Summary:
Issue scenario:
(1) We have 3 files in L1 and we issue a compaction that will compact them into 1 file in L2
(2) While compaction (1) is running, we flush a file into L0 and trigger another compaction that decide to move this file to L1 and then move it again to L2 (this file don't overlap with any other files)
(3) compaction (1) finishes and install the file it generated in L2, but this file overlap with the file we generated in (2) so we break the LSM consistency
Looks like this issue can be triggered by using non-exclusive manual compaction or AddFile()
Test Plan: unit tests
Reviewers: sdong
Reviewed By: sdong
Subscribers: hermanlee4, jkedgar, andrewkr, dhruba, yoshinorim
Differential Revision: https://reviews.facebook.net/D64947
Summary:
* Change constructor of MutableCFOptions to depends only on ColumnFamilyOptions.
* Move `max_subcompactions`, `compaction_options_fifo` and `compaction_pri` to ImmutableCFOptions to make it clear that they are immutable.
Test Plan: existing unit tests.
Reviewers: yhchiang, IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D63945
Summary: To reduce number of options, merge source_compaction_factor, max_grandparent_overlap_bytes and expanded_compaction_factor into max_compaction_bytes.
Test Plan: Add two new unit tests. Run all existing tests, including jtest.
Reviewers: yhchiang, igor, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D59829
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: We may wrongly drop delete operation if we pick a file with the entry to be delete, the put entry of the same user key is in the next file in the level, and the next file is not picked. We expand compaction inputs for output level too.
Test Plan: Add unit tests that reproduct the bug of dropping delete entry. Change compaction_picker_test to assert the new behavior.
Reviewers: IslamAbdelRahman, igor
Reviewed By: igor
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D61173
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
Summary: Make CompactionOptionsFIFO a part of mutable_cf_options
Test Plan: UT
Reviewers: sdong
Reviewed By: sdong
Subscribers: andrewkr, lgalanis, dhruba
Differential Revision: https://reviews.facebook.net/D58653
Summary:
Add a new option that can be used to set a specific compression algorithm for bottommost level.
This option will only affect levels larger than base level.
I have also updated CompactionJobInfo to include the compression algorithm used in compaction
Test Plan:
added new unittest
existing unittests
Reviewers: andrewkr, yhchiang, sdong
Reviewed By: sdong
Subscribers: lightmark, andrewkr, dhruba, yoshinorim
Differential Revision: https://reviews.facebook.net/D57669
Summary: We always put compaction to level0_compactions_in_progress_ for universal compaction, so we should also remove it. The bug causes assert failure when running manual compaction.
Test Plan:
TEST_TMPDIR=/dev/shm/ ./db_bench --benchmarks=fillrandom,compact --subcompactions=16 --compaction_style=1
always fails on my host. After the fix, it doesn't fail any more.
Reviewers: IslamAbdelRahman, andrewkr, kradhakrishnan, yhchiang
Reviewed By: yhchiang
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D55017
Summary: After we made manual compaction runnable concurrently with automaticallly compaction, we need to run ComputeCompactionScore() to prepare a coming compaction picking call before the compaction finishes.
Test Plan: Run existing tests.
Reviewers: yhchiang, IslamAbdelRahman, andrewkr, kradhakrishnan, anthony, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D54891
Summary: When L0->L1 is pending, there may be one L1->L2 compaction going on which prevents the L0->L1 compaction from happening. If L1 needs more data to be moved to L2, then we may continue scheduling more L1->L2 compactions. The end result may be that L0->L1 compaction will not happen until L1 size drops to below target size. We can reduce the stalling because of number of L0 files by stopping schedling new L1->L2 compaction when L0's score is higher than L1.
Test Plan: Run all existing tests.
Reviewers: yhchiang, MarkCallaghan, rven, anthony, IslamAbdelRahman, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D52401
Summary:
Add CompactionReason to CompactionJobInfo
This will allow users to understand why compaction started which will help options tuning
Test Plan:
added new tests
make check -j64
Reviewers: yhchiang, anthony, kradhakrishnan, sdong, rven
Reviewed By: rven
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D51975
Summary:
List of changes:
1) Fix the snprintf() usage in cases where wrong variable was used to determine the output buffer size.
2) Remove unnecessary checks before calling delete operator.
3) Increase code correctness by using size_t type when getting vector's size.
4) Unify the coding style by removing namespace::std usage at the top of the file to confirm to the majority usage.
5) Fix various lint errors pointed out by 'arc lint'.
Test Plan:
Code review and build:
git diff
make clean
make -j 32 commit-prereq
arc lint
Reviewers: kradhakrishnan, sdong, rven, anthony, yhchiang, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D51849
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:
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:
Since level 0 files can overlap, two level 0 compactions cannot
run in parallel. Compact files needs to check this before running a
compaction.
Test Plan: CompactFilesTest.L0ConflictsFiles
Reviewers: igor, IslamAbdelRahman, anthony, sdong, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D50079
Summary:
Add options.compaction_pri, which specifies the policy about which file to compact first.
kCompactionPriByLargestSeq will compact oldest files first.
Verified the behavior in db_bench but did not write unit tests yet. Also need to make it settable through option string and dynamically changeable.
Test Plan: Will write unit tests
Reviewers: igor, rven, anthony, kradhakrishnan, IslamAbdelRahman, yhchiang, MarkCallaghan
Reviewed By: yhchiang
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D45951
Summary: The diff modifies the condition checked to determine the bottommost level during compaction. Previously, absence of files in higher levels alone was used as the condition. Now, the function additionally evaluates if the higher levels have files which have non-overlapping key ranges, then the level can be safely considered as the bottommost level.
Test Plan: Unit test cases added and passing. However, unit tests of universal compaction are failing as a result of the changes made in this diff. Need to understand why that is happening.
Reviewers: igor
Subscribers: dhruba, sdong, lgalanis, meyering
Differential Revision: https://reviews.facebook.net/D46473
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:
The compact files API had a bug where some overlapping files
are not added. These are files which overlap with files which were
added to the compaction input files, but not to the original set of
input files. This happens only when there are more than two levels
involved in the compaction. An example will illustrate this better.
Level 2 has 1 input file 1.sst which spans [20,30].
Level 3 has added file 2.sst which spans [10,25]
Level 4 has file 3.sst which spans [35,40] and
input file 4.sst which spans [46,50].
The existing code would not add 3.sst to the set of input_files because
it only becomes an overlapping file in level 4 and it wasn't one in
level 3.
When installing the results of the compaction, 3.sst would overlap with
output file from the compact files and result in the assertion in
version_set.cc:1130
// Must not overlap
assert(level <= 0 || level_files->empty() ||
internal_comparator_->Compare(
(*level_files)[level_files->size() - 1]->largest, f->smallest) <
0);
This change now adds overlapping files from the current level to the set
of input files also so that we don't hit the assertion above.
Test Plan:
d=/tmp/j; rm -rf $d; seq 1000 | parallel --gnu --eta
'd=/tmp/j/d-{}; mkdir -p $d; TEST_TMPDIR=$d ./db_compaction_test
--gtest_filter=*CompactilesOnLevel* --gtest_also_run_disabled_tests >&
'$d'/log-{}'
Reviewers: igor, yhchiang, sdong
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D43437
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: gcc-4.9-glibc-2.20 complains about uninitialized variable.
db/compaction_picker.cc: In member function 'bool
rocksdb::CompactionPicker::IsInputNonOverlapping(rocksdb::Compaction*)':
db/compaction_picker.cc:1174:17: error:
'prev.rocksdb::{anonymous}::InputFileInfo::f' may be used uninitialized in this
function [-Werror=maybe-uninitialized]
InputFileInfo prev, curr, next;
Test Plan: pmake on local environment
Reviewers: sdong igor
CC: leveldb@
Task ID: #
Blame Rev:
Summary: Block reduce_levels_test in ROCKSDB_LITE as LDBCommand is not supported
Test Plan:
make reduce_levels_test -j64
OPT=-DROCKSDB_LITE make reduce_levels_test -j64
make check -j64
Reviewers: sdong, igor, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D41967
Summary: This helps Windows port to format their changes, as discussed. Might have formatted some other codes too becasue last 10 commits include more.
Test Plan: Build it.
Reviewers: anthony, IslamAbdelRahman, kradhakrishnan, yhchiang, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D41961
Summary: This change enables trivial move if all the input files are non onverlapping while doing Universal Compaction.
Test Plan: ./compaction_picker_test and db_test ran successfully with the new testcases.
Reviewers: sdong
Reviewed By: sdong
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D40875
Summary: Make RocksDb build and run on Windows to be functionally
complete and performant. All existing test cases run with no
regressions. Performance numbers are in the pull-request.
Test plan: make all of the existing unit tests pass, obtain perf numbers.
Co-authored-by: Praveen Rao praveensinghrao@outlook.com
Co-authored-by: Sherlock Huang baihan.huang@gmail.com
Co-authored-by: Alex Zinoviev alexander.zinoviev@me.com
Co-authored-by: Dmitri Smirnov dmitrism@microsoft.com
Summary: With experimental feature SuggestCompactRange() we don't restrict running two L0->L1 compactions in parallel. This diff fixes this.
Test Plan: added a unit test to reproduce the failure. fixed the unit test
Reviewers: yhchiang, rven, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D39981
Summary: CompactRange() now is much more expensive for dynamic level base size as it goes through all the levels. Skip those not used levels between level 0 an base level.
Test Plan: Run all unit tests
Reviewers: yhchiang, rven, anthony, kradhakrishnan, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D37125
Summary:
When trying to compact entire database with SuggestCompactRange(), we'll first try the left-most files. This is pretty bad, because:
1) the left part of LSM tree will be overly compacted, but right part will not be touched
2) First compaction will pick up the left-most file. Second compaction will try to pick up next left-most, but this will not be possible, because there's a big chance that second's file range on N+1 level is already being compacted.
I observe both of those problems when running Mongo+RocksDB and trying to compact the DB to clean up tombstones. I'm unable to clean them up :(
This diff adds a bit of randomness into choosing a file. First, it chooses a file at random and tries to compact that one. This should solve both problems specified here.
Test Plan: make check
Reviewers: yhchiang, rven, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38379
Summary: This caused a crash of our MongoDB + RocksDB instance. PickCompactionBySize() sets its own parent_index. We never reset this parent_index when picking PickFilesMarkedForCompactionExperimental(). So we might end up doing SetupOtherInputs() with parent_index that was set by PickCompactionBySize, although we're using compaction calculated using PickFilesMarkedForCompactionExperimental.
Test Plan: Added a unit test that fails with assertion on master.
Reviewers: yhchiang, rven, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38337
Summary: When reporting compaction that was started because of SuggestCompactRange() we should treat it as manual compaction.
Test Plan: none
Reviewers: yhchiang, rven
Reviewed By: rven
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D38139
Summary: Optimize GetRange Function by checking the level of the files
Test Plan: pass make all check
Reviewers: rven, yhchiang, igor
Reviewed By: igor
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D37977
Summary:
CompactRange for universal compaction with num_levels > 1 seems to have a bug. The unit test also has a bug so it doesn't capture the problem.
Fix it. Revert the compact range to the logic equivalent to num_levels=1. Always compact all files together.
It should also fix DBTest.IncreaseUniversalCompactionNumLevels. The issue was that options.write_buffer_size = 100 << 10 and options.write_buffer_size = 100 << 10 are not used in later test scenarios. So write_buffer_size of 4MB was used. The compaction trigger condition is not anymore obvious as expected.
Test Plan: Run the new test and all test suites
Reviewers: yhchiang, rven, kradhakrishnan, anthony, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D37551
Summary: Reading CompactionPicker I noticed this dangerous substraction of two unsigned integers. We should assert to mark this as safe.
Test Plan: make check
Reviewers: anthony, rven, yhchiang, sdong
Reviewed By: sdong
Subscribers: kradhakrishnan, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D37041
Summary:
Some Mongo+Rocks datasets in Parse's environment are not doing compactions very frequently. During the quiet period (with no IO), we'd like to schedule compactions so that our reads become faster. Also, aggressively compacting during quiet periods helps when write bursts happen. In addition, we also want to compact files that are containing deleted key ranges (like old oplog keys).
All of this is currently not possible with CompactRange() because it's single-threaded and blocks all other compactions from happening. Running CompactRange() risks an issue of blocking writes because we generate too much Level 0 files before the compaction is over. Stopping writes is very dangerous because they hold transaction locks. We tried running manual compaction once on Mongo+Rocks and everything fell apart.
MarkForCompaction() solves all of those problems. This is very light-weight manual compaction. It is lower priority than automatic compactions, which means it shouldn't interfere with background process keeping the LSM tree clean. However, if no automatic compactions need to be run (or we have extra background threads available), we will start compacting files that are marked for compaction.
Test Plan: added a new unit test
Reviewers: yhchiang, rven, MarkCallaghan, sdong
Reviewed By: sdong
Subscribers: yoshinorim, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D37083
Summary: If ExpandWhileOverlapping() we don't clear inputs. That's a bug introduced by my recent patch https://reviews.facebook.net/D36687. However, we have no tests covering ExpandWhileOverlapping(). I created a task t6771252 to add ExpandWhileOverlapping() tests.
Test Plan: make check
Reviewers: sdong, rven, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D37077
Summary:
Allow users to give a callback function with parameter using sync point, so more complicated verification can be done in tests.
Use it in DBTest.DynamicLevelCompressionPerLevel2 so that failures will be more easy to debug.
Test Plan: Run all tests. Run DBTest.DynamicLevelCompressionPerLevel2 with valgrind check.
Reviewers: rven, yhchiang, anthony, kradhakrishnan, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D36999
Summary:
The goal of this diff is to make Compaction class easier to use. This should also make new compaction algorithms easier to write (like CompactFiles from @yhchiang and dynamic leveled and multi-leveled universal from @sdong).
Here are couple of things demonstrating that Compaction class is hard to use:
1. we have two constructors of Compaction class
2. there's this thing called grandparents_, but it appears to only be setup for leveled compaction and not compactfiles
3. it's easy to introduce a subtle and dangerous bug like this: D36225
4. SetupBottomMostLevel() is hard to understand and it shouldn't be. See this comment: afbafeaeae/db/compaction.cc (L236-L241). It also made it harder for @yhchiang to write CompactFiles, as evidenced by this: afbafeaeae/db/compaction_picker.cc (L204-L210)
The problem is that we create Compaction object, which holds a lot of state, and then pass it around to some functions. After those functions are done mutating, then we call couple of functions on Compaction object, like SetupBottommostLevel() and MarkFilesBeingCompacted(). It is very hard to see what's happening with all that Compaction's state while it's travelling across different functions. If you're writing a new PickCompaction() function you need to try really hard to understand what are all the functions you need to run on Compaction object and what state you need to setup.
My proposed solution is to make important parts of Compaction immutable after construction. PickCompaction() should calculate compaction inputs and then pass them onto Compaction object once they are finalized. That makes it easy to create a new compaction -- just provide all the parameters to the constructor and you're done. No need to call confusing functions after you created your object.
This diff doesn't fully achieve that goal, but it comes pretty close. Here are some of the changes:
* have one Compaction constructor instead of two.
* inputs_ is constant after construction
* MarkFilesBeingCompacted() is now private to Compaction class and automatically called on construction/destruction.
* SetupBottommostLevel() is gone. Compaction figures it out on its own based on the input.
* CompactionPicker's functions are not passing around Compaction object anymore. They are only passing around the state that they need.
Test Plan:
make check
make asan_check
make valgrind_check
Reviewers: rven, anthony, sdong, yhchiang
Reviewed By: yhchiang
Subscribers: sdong, yhchiang, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D36687
Summary:
With this change, we use L1 and up to store compaction outputs in universal compaction.
The compaction pick logic stays the same. Outputs are stored in the largest "level" as possible.
If options.num_levels=1, it behaves all the same as now.
Test Plan:
1) convert most of existing unit tests for universal comapaction to include the option of one level and multiple levels.
2) add a unit test to cover parallel compaction in universal compaction and run it in one level and multiple levels
3) add unit test to migrate from multiple level setting back to one level setting
4) add a unit test to insert keys to trigger multiple rounds of compactions and verify results.
Reviewers: rven, kradhakrishnan, yhchiang, igor
Reviewed By: igor
Subscribers: meyering, leveldb, MarkCallaghan, dhruba
Differential Revision: https://reviews.facebook.net/D34539
Summary: Suprisingly, the only way we use this vector is to keep track of level0 compactions. Thus, I simplified it.
Test Plan: make check
Reviewers: rven, yhchiang, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D35313
Summary:
Change the way options.compression_per_level is used when options.level_compaction_dynamic_level_bytes=true so that options.compression_per_level[1] determines compression for the level L0 is merged to, options.compression_per_level[2] to the level after that, etc.
Test Plan: run all tests
Reviewers: rven, yhchiang, kradhakrishnan, igor
Reviewed By: igor
Subscribers: yoshinorim, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D34431
Summary:
When having fixed max_bytes_for_level_base, the ratio of size of largest level and the second one can range from 0 to the multiplier. This makes LSM tree frequently irregular and unpredictable. It can also cause poor space amplification in some cases.
In this improvement (proposed by Igor Kabiljo), we introduce a parameter option.level_compaction_use_dynamic_max_bytes. When turning it on, RocksDB is free to pick a level base in the range of (options.max_bytes_for_level_base/options.max_bytes_for_level_multiplier, options.max_bytes_for_level_base] so that real level ratios are close to options.max_bytes_for_level_multiplier.
Test Plan: New unit tests and pass tests suites including valgrind.
Reviewers: MarkCallaghan, rven, yhchiang, igor, ikabiljo
Reviewed By: ikabiljo
Subscribers: yoshinorim, ikabiljo, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D31437
Summary: Added requirement that ComputeCompactionScore() be executed in mutex, since it's accessing being_compacted bool, which can be mutated by other threads. Also added more comments about thread safety of FileMetaData, since it was a bit confusing. However, it seems that FileMetaData doesn't have data races (except being_compacted)
Test Plan: Ran 100 ConvertCompactionStyle tests with thread sanitizer. On master -- some failures. With this patch -- none.
Reviewers: yhchiang, rven, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D32283
Summary:
When scaling to higher number of column families, the worst bottleneck was MaybeScheduleFlushOrCompaction(), which did a for loop over all column families while holding a mutex. This patch addresses the issue.
The approach is similar to our earlier efforts: instead of a pull-model, where we do something for every column family, we can do a push-based model -- when we detect that column family is ready to be flushed/compacted, we add it to the flush_queue_/compaction_queue_. That way we don't need to loop over every column family in MaybeScheduleFlushOrCompaction.
Here are the performance results:
Command:
./db_bench --write_buffer_size=268435456 --db_write_buffer_size=268435456 --db=/fast-rocksdb-tmp/rocks_lots_of_cf --use_existing_db=0 --open_files=55000 --statistics=1 --histogram=1 --disable_data_sync=1 --max_write_buffer_number=2 --sync=0 --benchmarks=fillrandom --threads=16 --num_column_families=5000 --disable_wal=1 --max_background_flushes=16 --max_background_compactions=16 --level0_file_num_compaction_trigger=2 --level0_slowdown_writes_trigger=2 --level0_stop_writes_trigger=3 --hard_rate_limit=1 --num=33333333 --writes=33333333
Before the patch:
fillrandom : 26.950 micros/op 37105 ops/sec; 4.1 MB/s
After the patch:
fillrandom : 17.404 micros/op 57456 ops/sec; 6.4 MB/s
Next bottleneck is VersionSet::AddLiveFiles, which is painfully slow when we have a lot of files. This is coming in the next patch, but when I removed that code, here's what I got:
fillrandom : 7.590 micros/op 131758 ops/sec; 14.6 MB/s
Test Plan:
make check
two stress tests:
Big number of compactions and flushes:
./db_stress --threads=30 --ops_per_thread=20000000 --max_key=10000 --column_families=20 --clear_column_family_one_in=10000000 --verify_before_write=0 --reopen=15 --max_background_compactions=10 --max_background_flushes=10 --db=/fast-rocksdb-tmp/db_stress --prefixpercent=0 --iterpercent=0 --writepercent=75 --db_write_buffer_size=2000000
max_background_flushes=0, to verify that this case also works correctly
./db_stress --threads=30 --ops_per_thread=2000000 --max_key=10000 --column_families=20 --clear_column_family_one_in=10000000 --verify_before_write=0 --reopen=3 --max_background_compactions=3 --max_background_flushes=0 --db=/fast-rocksdb-tmp/db_stress --prefixpercent=0 --iterpercent=0 --writepercent=75 --db_write_buffer_size=2000000
Reviewers: ljin, rven, yhchiang, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D30123
Summary:
Allow Level-style compaction to place files in different paths
This diff provides the code for task 4854591. We now support level-compaction
to place files in different paths by specifying them in db_paths along with
the minimum level for files to store in that path.
Test Plan: ManualLevelCompactionOutputPathId in db_test.cc
Reviewers: yhchiang, MarkCallaghan, dhruba, yoshinorim, sdong
Reviewed By: sdong
Subscribers: yoshinorim, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D29799
Summary: Block Universal and FIFO compactions in ROCKSDB_LITE
Test Plan:
make shared_lib -j32
make OPT=-DROCKSDB_LITE shared_lib
Reviewers: ljin, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D29589
Summary:
In some environment such as android, the c++ library does not have
std::to_string. This path adds rocksdb::ToString(), which wraps std::to_string
when std::to_string is not available, and implements std::to_string
in the other case.
Test Plan:
make dbg -j32
./db_test
make clean
make dbg OPT=-DOS_ANDROID -j32
./db_test
Reviewers: ljin, sdong, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D29181
Summary: As a short-term fix, let's go back to previous way of calculating NeedsCompaction(). SIGSEGV happens because NeedsCompaction() can happen before super_version (and thus MutableCFOptions) is initialized.
Test Plan: make check
Reviewers: ljin, sdong, rven, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D28875
Summary:
Move NeedsCompaction() from VersionStorageInfo to CompactionPicker
to allow different compaction strategy to have their own way to
determine whether doing compaction is necessary.
When compaction style is set to kCompactionStyleNone, then
NeedsCompaction() will always return false.
Test Plan:
export ROCKSDB_TESTS=Compact
./db_test
Reviewers: ljin, sdong, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D28719
Summary:
We need to turn on -Wshorten-64-to-32 for mobile. See D1671432 (internal phabricator) for details.
This diff turns on the warning flag and fixes all the errors. There were also some interesting errors that I might call bugs, especially in plain table. Going forward, I think it makes sense to have this flag turned on and be very very careful when converting 64-bit to 32-bit variables.
Test Plan: compiles
Reviewers: ljin, rven, yhchiang, sdong
Reviewed By: yhchiang
Subscribers: bobbaldwin, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D28689
Summary:
This diff adds three sets of APIs to RocksDB.
= GetColumnFamilyMetaData =
* This APIs allow users to obtain the current state of a RocksDB instance on one column family.
* See GetColumnFamilyMetaData in include/rocksdb/db.h
= EventListener =
* A virtual class that allows users to implement a set of
call-back functions which will be called when specific
events of a RocksDB instance happens.
* To register EventListener, simply insert an EventListener to ColumnFamilyOptions::listeners
= CompactFiles =
* CompactFiles API inputs a set of file numbers and an output level, and RocksDB
will try to compact those files into the specified level.
= Example =
* Example code can be found in example/compact_files_example.cc, which implements
a simple external compactor using EventListener, GetColumnFamilyMetaData, and
CompactFiles API.
Test Plan:
listener_test
compactor_test
example/compact_files_example
export ROCKSDB_TESTS=CompactFiles
db_test
export ROCKSDB_TESTS=MetaData
db_test
Reviewers: ljin, igor, rven, sdong
Reviewed By: sdong
Subscribers: MarkCallaghan, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D24705
Summary: Enforce the accessier naming convention in functions in version_set.h
Test Plan: make all check
Reviewers: ljin, yhchiang, rven, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D28143
Summary:
...and fix all the errors :)
Jim suggested turning on -Wshadow because it helped him fix number of critical bugs in fbcode. I think it's a good idea to be -Wshadow clean.
Test Plan: compiles
Reviewers: yhchiang, rven, sdong, ljin
Reviewed By: ljin
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D27711
Summary:
Make compaction picker easier to test.
The basic idea is to separate a minimum subcomponent of Version to VersionStorageInfo, which just responsible to LSM tree. A stub VersionStorageInfo can then be easily created and passed into compaction picker so that we can check the outputs.
It now passes most tests. Still two things need to be done:
(1) deal with the FIFO compaction's file size.
(2) write an example test to make sure the interface can do the job.
Add a compaction_picker_test to make sure compaction picker codes can be easily unit tested.
Test Plan:
Pass all unit tests and compaction_picker_test
Reviewers: yhchiang, rven, igor, ljin
Reviewed By: ljin
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D27639
Summary: Apply InfoLogLevel to the logs in db/compaction_picker.cc
Test Plan: make
Reviewers: ljin, sdong, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D27837
Summary: as title
Test Plan:
make release
I will run make all check for all stacked diffs before commit
Reviewers: sdong, yhchiang, rven, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D27573
Summary: as title
Test Plan: running make all check
Reviewers: sdong, yhchiang, rven, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D27549
Summary:
Previously, the log for Universal Compaction does not include the current
number of files in case the compaction is triggered by the number of files.
This diff includes the number of files in the log.
Test Plan:
make
Summary:
make compaction related options changeable. Most of changes are tedious,
following the same convention: grabs MutableCFOptions at the beginning
of compaction under mutex, then pass it throughout the job and register
it in SuperVersion at the end.
Test Plan: make all check
Reviewers: igor, yhchiang, sdong
Reviewed By: sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D23349
Fix for:
[db/compaction_picker.cc:923]: (style) Unsigned variable
'start_index' can't be negative so it is unnecessary to test it.
Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
Summary: There is a possible overflow case in universal compaction picker. Use double to make the logic straight-forward
Test Plan: make all check
Reviewers: yhchiang, igor, MarkCallaghan, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D23817
Summary:
Now the file summary is too small for printing. Enlarge it.
To enable it, allow to pass a size to log buffer.
Test Plan:
Add a unit test.
make all check
Reviewers: ljin, yhchiang
Reviewed By: yhchiang
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D21723
Summary: Correct some comments and typos in RocksDB.
Test Plan: Inspection
Reviewers: sdong, igor
Reviewed By: igor
Differential Revision: https://reviews.facebook.net/D23133
* Script for building the unity.cc file via Makefile
* Unity executable Makefile target for testing builds
* Source code changes to fix compilation of unity build
Summary:
Make StatisticsImpl being able to forward stats to provided statistics
implementation. The main purpose is to allow us to collect internal
stats in the future even when user supplies custom statistics
implementation. It avoids intrumenting 2 sets of stats collection code.
One immediate use case is tuning advisor, which needs to collect some
internal stats, users may not be interested.
Test Plan:
ran db_bench and see stats show up at the end of run
Will run make all check since some tests rely on statistics
Reviewers: yhchiang, sdong, igor
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D20145
Summary: Add a parameter path_id to DB::CompactRange(), to indicate where the output file should be placed to.
Test Plan: add a unit test
Reviewers: yhchiang, ljin
Reviewed By: ljin
Subscribers: xjin, igor, dhruba, MarkCallaghan, leveldb
Differential Revision: https://reviews.facebook.net/D20085
Summary:
This patch adds a target size parameter in options.db_paths and universal compaction will base it to determine which DB path to place a new file.
Level-style stays the same.
Test Plan: Add new unit tests
Reviewers: ljin, yhchiang
Reviewed By: yhchiang
Subscribers: MarkCallaghan, dhruba, igor, leveldb
Differential Revision: https://reviews.facebook.net/D19869
Summary:
This patch include two fixes:
1. newly created Version will now takes the aggregated stats for average-value-size from the latest Version.
2. compensated size of a file is now computed only for newly created / loaded file, this addresses the issue where files are already sorted by their compensated file size but might sometimes observe some out-of-order due to later update on compensated file size.
Test Plan:
export ROCKSDB_TESTS=CompactionDele
./db_test
Reviewers: ljin, igor, sdong
Reviewed By: sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19557
Summary:
In this patch, we allow RocksDB to support multiple DB paths internally.
No user interface is supported yet so this patch is silent to users.
Test Plan: make all check
Reviewers: igor, haobo, ljin, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D18921
Summary:
Before this diff, we're deciding enable_compression in CompactionPicker and then we're deciding final compression type in DBImpl. This is kind of confusing.
After the diff, the final compression type will be decided in CompactionPicker.
The reason for this is that I want CompactFiles() to specify output compression type, so that people can mix and match compression styles in their compaction algorithms. This diff makes it much easier to do that.
Test Plan: make check
Reviewers: dhruba, haobo, sdong, yhchiang, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19137
Summary: files_by_size_ is sorted by time in case of universal compaction. However, Version::files_ is also sorted by time. So no need for files_by_size_
Test Plan:
1) make check with the change
2) make check with `assert(last_index == c->input_version_->files_[level].size() - 1);` in compaction picker
Reviewers: dhruba, haobo, yhchiang, sdong, ljin
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19125
Summary: Code cleaning up, since we are already using __STDC_FORMAT_MACROS in printing uint64_t, change other places. Only logging is changed.
Test Plan: make all check
Reviewers: ljin
Reviewed By: ljin
Subscribers: dhruba, yhchiang, haobo, leveldb
Differential Revision: https://reviews.facebook.net/D19113
Summary:
This diff allows compaction to reclaim storage more effectively.
In the current design, compactions are mainly triggered based on
the file sizes. However, since deletion entries does not have
value, files which have many deletion entries are less likely
to be compacted. As a result, it may took a while to make
deletion entries to be compacted.
This diff address issue by compensating the size of deletion
entries during compaction process: the size of each deletion
entry in the compaction process is augmented by 2x average
value size. The diff applies to both leveled and universal
compacitons.
Test Plan:
develop CompactionDeletionTrigger
make db_test
./db_test
Reviewers: haobo, igor, ljin, sdong
Reviewed By: sdong
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19029
Summary:
As discussed in our internal group, we don't get much use of seek compaction at the moment, while it's making code more complicated and slower in some cases.
This diff removes seek compaction and (hopefully) all code that was introduced to support seek compaction.
There is one test case that relied on didIO information. I'll try to find another way to implement it.
Test Plan: make check
Reviewers: sdong, haobo, yhchiang, ljin, dhruba
Reviewed By: ljin
Subscribers: leveldb
Differential Revision: https://reviews.facebook.net/D19161
Summary:
We added multiple fields to FileMetaData recently and are planning to add more.
This refactoring separate the minimum information for accessing the file. This object is copyable (FileMetaData is not copyable since the ref counter). I hope this refactoring can enable further improvements:
(1) use it to design a more efficient data structure to speed up read queries.
(2) in the future, when we add information of storage level, we can easily do the encoding, instead of enlarge this structure, which might expand memory work set for file meta data.
The definition is same as current EncodedFileMetaData used in two level iterator, so now the logic in two level iterator is easier to understand.
Test Plan: make all check
Reviewers: haobo, igor, ljin
Reviewed By: ljin
Subscribers: leveldb, dhruba, yhchiang
Differential Revision: https://reviews.facebook.net/D18933
Summary:
Introducing new compaction style -- FIFO.
FIFO compaction style has write amplification of 1 (+1 for WAL) and it deletes the oldest files when the total DB size exceeds pre-configured values.
FIFO compaction style is suited for storing high-frequency event logs.
Test Plan: Added a unit test
Reviewers: dhruba, haobo, sdong
Reviewed By: dhruba
Subscribers: alberts, leveldb
Differential Revision: https://reviews.facebook.net/D18765
Summary:
Now that we have column families involved, we need to add extra context to every log message. They now start with "[column family name] log message"
Also added some logging that I think would be useful, like level summary after every flush (I often needed that when going through the logs).
Test Plan: make check + ran db_bench to confirm I'm happy with log output
Reviewers: dhruba, haobo, ljin, yhchiang, sdong
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D18303
Summary: Move several some common logging still in DB mutex to log buffer.
Test Plan: make all check
Reviewers: haobo, igor, ljin, nkg-
Reviewed By: nkg-
CC: nkg-, yhchiang, leveldb
Differential Revision: https://reviews.facebook.net/D17439
Summary:
As it turns out, we need the call to ComputeCompactionScore (previously: Finalize) in CompactionPicker.
The issue caused a deadlock in db_stress: http://ci-builds.fb.com/job/rocksdb_crashtest/290/console
The last two lines before a deadlock were:
2014/03/18-22:43:41.481029 7facafbee700 (Original Log Time 2014/03/18-22:43:41.480989) Compaction nothing to do
2014/03/18-22:43:41.481041 7faccf7fc700 wait for fewer level0 files...
"Compaction nothing to do" and other thread waiting for fewer level0 files. Hm hm.
I moved the pre-sorting to SaveTo, which should fix both the original and the new issue.
Test Plan: make check for now, will run db_stress in jenkins
Reviewers: dhruba, haobo, sdong
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D17037
Summary:
We have an issue with internal service trying to run compaction with zero input files:
2014/02/07-02:26:58.386531 7f79117ec700 Compaction start summary: Base version 1420 Base level 3, seek compaction:0, inputs:[ϛ~^Qy^?],[]
2014/02/07-02:26:58.386539 7f79117ec700 Compacted 0@3 + 0@4 files => 0 bytes
There are two issues:
* inputsummary is printing out junk
* it's constantly retrying (since I guess madeProgress is true), so it prints out a lot of data in the LOG file (40GB in one day).
I read through the Level compaction picker and added some failure condition if input[0] is empty. I think PickCompaction() should not return compaction with zero input files with this change. I'm not confident enough to add an assertion though :)
Test Plan: make check
Reviewers: dhruba, haobo, sdong, kailiu
Reviewed By: haobo
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16005
Summary:
Finalize re-sorts (read: mutates) the files_ in Version* and it is called by CompactionPicker during normal runtime. At the same time, this same Version* lives in the SuperVersion* and is accessed without the mutex in GetImpl() code path.
Mutating the files_ in one thread and reading the same files_ in another thread is a bad idea. It caused this issue: http://ci-builds.fb.com/job/rocksdb_crashtest/285/console
Long-term, we need to be more careful with method contracts and clearly document what state can be mutated when. Now that we are much faster because we don't lock in GetImpl(), we keep running into data races that were not a problem before when we were slower. db_stress has been very helpful in detecting those.
Short-term, I removed Finalize() from CompactionPicker.
Note: I believe this is an issue in current 2.7 version running in production.
Test Plan:
make check
Will also run db_stress to see if issue is gone
Reviewers: sdong, ljin, dhruba, haobo
Reviewed By: sdong
CC: leveldb
Differential Revision: https://reviews.facebook.net/D16983
