Summary:
Three small optimizations:
(1) iter_->IsKeyPinned() shouldn't be called if read_options.pin_data is not true. This may trigger function call all the way down the iterator tree.
(2) reuse the iterator key object in DBIter::FindNextUserEntryInternal(). The constructor of the class has some overheads.
(3) Move the switching direction logic in MergingIterator::Next() to a separate function.
These three in total improves readseq performance by about 3% in my benchmark setting.
Closes https://github.com/facebook/rocksdb/pull/2880
Differential Revision: D5829252
Pulled By: siying
fbshipit-source-id: 991aea10c6d6c3b43769cb4db168db62954ad1e3
Summary:
Move uncommon code paths in RangeDelAggregator::ShouldDelete() and IterKey::EnlargeBufferIfNeeded() to a separate function, so that the inlined strcuture can be more optimized.
Optimize it because these places show up in CPU profiling, though minimum. The performance is really hard measure. I ran db_bench with readseq benchmark against in-memory DB many times. The variation is big, but it seems to show 1% improvements.
Closes https://github.com/facebook/rocksdb/pull/2877
Differential Revision: D5828123
Pulled By: siying
fbshipit-source-id: 41a49e229f91e9f8409f85cc6f0dc70e31334e4b
Summary:
Added possibility to set save points in transactions and then rollback to them
Closes https://github.com/facebook/rocksdb/pull/2876
Differential Revision: D5825829
Pulled By: yiwu-arbug
fbshipit-source-id: 62168992340bbcddecdaea3baa2a678475d1429d
Summary:
Bug report: https://www.facebook.com/groups/rocksdb.dev/permalink/1389452781153232/
Non-empty `level0_compactions_in_progress_` was aborting `CompactFiles` after incrementing `bg_compaction_scheduled_`, and in that case we never decremented it. This blocked future compactions and prevented DB close as we wait for scheduled compactions to finish/abort during close.
I eliminated `CompactFiles`'s dependency on `level0_compactions_in_progress_`. Since it takes a contiguous span of L0 files -- through the last L0 file if any L1+ files are included -- it's fine to run in parallel with other compactions involving L0. We make the same assumption in intra-L0 compaction.
Closes https://github.com/facebook/rocksdb/pull/2849
Differential Revision: D5780440
Pulled By: ajkr
fbshipit-source-id: 15b15d3faf5a699aed4b82a58352d4a7bb23e027
Summary:
Added some bindings for `OptimisticTransactionDB` in C API
Closes https://github.com/facebook/rocksdb/pull/2823
Differential Revision: D5820672
Pulled By: yiwu-arbug
fbshipit-source-id: 7efd17f619cc0741feddd2050b8fc856f9288350
Summary:
- Switched all instances of SetMinPossibleForUserKey and SetMaxPossibleForUserKey in accordance to InternalKeyComparator's comparison logic
Closes https://github.com/facebook/rocksdb/pull/2868
Differential Revision: D5804152
Pulled By: axxufb
fbshipit-source-id: 80be35e04f2e8abc35cc64abe1fecb03af24e183
Summary:
options.enable_pipelined_write and options.concurrent_prepare are incompatible and should not be set together.
Closes https://github.com/facebook/rocksdb/pull/2875
Differential Revision: D5818358
Pulled By: maysamyabandeh
fbshipit-source-id: dad862508f00817ab302f8b61729accf38315fb8
Summary:
Changes:
* added check for value before merge is called on code path that should check if key exists
Closes https://github.com/facebook/rocksdb/pull/2814
Reviewed By: IslamAbdelRahman
Differential Revision: D5743966
Pulled By: armishra
fbshipit-source-id: 6ac4283bc510c8ca50827d87ef0ba631f2b33b18
Summary:
it sometimes takes more than 10 minutes (i.e., times out) on our internal CI. mainly because bzip is super slow. so I reduced the amount of work it tries to do.
Closes https://github.com/facebook/rocksdb/pull/2856
Differential Revision: D5795883
Pulled By: ajkr
fbshipit-source-id: e69f986ae60b44ecc26b6b024abd0f13bdf3a3c5
Summary:
Merging iterator invokes InternalKeyComparator.Compare() frequently to heap merge. By making InternalKeyComparator final and merging iterator to directly use InternalKeyComparator rather than through Iterator interface, we can give compiler a choice to avoid one more virtual function call if possible. I ran readseq benchmark in memory-only use case to make sure the performance at least doesn't regress.
I have to disable the final key word in debug build, as a hack test class depends on overriding the class.
Closes https://github.com/facebook/rocksdb/pull/2860
Differential Revision: D5800461
Pulled By: siying
fbshipit-source-id: ab876f22a09bb5c560740911412336e0e25ccb53
Summary:
DBIter is referenced in ArenaWrappedDBIter, which is a simple wrapper. If DBIter is final, some virtual function call can be avoided. Some functions can even be inlined, like DBIter.value() to ArenaWrappedDBIter.value() and DBIter.key() to ArenaWrappedDBIter.key(). The performance gain is hard to measure. I just ran the memory-only benchmark for readseq and saw it didn't regress. There shouldn't be any harm doing it. Just give compiler more choices.
Closes https://github.com/facebook/rocksdb/pull/2859
Differential Revision: D5799888
Pulled By: siying
fbshipit-source-id: 829788f91310c40282dcfb7e412e6ef489931143
Summary:
This patch instruments the read path to verify each read value against an optional ReadCallback class. If the value is rejected, the reader moves on to the next value. The WritePreparedTxn makes use of this feature to skip sequence numbers that are not in the read snapshot.
Closes https://github.com/facebook/rocksdb/pull/2850
Differential Revision: D5787375
Pulled By: maysamyabandeh
fbshipit-source-id: 49d808b3062ab35e7ae98ad388f659757794184c
Summary:
Some of these names, like `MEMTABLE_COMPACTION`, did not mean anything. Tried to give them descriptive names.
Closes https://github.com/facebook/rocksdb/pull/2852
Differential Revision: D5782822
Pulled By: ajkr
fbshipit-source-id: f2695c4124af4073da4492d7135bae2411220f3a
Summary:
if we're moving any L0 files down, we need to include older L0 files since they may contain older versions of the keys being moved down.
Closes https://github.com/facebook/rocksdb/pull/2845
Differential Revision: D5773800
Pulled By: ajkr
fbshipit-source-id: 9f0770a8eaaeea4c87df2e7a2a1d65bf9d7f4f7e
Summary:
This branch extends existing property map which keeps values in doubles to keep values in strings so that it can be used to provide wider range of properties. The immediate need for that is to provide IO stall stats in an easy parseable way to MyRocks which is also part of this branch.
Closes https://github.com/facebook/rocksdb/pull/2794
Differential Revision: D5717676
Pulled By: Tema
fbshipit-source-id: e34ba5b79ba774697f7b97ce1138d8fd55471b8a
Summary:
* db/range_del_aggregator.cc (AddTombstone): Avoid a potential
use-after-move bug. The original code would both use and move
`tombstone` in a context where the order of those operations is
not specified. The fix is to perform the use on a new, preceding
statement.
Author: meyering
Closes https://github.com/facebook/rocksdb/pull/2796
Differential Revision: D5721163
Pulled By: ajkr
fbshipit-source-id: a1d328d6a77a17c6425e8069860a202e615e2f48
Summary:
Divide the old snapshots to two lists: a few that fit into a cached array and the rest in a vector, which is expected to be empty in normal cases. The former is to optimize concurrent reads from snapshots without requiring locks. It is done by an array of std::atomic, from which std::memory_order_acquire reads are compiled to simple read instructions in most of the x86_64 architectures.
Closes https://github.com/facebook/rocksdb/pull/2758
Differential Revision: D5660504
Pulled By: maysamyabandeh
fbshipit-source-id: 524fcf9a8e7f90a92324536456912a99aaa6740c
Summary:
Allow user to reduce number of levels in LSM by issue a full CompactRange() and put the result in a lower level, and then reopen DB with reduced options.num_levels. Previous this will fail on reopen on when recovery replaying the previous MANIFEST and found a historical file was on a higher level than the new options.num_levels. The workaround was after CompactRange(), reopen the DB with old num_levels, which will create a new MANIFEST, and then reopen the DB again with new num_levels.
This patch relax the check of levels during recovery. It allows DB to open if there was a historical file on level > options.num_levels, but was also deleted.
Closes https://github.com/facebook/rocksdb/pull/2740
Differential Revision: D5629354
Pulled By: yiwu-arbug
fbshipit-source-id: 545903f6b36b6083e8cbaf777176aef2f488021d
Summary:
It should hold db mutex while accessing max_total_in_memory_state_.
Closes https://github.com/facebook/rocksdb/pull/2784
Differential Revision: D5696536
Pulled By: yiwu-arbug
fbshipit-source-id: 45430634d7fe11909b38e42e5f169f618681c4ee
Summary:
store a zero as the checksum when disabled since it's easier to keep block trailer a fixed length.
Closes https://github.com/facebook/rocksdb/pull/2781
Differential Revision: D5694702
Pulled By: ajkr
fbshipit-source-id: 69cea9da415778ba2b600dfd9d0dfc8cb5188ecd
Summary:
One of the core assumptions of DeleteRange is that files containing portions of the same range tombstone are treated as a single unit from the perspective of compaction picker. Need better tests for this. This PR adds the tests for manual compaction.
Closes https://github.com/facebook/rocksdb/pull/2769
Differential Revision: D5676677
Pulled By: ajkr
fbshipit-source-id: 1b4b3382b300ff7048b872911405fdf900e4fbec
Summary:
Solves #2632
Added OptimisticTransactionDB to the C API.
Added missing merge operations to Transaction.
Added missing get_for_update operation to transaction
If required I will create tests for this another day.
Closes https://github.com/facebook/rocksdb/pull/2633
Differential Revision: D5600906
Pulled By: yiwu-arbug
fbshipit-source-id: da23e4484433d8f59d471f778ff2ae210e3fe4eb
Summary:
add this counter stat to track usage of deletion-dropping optimization. if usage is low, we can delete it to prevent bugs like #2726.
Closes https://github.com/facebook/rocksdb/pull/2761
Differential Revision: D5665421
Pulled By: ajkr
fbshipit-source-id: 881befa2d199838dac88709e7b376a43d304e3d4
Summary:
With this PR, we can measure read-amp for queries where perf_context is enabled as follows:
```
SetPerfLevel(kEnableCount);
Get(1, "foo");
double read_amp = static_cast<double>(get_perf_context()->block_read_byte / get_perf_context()->get_read_bytes);
SetPerfLevel(kDisable);
```
Our internal infra enables perf_context for a sampling of queries. So we'll be able to compute the read-amp for the sample set, which can give us a good estimate of read-amp.
Closes https://github.com/facebook/rocksdb/pull/2749
Differential Revision: D5647240
Pulled By: ajkr
fbshipit-source-id: ad73550b06990cf040cc4528fa885360f308ec12
Summary:
Added a function `MergeOperator::DoesAllowSingleMergeOperand()` to allow invoking a merge operator even with a single merge operand, if overriden.
This is needed for Cassandra-on-RocksDB work. All Cassandra writes are through merges and this will allow a single merge-value to be updated in the merge-operator invoked via a compaction, if needed, due to an expired TTL.
Closes https://github.com/facebook/rocksdb/pull/2721
Differential Revision: D5608706
Pulled By: sagar0
fbshipit-source-id: f299f9f91c4d1ac26e48bd5906e122c1c5e5f3fc
Summary:
the range delete tombstones in memtable should be added to the aggregator even when the memtable's prefix bloom filter tells us the lookup key's not there. This bug could cause data to temporarily reappear until the memtable containing range deletions is flushed.
Reported in #2743.
Closes https://github.com/facebook/rocksdb/pull/2745
Differential Revision: D5639007
Pulled By: ajkr
fbshipit-source-id: 04fc6facb6f978340a3f639536f4ca7c0d73dfc9
Summary:
We forgot to recompute compaction scores after picking a universal compaction like we do in level compaction (a34b2e388e/db/compaction_picker.cc (L691-L695)). This leads to a fairness issue where we waste compactions on CFs/DB instances that don't need it while others can starve.
Previously, ccecf3f4fb fixed the issue for the read-amp-based compaction case; this PR avoids the issue earlier and also for size-ratio-based compactions.
Closes https://github.com/facebook/rocksdb/pull/2688
Differential Revision: D5566191
Pulled By: ajkr
fbshipit-source-id: 010bccb2a107f6a76f3d3022b90aadce5cc48feb
Summary:
Implement the main body of WritePrepared pseudo code. This includes PrepareInternal and CommitInternal, as well as AddCommitted which updates the commit map. It also provides a IsInSnapshot method that could be later called form the read path to decide if a version is in the read snapshot or it should other be skipped.
This patch lacks unit tests and does not attempt to offer an efficient implementation. The idea is that to have the API specified so that we can work on related tasks in parallel.
Closes https://github.com/facebook/rocksdb/pull/2713
Differential Revision: D5640021
Pulled By: maysamyabandeh
fbshipit-source-id: bfa7a05e8d8498811fab714ce4b9c21530514e1c
Summary:
Similar to the bug fixed by https://github.com/facebook/rocksdb/pull/2726, FIFO with compaction and kCompactionStyleNone during user customized CompactFiles() with output level to be 0 can suffer from the same problem. Fix it by leveraging the bottommost_level_ flag.
Closes https://github.com/facebook/rocksdb/pull/2735
Differential Revision: D5626906
Pulled By: siying
fbshipit-source-id: 2b148d0461c61dbd986d74655e384419ae442158
Summary:
`KeyNotExistsBeyondOutputLevel` didn't consider L0 files' key-ranges. So if a key only was covered by older L0 files' key-ranges, we would incorrectly drop deletions of that key. This PR just skips the deletion-dropping optimization when output level is L0.
Closes https://github.com/facebook/rocksdb/pull/2726
Differential Revision: D5617286
Pulled By: ajkr
fbshipit-source-id: 4bff1396b06d49a828ba4542f249191052915bce
Summary:
It would be super helpful to not have to recompile rocksdb to get this performance tweak for mechanical disks.
I have signed the CLA.
Closes https://github.com/facebook/rocksdb/pull/2718
Differential Revision: D5606994
Pulled By: yiwu-arbug
fbshipit-source-id: c05e92bad0d03bd38211af1e1ced0d0d1e02f634
Summary:
Right now, if direct I/O is enabled, prefetching the last 512KB cannot be applied, except compaction inputs or readahead is enabled for iterators. This can create a lot of I/O for HDD cases. To solve the problem, the 512KB is prefetched in block based table if direct I/O is enabled. The prefetched buffer is passed in totegher with random access file reader, so that we try to read from the buffer before reading from the file. This can be extended in the future to support flexible user iterator readahead too.
Closes https://github.com/facebook/rocksdb/pull/2708
Differential Revision: D5593091
Pulled By: siying
fbshipit-source-id: ee36ff6d8af11c312a2622272b21957a7b5c81e7
Summary:
We need a tool to check any sst file corruption in the db.
It will check all the sst files in current version and read all the blocks (data, meta, index) with checksum verification. If any verification fails, the function will return non-OK status.
Closes https://github.com/facebook/rocksdb/pull/2498
Differential Revision: D5324269
Pulled By: lightmark
fbshipit-source-id: 6f8a272008b722402a772acfc804524c9d1a483b
Summary:
We should search wal_dir in Repairer::FindFiles function, and avoid use
LogFileNmae(dbname, number) to get WAL file's name, which will get a wrong
WAL filename. as following:
```
[WARN] [/home/liuchang/Workspace/rocksdb/db/repair.cc:310] Log #3: ignoring conversion error: IO error: While opening a file for sequentially reading: /tmp/rocksdbtest-1000/repair_test/000003.log: No such file or directory
```
I have added a new test case to repair_test.cc, which try to repair db with all WAL options.
Signed-off-by: Chang Liu <liuchang0812@gmail.com>
Closes https://github.com/facebook/rocksdb/pull/2692
Differential Revision: D5575888
Pulled By: ajkr
fbshipit-source-id: 5b93e9f85cddc01663ccecd87631fa723ac466a3
Summary:
This patch splits Commit and Prepare into lock-related logic and db-write-related logic. It moves lock-related logic to PessimisticTransaction to be reused by all children classes and movies the existing impl of db-write-related to PrepareInternal, CommitSingleInternal, and CommitInternal in WriteCommittedTxnImpl.
Closes https://github.com/facebook/rocksdb/pull/2691
Differential Revision: D5569464
Pulled By: maysamyabandeh
fbshipit-source-id: d1b8698e69801a4126c7bc211745d05c636f5325
Summary:
In the condition:
```
if (range_del_agg != nullptr &&
range_del_agg->ShouldDelete(
iter->key(),
RangeDelAggregator::RangePositioningMode::kForwardTraversal) &&
filter != CompactionFilter::Decision::kRemoveAndSkipUntil) {
...
}
```
it could be possible that all the work done in `range_del_agg->ShouldDelete` is wasted due to not having the right `filter` value later on.
Instead, check `filter` value before even calling `range_del_agg->ShouldDelete`, which is a much more involved function.
Closes https://github.com/facebook/rocksdb/pull/2690
Differential Revision: D5568931
Pulled By: sagar0
fbshipit-source-id: 17512d52360425c7ae9de7675383f5d7bc3dad58
Summary:
When we had a single thread pool for compactions, a thread could be busy for a long time (minutes) executing a compaction involving the bottom level. In multi-instance setups, the entire thread pool could be consumed by such bottom-level compactions. Then, top-level compactions (e.g., a few L0 files) would be blocked for a long time ("head-of-line blocking"). Such top-level compactions are critical to prevent compaction stalls as they can quickly reduce number of L0 files / sorted runs.
This diff introduces a bottom-priority queue for universal compactions including the bottom level. This alleviates the head-of-line blocking situation for fast, top-level compactions.
- Added `Env::Priority::BOTTOM` thread pool. This feature is only enabled if user explicitly configures it to have a positive number of threads.
- Changed `ThreadPoolImpl`'s default thread limit from one to zero. This change is invisible to users as we call `IncBackgroundThreadsIfNeeded` on the low-pri/high-pri pools during `DB::Open` with values of at least one. It is necessary, though, for bottom-pri to start with zero threads so the feature is disabled by default.
- Separated `ManualCompaction` into two parts in `PrepickedCompaction`. `PrepickedCompaction` is used for any compaction that's picked outside of its execution thread, either manual or automatic.
- Forward universal compactions involving last level to the bottom pool (worker thread's entry point is `BGWorkBottomCompaction`).
- Track `bg_bottom_compaction_scheduled_` so we can wait for bottom-level compactions to finish. We don't count them against the background jobs limits. So users of this feature will get an extra compaction for free.
Closes https://github.com/facebook/rocksdb/pull/2580
Differential Revision: D5422916
Pulled By: ajkr
fbshipit-source-id: a74bd11f1ea4933df3739b16808bb21fcd512333
