Summary:
This is the start of some JMH microbenchmarks for RocksJava.
Such benchmarks can help us decide on performance improvements of the Java API.
At the moment, I have only added benchmarks for various Comparator options, as that is one of the first areas where I want to improve performance. I plan to expand this to many more tests.
Details of how to compile and run the benchmarks are in the `README.md`.
A run of these on a XEON 3.5 GHz 4vCPU (QEMU Virtual CPU version 2.5+) / 8GB RAM KVM with Ubuntu 18.04, OpenJDK 1.8.0_232, and gcc 8.3.0 produced the following:
```
# Run complete. Total time: 01:43:17
REMEMBER: The numbers below are just data. To gain reusable insights, you need to follow up on
why the numbers are the way they are. Use profilers (see -prof, -lprof), design factorial
experiments, perform baseline and negative tests that provide experimental control, make sure
the benchmarking environment is safe on JVM/OS/HW level, ask for reviews from the domain experts.
Do not assume the numbers tell you what you want them to tell.
Benchmark (comparatorName) Mode Cnt Score Error Units
ComparatorBenchmarks.put native_bytewise thrpt 25 122373.920 ± 2200.538 ops/s
ComparatorBenchmarks.put java_bytewise_adaptive_mutex thrpt 25 17388.201 ± 1444.006 ops/s
ComparatorBenchmarks.put java_bytewise_non-adaptive_mutex thrpt 25 16887.150 ± 1632.204 ops/s
ComparatorBenchmarks.put java_direct_bytewise_adaptive_mutex thrpt 25 15644.572 ± 1791.189 ops/s
ComparatorBenchmarks.put java_direct_bytewise_non-adaptive_mutex thrpt 25 14869.601 ± 2252.135 ops/s
ComparatorBenchmarks.put native_reverse_bytewise thrpt 25 116528.735 ± 4168.797 ops/s
ComparatorBenchmarks.put java_reverse_bytewise_adaptive_mutex thrpt 25 10651.975 ± 545.998 ops/s
ComparatorBenchmarks.put java_reverse_bytewise_non-adaptive_mutex thrpt 25 10514.224 ± 930.069 ops/s
```
Indicating a ~7x difference between comparators implemented natively (C++) and those implemented in Java. Let's see if we can't improve on that in the near future...
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6241
Differential Revision: D19290410
Pulled By: pdillinger
fbshipit-source-id: 25d44bf3a31de265502ed0c5d8a28cf4c7cb9c0b
Summary:
There are no API changes ;-)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6218
Differential Revision: D19200373
Pulled By: pdillinger
fbshipit-source-id: 58d34b01ea53b75a1eccbd72f8b14d6256a7380f
Summary:
Should fix Travis build error that randomly showed up upon
using Java 13 version of javadoc.
AdvancedColumnFamilyOptionsInterface.java:257: error:
unexpected heading used: <H2>, compared to implicit preceding heading: <H3>
According to this reference https://bugs.openjdk.java.net/browse/JDK-8220379
it should work to start at h4, but that didn't work, so avoiding
headings should be fine.
Also fix Java EnvironmentTest for JDK13.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6208
Test Plan: Travis run on PR (don't have Java 13 handy)
Differential Revision: D19163105
Pulled By: pdillinger
fbshipit-source-id: 4a9419cbe7ef780fba771b8a1508e1ea80d17b3e
Summary:
Add an option to explicitly disable building shared versions of the
RocksDB libraries. The shared libraries cannot be built in cases where
some dependencies are only available as static libraries. This allows
still building RocksDB in these situations.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6122
Differential Revision: D18920740
fbshipit-source-id: d24f66d93c68a1e65635e6e0b663bae62c903bca
Summary:
Add the jni library for musl-libc, specifically for incorporating into Alpine based docker images. The classifier is `musl64`.
I have signed the CLA electronically.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/3143
Differential Revision: D18719372
fbshipit-source-id: 6189d149310b6436d6def7d808566b0234b23313
Summary:
There's no technological impediment to allowing the Bloom
filter bits/key to be non-integer (fractional/decimal) values, and it
provides finer control over the memory vs. accuracy trade-off. This is
especially handy in using the format_version=5 Bloom filter in place
of the old one, because bits_per_key=9.55 provides the same accuracy as
the old bits_per_key=10.
This change not only requires refining the logic for choosing the best
num_probes for a given bits/key setting, it revealed a flaw in that logic.
As bits/key gets higher, the best num_probes for a cache-local Bloom
filter is closer to bpk / 2 than to bpk * 0.69, the best choice for a
standard Bloom filter. For example, at 16 bits per key, the best
num_probes is 9 (FP rate = 0.0843%) not 11 (FP rate = 0.0884%).
This change fixes and refines that logic (for the format_version=5
Bloom filter only, just in case) based on empirical tests to find
accuracy inflection points between each num_probes.
Although bits_per_key is now specified as a double, the new Bloom
filter converts/rounds this to "millibits / key" for predictable/precise
internal computations. Just in case of unforeseen compatibility
issues, we round to the nearest whole number bits / key for the
legacy Bloom filter, so as not to unlock new behaviors for it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6092
Test Plan: unit tests included
Differential Revision: D18711313
Pulled By: pdillinger
fbshipit-source-id: 1aa73295f152a995328cb846ef9157ae8a05522a
Summary:
* We can reuse downloaded 3rd-party libraries
* We can isolate the build to a Docker volume. This is useful for investigating failed builds, as we can examine the volume by assigning it a name during the build.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6079
Differential Revision: D18710263
fbshipit-source-id: 93f456ba44b49e48941c43b0c4d53995ecc1f404
Summary:
Add unordered_write option api and related ut to rocksjava
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5839
Differential Revision: D17604446
Pulled By: maysamyabandeh
fbshipit-source-id: c6b07e85ca9d5e3a92973ddb6ab2bc079e53c9c1
Summary:
The comparison of va_list and nullptr is always False under any arch, and will raise invalid operands of types error in aarch64 env (`error: invalid operands of types ‘va_list {aka __va_list}’ and ‘std::nullptr_t’ to binary ‘operator!=’`).
This patch removes this invalid assert.
Closes: https://github.com/facebook/rocksdb/issues/4277
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5836
Differential Revision: D17532470
fbshipit-source-id: ca98078ecbc6a9416c69de3bd6ffcfa33a0f0185
Summary:
Further apply formatter to more recent commits.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5830
Test Plan: Run all existing tests.
Differential Revision: D17488031
fbshipit-source-id: 137458fd94d56dd271b8b40c522b03036943a2ab
Summary:
Some recent commits might not have passed through the formatter. I formatted recent 45 commits. The script hangs for more commits so I stopped there.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5827
Test Plan: Run all existing tests.
Differential Revision: D17483727
fbshipit-source-id: af23113ee63015d8a43d89a3bc2c1056189afe8f
Summary:
for fillbatch benchmar, the numEntries should be [num_] but not [num_ / 1000] because numEntries is just the total entries we want to test
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5198
Differential Revision: D17274664
Pulled By: anand1976
fbshipit-source-id: f96e952babdbac63fb99d14e1254d478a10437be
Summary:
MyRocks currently sets `max_write_buffer_number_to_maintain` in order to maintain enough history for transaction conflict checking. The effectiveness of this approach depends on the size of memtables. When memtables are small, it may not keep enough history; when memtables are large, this may consume too much memory.
We are proposing a new way to configure memtable list history: by limiting the memory usage of immutable memtables. The new option is `max_write_buffer_size_to_maintain` and it will take precedence over the old `max_write_buffer_number_to_maintain` if they are both set to non-zero values. The new option accounts for the total memory usage of flushed immutable memtables and mutable memtable. When the total usage exceeds the limit, RocksDB may start dropping immutable memtables (which is also called trimming history), starting from the oldest one.
The semantics of the old option actually works both as an upper bound and lower bound. History trimming will start if number of immutable memtables exceeds the limit, but it will never go below (limit-1) due to history trimming.
In order the mimic the behavior with the new option, history trimming will stop if dropping the next immutable memtable causes the total memory usage go below the size limit. For example, assuming the size limit is set to 64MB, and there are 3 immutable memtables with sizes of 20, 30, 30. Although the total memory usage is 80MB > 64MB, dropping the oldest memtable will reduce the memory usage to 60MB < 64MB, so in this case no memtable will be dropped.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5022
Differential Revision: D14394062
Pulled By: miasantreble
fbshipit-source-id: 60457a509c6af89d0993f988c9b5c2aa9e45f5c5
Summary:
The actual value of default write buffer size within `rocksdb/include/rocksdb/options.h` is 64 MB, we should correct this value in java doc.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5670
Differential Revision: D16668815
Pulled By: maysamyabandeh
fbshipit-source-id: cc3a981c9f1c2cd4a8392b0ed5f1fd0a2d729afb
Summary:
if read_options.snapshot is not set, ::Get will take the last sequence number after taking a super-version and uses that as the sequence number. Theoretically max_eviceted_seq_ could advance this sequence number. This could lead ::IsInSnapshot that will be invoked by the ReadCallback to notice the absence of the snapshot. In this case, the ReadCallback should have passed a non-value to snap_released so that it could be set by the ::IsInSnapshot. The patch does that, and adds a unit test to verify it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5664
Differential Revision: D16614033
Pulled By: maysamyabandeh
fbshipit-source-id: 06fb3fd4aacd75806ed1a1acec7961f5d02486f2
Summary:
The first key is used to defer reading the data block until this file gets to the top of merging iterator's heap. For short range scans, most files never make it to the top of the heap, so this change can reduce read amplification by a lot sometimes.
Consider the following workload. There are a few data streams (we'll be calling them "logs"), each stream consisting of a sequence of blobs (we'll be calling them "records"). Each record is identified by log ID and a sequence number within the log. RocksDB key is concatenation of log ID and sequence number (big endian). Reads are mostly relatively short range scans, each within a single log. Writes are mostly sequential for each log, but writes to different logs are randomly interleaved. Compactions are disabled; instead, when we accumulate a few tens of sst files, we create a new column family and start writing to it.
So, a typical sst file consists of a few ranges of blocks, each range corresponding to one log ID (we use FlushBlockPolicy to cut blocks at log boundaries). A typical read would go like this. First, iterator Seek() reads one block from each sst file. Then a series of Next()s move through one sst file (since writes to each log are mostly sequential) until the subiterator reaches the end of this log in this sst file; then Next() switches to the next sst file and reads sequentially from that, and so on. Often a range scan will only return records from a small number of blocks in small number of sst files; in this case, the cost of initial Seek() reading one block from each file may be bigger than the cost of reading the actually useful blocks.
Neither iterate_upper_bound nor bloom filters can prevent reading one block from each file in Seek(). But this PR can: if the index contains first key from each block, we don't have to read the block until this block actually makes it to the top of merging iterator's heap, so for short range scans we won't read any blocks from most of the sst files.
This PR does the deferred block loading inside value() call. This is not ideal: there's no good way to report an IO error from inside value(). As discussed with siying offline, it would probably be better to change InternalIterator's interface to explicitly fetch deferred value and get status. I'll do it in a separate PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5289
Differential Revision: D15256423
Pulled By: al13n321
fbshipit-source-id: 750e4c39ce88e8d41662f701cf6275d9388ba46a
Summary:
As [BlockBasedTableConfig setBlockCacheSize()](1966a7c055/java/src/main/java/org/rocksdb/BlockBasedTableConfig.java (L728)) said, If cacheSize is non-positive, then cache will not be used. but when we configure a negative number or 0, there is an unexpected result: the block cache becomes 8M.
- Allow 0 as a valid size. When block cache size is 0, an 8MB block cache is created, as it is the default C++ API behavior. Also updated the comment.
- Set no_block_cache true if negative value is passed to block cache size, and no block cache will be created.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5465
Differential Revision: D15968788
Pulled By: sagar0
fbshipit-source-id: ee02d6e95841c9e2c316a64bfdf192d46ff5638a
Summary:
Make the generics of the Options interfaces more strict so they are usable in a Kotlin Multiplatform expect/actual typealias implementation without causing a Violation of Finite Bound Restriction.
This fix would enable the creation of a generic Kotlin multiplatform library by just typealiasing the JVM implementation to the current Java implementation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5461
Differential Revision: D15903288
Pulled By: sagar0
fbshipit-source-id: 75e83fdf5d2fcede40744a17e767563d6a4b0696
Summary:
I think this should now also run on Travis's new virtualised infrastructure which affords more memory and CPU.
We also need to think about migrating from travis-ci.org to travis-ci.com.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4789
Differential Revision: D15856272
fbshipit-source-id: 10b41d21924e8a362bc9646a63ccd1a5dfc437c6
Summary:
Many logging related source files are under util/. It will be more structured if they are together.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5387
Differential Revision: D15579036
Pulled By: siying
fbshipit-source-id: 3850134ed50b8c0bb40a0c8ae1f184fa4081303f
Summary:
There are too many types of files under util/. Some test related files don't belong to there or just are just loosely related. Mo
ve them to a new directory test_util/, so that util/ is cleaner.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5377
Differential Revision: D15551366
Pulled By: siying
fbshipit-source-id: 0f5c8653832354ef8caa31749c0143815d719e2c
Summary:
Depending on the config, manual compaction (leveled compaction style) does following compactions:
L0->L1
L1->L2
...
Ln-1 -> Ln
Ln -> Ln
The final Ln -> Ln compaction is partly unnecessary as it recompacts all the files that were just generated by the Ln-1 -> Ln. We should avoid recompacting such files. This rule should be applied to Lmax only.
Resolves issue https://github.com/facebook/rocksdb/issues/4995
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5138
Differential Revision: D14940106
Pulled By: miasantreble
fbshipit-source-id: 8d3cf5507a17e76f3333cfd4bac5256d005636e5
Summary:
I would like to be able to read out the current Filter that has been set (or not) for a BlockBasedTableConfig. Added one public method to BlockBasedTableConfig:
public Filter filterPolicy() {
return filterPolicy;
}
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5186
Differential Revision: D14921415
Pulled By: siying
fbshipit-source-id: 2a63c8685480197862b49fc48916c757cd6daf95
Summary:
BackupEngine relies on write-ahead logs to back up the memtable. Disabling write-ahead logs
can result in backups failing to preserve unflushed keys. This PR updates the documentation to specify this behavior, and suggest always flushing the memtable when write-ahead logs are disabled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5071
Differential Revision: D14524124
Pulled By: miasantreble
fbshipit-source-id: 635f855f8a42ad60273b5efd226139b511e3e5d5
Summary:
Disabling `org.rocksdb.RocksDBTest.getApproximateSizes` test as it is frequently crashing on travis (#5020). It will be re-enabled once the root-cause is found and fixed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5035
Differential Revision: D14294736
Pulled By: sagar0
fbshipit-source-id: e28bff0d143a58ad6c82991fec3d4cf8c0209995
Summary:
This reverts commit ee1818081f.
We are not ready to deprecate this feature. revert it for now.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5034
Differential Revision: D14287246
Pulled By: siying
fbshipit-source-id: e4beafdeaee1c94364fdaa6ba198218d158339f7
Summary:
Right now, users can change statistics.stats_level while DB is running, but TSAN may report
data race. We make stats_level_ to be atomic, and access them using accessors.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5030
Differential Revision: D14267519
Pulled By: siying
fbshipit-source-id: 37d7ebeff7a43a406230143422a16af899163f73
Summary:
`DefaultEnvTest.incBackgroundThreadsIfNeeded` jtest should assert that the number of threads is greater than or equal to the minimum number of threads.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5021
Differential Revision: D14268311
Pulled By: sagar0
fbshipit-source-id: 01fb32b5b3ce636451d162fa1a2bbc5bd1974682
Summary:
This is my latest round of changes to add missing items to RocksJava. More to come in future PRs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4833
Differential Revision: D14152266
Pulled By: sagar0
fbshipit-source-id: d6cff67e26da06c131491b5cf6911a8cd0db0775
Summary:
This PR adds public `GetStatsHistory` API to retrieve stats history in the form of an std map. The key of the map is the timestamp in microseconds when the stats snapshot is taken, the value is another std map from stats name to stats value (stored in std string). Two DBOptions are introduced: `stats_persist_period_sec` (default 10 minutes) controls the intervals between two snapshots are taken; `max_stats_history_count` (default 10) controls the max number of history snapshots to keep in memory. RocksDB will stop collecting stats snapshots if `stats_persist_period_sec` is set to 0.
(This PR is the in-memory part of https://github.com/facebook/rocksdb/pull/4535)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4748
Differential Revision: D13961471
Pulled By: miasantreble
fbshipit-source-id: ac836d401ecb84ea92216bf9966f969dedf4ad04
Summary:
The info log header feature never worked well, because log level Header was not
translated to Logger::LogHeader() call. Fix it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4980
Differential Revision: D14087283
Pulled By: siying
fbshipit-source-id: 7e7d03ce35fa8d13d4ee549f46f7326f7bc0006d
Summary:
We introduced ttl option in CompactionOptionsFIFO when ttl-based file
deletion (compaction) was supported only as part of FIFO Compaction. But
with the extension of ttl semantics even to Level compaction,
CompactionOptionsFIFO.ttl can now be deprecated. Instead we will start
using ColumnFamilyOptions.ttl for FIFO compaction as well.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4965
Differential Revision: D14072960
Pulled By: sagar0
fbshipit-source-id: c98cc2ae695a28136295787cd88d36a220fc219e
Adam Retter