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
Summary:
This patch refactors TransactionImpl by separating the logic for pessimistic concurrency control from the implementation of how to write the data to rocksdb. The existing implementation is named WriteCommittedTxnImpl as it writes committed data to the db. A template named WritePreparedTxnImpl is also added which will be later completed to provide a an alternative implementation.
Closes https://github.com/facebook/rocksdb/pull/2676
Differential Revision: D5549998
Pulled By: maysamyabandeh
fbshipit-source-id: 16298e86b43ca4849324c1f35c731913c6d17bec
Summary:
this value ``` Compaction::is_trivial_move_ ``` uninitialized .
under universal compaction , we enable ``` CompactionOptionsUniversal::allow_trivial_move ``` ,
9b11d4345a/db/compaction.cc (L245)
here is a disastrous bug , some sst trivial move to target level without overlap check ...
THEN , DATABASE DAMAGED , WE GOT A LEVEL WITH OVERLAP !
Closes https://github.com/facebook/rocksdb/pull/2634
Differential Revision: D5530722
Pulled By: siying
fbshipit-source-id: 425ab55bca5967110377d634258360bcf88c200e
Summary:
we were passing `record_read_stats` (a bool) as the `hist_type` argument, which meant we were updating either `rocksdb.db.get.micros` (`hist_type == 0`) or `rocksdb.db.write.micros` (`hist_type == 1`) with wrong data.
Closes https://github.com/facebook/rocksdb/pull/2666
Differential Revision: D5520384
Pulled By: ajkr
fbshipit-source-id: 2f7c956aec32f8b58c5c18845ac478e0230c9516
Summary:
Replace dynamic_cast<> so that users can choose to build with RTTI off, so that they can save several bytes per object, and get tiny more memory available.
Some nontrivial changes:
1. Add Comparator::GetRootComparator() to get around the internal comparator hack
2. Add the two experiemental functions to DB
3. Add TableFactory::GetOptionString() to avoid unnecessary casting to get the option string
4. Since 3 is done, move the parsing option functions for table factory to table factory files too, to be symmetric.
Closes https://github.com/facebook/rocksdb/pull/2645
Differential Revision: D5502723
Pulled By: siying
fbshipit-source-id: fd13cec5601cf68a554d87bfcf056f2ffa5fbf7c
Summary:
- FIFOCompactionWithTTLTest was flaky when run in parallel earlier, and hence it was disabled. Fixed it now.
- Also, faking sleep now instead of really sleeping to make tests more realistic by using TTLs like 1 hour and 1 day.
Closes https://github.com/facebook/rocksdb/pull/2650
Differential Revision: D5506038
Pulled By: sagar0
fbshipit-source-id: deb429a527f045e3e2c5138b547c3e8ac8586aa2
Summary:
Breaking commit: d12691b86f
In the above commit, I moved the `TableCache` cleanup logic from `Version` destructor into `PurgeObsoleteFiles`. I missed cleaning up `TableCache` entries for the current `Version` during DB destruction.
This PR adds that logic to `VersionSet` destructor. One unfortunate side effect is now we're potentially deleting `TableReader`s after `column_family_set_.reset()`, which means we can't call `BlockBasedTableReader::Close` a second time as the block cache might already be destroyed.
Closes https://github.com/facebook/rocksdb/pull/2662
Differential Revision: D5515108
Pulled By: ajkr
fbshipit-source-id: 2cb820e19aa813e0d258d17f76b2d7b6b7ee0b18
Summary:
platform_dependent tests in Travis now builds all tests, which is not needed. Only build those tests we need to run.
Closes https://github.com/facebook/rocksdb/pull/2647
Differential Revision: D5513954
Pulled By: siying
fbshipit-source-id: 4d540b146124e70dd25586c47939d19f93655b0a
Summary:
Post-compaction work holds onto db mutex for the longest time (found by tracing lock acquires/releases with LTTng and correlating timestamps with our info log). Further experimentation showed `TableCache::EraseHandle` is responsible for ~86% of time mutex is held. We can just release the handle outside the db mutex.
Closes https://github.com/facebook/rocksdb/pull/2654
Differential Revision: D5507126
Pulled By: ajkr
fbshipit-source-id: 703c01ddf2aea16bc0f9e33c08935d78aa6b781d
Summary:
A FIFO compaction picker test is accidentally testing against an instance of level compaction picker.
Closes https://github.com/facebook/rocksdb/pull/2641
Differential Revision: D5495390
Pulled By: sagar0
fbshipit-source-id: 301962736f629b1c499570fb504cdbe66bacb46f
Summary:
We initially had disabled support for write_options.sync when concurrent_prepare_ is set. We later added this support but the statement that asserts this combination is not used was left there. This patch cleans it up.
Closes https://github.com/facebook/rocksdb/pull/2642
Differential Revision: D5496101
Pulled By: maysamyabandeh
fbshipit-source-id: becbc503446f2a51bee24cc861958c090c724ec2
Summary:
The test is failing occasionally on the assert: `ASSERT_TRUE(writer->state == WriteThread::State::STATE_INIT)`. This is because the test don't make the leader wait for long enough before updating state for its followers. The patch move the update to `threads_waiting` to the end of `WriteThread::JoinBatchGroup:Wait` callback to avoid this happening.
Also adding `WriteThread::JoinBatchGroup:Start` and have each thread wait there while another thread is linking to the linked-list. This is to make the check of `is_leader` more deterministic.
Also changing two while-loops of `compare_exchange_strong` to plain `fetch_add`, to make it look cleaner.
Closes https://github.com/facebook/rocksdb/pull/2640
Differential Revision: D5491525
Pulled By: yiwu-arbug
fbshipit-source-id: 6e897f122082bd6f98e6d51b31a25e5fd0a3fb82
Summary:
We will divide by zero if `stats.micros` is zero, just add a simple check
This happens sometimes during running tests and UBSAN complains
Closes https://github.com/facebook/rocksdb/pull/2631
Differential Revision: D5481455
Pulled By: IslamAbdelRahman
fbshipit-source-id: 69aa24e64e21de15d9e2b8009adf01675fcc6598
Summary:
I haven't looked to see if a class variable inside a loop like this is always initialised.
Closes https://github.com/facebook/rocksdb/pull/2602
Differential Revision: D5475937
Pulled By: IslamAbdelRahman
fbshipit-source-id: 8570b308f9a4b49e2a56ccc9e9b84d7c46568c15
Summary:
Add and implement Iterator::Refresh(). When this function is called, if the super version doesn't change, update the sequence number of the iterator to the latest one and invalidate the iterator. If the super version changed, recreated the whole iterator. This can help users reuse the iterator more easily.
Closes https://github.com/facebook/rocksdb/pull/2621
Differential Revision: D5464500
Pulled By: siying
fbshipit-source-id: f548bd35e85c1efca2ea69273802f6704eba6ba9
Summary:
The previous implementation of caching `file_size` index made no sense. It only remembered the original span of locked files starting from beginning of `file_size`. We should remember the index after all compactions that have been considered but rejected. This will reduce the work we do while holding the db mutex.
Closes https://github.com/facebook/rocksdb/pull/2624
Differential Revision: D5468152
Pulled By: ajkr
fbshipit-source-id: ab92a4bffe76f9f174d861bb5812b974d1013400
Summary:
This reverts the previous commit 1d7048c598, which broke the build.
Did a `git revert 1d7048c`.
Closes https://github.com/facebook/rocksdb/pull/2627
Differential Revision: D5476473
Pulled By: sagar0
fbshipit-source-id: 4756ff5c0dfc88c17eceb00e02c36176de728d06
Summary: This uses `clang-tidy` to comment out unused parameters (in functions, methods and lambdas) in fbcode. Cases that the tool failed to handle are fixed manually.
Reviewed By: igorsugak
Differential Revision: D5454343
fbshipit-source-id: 5dee339b4334e25e963891b519a5aa81fbf627b2
Summary:
This diff addresses two problems. Both problems cause us to miss scheduling desirable compactions. One side effect is compaction picking can spam logs, as there's no delay after failed attempts to pick compactions.
1. If a compaction pulled in a locked input-level file due to user-key overlap, we would not consider picking another file from the same input level.
2. If a compaction pulled in a locked output-level file due to user-key overlap, we would not consider picking any other compaction on any level.
The code changes are dependent, which is why I solved both problems in a single diff.
- Moved input-level `ExpandInputsToCleanCut` into the loop inside `PickFileToCompact`. This gives two benefits: (1) if it fails, we will try the next-largest file on the same input level; (2) we get the fully-expanded input-level key-range with which we can check for pending compactions in output level.
- Added another call to `ExpandInputsToCleanCut` inside `PickFileToCompact`'s to check for compaction conflicts in output level.
- Deleted call to `IsRangeInCompaction` in `PickFileToCompact`, as `ExpandInputsToCleanCut` also correctly handles the case where original output-level files (i.e., ones not pulled in due to user-key overlap) are pending compaction.
Closes https://github.com/facebook/rocksdb/pull/2615
Differential Revision: D5454643
Pulled By: ajkr
fbshipit-source-id: ea3fb5477d83e97148951af3fd4558d2039e9872
Summary:
I decided not even to keep it as an INFO-level log as it is too normal for compactions to be skipped due to locked input files. Removing logging here makes us consistent with how we treat locked files that weren't pulled in due to overlap.
We may want some error handling on line 422, which should never happen when called by `LevelCompactionBuilder::PickCompaction`, as `SetupInitialFiles` skips compactions where overlap causes the output level to pull in locked files.
Closes https://github.com/facebook/rocksdb/pull/2617
Differential Revision: D5458502
Pulled By: ajkr
fbshipit-source-id: c2e5f867c0a77c1812ce4242ab3e085b3eee0bae
Summary:
This patch enables using PinnableSlice for RowCache, changes include
not releasing the cache handle immediately after lookup in TableCache::Get, instead pass a Cleanble function which does Cache::RleaseHandle.
Closes https://github.com/facebook/rocksdb/pull/2492
Differential Revision: D5316216
Pulled By: maysamyabandeh
fbshipit-source-id: d2a684bd7e4ba73772f762e58a82b5f4fbd5d362
Summary:
Fix column_family_test with LITE build. I need this patch to fix 5.6 branch.
Closes https://github.com/facebook/rocksdb/pull/2597
Differential Revision: D5437171
Pulled By: yiwu-arbug
fbshipit-source-id: 88b9dc5925a6b47af10c1b41bc5b07c4251a84b5
