Summary:
This is a feature to sample data-block compressibility and and report them as stats. 1 in N (tunable) blocks is sampled for compressibility using two algorithms:
1. lz4 or snappy for fast compression
2. zstd or zlib for slow but higher compression.
The stats are reported to the caller as raw-bytes and compressed-bytes. The block continues to be compressed for storage using the specified CompressionType.
The db_bench_tool how has a command line option for specifying the sampling rate. It's default value is 0 (no sampling). To test the overhead for a certain value, users can compare the performance of db_bench_tool, varying the sampling rate. It is unlikely to have a noticeable impact for high values like 20.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4842
Differential Revision: D13629011
Pulled By: shobhitdayal
fbshipit-source-id: 14ca668bcab6499b2a1734edf848eb62a4f4fafa
Summary:
Since this feature affects the WAL behavior, it seems important our crash-recovery tests cover it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5070
Differential Revision: D14470085
Pulled By: miasantreble
fbshipit-source-id: 9b9682a718a926d57d055e0a5ec867efbd2eb9c1
Summary:
In the current trace_analyzer implementation, once the trace file has corrupted content, which can be caused by unexpected tracing operations or other reasons, trace_analyzer will print the error and stop analyzing.
By adding the -try_process_corrupted_trace option, user can try to process the corrupted trace file and get the analyzing results of the trace records from the beginning to the the first corrupted point in the trace file. Analyzing might fail even this option is enabled.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5067
Differential Revision: D14433037
Pulled By: zhichao-cao
fbshipit-source-id: d095233ba371726869af0def0cdee23b69896831
Summary:
Without `total_order_seek=true`, using this command with `prefix_extractor` set skips over lots of keys.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5066
Differential Revision: D14425967
Pulled By: sagar0
fbshipit-source-id: f6f142733258d92604f920615be9266e1fe797f8
Summary:
In the MixGraph benchmark of db_bench, The max buffer size used for value of KV-pair might be extremely large (64MB), which might cause function stack overflow in some platforms, reduced to 1MB.
Added the finished ops printing in MixGraph benchmark.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5051
Differential Revision: D14379571
Pulled By: zhichao-cao
fbshipit-source-id: 24084fbe38f60f2902d9a40f6bc9a25e4e2c9bb9
Summary:
Added an option, `-use_existing_keys`, which can be set to run
benchmarks against an arbitrary existing database. Now users can
benchmark against their actual database rather than synthetic data.
Before the run begins, it loads all the keys into memory, then uses that
set of keys rather than synthesizing new ones in `GenerateKeyFromInt`.
This is mainly intended for small-scale DBs where the memory consumption
is not a concern.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5017
Differential Revision: D14270303
Pulled By: riversand963
fbshipit-source-id: 6328df9dffb5e19170270dd00a69f4bbe424e5ed
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:
This the hackish script we used to find the root cause of failures in transaction stress tests. It is not well-written and does not require rigorous reviewing but it is better than starting from scratch each time we observe an issue. The stress tests would just say that at which snapshots the sum of all the keys in a set is inconsistent with another set. To help debugging one need to know which key exactly returned inconsistent results. The script looks at the transactions between two conflicting snapshots, and performs thee changes manually to see for which key the read value was inconsistent.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5033
Differential Revision: D14280362
Pulled By: maysamyabandeh
fbshipit-source-id: d5826055c46711460ba81480d96cb5ea082814a5
Summary:
Statistics cost too much CPU for some use cases. Add two stats levels
so that people can choose to skip two types of expensive stats, timers and
histograms.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5027
Differential Revision: D14252765
Pulled By: siying
fbshipit-source-id: 75ecec9eaa44c06118229df4f80c366115346592
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:
MyRocks calls `GetForUpdate` on `INSERT`, for unique key check, and in almost all cases GetForUpdate returns empty result. For such cases, whole key bloom filter is helpful.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4985
Differential Revision: D14118257
Pulled By: miasantreble
fbshipit-source-id: d35cb7109c62fd5ad541a26968e3a3e16d3e85ea
Summary:
LITE mode has EventListener to be an empty class. However in db_bench,
it is used. When "override" is added to the functions, the build breaks. Fix it
by keeping the listener empty in LITE mode.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4989
Differential Revision: D14108132
Pulled By: siying
fbshipit-source-id: 80121aab35b1120e502b37b782301dd700692697
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
Summary:
if an operation just involves a single column family, then we do
not have to set the kInAtomicGroup tag when writing to MANIFEST. This change
can fix a compatibility test failure, i.e. 5.15 and earlier cannot recognize
kInAtomicGroup tag.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4981
Differential Revision: D14072687
Pulled By: riversand963
fbshipit-source-id: 46b0c61e399f16c6b7169de0b33430d0ed90d6d4
Summary:
Our previous approach was to train one compression dictionary per compaction, using the first output SST to train a dictionary, and then applying it on subsequent SSTs in the same compaction. While this was great for minimizing CPU/memory/I/O overhead, it did not achieve good compression ratios in practice. In our most promising potential use case, moderate reductions in a dictionary's scope make a major difference on compression ratio.
So, this PR changes compression dictionary to be scoped per-SST. It accepts the tradeoff during table building to use more memory and CPU. Important changes include:
- The `BlockBasedTableBuilder` has a new state when dictionary compression is in-use: `kBuffered`. In that state it accumulates uncompressed data in-memory whenever `Add` is called.
- After accumulating target file size bytes or calling `BlockBasedTableBuilder::Finish`, a `BlockBasedTableBuilder` moves to the `kUnbuffered` state. The transition (`EnterUnbuffered()`) involves sampling the buffered data, training a dictionary, and compressing/writing out all buffered data. In the `kUnbuffered` state, a `BlockBasedTableBuilder` behaves the same as before -- blocks are compressed/written out as soon as they fill up.
- Samples are now whole uncompressed data blocks, except the final sample may be a partial data block so we don't breach the user's configured `max_dict_bytes` or `zstd_max_train_bytes`. The dictionary trainer is supposed to work better when we pass it real units of compression. Previously we were passing 64-byte KV samples which was not realistic.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4952
Differential Revision: D13967980
Pulled By: ajkr
fbshipit-source-id: 82bea6f7537e1529c7a1a4cdee84585f5949300f
Summary:
Previously `finalize_and_sanitize` function was always zeroing out `compression_zstd_max_train_bytes`. It was only supposed to do that when non-ZSTD compression was used. But since `--compression_type` was an unknown argument (i.e., one that `db_crashtest.py` does not recognize and blindly forwards to `db_stress`), `finalize_and_sanitize` could not tell whether ZSTD was used. This PR fixes it simply by making `--compression_type` a known argument with snappy as default (same as `db_stress`).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4957
Differential Revision: D13994302
Pulled By: ajkr
fbshipit-source-id: 1b0baea7331397822830970d3698642eb7a7df65
Summary:
Cuckoo Hash is less useful than we initially expected. Remove it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4953
Differential Revision: D13979264
Pulled By: siying
fbshipit-source-id: 2a60afdaa989f045357398b43a1cc5d46f4492ed
Summary:
4985a9f73b (diff-e5276985b26a0551957144f4420a594bR511)
changes the meaning of latency reporting from running time per query, to elapse_time / #ops, without providing a reason why.
Considering that this is a counter-intuitive reporting, Reverting the change.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4949
Differential Revision: D13964684
Pulled By: siying
fbshipit-source-id: d6304d3d4b5a802daa292302623c7dbca9a680bc
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:
In the MixGraph benchmark of db_bench #4788 , the char array is initialized with an argument from user's input, which can cause build error on some platforms. Also, the msg char array size can be potentially smaller than the printed data, which should be extended from 100 to 256.
Tested with make check.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4918
Differential Revision: D13844298
Pulled By: sagar0
fbshipit-source-id: 33c4809c5c4438f0a9f7b289d3f42e20c545bbab
Summary:
- When building with internal dependencies, specify this toolchain by setting `ROCKSDB_FBCODE_BUILD_WITH_PLATFORM007=1`
- It is not enabled by default. However, it is enabled for TSAN builds in CI since there is a known problem with TSAN in gcc-5: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71090
- I did not add support for Lua since (1) we agreed to deprecate it, and (2) we only have an internal build for v5.3 with this toolchain while that has breaking changes compared to our current version (v5.2).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4923
Differential Revision: D13827226
Pulled By: ajkr
fbshipit-source-id: 9aa3388ed3679777cfb15ef8cbcb83c07f62f947
Summary:
Fixed clang static analyzer warning about division by 0.
```
ar: creating librocksdb_debug.a
tools/db_bench_tool.cc:4650:43: warning: Division by zero
int pos = static_cast<int>(rand_num % range_);
~~~~~~~~~^~~~~~~~
1 warning generated.
make: *** [analyze] Error 1
```
This is from the new code I recently merged in ce8e88d2d7.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4910
Differential Revision: D13788037
Pulled By: sagar0
fbshipit-source-id: f48851dca85047c19fbb1a361e25ce643aa4c7ea
Summary:
Based on the specific workload models (key access distribution, value size distribution, and iterator scan length distribution, the QPS variation), the MixGraph benchmark generate the synthetic workload according to these distributions which can reflect the real-world workload characteristics.
After user enable the tracing function, they will get the trace file. By analyzing the trace file with the trace_analyzer tool, user can generate a set of statistic data files including. The *_accessed_key_stats.txt, *-accessed_value_size_distribution.txt, *-iterator_length_distribution.txt, and *-qps_stats.txt are mainly used to fit the Matlab model fitting. After that, user can get the parameters of the workload distributions (the modeling details are described: [here](https://github.com/facebook/rocksdb/wiki/RocksDB-Trace%2C-Replay%2C-and-Analyzer))
The key access distribution follows the The two-term power model. The probability density function is: `f(x) = ax^{b}+c`. The corresponding parameters are key_dist_a, key_dist_b, and key_dist_c in db_bench
For the value size distribution and iterator scan length distribution, they both follow the Generalized Pareto Distribution. The probability density function is `f(x) = (1/sigma)(1+k*(x-theta)/sigma))^{-1-1/k)`. The parameters are: value_k, value_theta, value_sigma and iter_k, iter_theta, iter_sigma. For more information about the Generalized Pareto Distribution, users can find the [wiki](https://en.wikipedia.org/wiki/Generalized_Pareto_distribution) and [Matalb page](https://www.mathworks.com/help/stats/generalized-pareto-distribution.html)
As for the QPS, it follows the diurnal pattern. So Sine is a good model to fit it. `F(x) = sine_a*sin(sine_b*x + sine_c) + sine_d`. The trace_will tell you the average QPS in the print out resutls, which is sine_d. After user fit the "*-qps_stats.txt" to the Matlab model, user can get the sine_a, sine_b, and sine_c. By using the 4 parameters, user can control the QPS variation including the period, average, changes.
To use the bench mark, user can indicate the following parameters as examples:
```
-benchmarks="mixgraph" -key_dist_a=0.002312 -key_dist_b=0.3467 -value_k=0.9233 -value_sigma=226.4092 -iter_k=2.517 -iter_sigma=14.236 -mix_get_ratio=0.7 -mix_put_ratio=0.25 -mix_seek_ratio=0.05 -sine_mix_rate_interval_milliseconds=500 -sine_a=15000 -sine_b=1 -sine_d=20000
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4788
Differential Revision: D13573940
Pulled By: sagar0
fbshipit-source-id: e184c27e07b4f1bc0b436c2be36c5090c1fb0222
Summary:
This is essentially a re-submission of #4251 with a few improvements:
- Split `CompressionDict` into two separate classes: `CompressionDict` and `UncompressionDict`
- Eliminated `Init` functions. Instead do all initialization work in constructors.
- Added test case for parallel DB open, which is the scenario where #4251 failed under TSAN.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4849
Differential Revision: D13606039
Pulled By: ajkr
fbshipit-source-id: 08c236059798c710db9cbf545fce0f371232d447
Summary:
LDB is frequently used to exam data copied. wal_dir in option file is not modified and it usually points to the path it copied from.
The user experience will be better if when ldb sees wal_dir pointed by the option file doesn't exist, rather than fail, just ignore it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4875
Differential Revision: D13643173
Pulled By: siying
fbshipit-source-id: 2e64d4ea2ec49a6794b9a706b7fc1ba901128bb8
Summary:
as titled.
We can remove the assersion because we do not perform verification in
AtomicFlushStressTest::TestCheckpoint for similar reasons to TestGet, TestPut,
etc.
Therefore, we override TestCheckpoint in AtomicFlushStressTest so that the
assertion `rand_column_families.size() == rand_keys.size()' is removed, and we
do not verify the DB in this function.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4846
Differential Revision: D13583377
Pulled By: riversand963
fbshipit-source-id: 03647f3da67e27a397413fd666e3bb43003bf596
Summary:
The current implementation hardcode the default options in different
places, which makes it impossible to support other environments (like
encrypted environment).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4839
Differential Revision: D13573578
Pulled By: sagar0
fbshipit-source-id: 76b58b4b758902798d10ff2f52d9f39abff015e7
Summary:
Updated stress test will support testing of db in read-only mode.
The user has to make sure that only read/scan operations are enabled.
This PR relies on #4681.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4690
Differential Revision: D13102741
Pulled By: riversand963
fbshipit-source-id: f5a36b34db187fe12dd355f7eda161f99d6c75e4
Summary:
- To be consistent with the accounting of other optypes in `TableProperties`, we should count range tombstones in `TableProperties::num_entries` and `TableProperties::num_deletions`.
- Updated assertions in stress test's `OnTableFileCreated` handler to accept files with range tombstones only.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4841
Differential Revision: D13568424
Pulled By: ajkr
fbshipit-source-id: 0139d7806494eda20ece67ec460d2458dbbf6026
Summary:
Separate flag for enabling option from flag for enabling dedicated atomic stress test. I have found setting the former without setting the latter can detect different problems.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4781
Differential Revision: D13463211
Pulled By: ajkr
fbshipit-source-id: 054f777885b2dc7d5ea99faafa21d6537eee45fd
Summary:
**Summary:**
Simplified the code layout by moving FIFOCompactionPicker to a separate file.
**Why?:**
While trying to add ttl functionality to universal compaction, I found that `FIFOCompactionPicker` class and its impl methods to be interspersed between `LevelCompactionPicker` methods which kind-of made the code a little hard to traverse. So I moved `FIFOCompactionPicker` to a separate compaction_picker_fifo.h/cc file, similar to `UniversalCompactionPicker`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4724
Differential Revision: D13227914
Pulled By: sagar0
fbshipit-source-id: 89471766ea67fa4d87664a41c057dd7df4b3d4e3
Summary:
A user friendly sst file reader is useful when we want to access sst
files outside of RocksDB. For example, we can generate an sst file
with SstFileWriter and send it to other places, then use SstFileReader
to read the file and process the entries in other ways.
Also rename the original SstFileReader to SstFileDumper because of
name conflict, and seems SstFileDumper is more appropriate for tools.
TODO: there is only a very simple test now, because I want to get some feedback first.
If the changes look good, I will add more tests soon.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4717
Differential Revision: D13212686
Pulled By: ajkr
fbshipit-source-id: 737593383264c954b79e63edaf44aaae0d947e56
Summary:
The error message of databases/rocksdb-lite (FreeBSD port) is as follows:
```
tools/db_bench_tool.cc:1976:16: error: private field 'trace_options_' is not used [-Werror,-Wunused-private-field]
TraceOptions trace_options_;
^
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4715
Differential Revision: D13207902
Pulled By: ajkr
fbshipit-source-id: be3c612eba656aeddb77e35e2f201dd25dc92f7e
Summary:
The new flag makes it possible to constrain iterator traversal
by the upper/lower bound the iterator is expected to pass. This allows
seekrandom results to be more easily comparable between DBs with and
without deletions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4660
Differential Revision: D13053111
Pulled By: abhimadan
fbshipit-source-id: 33e250f2e2d210b54c7726399da30a33f723c33c
Summary:
When iterator becomes invalid, there are two possibilities.
First, all data in the column family have been scanned and there is nothing
more to scan.
Second, an underlying error has occurred, causing `status()` to be !ok.
Therefore, we need to check for both cases when `!iter->Valid()`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4648
Differential Revision: D12959601
Pulled By: riversand963
fbshipit-source-id: 49c9382c9ea9e78f2e2b6f3708f0670b822ca8dd
Summary:
Changes:
1. in current version, key size distribution is printed out as the result. In this change, the result will be output to a file to make further analyze easier
2. To understand how the unique keys are accessed over time, the total unique key number of each CF of each query type in each second over time is output to a file. In this way, user could know when the unique keys are accessed frequently or accessed rarely.
3. output the total QPS of each CF to a file
4. Add the print result of total queries of each CF of each query type.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4646
Differential Revision: D12968156
Pulled By: zhichao-cao
fbshipit-source-id: 6c411c7ec47c7843a70929136efd71a150db0e4c
Summary:
Ran the following commands to recursively change all the files under RocksDB:
```
find . -type f -name "*.cc" -exec sed -i 's/ unique_ptr/ std::unique_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/<unique_ptr/<std::unique_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/ shared_ptr/ std::shared_ptr/g' {} +
find . -type f -name "*.cc" -exec sed -i 's/<shared_ptr/<std::shared_ptr/g' {} +
```
Running `make format` updated some formatting on the files touched.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4638
Differential Revision: D12934992
Pulled By: sagar0
fbshipit-source-id: 45a15d23c230cdd64c08f9c0243e5183934338a8
Summary:
We already exercised backup functionality in `db_stress` according to the `-backup_one_in` flag. This PR verifies the backup can be restored/opened and sanity checks a few keys. Changes in this PR:
- Extracted existing backup-related logic to a helper function, `TestBackupRestore`
- Added restore logic, which targets a hidden directory named "./.restore\<thread number\>", similar to how backups target hidden directories named "./.backup\<thread number\>".
- After restore, check the existence/non-existence of a few keys.
- With this PR, backup is no longer compatible with clearing column families.
- Also included unrelated fixes to set `ReadOptions::total_order_seek=true` when using `-compare_full_db_state_snapshot`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4655
Differential Revision: D12972496
Pulled By: ajkr
fbshipit-source-id: 481a40052d9a38d1bd5c5159aa4d7c5a4b546b80
Summary:
Originally, the manual flush calls in db_stress flushes only a single column
family, which is not sufficient when atomic flush is enabled.
With atomic flush, we should call `Flush(flush_opts, cfhs)` to better test this
new feature. Specifically, we manuall flush all column families so that
database verification is easier.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4608
Differential Revision: D12849160
Pulled By: riversand963
fbshipit-source-id: ae1f0dd825247b42c0aba520a5c967335102c876
Summary:
Since the number of range deletions are reported in
TableProperties, it is confusing to not report the number of merge
operands and point deletions as top-level properties; they are
accessible through the public API, but since they are not the "main"
properties, they do not appear in aggregated table properties, or the
string representation of table properties.
This change promotes those two property keys to
`rocksdb/table_properties.h`, adds corresponding uint64 members for
them, deprecates the old access methods `GetDeletedKeys()` and
`GetMergeOperands()` (though they are still usable for now), and removes
`InternalKeyPropertiesCollector`. The property key strings are the same
as before this change, so this should be able to read DBs written from older
versions (though I haven't tested this yet).
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4594
Differential Revision: D12826893
Pulled By: abhimadan
fbshipit-source-id: 9e4e4fbdc5b0da161c89582566d184101ba8eb68
Shobhit Dayal