Summary:
As of now compactions involving files from Level 0 and Level 1 are single
threaded because the files in L0, although sorted, are not range partitioned like
the other levels. This means that during L0-L1 compaction each file from L1
needs to be merged with potentially all the files from L0.
This attempt to parallelize the L0-L1 compaction assigns a thread and a
corresponding iterator to each L1 file that then considers only the key range
found in that L1 file and only the L0 files that have those keys (and only the
specific portion of those L0 files in which those keys are found). In this way
the overlap is minimized and potentially eliminated between different iterators
focusing on the same files.
The first step is to restructure the compaction logic to break L0-L1 compactions
into multiple, smaller, sequential compactions. Eventually each of these smaller
jobs will be run simultaneously. Areas to pay extra attention to are
# Correct aggregation of compaction job statistics across multiple threads
# Proper opening/closing of output files (make sure each thread's is unique)
# Keys that span multiple L1 files
# Skewed distributions of keys within L0 files
Test Plan: Make and run db_test (newer version has separate compaction tests) and compaction_job_stats_test
Reviewers: igor, noetzli, anthony, sdong, yhchiang
Reviewed By: yhchiang
Subscribers: MarkCallaghan, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42699
Summary: Now ldb dump_manifest refuses to work if there are 20 levels. Extend the limit to 64.
Test Plan: Run the tool with 20 number of levels
Reviewers: kradhakrishnan, anthony, IslamAbdelRahman, yhchiang
Reviewed By: yhchiang
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D42879
Summary:
sst_dump_tool contains two instances of `fprintf`s where the `format` argument is not
a string literal. This prevents the code from compiling with some compilers/compiler
options because of the potential security risks associated with printing non-literals.
Test Plan: make all
Reviewers: rven, igor, yhchiang, sdong, anthony
Reviewed By: anthony
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D43305
Summary:
Added a new feature to sst_dump_tool.cc to allow a user to see the sizes of the different compression algorithms on an .sst file.
Usage:
./sst_dump --file=<filename> --show_compression_sizes
./sst_dump --file=<filename> --show_compression_sizes --set_block_size=<block_size>
Note: If you do not set a block size, it will default to 16kb
Test Plan: manual test and the write a unit test
Reviewers: IslamAbdelRahman, anthony, yhchiang, rven, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D42963
Summary:
For task #7771355, we would like to log the number of corrupt keys
during a compaction. This patch implements and tests the count
as part of CompactionJobStats.
Test Plan: make && make check
Reviewers: rven, igor, yhchiang, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42921
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
* std::chrono does not provide enough granularity for microsecs and periodically emits
duplicates
* the bug is manifested in log rotation logic where we get duplicate
log file names and loose previous log content
* msvc does not imlement COW on std::strings adjusted the test to use
refs in the loops as auto does not retain ref info
* adjust auto_log rotation test with Windows specific command to remove
a folder. The test previously worked because we have unix utils installed
in house but this may not be the case for everyone.
Summary: https://reviews.facebook.net/D42321 has left PosixMmapFile in some weird state. This diff removes pending_sync_ that was now unused, fixes indentation and prevents Fsync() from calling both fsync() and fdatasync().
Test Plan: `make -j check`
Reviewers: sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D42885
Summary: Directly using TMPDIR can cause problems when running tests using parallel option. Fix them.
Test Plan: Run all tests in parallel
Reviewers: kradhakrishnan, yhchiang, IslamAbdelRahman, anthony
Reviewed By: anthony
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D42807
Summary:
From other ones' investigation:
"sync_file_range() behavior highly depends on kernel version and filesystem.
xfs does neighbor page flushing outside of the specified ranges. For example, sync_file_range(fd, 8192, 16384) does not only trigger flushing page #3 to #4, but also flushing many more dirty pages (i.e. up to page#16)... Ranges of the sync_file_range() should be far enough from write() offset (at least 1MB)."
Test Plan: make all check
Reviewers: igor, rven, kradhakrishnan, yhchiang, IslamAbdelRahman, anthony
Reviewed By: anthony
Subscribers: yoshinorim, MarkCallaghan, sumeet, domas, dhruba, leveldb, ljin
Differential Revision: https://reviews.facebook.net/D15807
Summary: Add new CheckFileExists method. Considered changing the FileExists api but didn't want to break anyone's builds.
Test Plan: unit tests
Reviewers: yhchiang, igor, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42003
Summary:
Skipping these tests in ROCKSDB_LITE since they are not supported
json_document_test
wal_manager_test
ttl_test
sst_dump_test
deletefile_test
compact_files_test
prefix_test
checkpoint_test
Test Plan:
json_document_test
wal_manager_test
ttl_test
sst_dump_test
deletefile_test
compact_files_test
prefix_test
checkpoint_test
Reviewers: igor, sdong, yhchiang, kradhakrishnan, anthony
Reviewed By: anthony
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D42573
Summary: Make mock_env_test runnable in ROCKSDB_LITE
Test Plan: mock_env_test
Reviewers: igor, sdong, yhchiang, kradhakrishnan, anthony
Reviewed By: anthony
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D42585
Summary: We want to keep Env a think layer for better portability. Less platform dependent codes should be moved out of Env. In this patch, I create a wrapper of file readers and writers, and put rate limiting, write buffering, as well as most perf context instrumentation and random kill out of Env. It will make it easier to maintain multiple Env in the future.
Test Plan: Run all existing unit tests.
Reviewers: anthony, kradhakrishnan, IslamAbdelRahman, yhchiang, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D42321
Summary: CYGWIN avoided fread_unlocked in a wrong way. Fix it to the standard way.
Test Plan: Run tests
Reviewers: anthony, kradhakrishnan, IslamAbdelRahman, yhchiang, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D42549
Summary:
When we first started, max_background_flushes was 0 by default and compaction thread was executing flushes (since there was no flush thread). Then, we switched the default max_background_flushes to 1. However, we still support the case where there is no flush thread and flushes are done in compaction. This is making our code a bit more complicated. By not supporting this use-case we can make our code simpler.
We have a special case that when you set max_background_flushes to 0, we
schedule the flush to execute on the compaction thread.
Test Plan: make check (there might be some unit tests that depend on this behavior)
Reviewers: IslamAbdelRahman, yhchiang, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D41931
Summary:
ROCKSDB_WARNING is only defined if either ROCKSDB_PLATFORM_POSIX or OS_WIN is defined. This works well for building rocksdb with its own build scripts. But this won't work when an outside project(like mongodb) doesn't define ROCKSDB_PLATFORM_POSIX.
This fix defines ROCKSDB_WARNING for all platforms. No idea if its defined correctly on non-posix,non-windows platforms but this is no worse that the current situation where this macro is missing on unexpected platforms.
This fix should hopefully fix anyone whose build broke now that we've switched from using #warning to Pragma (to support windows). Unfortunately, while mongo-rocks compiles, it ignores the Pragma and doesn't print a warning. I have not been able to figure out a way to implement this portably on all platforms.
Of course, an alternate solution would be to just get rid of ROCKSDB_WARNING and live with include file redirects indefinitely. Thoughts?
Test Plan: build rocks, build mongorocks
Reviewers: igor, kradhakrishnan, IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42477
Summary: It has been around for a while and it looks like it never found any uses in the wild. It's also complicating our compaction_job code quite a bit. We're deprecating it in 3.13, but will put it back in 3.14 if we actually find users that need this feature.
Test Plan: make check
Reviewers: noetzli, yhchiang, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42405
Summary:
MergeUntil was not reporting a success when merging an operand with
a Value/Deletion despite the comments in MergeHelper and CompactionJob
indicating otherwise. This lead to operands being written to the compaction
output unnecessarily:
M1 M2 M3 P M4 M5 --> (P+M1+M2+M3) M2 M3 M4 M5 (before the diff)
M1 M2 M3 P M4 M5 --> (P+M1+M2+M3) M4 M5 (after the diff)
In addition, the code handling Values/Deletion was basically identical.
This patch unifies the code. Finally, this patch also adds testing for
merge_helper.
Test Plan: make && make check
Reviewers: sdong, rven, yhchiang, tnovak, igor
Reviewed By: igor
Subscribers: tnovak, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42351
- Remove make file defines from public headers and use _WIN32 because it is compiler defined
- use __GNUC__ and __clang__ to guard non-portable attributes
- add #include "port/port.h" to some new .cc files.
- minor changes in CMakeLists to reflect recent changes
- Remove make file defines from public headers and use _WIN32 because it is compiler defined
- use __GNUC__ and __clang__ to guard non-portable attributes
- add #include "port/port.h" to some new .cc files.
- minor changes in CMakeLists to reflect recent changes
Summary: Moved convenience.h out of utilities to remove a dependency on utilities in db.
Test Plan: unit tests. Also compiled a link to the old location to verify the _Pragma works.
Reviewers: sdong, yhchiang, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42201
Summary:
Trvial move in universal compaction was failing when trying to move files from levels other than 0.
This was because the DeleteFile while trivially moving, was only deleting files of level 0 which caused duplication of same file in different levels.
This is fixed by passing the right level as argument in the call of DeleteFile while doing trivial move.
Test Plan: ./db_test ran successfully with the new test cases.
Reviewers: sdong
Reviewed By: sdong
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D42135
Summary: Make TransactionLogIterator related tests from db_test.cc to db_log_iter_test.cc
Test Plan:
db_test
db_log_iter_test
Reviewers: sdong, IslamAbdelRahman, igor, anthony
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42045
Summary: This option is guarding the feature implemented 2 and a half years ago: D8991. The feature was enabled by default back then and has been running without issues. There is no reason why any client would turn this feature off. I found no reference in fbcode.
Test Plan: none
Reviewers: sdong, yhchiang, anthony, dhruba
Reviewed By: dhruba
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D42063
Summary:
In one of our recent meetings, we discussed deprecating features that are not being actively used. One of those features, at least within Facebook, is timeout_hint. The feature is really nicely implemented, but if nobody needs it, we should remove it from our code-base (until we get a valid use-case). Some arguments:
* Less code == better icache hit rate, smaller builds, simpler code
* The motivation for adding timeout_hint_us was to work-around RocksDB's stall issue. However, we're currently addressing the stall issue itself (see @sdong's recent work on stall write_rate), so we should never see sharp lock-ups in the future.
* Nobody is using the feature within Facebook's code-base. Googling for `timeout_hint_us` also doesn't yield any users.
Test Plan: make check
Reviewers: anthony, kradhakrishnan, sdong, yhchiang
Reviewed By: yhchiang
Subscribers: sdong, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D41937
Summary:
Move global static functions in db_test_util to DBTestBase.
This is to prevent unused function warning when decoupling
db_test.cc into multiple files.
Test Plan: db_test
Reviewers: igor, sdong, anthony, IslamAbdelRahman, kradhakrishnan
Reviewed By: kradhakrishnan
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D42009
Summary:
Move reusable part of db_test.cc to util/db_test_util.h.
This makes it more possible to partition db_test.cc into
multiple smaller test files.
Also, fixed many old lint errors in db_test.
Test Plan: db_test
Reviewers: igor, anthony, IslamAbdelRahman, sdong, kradhakrishnan
Reviewed By: sdong, kradhakrishnan
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D41973
Summary:
Added new statistics in CompactionJobStats to keep track of
deletion entries and the expiration of those entries. Updated these
fields in compaction_job.cc as compaction took place and wrote a new
test in compaction_job_stats_test.cc to verify accuracy.
Test Plan:
Wrote new test DeletionStatsTest in
compaction_job_stats_test.cc to verify
Reviewers: sdong, igor, yhchiang
Reviewed By: yhchiang
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D41355
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:
Public API depends on port/port.h which is wrong. Fix it.
Also with gcc 4.8.1 build was broken as MAX_INT32 was not recognized. Fix it by using ::max in linux.
Test Plan: Build it and try to build an external project on top of it.
Reviewers: anthony, yhchiang, kradhakrishnan, igor
Reviewed By: igor
Subscribers: yoshinorim, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D41745
Summary: Print whether fast CRC32 is supported in DB info LOG
Test Plan: Run db_bench and see it prints out correctly.
Reviewers: yhchiang, anthony, kradhakrishnan, igor
Reviewed By: igor
Subscribers: MarkCallaghan, yoshinorim, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D41733
Summary:
new_table_iterator_nanos is not cleaned in PerfContext::Reset() while new_table_block_iter_nanos is cleaned twice. Fix it.
Also fix a comment.
Test Plan: Build and db_bench with --perf_context to see the value shown.
Reviewers: kradhakrishnan, anthony, yhchiang, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D41721
Summary: Add a perf context counter to help users figure out time spent on reading indexes and bloom filter blocks.
Test Plan: Will write a unit test
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D41433
Summary:
While profiling compaction in our service I noticed a lot of CPU (~15% of compaction) being spent in MergingIterator and key comparison. Looking at the code I found MergingIterator was (understandably) using std::priority_queue for the multiway merge.
Keys in our dataset include sequence numbers that increase with time. Adjacent keys in an L0 file are very likely to be adjacent in the full database. Consequently, compaction will often pick a chunk of rows from the same L0 file before switching to another one. It would be great to avoid the O(log K) operation per row while compacting.
This diff replaces std::priority_queue with a custom binary heap implementation. It has a "replace top" operation that is cheap when the new top is the same as the old one (i.e. the priority of the top entry is decreased but it still stays on top).
Test Plan:
make check
To test the effect on performance, I generated databases with data patterns that mimic what I describe in the summary (rows have a mostly increasing sequence number). I see a 10-15% CPU decrease for compaction (and a matching throughput improvement on tmpfs). The exact improvement depends on the number of L0 files and the amount of locality. Performance on randomly distributed keys seems on par with the old code.
Reviewers: kailiu, sdong, igor
Reviewed By: igor
Subscribers: yoshinorim, dhruba, tnovak
Differential Revision: https://reviews.facebook.net/D29133
Summary:
Introduced a new category in the enum InfoLogLevel in env.h.
Modifed Log() in env.cc to use the Header()
when the InfoLogLevel == HEADER_LEVEL.
Updated tests in auto_roll_logger_test to ensure
the header is handled properly in these cases.
Test Plan: Augment existing tests in auto_roll_logger_test
Reviewers: igor, sdong, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D41067
Summary:
Add a new field: BackupableDBOptions.max_background_copies.
CreateNewBackup() and RestoreDBFromBackup() will use this number of threads to perform copies.
If there is a backup rate limit, then max_background_copies must be 1.
Update backupable_db_test.cc to test multi-threaded backup and restore.
Update backupable_db_test.cc to test backups when the backup environment is not the same as the database environment.
Test Plan:
Run ./backupable_db_test
Run valgrind ./backupable_db_test
Run with TSAN and ASAN
Reviewers: yhchiang, rven, anthony, sdong, igor
Reviewed By: igor
Subscribers: yhchiang, anthony, sdong, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D40725
Ari Ekmekji