Summary:
Measure CPU time consumed for a compaction and report it in the stats report
Enable NowCPUNanos() to work for MacOS
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4889
Differential Revision: D13701276
Pulled By: zinoale
fbshipit-source-id: 5024e5bbccd4dd10fd90d947870237f436445055
Summary:
This property can help debug why SST files aren't being deleted. Previously we only had the property "rocksdb.is-file-deletions-enabled". However, even when that returned true, obsolete SSTs may still not be deleted due to the coarse-grained mechanism we use to prevent newly created SSTs from being accidentally deleted. That coarse-grained mechanism uses a lower bound file number for SSTs that should not be deleted, and this property exposes that lower bound.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4618
Differential Revision: D12898179
Pulled By: ajkr
fbshipit-source-id: fe68acc041ddbcc9276bbd48976524d95aafc776
Summary:
Add a new DB property to DB::GetProperty(), which returns the option.statistics. Test is updated to pass.
Closes https://github.com/facebook/rocksdb/pull/3966
Differential Revision: D8311139
Pulled By: zhichao-cao
fbshipit-source-id: ea78f4727358c807b0e5a0ea62e09defb10ad9ac
Summary:
This patch record min log number to keep to the manifest while flushing SST files to ignore them and any WAL older than them during recovery. This is to avoid scenarios when we have a gap between the WAL files are fed to the recovery procedure. The gap could happen by for example out-of-order WAL deletion. Such gap could cause problems in 2PC recovery where the prepared and commit entry are placed into two separate WAL and gap in the WALs could result into not processing the WAL with the commit entry and hence breaking the 2PC recovery logic.
Before the commit, for 2PC case, we determined which log number to keep in FindObsoleteFiles(). We looked at the earliest logs with outstanding prepare entries, or prepare entries whose respective commit or abort are in memtable. With the commit, the same calculation is done while we apply the SST flush. Just before installing the flush file, we precompute the earliest log file to keep after the flush finishes using the same logic (but skipping the memtables just flushed), record this information to the manifest entry for this new flushed SST file. This pre-computed value is also remembered in memory, and will later be used to determine whether a log file can be deleted. This value is unlikely to change until next flush because the commit entry will stay in memtable. (In WritePrepared, we could have removed the older log files as soon as all prepared entries are committed. It's not yet done anyway. Even if we do it, the only thing we loss with this new approach is earlier log deletion between two flushes, which does not guarantee to happen anyway because the obsolete file clean-up function is only executed after flush or compaction)
This min log number to keep is stored in the manifest using the safely-ignore customized field of AddFile entry, in order to guarantee that the DB generated using newer release can be opened by previous releases no older than 4.2.
Closes https://github.com/facebook/rocksdb/pull/3765
Differential Revision: D7747618
Pulled By: siying
fbshipit-source-id: d00c92105b4f83852e9754a1b70d6b64cb590729
Summary:
This PR comments out the rest of the unused arguments which allow us to turn on the -Wunused-parameter flag. This is the second part of a codemod relating to https://github.com/facebook/rocksdb/pull/3557.
Closes https://github.com/facebook/rocksdb/pull/3662
Differential Revision: D7426121
Pulled By: Dayvedde
fbshipit-source-id: 223994923b42bd4953eb016a0129e47560f7e352
Summary:
Add `compaction_reason` as part of event log for event `compaction started`.
Add counters for each `CompactionReason`.
Closes https://github.com/facebook/rocksdb/pull/3679
Differential Revision: D7550348
Pulled By: riversand963
fbshipit-source-id: a19cff3a678c785aa5ef41aac78b9a5968fcc34d
Summary:
Add "rocksdb.live-sst-files-size" DB property which only include files of latest version. Existing "rocksdb.total-sst-files-size" include files from all versions and thus include files that's obsolete but not yet deleted. I'm going to use this new property to cap blob db sst + blob files size.
Closes https://github.com/facebook/rocksdb/pull/3548
Differential Revision: D7116939
Pulled By: yiwu-arbug
fbshipit-source-id: c6a52e45ce0f24ef78708156e1a923c1dd6bc79a
Summary:
With FIFO compaction we would like to get the oldest data time for monitoring. The problem is we don't have timestamp for each key in the DB. As an approximation, we expose the earliest of sst file "creation_time" property.
My plan is to override the property with a more accurate value with blob db, where we actually have timestamp.
Closes https://github.com/facebook/rocksdb/pull/2842
Differential Revision: D5770600
Pulled By: yiwu-arbug
fbshipit-source-id: 03833c8f10bbfbee62f8ea5c0d03c0cafb5d853a
Summary:
Some of these names, like `MEMTABLE_COMPACTION`, did not mean anything. Tried to give them descriptive names.
Closes https://github.com/facebook/rocksdb/pull/2852
Differential Revision: D5782822
Pulled By: ajkr
fbshipit-source-id: f2695c4124af4073da4492d7135bae2411220f3a
Summary:
This branch extends existing property map which keeps values in doubles to keep values in strings so that it can be used to provide wider range of properties. The immediate need for that is to provide IO stall stats in an easy parseable way to MyRocks which is also part of this branch.
Closes https://github.com/facebook/rocksdb/pull/2794
Differential Revision: D5717676
Pulled By: Tema
fbshipit-source-id: e34ba5b79ba774697f7b97ce1138d8fd55471b8a
Summary:
AddDBStats is in two steps of load and store, which is more efficient than fetch_add. This is however not thread-safe. Currently we have to protect concurrent access to AddDBStats with a mutex which is less efficient that fetch_add.
This patch adds the option to do fetch_add when AddDBStats. The results for my 2pc benchmark on sysbench is:
- vanilla: 68618 tps
- removing mutex on AddDBStats (unsafe): 69767 tps
- fetch_add for all AddDBStats: 69200 tps
- fetch_add only for concurrently access AddDBStats (this patch): 69579 tps
Closes https://github.com/facebook/rocksdb/pull/2505
Differential Revision: D5330656
Pulled By: maysamyabandeh
fbshipit-source-id: af64d7bee135b0e86b4fac323a4f9d9113eaa383
Summary:
Replacement of #2147
The change was squashed due to a lot of conflicts.
Closes https://github.com/facebook/rocksdb/pull/2194
Differential Revision: D4929799
Pulled By: siying
fbshipit-source-id: 5cd49c254737a1d5ac13f3c035f128e86524c581
Summary:
Add a function to allow users to reset internal stats without restarting the DB.
Closes https://github.com/facebook/rocksdb/pull/2167
Differential Revision: D4907939
Pulled By: siying
fbshipit-source-id: ab2dd85b88aabe9380da7485320a1d460d3e1f68
Summary:
Currently level histogram is only printed out for DB stats and for default CF. This is confusing. Change to print for every CF instead.
Closes https://github.com/facebook/rocksdb/pull/2126
Differential Revision: D4865373
Pulled By: siying
fbshipit-source-id: 1c853e0ac66e00120ee931cabc9daf69ccc2d577
Summary:
Add two DB properties: rocksdb.actual_delayed_write_rate and rocksdb.is_write_stooped, for people to know whether current writes are being throttled.
Closes https://github.com/facebook/rocksdb/pull/2043
Differential Revision: D4782975
Pulled By: siying
fbshipit-source-id: 6b2f5cf
Summary:
If 2PC is enabled, checkpoint may not copy previous log files that contain uncommitted prepare records. In this diff we keep those files.
Closes https://github.com/facebook/rocksdb/pull/1724
Differential Revision: D4368319
Pulled By: siying
fbshipit-source-id: cc2c746
Summary:
Currently the compaction stats are printed to stdout. We want to export the compaction stats in a map format so that the upper layer apps (e.g., MySQL) could present
the stats in any format required by the them.
Closes https://github.com/facebook/rocksdb/pull/1477
Differential Revision: D4149836
Pulled By: maysamyabandeh
fbshipit-source-id: b3df19f
Summary:
Report more information about the ingested files in CF InternalStats
- Total files
- Total L0 files
- Total keys
There was also noticed that we were reporting files that failed to ingest, fix this bug
Test Plan: print stats in tests
Reviewers: sdong, andrewkr, lightmark
Reviewed By: lightmark
Subscribers: jkedgar, andrewkr, dhruba, yoshinorim
Differential Revision: https://reviews.facebook.net/D63039
Summary:
We dont report the bytes that we ingested from AddFile which make the write amplification numbers incorrect
Update InternalStats and add logging for AddFile()
Test Plan: Make sure the code compile and existing tests pass
Reviewers: lightmark, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D59763
Summary:
Now we collect compaction stats per column family, but report default colum family's stat as compaction stats for DB.
Fix it by reporting compaction stats per column family instead.
Test Plan: Run db_bench with --num_column_families=4 and see the number fixed.
Reviewers: IslamAbdelRahman, yhchiang
Reviewed By: yhchiang
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D57063
Summary:
This is needed so we can measure compression ratio improvements
achieved by D52287.
The property compares raw data size against the total file size for a given
level. If the level is empty it should return 0.0.
Test Plan: new unit test
Reviewers: IslamAbdelRahman, yhchiang, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D56967
Summary: I realized I again is wrong about the naming convention. Let me change it to the correct one.
Test Plan: Run unit tests.
Reviewers: IslamAbdelRahman, kradhakrishnan, yhchiang, andrewkr
Reviewed By: andrewkr
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D55041
Summary: Add a DB Property "rocksdb.current_version_number" for users to monitor version changes and stale iterators.
Test Plan: Add a unit test.
Reviewers: andrewkr, yhchiang, kradhakrishnan, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D54927
Summary:
Before this diff, there were duplicated constants to refer to properties (user-
facing API had strings and InternalStats had an enum). I noticed these were
inconsistent in terms of which constants are provided, names of constants, and
documentation of constants. Overall it seemed annoying/error-prone to maintain
these duplicated constants.
So, this diff gets rid of InternalStats's constants and replaces them with a map
keyed on the user-facing constant. The value in that map contains a function
pointer to get the property value, so we don't need to do string matching while
holding db->mutex_. This approach has a side benefit of making many small
handler functions rather than a giant switch-statement.
Test Plan: db_properties_test passes, running "make commit-prereq -j32"
Reviewers: sdong, yhchiang, kradhakrishnan, IslamAbdelRahman, rven, anthony
Reviewed By: anthony
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D53253
Summary:
This diff adds support for concurrent adds to the skiplist memtable
implementations. Memory allocation is made thread-safe by the addition of
a spinlock, with small per-core buffers to avoid contention. Concurrent
memtable writes are made via an additional method and don't impose a
performance overhead on the non-concurrent case, so parallelism can be
selected on a per-batch basis.
Write thread synchronization is an increasing bottleneck for higher levels
of concurrency, so this diff adds --enable_write_thread_adaptive_yield
(default off). This feature causes threads joining a write batch
group to spin for a short time (default 100 usec) using sched_yield,
rather than going to sleep on a mutex. If the timing of the yield calls
indicates that another thread has actually run during the yield then
spinning is avoided. This option improves performance for concurrent
situations even without parallel adds, although it has the potential to
increase CPU usage (and the heuristic adaptation is not yet mature).
Parallel writes are not currently compatible with
inplace updates, update callbacks, or delete filtering.
Enable it with --allow_concurrent_memtable_write (and
--enable_write_thread_adaptive_yield). Parallel memtable writes
are performance neutral when there is no actual parallelism, and in
my experiments (SSD server-class Linux and varying contention and key
sizes for fillrandom) they are always a performance win when there is
more than one thread.
Statistics are updated earlier in the write path, dropping the number
of DB mutex acquisitions from 2 to 1 for almost all cases.
This diff was motivated and inspired by Yahoo's cLSM work. It is more
conservative than cLSM: RocksDB's write batch group leader role is
preserved (along with all of the existing flush and write throttling
logic) and concurrent writers are blocked until all memtable insertions
have completed and the sequence number has been advanced, to preserve
linearizability.
My test config is "db_bench -benchmarks=fillrandom -threads=$T
-batch_size=1 -memtablerep=skip_list -value_size=100 --num=1000000/$T
-level0_slowdown_writes_trigger=9999 -level0_stop_writes_trigger=9999
-disable_auto_compactions --max_write_buffer_number=8
-max_background_flushes=8 --disable_wal --write_buffer_size=160000000
--block_size=16384 --allow_concurrent_memtable_write" on a two-socket
Xeon E5-2660 @ 2.2Ghz with lots of memory and an SSD hard drive. With 1
thread I get ~440Kops/sec. Peak performance for 1 socket (numactl
-N1) is slightly more than 1Mops/sec, at 16 threads. Peak performance
across both sockets happens at 30 threads, and is ~900Kops/sec, although
with fewer threads there is less performance loss when the system has
background work.
Test Plan:
1. concurrent stress tests for InlineSkipList and DynamicBloom
2. make clean; make check
3. make clean; DISABLE_JEMALLOC=1 make valgrind_check; valgrind db_bench
4. make clean; COMPILE_WITH_TSAN=1 make all check; db_bench
5. make clean; COMPILE_WITH_ASAN=1 make all check; db_bench
6. make clean; OPT=-DROCKSDB_LITE make check
7. verify no perf regressions when disabled
Reviewers: igor, sdong
Reviewed By: sdong
Subscribers: MarkCallaghan, IslamAbdelRahman, anthony, yhchiang, rven, sdong, guyg8, kradhakrishnan, dhruba
Differential Revision: https://reviews.facebook.net/D50589
Summary: Now if inserting to mem table is much faster than writing to files, there is no mechanism users can rely on to avoid stopping for reaching options.max_write_buffer_number. With the commit, if there are more than four maximum write buffers configured, we slow down to the rate of options.delayed_write_rate while we reach the last one.
Test Plan:
1. Add a new unit test.
2. Run db_bench with
./db_bench --benchmarks=fillrandom --num=10000000 --max_background_flushes=6 --batch_size=32 -max_write_buffer_number=4 --delayed_write_rate=500000 --statistics
based on hard drive and see stopping is avoided with the commit.
Reviewers: yhchiang, IslamAbdelRahman, anthony, rven, kradhakrishnan, igor
Reviewed By: igor
Subscribers: MarkCallaghan, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D52047
Summary: Deprecate options.soft_rate_limit, which is hard to tune, with options.soft_pending_compaction_bytes_limit, which would trigger the slowdown if estimated pending compaction bytes exceeds the threshold. The hope is to make it more striaght-forward to tune.
Test Plan: Modify DBTest.SoftLimit to cover options.soft_pending_compaction_bytes_limit instead; run all unit tests.
Reviewers: IslamAbdelRahman, yhchiang, rven, kradhakrishnan, igor, anthony
Reviewed By: anthony
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D51117
Summary:
Add rocksdb.num-running-compactions and rocksdb.num-running-flushes
to GetIntProperty() that reports the number of currently running
compactions / flushes.
Test Plan: augmented existing tests in db_test
Reviewers: igor, IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D48693
Summary: Add an option to stop writes if compaction lefts behind. If estimated pending compaction bytes is more than threshold specified by options.hard_pending_compaction_bytes_liimt, writes will stop until compactions are cleared to under the threshold.
Test Plan: Add unit test DBTest.HardLimit
Reviewers: rven, kradhakrishnan, anthony, IslamAbdelRahman, yhchiang, igor
Reviewed By: igor
Subscribers: MarkCallaghan, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D45999
Summary:
Although there are currently counters to keep track of the
stall caused by having too many L0 files, there is no distinction as
to whether when that stall occurs either (A) L0-L1 compaction is taking
place to try and mitigate it, or (B) no L0-L1 compaction has been scheduled
at the moment. This diff adds a counter for (A) so that the nature of L0
stalls can be better understood.
Test Plan: make all && make check
Reviewers: sdong, igor, anthony, noetzli, yhchiang
Reviewed By: yhchiang
Subscribers: MarkCallaghan, dhruba
Differential Revision: https://reviews.facebook.net/D46749
Summary:
This patch adds "rocksdb.aggregated-table-properties"
and "rocksdb.aggregated-table-properties-at-levelN", the former
returns the aggreated table properties of a column family,
while the later returns the aggregated table properties
of the specified level N.
Test Plan: Added tests in db_test
Reviewers: igor, sdong, IslamAbdelRahman, anthony
Reviewed By: anthony
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D45087
Summary:
Add a counter of estimated bytes the DB needs to compact for all the compactions to finish. Expose it as a DB Property.
In the future, we can use threshold of this counter to replace soft rate limit and hard rate limit. A single threshold of estimated compaction debt in bytes will be easier for users to reason about when should slow down and stopping than more abstract soft and hard rate limits.
Test Plan: Add unit tests
Reviewers: IslamAbdelRahman, yhchiang, rven, kradhakrishnan, anthony, igor
Reviewed By: igor
Subscribers: leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D44205
Summary: Add a new DB property that calculate the total size of files used by all RocksDB Versions
Test Plan: Unittests for the new property
Reviewers: igor, yhchiang, anthony, rven, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D44799
Summary:
Currently, GetIntProperty("rocksdb.cur-size-all-mem-tables") only returns
the memory usage by those memtables which have not yet been flushed.
This patch introduces GetIntProperty("rocksdb.size-all-mem-tables"),
which includes the memory usage by all the memtables, includes those
have been flushed but pinned by iterators.
Test Plan: Added a test in db_test
Reviewers: igor, anthony, IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D44229
Summary: In internal stats, remember read latency histogram, if statistics is enabled. It can be retrieved from DB::GetProperty() with "rocksdb.dbstats" property, if it is enabled.
Test Plan: Manually run db_bench and prints out "rocksdb.dbstats" by hand and make sure it prints out as expected
Reviewers: igor, IslamAbdelRahman, rven, kradhakrishnan, anthony, yhchiang
Reviewed By: yhchiang
Subscribers: MarkCallaghan, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D44193
Summary:
Fixes T6548822. Added a new function for estimating the size of the live data
as proposed in the task. The value can be accessed through the property
rocksdb.estimate-live-data-size.
Test Plan:
There are two unit tests in version_set_test and a simple test in db_test.
make version_set_test && ./version_set_test;
make db_test && ./db_test gtest_filter=GetProperty
Reviewers: rven, igor, yhchiang, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D41493
Summary:
Universal compaction can involves in multiple levels. However,
the current implementation of bytes_readn and bytes_readnp1
(and some other stats with postfix `n` and `np1`) assumes compaction
can only have two levels.
This patch fixes this bug and redefines bytes_readn and bytes_readnp1:
* bytes_readnp1: the number of bytes read in the compaction output level.
* bytes_readn: the total number of bytes read minus bytes_readnp1
Test Plan: Add a test in compaction_job_stats_test
Reviewers: igor, sdong, rven, anthony, kradhakrishnan, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D40239
Summary:
For transactions, we are using the memtables to validate that there are no write conflicts. But after flushing, we don't have any memtables, and transactions could fail to commit. So we want to someone keep around some extra history to use for conflict checking. In addition, we want to provide a way to increase the size of this history if too many transactions fail to commit.
After chatting with people, it seems like everyone prefers just using Memtables to store this history (instead of a separate history structure). It seems like the best place for this is abstracted inside the memtable_list. I decide to create a separate list in MemtableListVersion as using the same list complicated the flush/installalflushresults logic too much.
This diff adds a new parameter to control how much memtable history to keep around after flushing. However, it sounds like people aren't too fond of adding new parameters. So I am making the default size of flushed+not-flushed memtables be set to max_write_buffers. This should not change the maximum amount of memory used, but make it more likely we're using closer the the limit. (We are now postponing deleting flushed memtables until the max_write_buffer limit is reached). So while we might use more memory on average, we are still obeying the limit set (and you could argue it's better to go ahead and use up memory now instead of waiting for a write stall to happen to test this limit).
However, if people are opposed to this default behavior, we can easily set it to 0 and require this parameter be set in order to use transactions.
Test Plan: Added a xfunc test to play around with setting different values of this parameter in all tests. Added testing in memtablelist_test and planning on adding more testing here.
Reviewers: sdong, rven, igor
Reviewed By: igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D37443
Summary:
See https://gist.github.com/mdcallag/89ebb2b8cbd331854865 for the IO stats.
I added "Cumulative compaction:" and "Interval compaction:" lines. The IO rates
can be confusing. Rates fro per-level stats lines, Wr(MB/s) & Rd(MB/s), are computed
using the duration of the compaction job. If the job reads 10MB, writes 9MB and the job
(IO & merging) takes 1 second then the rates are 10MB/s for read and 9MB/s for writes.
The IO rates in the Cumulative compaction line uses the total uptime. The IO rates in the
Interval compaction line uses the interval uptime. So these Cumalative & Interval
compaction IO rates cannot be compared to the per-level IO rates. But both forms of
the rates are useful for debugging perf.
Task ID: #
Blame Rev:
Test Plan:
run db_bench
Revert Plan:
Database Impact:
Memcache Impact:
Other Notes:
EImportant:
- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -
Reviewers: igor
Reviewed By: igor
Subscribers: dhruba
Differential Revision: https://reviews.facebook.net/D38667
Summary:
Fix a compilation error in ROCKSDB_LITE in db/internal_stats.h
Other compilation errors will be fixed in a separate diff.
Test Plan: make OPT=-DROCKSDB_LITE
Reviewers: sdong, igor
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D36807
Summary: Add a DB property for number of deletions in memtables. It can sometimes help people debug slowness because of too many deletes.
Test Plan: Add test cases.
Reviewers: rven, yhchiang, kradhakrishnan, igor
Reviewed By: igor
Subscribers: leveldb, dhruba, yoshinorim
Differential Revision: https://reviews.facebook.net/D35247
Zhongyi Xie