cannot be used because ZSTD 1.4.5+ is not linked with the binary.
terminate called after throwing an instance of 'testing::internal::GoogleTestFailureException'
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10046
Test Plan: test pass with old zstd
Reviewed By: cbi42
Differential Revision: D36640067
Pulled By: jay-zhuang
fbshipit-source-id: b1c49fb7295f57f4515ce4eb3a52ae7d7e45da86
Summary:
Essentially refactored the RangeMayExist implementation in
FullFilterBlockReader to FilterBlockReaderCommon so that it applies to
partitioned filters as well. (The function is not called for the
block-based filter case.) RangeMayExist is essentially a series of checks
around a possible PrefixMayExist, and I'm confident those checks should
be the same for partitioned as for full filters. (I think it's likely
that bugs remain in those checks, but this change is overall a simplifying
one.)
Added auto_prefix_mode support to db_bench
Other small fixes as well
Fixes https://github.com/facebook/rocksdb/issues/10003
Pull Request resolved: https://github.com/facebook/rocksdb/pull/10012
Test Plan:
Expanded unit test that uses statistics to check for filter
optimization, fails without the production code changes here
Performance: populate two DBs with
```
TEST_TMPDIR=/dev/shm/rocksdb_nonpartitioned ./db_bench -benchmarks=fillrandom -num=10000000 -disable_wal=1 -write_buffer_size=30000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=8
TEST_TMPDIR=/dev/shm/rocksdb_partitioned ./db_bench -benchmarks=fillrandom -num=10000000 -disable_wal=1 -write_buffer_size=30000000 -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=8 -partition_index_and_filters
```
Observe no measurable change in non-partitioned performance
```
TEST_TMPDIR=/dev/shm/rocksdb_nonpartitioned ./db_bench -benchmarks=seekrandom[-X1000] -num=10000000 -readonly -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=8 -auto_prefix_mode -cache_index_and_filter_blocks=1 -cache_size=1000000000 -duration 20
```
Before: seekrandom [AVG 15 runs] : 11798 (± 331) ops/sec
After: seekrandom [AVG 15 runs] : 11724 (± 315) ops/sec
Observe big improvement with partitioned (also supported by bloom use statistics)
```
TEST_TMPDIR=/dev/shm/rocksdb_partitioned ./db_bench -benchmarks=seekrandom[-X1000] -num=10000000 -readonly -bloom_bits=16 -compaction_style=2 -fifo_compaction_max_table_files_size_mb=10000 -fifo_compaction_allow_compaction=0 -prefix_size=8 -partition_index_and_filters -auto_prefix_mode -cache_index_and_filter_blocks=1 -cache_size=1000000000 -duration 20
```
Before: seekrandom [AVG 12 runs] : 2942 (± 57) ops/sec
After: seekrandom [AVG 12 runs] : 7489 (± 184) ops/sec
Reviewed By: siying
Differential Revision: D36469796
Pulled By: pdillinger
fbshipit-source-id: bcf1e2a68d347b32adb2b27384f945434e7a266d
Summary:
Start tracking SST unique id in MANIFEST, which is used to verify with
SST properties to make sure the SST file is not overwritten or
misplaced. A DB option `try_verify_sst_unique_id` is introduced to
enable/disable the verification, if enabled, it opens all SST files
during DB-open to read the unique_id from table properties (default is
false), so it's recommended to use it with `max_open_files = -1` to
pre-open the files.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9990
Test Plan: unittests, format-compatible test, mini-crash
Reviewed By: anand1976
Differential Revision: D36381863
Pulled By: jay-zhuang
fbshipit-source-id: 89ea2eb6b35ed3e80ead9c724eb096083eaba63f
Summary:
### Context:
Background compactions and flush generate large reads and writes, and can be long running, especially for universal compaction. In some cases, this can impact foreground reads and writes by users.
### Solution
User, Flush, and Compaction reads share some code path. For this task, we update the rate_limiter_priority in ReadOptions for code paths (e.g. FindTable (mainly in BlockBasedTable::Open()) and various iterators), and eventually update the rate_limiter_priority in IOOptions for FSRandomAccessFile.
**This PR is for the Read path.** The **Read:** dynamic priority for different state are listed as follows:
| State | Normal | Delayed | Stalled |
| ----- | ------ | ------- | ------- |
| Flush (verification read in BuildTable()) | IO_USER | IO_USER | IO_USER |
| Compaction | IO_LOW | IO_USER | IO_USER |
| User | User provided | User provided | User provided |
We will respect the read_options that the user provided and will not set it.
The only sst read for Flush is the verification read in BuildTable(). It claims to be "regard as user read".
**Details**
1. Set read_options.rate_limiter_priority dynamically:
- User: Do not update the read_options. Use the read_options that the user provided.
- Compaction: Update read_options in CompactionJob::ProcessKeyValueCompaction().
- Flush: Update read_options in BuildTable().
2. Pass the rate limiter priority to FSRandomAccessFile functions:
- After calling the FindTable(), read_options is passed through GetTableReader(table_cache.cc), BlockBasedTableFactory::NewTableReader(block_based_table_factory.cc), and BlockBasedTable::Open(). The Open() needs some updates for the ReadOptions variable and the updates are also needed for the called functions, including PrefetchTail(), PrepareIOOptions(), ReadFooterFromFile(), ReadMetaIndexblock(), ReadPropertiesBlock(), PrefetchIndexAndFilterBlocks(), and ReadRangeDelBlock().
- In RandomAccessFileReader, the functions to be updated include Read(), MultiRead(), ReadAsync(), and Prefetch().
- Update the downstream functions of NewIndexIterator(), NewDataBlockIterator(), and BlockBasedTableIterator().
### Test Plans
Add unit tests.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9996
Reviewed By: anand1976
Differential Revision: D36452483
Pulled By: gitbw95
fbshipit-source-id: 60978204a4f849bb9261cb78d9bc1cb56d6008cf
Summary:
ToString() is created as some platform doesn't support std::to_string(). However, we've already used std::to_string() by mistake for 16 months (in db/db_info_dumper.cc). This commit just remove ToString().
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9955
Test Plan: Watch CI tests
Reviewed By: riversand963
Differential Revision: D36176799
fbshipit-source-id: bdb6dcd0e3a3ab96a1ac810f5d0188f684064471
