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 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:
A previous fix to DBTestUniversalCompaction.UniversalCompactionTrivialMoveTest2 didn't address the right problem. The problem is L0->L0 compaction is not trivial move in the scenario, not parallel compactions. Fix this.
Closes https://github.com/facebook/rocksdb/pull/1911
Differential Revision: D4608955
Pulled By: siying
fbshipit-source-id: 7a712cb
Summary: DBTestUniversalCompaction.UniversalCompactionTrivialMoveTest2 verifies non-trivial move is not triggered if we load data in sequential order. However, if there are multiple compaction threads, this conditon may not hold. Restrict the running condition to 1 compaction thread to make the test more robust.
Test Plan: Run the test and make sure at least it doesn't regress normally.
Reviewers: yhchiang, andrewkr, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D65277
Summary:
If we have total number of sorted runs greater than level0_file_num_compaction_trigger, Universal compaction will always issue a compaction
even if the number of sorted runs that are not being compacted is less than level0_file_num_compaction_trigger.
This diff changes this behaviour to relay on the `number of sorted runs not being compacted` instead of `total number of sorted runs`
Test Plan: New unit test
Reviewers: sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D61533
Summary: With max_size_amplification_percent = 0 to make sure that DBTestUniversalCompaction.UniversalCompactionSingleSortedRun tests the configuration to compact to one single sorted run.
Test Plan: Run all existing tests
Reviewers: yhchiang, andrewkr, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D60021
* Musl libc does not provide adaptive mutex. Added feature test for PTHREAD_MUTEX_ADAPTIVE_NP.
* Musl libc does not provide backtrace(3). Added a feature check for backtrace(3).
* Fixed compiler error.
* Musl libc does not implement backtrace(3). Added platform check for libexecinfo.
* Alpine does not appear to support gcc -pg option. By default (gcc has PIE option enabled) it fails with:
gcc: error: -pie and -pg|p|profile are incompatible when linking
When -fno-PIE and -nopie are used it fails with:
/usr/lib/gcc/x86_64-alpine-linux-musl/5.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: cannot find gcrt1.o: No such file or directory
Added gcc -pg platform test and output PROFILING_FLAGS accordingly. Replaced pg var in Makefile with PROFILING_FLAGS.
* fix segfault when TEST_IOCTL_FRIENDLY_TMPDIR is undefined and default candidates are not suitable
* use ASSERT_DOUBLE_EQ instead of ASSERT_EQ
* When compiled with ROCKSDB_MALLOC_USABLE_SIZE UniversalCompactionFourPaths and UniversalCompactionSecondPathRatio tests fail due to premature memtable flushes on systems with 16-byte alignment. Arena runs out of block space before GenerateNewFile() completes.
Increased options.write_buffer_size.
Summary: DBTestUniversalCompaction, IncreaseUniversalCompactionNumLevels fails one in about 30 runs when running in parallel. We wait for compaction after each flush to make the compaction behavior deterministic.
Test Plan: Run the test 1000 times in parallel and it still passes.
Reviewers: yhchiang, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: kradhakrishnan, yiwu, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56841
Summary: Change some RocksDB default options to make it more friendly to server workloads.
Test Plan: Run all existing tests
Reviewers: yhchiang, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: sumeet, muthu, benj, MarkCallaghan, igor, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D55941
Summary:
Based on thread scheduling, DBTestUniversalCompaction.IncreaseUniversalCompactionNumLevels can fail to flush enough files to trigger expected compactions. Fix it by waiting for flush after inserting each key.
There are failrue reported:
db/db_universal_compaction_test.cc:1134: Failure
Expected: (NumTableFilesAtLevel(options.num_levels - 1, 1)) > (0), actual: 0 vs 0
but I can't repro it. Try to fix the bug and see whether it goes away.
Test Plan: Run the test multiple time.
Reviewers: IslamAbdelRahman, anthony, andrewkr, kradhakrishnan, yhchiang
Reviewed By: yhchiang
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D54747
Summary:
Following up on D53493, we can still enable the filter-skipping
optimization for last file in L0. It's correct to assume the key will be present
in the last L0 file when we're hit-optimized and L0 is deepest.
The FilePicker encapsulates the state for traversing each level's files, so I
needed to make it expose whether the returned file is last in its level.
Test Plan:
verified below test fails before this patch and passes afterwards.
The change to how the test memtable is populated is needed so file 1 has keys
(0, 30, 60), file 2 has keys (10, 40, 70), etc.
$ ./db_universal_compaction_test --gtest_filter=UniversalCompactionNumLevels/DBTestUniversalCompaction.OptimizeFiltersForHits/*
Reviewers: sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D53583
Summary: It's a regression bug caused by e089db40f9. With the change, if options.optimize_filters_for_hits=true and there are only L0 files (like single level universal compaction), we skip all the files in L0, which is more than necessary. Fix it by always trying to query bloom filter for files in level 0.
Test Plan: Add a unit test for it.
Reviewers: anthony, rven, yhchiang, IslamAbdelRahman, kradhakrishnan, andrewkr
Reviewed By: andrewkr
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D53493
Summary:
This diff provides a framework for doing manual
compactions in parallel with other compactions. We now have a deque of manual compactions. We also pass manual compactions as an argument from RunManualCompactions down to
BackgroundCompactions, so that RunManualCompactions can be reentrant.
Parallelism is controlled by the two routines
ConflictingManualCompaction to allow/disallow new parallel/manual
compactions based on already existing ManualCompactions. In this diff, by default manual compactions still have to run exclusive of other compactions. However, by setting the compaction option, exclusive_manual_compaction to false, it is possible to run other compactions in parallel with a manual compaction. However, we are still restricted to one manual compaction per column family at a time. All of these restrictions will be relaxed in future diffs.
I will be adding more tests later.
Test Plan: Rocksdb regression + new tests + valgrind
Reviewers: igor, anthony, IslamAbdelRahman, kradhakrishnan, yhchiang, sdong
Reviewed By: sdong
Subscribers: yoshinorim, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D47973
Summary:
Fixing a valgrind failure in DBTestUniversalCompaction
in the IncreaseUniversalCompactionNumLevels test. Using
SpecialSkipList with 10 rows per file.
Test Plan: Run valgrind and functional tests.
Reviewers: anthony, yhchiang, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D51705
Summary:
db_universal_compaction_test is still failing because of
UniversalCompactionNumLevels/DBTestUniversalCompaction.UniversalCompactionSecondPathRatio/0
https://travis-ci.org/facebook/rocksdb/jobs/94949919
Use same approach to fix other tests to fix this test
Test Plan: Run ./db_universal_compaction_test on mac and make sure all the tests pass
Reviewers: kradhakrishnan, yhchiang, rven, anthony, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D51591
Summary: Skip list now cannot estimate memory across allocators
consistently and hence triggers flush at different time. This breaks certain
unit tests.
The fix is to adopt key count instead of size for flush.
Test Plan: Ran test on dev box and mac (where it used to fail)
Reviewers: sdong
CC: leveldb@
Task ID: #9273334
Blame Rev:
Summary:
Currently RocksDB may break in lines like this:
for (size_t i = sorted_runs.size() - 1; i >= first_index_after; i--) {
if options.level0_file_num_compaction_trigger=0.
Fix it by not executing the logic of picking compactions if there is no file (sorted_runs.size() = 0). Also internally set options.level0_file_num_compaction_trigger=1 if users give a 0. 0 is a value makes no sense in RocksDB.
Test Plan: Run all tests. Will add a unit test too.
Reviewers: yhchiang, IslamAbdelRahman, anthony, kradhakrishnan, rven
Reviewed By: rven
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D50727
Summary:
Using a TLS random instance for skiplist makes it smaller
(useful for hash_skiplist_rep) and prepares skiplist for concurrent
adds. This diff also modifies the branching factor math to avoid an
unnecessary division.
This diff has the effect of changing the sequence of skip list node
height choices made by tests, so it has the potential to cause unit
test failures for tests that implicitly rely on the exact structure
of the skip list. Tests that try to exactly trigger a compaction are
likely suspects for this problem (these tests have always been brittle to
changes in the skiplist details). I've minimizes this risk by reseeding
the main thread's Random at the beginning of each test, increasing the
universal compaction size_ratio limit from 101% to 105% for some tests,
and verifying that the tests pass many times.
Test Plan: for i in `seq 0 9`; do make check; done
Reviewers: sdong, igor
Reviewed By: igor
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D50439
Summary:
This patch will block all tests (not including db_test) that don't compile / fail under ROCKSDB_LITE
Test Plan:
OPT=-DROCKSDB_LITE make db_compaction_filter_test -j64 &&
OPT=-DROCKSDB_LITE make db_compaction_test -j64 &&
OPT=-DROCKSDB_LITE make db_dynamic_level_test -j64 &&
OPT=-DROCKSDB_LITE make db_log_iter_test -j64 &&
OPT=-DROCKSDB_LITE make db_tailing_iter_test -j64 &&
OPT=-DROCKSDB_LITE make db_universal_compaction_test -j64 &&
OPT=-DROCKSDB_LITE make ldb_cmd_test -j64
make clean
make db_compaction_filter_test -j64 &&
make db_compaction_test -j64 &&
make db_dynamic_level_test -j64 &&
make db_log_iter_test -j64 &&
make db_tailing_iter_test -j64 &&
make db_universal_compaction_test -j64 &&
make ldb_cmd_test -j64
Reviewers: yhchiang, igor, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D48723
Summary:
As part of tech debt week, we are cleaning up dependencies.
This diff moves db_test_util.[h,cc] from util to db directory.
Test Plan: make check
Reviewers: igor, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D48543
Summary: malloc_usable_size() gets a better estimation of memory usage. It is already used to calculate block cache memory usage. Use it in arena too.
Test Plan: Run all unit tests
Reviewers: anthony, kradhakrishnan, rven, IslamAbdelRahman, yhchiang
Reviewed By: yhchiang
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D43317
Summary:
See task #7983654. The example was triggering an assert in compaction job
because the compaction was not marked as manual. With this patch,
CompactionPicker::FormCompaction() marks compactions as manual. This patch
also fixes a couple of typos, adds optimistic_transaction_example to
.gitignore and librocksdb as a dependency for examples. Adding librocksdb as
a dependency makes sure that the examples are built with the latest changes
in librocksdb.
Test Plan: make clean && cd examples && make all && ./compact_files_example
Reviewers: rven, sdong, anthony, igor, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D45117
Summary: Fix for universal compaction with trivial move, when the ouput level is 0. The tests where failing. Fixed by allowing normal compaction when output level is 0.
Test Plan: modified test cases run successfully.
Reviewers: sdong, yhchiang, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: anthony, kradhakrishnan, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D42933
Summary:
Fixed DBTestUniversalManualCompactionOutputPathId test
by changing the expected number of files when setting up
the test as flushes no-longer preempt compactions
in patch https://reviews.facebook.net/D41931.
Also, include db_universal_copaction_test in make all check.
Test Plan: db_universal_copaction_test
Reviewers: igor, sdong, IslamAbdelRahman, anthony
Reviewed By: anthony
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42639
Summary: Move UniversalCompaction related db-tests to db_universal_compaction_test.cc
Test Plan:
db_test
db_universal_compaction_test
Reviewers: igor, sdong, IslamAbdelRahman, anthony
Reviewed By: anthony
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42225
Andrew Kryczka