Summary:
Adding DB::CreateColumnFamilie() and DB::DropColumnFamilies() to bulk create/drop column families. This is to address the problem creating/dropping 1k column families takes minutes. The bottleneck is we persist options files for every single column family create/drop, and it parses the persisted options file for verification, which take a lot CPU time.
The new APIs simply create/drop column families individually, and persist options file once at the end. This improves create 1k column families to within ~0.1s. Further improvement can be merge manifest write to one IO.
Closes https://github.com/facebook/rocksdb/pull/2248
Differential Revision: D5001578
Pulled By: yiwu-arbug
fbshipit-source-id: d4e00bda671451e0b314c13e12ad194b1704aa03
Summary:
- downcase includes for case-sensitive filesystems
- give targets the same name (librocksdb) on all platforms
With this patch it is possible to cross-compile RocksDB for Windows
from a Linux host using mingw.
cc yuslepukhin orgads
Closes https://github.com/facebook/rocksdb/pull/2107
Differential Revision: D4849784
Pulled By: siying
fbshipit-source-id: ad26ed6b4d393851aa6551e6aa4201faba82ef60
Summary:
Now if we have iterate_upper_bound set, we continue read until get a key >= upper_bound. For a lot of cases that neighboring data blocks have a user key gap between them, our index key will be a user key in the middle to get a shorter size. For example, if we have blocks:
[a b c d][f g h]
Then the index key for the first block will be 'e'.
then if upper bound is any key between 'd' and 'e', for example, d1, d2, ..., d99999999999, we don't have to read the second block and also know that we have done our iteration by reaching the last key that smaller the upper bound already.
This diff can reduce RA in most cases.
Closes https://github.com/facebook/rocksdb/pull/2239
Differential Revision: D4990693
Pulled By: lightmark
fbshipit-source-id: ab30ea2e3c6edf3fddd5efed3c34fcf7739827ff
Summary:
Allow an option for users to do some compaction in FIFO compaction, to pay some write amplification for fewer number of files.
Closes https://github.com/facebook/rocksdb/pull/2163
Differential Revision: D4895953
Pulled By: siying
fbshipit-source-id: a1ab608dd0627211f3e1f588a2e97159646e1231
Summary:
Changed dynamic leveling to stop setting the base level's size bound below `max_bytes_for_level_base`.
Behavior for config where `max_bytes_for_level_base == level0_file_num_compaction_trigger * write_buffer_size` and same amount of data in L0 and base-level:
- Before #2027, compaction scoring would favor base-level due to dividing by size smaller than `max_bytes_for_level_base`.
- After #2027, L0 and Lbase get equal scores. The disadvantage is L0 is often compacted before reaching the num files trigger since `write_buffer_size` can be bigger than the dynamically chosen base-level size. This increases write-amp.
- After this diff, L0 and Lbase still get equal scores. Now it takes `level0_file_num_compaction_trigger` files of size `write_buffer_size` to trigger L0 compaction by size, fixing the write-amp problem above.
Closes https://github.com/facebook/rocksdb/pull/2123
Differential Revision: D4861570
Pulled By: ajkr
fbshipit-source-id: 467ddef56ed1f647c14d86bb018bcb044c39b964
Summary:
When user doesn't set a limit on compaction output file size, let's use the sum of the input files' sizes. This will avoid passing UINT64_MAX as fallocate()'s length. Reported in #2249.
Test setup:
- command: `TEST_TMPDIR=/data/rocksdb-test/ strace -e fallocate ./db_compaction_test --gtest_filter=DBCompactionTest.ManualCompactionUnknownOutputSize`
- filesystem: xfs
before this diff:
`fallocate(10, 01, 0, 1844674407370955160) = -1 ENOSPC (No space left on device)`
after this diff:
`fallocate(10, 01, 0, 1977) = 0`
Closes https://github.com/facebook/rocksdb/pull/2252
Differential Revision: D5007275
Pulled By: ajkr
fbshipit-source-id: 4491404a6ae8a41328aede2e2d6f4d9ac3e38880
Summary:
Makes max_open_files db option dynamically set-able by SetDBOptions. During the call of SetDBOptions we call SetCapacity on the table cache, which is a LRUCache.
Closes https://github.com/facebook/rocksdb/pull/2185
Differential Revision: D4979189
Pulled By: yiwu-arbug
fbshipit-source-id: ca7e8dc5e3619c79434f579be4847c0f7e56afda
Summary:
A data race between a manual and an auto compaction can cause a scheduled automatic compaction to be cancelled and never rescheduled again. This may cause a condition of hanging forever. Fix this by always making sure the cancelled compaction is put back to the compaction queue.
Closes https://github.com/facebook/rocksdb/pull/2238
Differential Revision: D4984591
Pulled By: siying
fbshipit-source-id: 3ab153886403c7b991896dcb2158b96cac12f227
Summary:
ColumnFamilyData::ConstructNewMemtable is called out of DB mutex, and it asserts current_ is not empty, but current_ should only be accessed inside DB mutex. Remove this assert to make TSAN happy.
Closes https://github.com/facebook/rocksdb/pull/2235
Differential Revision: D4978531
Pulled By: siying
fbshipit-source-id: 423685a7dae88ed3faaa9e1b9ccb3427ac704a4b
Summary:
In case users cast a subclass of db* into dbimpl*
Closes https://github.com/facebook/rocksdb/pull/2222
Differential Revision: D4964486
Pulled By: lightmark
fbshipit-source-id: 0ccdc08ee8e7a193dfbbe0218c3cbfd795662ca1
Summary:
Remove double buffering on RandomRead on Windows.
With more logic appear in file reader/write Read no longer
obeys forwarding calls to Windows implementation.
Previously direct_io (unbuffered) was only available on Windows
but now is supported as generic.
We remove intermediate buffering on Windows.
Remove random_access_max_buffer_size option which was windows specific.
Non-zero values for that opton introduced unnecessary lock contention.
Remove Env::EnableReadAhead(), Env::ShouldForwardRawRequest() that are
no longer necessary.
Add aligned buffer reads for cases when requested reads exceed read ahead size.
Closes https://github.com/facebook/rocksdb/pull/2105
Differential Revision: D4847770
Pulled By: siying
fbshipit-source-id: 8ab48f8e854ab498a4fd398a6934859792a2788f
Summary:
It resets all the ticker and histogram stats to zero. Needed to change the locking a bit since Reset() is the only operation that manipulates multiple tickers/histograms together, and that operation should be seen as atomic by other operations that access tickers/histograms.
Closes https://github.com/facebook/rocksdb/pull/2213
Differential Revision: D4952232
Pulled By: ajkr
fbshipit-source-id: c0475c3e4c7b940120d53891b69c3091149a0679
Summary:
I'm going to add more DB tests for statistics as currently we have very few. I started a file dedicated to this purpose and moved the existing stats-specific tests there.
Closes https://github.com/facebook/rocksdb/pull/2211
Differential Revision: D4951558
Pulled By: ajkr
fbshipit-source-id: 05d11c35079c40ecabdfd2cf5556ccb761f694a4
Summary:
Support buck load with universal compaction.
More test cases to be added.
Closes https://github.com/facebook/rocksdb/pull/2202
Differential Revision: D4935360
Pulled By: lightmark
fbshipit-source-id: cc3ca1b6f42faa503207dab1408d6bcf393ee5b5
Summary:
User could call this with wrapper class of DB or DBImpl
Closes https://github.com/facebook/rocksdb/pull/2200
Differential Revision: D4935530
Pulled By: lightmark
fbshipit-source-id: df9cb61d67d0f3bbcf62f714d77523a459a92883
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:
It is a potential bug that will be triggered if we ingest files before inserting the first key into an empty db.
0 is a special value reserved to indicate the concept of non-existence. But not good for seqno in this case because 0 is a valid seqno for ingestion(bulk loading)
Closes https://github.com/facebook/rocksdb/pull/2183
Differential Revision: D4919827
Pulled By: lightmark
fbshipit-source-id: 237eea40f88bd6487b66806109d90065dc02c362
Summary:
The goal is to avoid the problem of small number of L0 files triggering compaction to base level (which increased write-amp), while still allowing L0 compaction-by-size (so intra-L0 compactions cause score to increase).
Closes https://github.com/facebook/rocksdb/pull/2172
Differential Revision: D4908552
Pulled By: ajkr
fbshipit-source-id: 4b170142b2b368e24bd7948b2a6f24c69fabf73d
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:
The concept about early exit in write thread implementation is a confusing one. It means that if early exit is allowed, batch group leader will not responsible to exit the batch group, but the last finished writer do. In case we need to mark log synced, or encounter memtable insert error, early exit is disallowed.
This patch remove such a concept by:
* In all cases, the last finished writer (not necessary leader) is responsible to exit batch group.
* In case of parallel memtable write, leader will also mark log synced after memtable insert and before signal finish (call `CompleteParallelWorker()`). The purpose is to allow mark log synced (which require locking mutex) can run in parallel to memtable insert in other writers.
* The last finish writer should handle memtable insert error (update bg_error_) before exiting batch group.
Closes https://github.com/facebook/rocksdb/pull/2134
Differential Revision: D4869667
Pulled By: yiwu-arbug
fbshipit-source-id: aec170847c85b90f4179d6a4608a4fe1361544e3
Summary:
Replace Options::use_direct_writes with Options::use_direct_io_for_flush_and_compaction
Now if Options::use_direct_io_for_flush_and_compaction = true, we will enable direct io for both reads and writes for flush and compaction job. Whereas Options::use_direct_reads controls user reads like iterator and Get().
Closes https://github.com/facebook/rocksdb/pull/2117
Differential Revision: D4860912
Pulled By: lightmark
fbshipit-source-id: d93575a8a5e780cf7e40797287edc425ee648c19
Summary:
BYTES_WRITTEN accounting doesn't work with disabled WAL. For example, this is what we
get in the LOG:
```
Cumulative writes: 9794K writes, 228M keys, 9794K commit groups, 1.0
writes per commit group, ingest: 0.00 GB, 0.00 MB/s
```
WAL bytes are tracked in a different statistic:
https://github.com/facebook/rocksdb/blob/master/db/internal_stats.h#L105.
BYTES_WRITTEN should count all the writes.
Closes https://github.com/facebook/rocksdb/pull/2133
Differential Revision: D4880615
Pulled By: yiwu-arbug
fbshipit-source-id: 8fd0b223099f3f5ad7df79d4e737d313687fec69
Summary:
Moved MergeOperatorPinning tests from db_test2.cc to db_merge_operator_test.cc.
[This is the same code as PR #2104 , which has already been reviewed, but I am creating a new PR as I cannot import from #2104 onto phabricator anymore even after rebasing. I'll close and discard #2104.]
Closes https://github.com/facebook/rocksdb/pull/2125
Differential Revision: D4863312
Pulled By: sagar0
fbshipit-source-id: 0f71a7690aa09c1d03ee85ce2bc1d2d89e4f4399
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:
Extend TransactionOptions to include max_write_batch_size which determines the maximum size of the writebatch representation. If memory limit is exceeded, the operation will abort with subcode kMemoryLimit.
Closes https://github.com/facebook/rocksdb/pull/2124
Differential Revision: D4861842
Pulled By: lth
fbshipit-source-id: 46fd172ea67cc90bbba829bf0d70cfab2261c161
Summary:
also did minor refactoring
Closes https://github.com/facebook/rocksdb/pull/2115
Differential Revision: D4855818
Pulled By: maysamyabandeh
fbshipit-source-id: fbca6ac57e5c6677fffe8354f7291e596a50cb77
Summary:
DBIter, and in-turn NewDBIterator and NewArenaWrappedDBIterator, take a bunch of params. They can be reduced by passing in ReadOptions directly instead of passing in every new param separately. It also seems much cleaner as a bunch of the params towards the end seem to be optional.
(Recently I introduced max_skippable_internal_keys, which added one more to the already huge count).
Idea courtesy IslamAbdelRahman
Closes https://github.com/facebook/rocksdb/pull/2116
Differential Revision: D4857128
Pulled By: sagar0
fbshipit-source-id: 7d239df094b94bd9ea79d145cdf825478ac037a8
Summary:
1. Move universal compaction picker to separate files compaction_picker_universal.cc and compaction_picker_universal.h.
2. Rename some functions to make the code easier to understand.
3. Move leveled compaction picking code to a dedicated class, so that we we don't need to pass some common variable around when calling functions. It also allowed us to break down LevelCompactionPicker::PickCompaction() to smaller functions.
Closes https://github.com/facebook/rocksdb/pull/2100
Differential Revision: D4845948
Pulled By: siying
fbshipit-source-id: efa0ab4
Summary:
This is an effort to club all string related utility functions into one common place, in string_util, so that it is easier for everyone to know what string processing functions are available. Right now they seem to be spread out across multiple modules, like logging and options_helper.
Check the sub-commits for easier reviewing.
Closes https://github.com/facebook/rocksdb/pull/2094
Differential Revision: D4837730
Pulled By: sagar0
fbshipit-source-id: 344278a
Summary:
siying this is a resubmission of #2081 with the 4th commit fixed. From that commit message:
> Note that the previous use of quotes in PLATFORM_{CC,CXX}FLAGS was
incorrect and caused GCC to produce the incorrect define:
>
> #define ROCKSDB_JEMALLOC -DJEMALLOC_NO_DEMANGLE 1
>
> This was the cause of the Linux build failure on the previous version
of this change.
I've tested this locally, and the Linux build succeeds now.
Closes https://github.com/facebook/rocksdb/pull/2097
Differential Revision: D4839964
Pulled By: siying
fbshipit-source-id: cc51322
Summary:
Move some files under util/ to new directories env/, monitoring/ options/ and cache/
Closes https://github.com/facebook/rocksdb/pull/2090
Differential Revision: D4833681
Pulled By: siying
fbshipit-source-id: 2fd8bef
Summary:
db_impl.cc is too large to manage. Divide db_impl.cc into db/db_impl.cc, db/db_impl_compaction_flush.cc, db/db_impl_files.cc, db/db_impl_open.cc and db/db_impl_write.cc.
Closes https://github.com/facebook/rocksdb/pull/2095
Differential Revision: D4838188
Pulled By: siying
fbshipit-source-id: c5f3059
Summary:
Level-based L0->L0 compaction operates on spans of files that aren't currently being compacted. It reduces the number of L0 files, thus making write stall conditions harder to reach.
- L0->L0 is triggered when base level is unavailable due to pending compactions
- L0->L0 always outputs one file of at most `max_level0_burst_file_size` bytes.
- Subcompactions are disabled for L0->L0 since we want to output one file.
- Input files are chosen as the longest span of available files that will fit within the size limit. This minimizes number of files in L0.
Closes https://github.com/facebook/rocksdb/pull/2027
Differential Revision: D4760318
Pulled By: ajkr
fbshipit-source-id: 9d07183
Summary:
to void future bug that caused by the mix of userkey/internalkey
Closes https://github.com/facebook/rocksdb/pull/2084
Differential Revision: D4825889
Pulled By: lightmark
fbshipit-source-id: 28411db
Summary:
Refactor WriteImpl() so when I plug-in the pipeline write code (which is
an alternative approach for WriteThread), some of the logic can be
reuse. I split out the following methods from WriteImpl():
* PreprocessWrite()
* HandleWALFull() (previous MaybeFlushColumnFamilies())
* HandleWriteBufferFull()
* WriteToWAL()
Also adding a constructor to WriteThread::Writer, and move WriteContext into db_impl.h.
No real logic change in this patch.
Closes https://github.com/facebook/rocksdb/pull/2042
Differential Revision: D4781014
Pulled By: yiwu-arbug
fbshipit-source-id: d45ca18
Summary:
It is confusing to have auto_roll_logger to stay under db/, which has nothing to do with database. Move filename together as it is a dependency.
Closes https://github.com/facebook/rocksdb/pull/2080
Differential Revision: D4821141
Pulled By: siying
fbshipit-source-id: ca7d768
Summary:
auto_roll_logger_test relies on timing conditon that some operations finish within 1 seconds. This caused flaky tests. Move away from real timing and sleep and use fake time to verify the time-based rolling.
Closes https://github.com/facebook/rocksdb/pull/2066
Differential Revision: D4810647
Pulled By: siying
fbshipit-source-id: c54d994
Summary:
`uint` is nonstandard and not a built-in type on all compilers; replace it
with the always-valid `unsigned int`. I assume this went unnoticed because
it's inside an `#ifdef ROCKDB_JEMALLOC`.
Closes https://github.com/facebook/rocksdb/pull/2075
Differential Revision: D4820427
Pulled By: ajkr
fbshipit-source-id: 0876561
Summary:
Previously it always showed 0.0 for L0 write-amp because we were dividing by bytes read from non-output level. For L0, we should instead divide by bytes ingested to the DB. Note the numerator (bytes written to L0) includes flush bytes.
Closes https://github.com/facebook/rocksdb/pull/2078
Differential Revision: D4816902
Pulled By: ajkr
fbshipit-source-id: 7dca31a
Summary:
There still are many warnings (most of them about invalid printf format
for long long), but it builds if FAIL_ON_WARNINGS is disabled.
Closes https://github.com/facebook/rocksdb/pull/2052
Differential Revision: D4807355
Pulled By: siying
fbshipit-source-id: ef03786
Summary:
Operations like Seek/Next/Prev sometimes take too long to complete when there are many internal keys to be skipped. Adding an option, max_skippable_internal_keys -- which could be used to set a threshold for the maximum number of keys that can be skipped, will help to address these cases where it is much better to fail a request (as incomplete) than to wait for a considerable time for the request to complete.
This feature -- to fail an iterator seek request as incomplete, is disabled by default when max_skippable_internal_keys = 0. It is enabled only when max_skippable_internal_keys > 0.
This feature is based on the discussion mentioned in the PR https://github.com/facebook/rocksdb/pull/1084.
Closes https://github.com/facebook/rocksdb/pull/2000
Differential Revision: D4753223
Pulled By: sagar0
fbshipit-source-id: 1c973f7
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:
Allow the users to specify the target index partition size.
With this patch an index partition is cut before its estimated in-memory size goes above the configured value for metadata_block_size. The filter partitions are still cut right after an index partition is cut.
Closes https://github.com/facebook/rocksdb/pull/2041
Differential Revision: D4780216
Pulled By: maysamyabandeh
fbshipit-source-id: 95a0831
Summary:
I've added functions to the C API to support WriteBatchWithIndex as requested in #1833.
I've also added unit tests to c_test
I've implemented the WriteBatchWithIndex variation of every function available for regular WriteBatch. And added additional functions unique to WriteBatchWithIndex.
For now, the following is omitted:
1. The ability to create WriteBatchWithIndex's custom batch-only iterator as I'm not sure what its purpose is. It should be possible to add later if anyone wants it.
2. The ability to create the batch with a fallback comparator, since it appears to be unnecessary. I believe the column family comparator will be used for this, meaning those using a custom comparator can just use the column family variations.
Closes https://github.com/facebook/rocksdb/pull/1985
Differential Revision: D4760039
Pulled By: siying
fbshipit-source-id: 393227e
Summary:
MemTableInserter default constructs Post processing info
std::map. However, on Windows with 2015 STL the default
constructed map still dynamically allocates one node
which shows up on a profiler and we loose ~40% throughput
on fillrandom benchmark.
Solution: declare a map as std::aligned storage and optionally
construct.
This addresses https://github.com/facebook/rocksdb/issues/1976
Before:
-------------------------------------------------------------------
Initializing RocksDB Options from command-line flags
DB path: [k:\data\BulkLoadRandom_10M_fillonly]
fillrandom : 2.775 micros/op 360334 ops/sec; 280.4 MB/s
Microseconds per write:
Count: 10000000 Average: 2.7749 StdDev: 39.92
Min: 1 Median: 2.0826 Max: 26051
Percentiles: P50: 2.08 P75: 2.55 P99: 3.55 P99.9: 9.58 P99.99: 51.5**6
------------------------------------------------------
After:
Initializing RocksDB Options from command-line flags
DB path: [k:\data\BulkLoadRandom_10M_fillon
Closes https://github.com/facebook/rocksdb/pull/2011
Differential Revision: D4740823
Pulled By: siying
fbshipit-source-id: 1daaa2c
Summary:
Previously, when DB write buffer size triggers, we always pick the CF with most data in its memtable to flush. This approach can minimize total flush happens. Change the behavior to always pick the oldest unflushed CF, which makes it the same behavior when max_total_wal_size hits. This approach will minimize size used by max_total_wal_size.
Closes https://github.com/facebook/rocksdb/pull/1987
Differential Revision: D4703214
Pulled By: siying
fbshipit-source-id: 9ff8b09
Summary:
PinnableSlice
Summary:
Currently the point lookup values are copied to a string provided by the
user. This incures an extra memcpy cost. This patch allows doing point lookup
via a PinnableSlice which pins the source memory location (instead of
copying their content) and releases them after the content is consumed
by the user. The old API of Get(string) is translated to the new API
underneath.
Here is the summary for improvements:
value 100 byte: 1.8% regular, 1.2% merge values
value 1k byte: 11.5% regular, 7.5% merge values
value 10k byte: 26% regular, 29.9% merge values
The improvement for merge could be more if we extend this approach to
pin the merge output and delay the full merge operation until the user
actually needs it. We have put that for future work.
PS:
Sometimes we observe a small decrease in performance when switching from
t5452014 to this patch but with the old Get(string) API. The d
Closes https://github.com/facebook/rocksdb/pull/1756
Differential Revision: D4391738
Pulled By: maysamyabandeh
fbshipit-source-id: 6f3edd3
Summary:
The comparator param in SstFileWriter constructor is redundant as it already exists as a field in options. So the current SstFileWriter constructor should be deprecated in favor of a new one which does not take a comparator.
Note that the jni/java apis have not been touched yet.
Closes https://github.com/facebook/rocksdb/pull/1978
Differential Revision: D4685629
Pulled By: sagar0
fbshipit-source-id: 372ce96
Summary:
Add the flag --prefix to the sst_dump tool
This flag is similar to, and exclusive from, the --from flag.
--prefix=0x00FF will return all rows prefixed with 0x00FF.
The --to flag may also be specified and will work as expected.
These changes were used to help in debugging the power cycle corruption issue and theses changes were tested by scanning through a udb.
Closes https://github.com/facebook/rocksdb/pull/1984
Differential Revision: D4691814
Pulled By: reidHoruff
fbshipit-source-id: 027f261
Summary:
Fixing some bugs in MockEnv so it be actually used.
Closes https://github.com/facebook/rocksdb/pull/1914
Differential Revision: D4609923
Pulled By: maysamyabandeh
fbshipit-source-id: ca25735
Summary:
the 50%+ drained constraint wasn't working consistently in some of our test environments, maybe their resources are too low. relax the constraints a bit.
Closes https://github.com/facebook/rocksdb/pull/1970
Differential Revision: D4679419
Pulled By: ajkr
fbshipit-source-id: 3789cd8
Summary:
This PR is to support a way to iterate over all the keys that are just in memtables.
Closes https://github.com/facebook/rocksdb/pull/1953
Differential Revision: D4663500
Pulled By: sagar0
fbshipit-source-id: 144e177
Summary:
db_sst_test had been flaky occasionally in the following way: reached_max_space_on_compaction can in very rare cases be 0. This happens when the limit on maximum allowable space set using SetMaxAllowedSpaceUsage is hit during flush for all test db sizes (1,2,4,8 and 10MB).The fix clears the error returned when the the space limit is reached during flush. This ensures that the compaction call back will always be called. The runtime is increased slightly because the 1MB loop writes more data and hits the limit during multiple flushes until compaction is scheduled.
Closes https://github.com/facebook/rocksdb/pull/1861
Differential Revision: D4557396
Pulled By: lgalanis
fbshipit-source-id: ff778d1
Summary:
Relating to #1903:
In MaybeFlushColumnFamilies() we want to modify the 'getting_flushed' flag before releasing the db mutex when SwitchMemtable() is called.
The following 2 actions need to be atomic in MaybeFlushColumnFamilies()
- getting_flushed is false on oldest log
- we determine that all CFs can be flushed to successfully release oldest log
- we set getting_flushed = true on the oldest log.
-------
- getting_flushed is false on oldest log
- we determine that all CFs can NOT be flushed to successfully release oldest log
- we set unable_to_flush_oldest_log_ = true on the oldest log.
#### In the 2pc case:
T1 enters function but is unable to flush all CFs to release log
T1 sets unable_to_flush_oldest_log_ = true
T1 begins flushing all CFs possible
T2 enters function but is unable to flush all CFs to release log
T2 sees unable_to_flush_oldes_log_ has been set so exits
T3 enters function and will be able to flush all CFs to release oldest log
T3 sets getting_flushed = true on oldes
Closes https://github.com/facebook/rocksdb/pull/1909
Differential Revision: D4646235
Pulled By: reidHoruff
fbshipit-source-id: c8d0447
Summary:
Note: Using the default operator= is an unsafe approach for Options since it destructs shared_ptr in
the same order of their creation, in contrast to destructors which
destructs them in the opposite order of creation. One particular problme is
that the cache destructor might invoke callback functions that use Option
members such as statistics. To work around this problem, we manually call
destructor of table_facotry which eventually clears the block cache.
Closes https://github.com/facebook/rocksdb/pull/1950
Differential Revision: D4655473
Pulled By: maysamyabandeh
fbshipit-source-id: 6c4bbff
Summary:
fix when elapsed time spans non-integral number of intervals since the rate limiter may still be drained during a partial interval.
Closes https://github.com/facebook/rocksdb/pull/1948
Differential Revision: D4651304
Pulled By: ajkr
fbshipit-source-id: b1f9e70
Summary:
This is the metric I plan to use for adaptive rate limiting. The statistics are updated only if the rate limiter is drained by flush or compaction. I believe (but am not certain) that this is the normal case.
The Statistics object is passed in RateLimiter::Request() to avoid requiring changes to client code, which would've been necessary if we passed it in the RateLimiter constructor.
Closes https://github.com/facebook/rocksdb/pull/1946
Differential Revision: D4646489
Pulled By: ajkr
fbshipit-source-id: d8e0161
Summary:
This option is needed to be enabled for Direct IO
and I cannot think of a reason where we need to disable it
remove it and default it to true
Closes https://github.com/facebook/rocksdb/pull/1944
Differential Revision: D4641088
Pulled By: IslamAbdelRahman
fbshipit-source-id: d7085b9
Summary:
Avoid to run db_wal_test in all the DB test options, and some small changes.
Closes https://github.com/facebook/rocksdb/pull/1921
Differential Revision: D4622054
Pulled By: siying
fbshipit-source-id: 890fd64
Summary:
Separate the platform dependent tests from external_sst_file_test. Only those tests need to run on platforms like OSX
Closes https://github.com/facebook/rocksdb/pull/1923
Differential Revision: D4622461
Pulled By: siying
fbshipit-source-id: d2d6f04
Summary:
Separate a smal subset of tests in DBTest to DBBasicTest. Tests in DBTest don't have to run in CI tests on platforms like OSX, as long as they are covered by Linux.
Closes https://github.com/facebook/rocksdb/pull/1924
Differential Revision: D4616702
Pulled By: siying
fbshipit-source-id: 13e6549
Summary:
A previous fix to DBTestUniversalCompaction.UniversalCompactionTrivialMoveTest2 didn't address the right problem. The problem is L0->L0 compaction is not trivial move in the scenario, not parallel compactions. Fix this.
Closes https://github.com/facebook/rocksdb/pull/1911
Differential Revision: D4608955
Pulled By: siying
fbshipit-source-id: 7a712cb
Summary:
…action
The two options, min_partial_merge_operands and verify_checksums_in_compaction, are not seldom used. Remove them to reduce the total number of options. Also remove them from Java and C interface.
Closes https://github.com/facebook/rocksdb/pull/1902
Differential Revision: D4601219
Pulled By: siying
fbshipit-source-id: aad4cb2
Summary:
querying logical sector size from the device instead of hardcoding it for linux platform.
Closes https://github.com/facebook/rocksdb/pull/1875
Differential Revision: D4591946
Pulled By: ajkr
fbshipit-source-id: 4e9805c
Summary:
we occasionally missing this call so the file size will be wrong
Closes https://github.com/facebook/rocksdb/pull/1894
Differential Revision: D4598446
Pulled By: lightmark
fbshipit-source-id: 42b6ef5
Summary:
This is a trivial fix for OOMs we've seen a few days ago in logdevice.
RocksDB get into the following state:
(1) Write throughput is too high for flushes to keep up. Compactions are out of the picture - automatic compactions are disabled, and for manual compactions we don't care that much if they fall behind. We write to many CFs, with only a few L0 sst files in each, so compactions are not needed most of the time.
(2) total_log_size_ is consistently greater than GetMaxTotalWalSize(). It doesn't get smaller since flushes are falling ever further behind.
(3) Total size of memtables is way above db_write_buffer_size and keeps growing. But the write_buffer_manager_->ShouldFlush() is not checked because (2) prevents it (for no good reason, afaict; this is what this commit fixes).
(4) Every call to WriteImpl() hits the MaybeFlushColumnFamilies() path. This keeps flushing the memtables one by one in order of increasing log file number.
(5) No write stalling trigger is hit. We rely on max_write_buffer_number
Closes https://github.com/facebook/rocksdb/pull/1893
Differential Revision: D4593590
Pulled By: yiwu-arbug
fbshipit-source-id: af79c5f
Summary:
reimplement the compaction expansion on lower level.
Considering such a case:
input level file: 1[B E] 2[F G] 3[H I] 4 [J M]
output level file: 5[A C] 6[D K] 7[L O]
If we initially pick file 2, now we will compact file 2 and 6. But we can safely compact 2, 3 and 6 without expanding the output level.
The previous code is messy and wrong.
In this diff, I first determine the input range [a, b], and output range [c, d],
then we get the range [e,f] = [min(a, c), max(b, d] and put all eligible clean-cut files within [e, f] into this compaction.
**Note: clean-cut means the files don't have the same user key on the boundaries of some files that are not chosen in this compaction**.
Closes https://github.com/facebook/rocksdb/pull/1760
Differential Revision: D4395564
Pulled By: lightmark
fbshipit-source-id: 2dc2c5c
Summary:
The option has been deprecated for two years and has no effect. Removing.
Closes https://github.com/facebook/rocksdb/pull/1866
Differential Revision: D4555203
Pulled By: yiwu-arbug
fbshipit-source-id: c48f627
Summary:
fix lite bugs
disable direct io in lite mode
Closes https://github.com/facebook/rocksdb/pull/1870
Differential Revision: D4559866
Pulled By: yiwu-arbug
fbshipit-source-id: 3761c51
Summary:
RepairDB isn't included in rocksdb lite, so don't test it.
Closes https://github.com/facebook/rocksdb/pull/1873
Differential Revision: D4565094
Pulled By: ajkr
fbshipit-source-id: 8cc0898
Summary:
NowMicros() provides non-monotonic time. When wall clock is
synchronized or changed, the non-monotonicity time points will affect write rate
controllers. This patch changes write_controller.cc and rate_limiter.cc to use
monotonic time points.
Closes https://github.com/facebook/rocksdb/pull/1865
Differential Revision: D4561732
Pulled By: siying
fbshipit-source-id: 95ece62
Summary:
Seems to me `has_unpersisted_data_` is read from read thread and write
from write thread concurrently without synchronization. Making it an
atomic.
I update the logic not because seeing any problem with it, but it just
feel confusing.
Closes https://github.com/facebook/rocksdb/pull/1869
Differential Revision: D4555837
Pulled By: yiwu-arbug
fbshipit-source-id: eff2ab8
Summary:
Remove disableDataSync, and another similarly named disable_data_sync options.
This is being done to simplify options, and also because the performance gains of this feature can be achieved by other methods.
Closes https://github.com/facebook/rocksdb/pull/1859
Differential Revision: D4541292
Pulled By: sagar0
fbshipit-source-id: 5b3a6ca
Summary:
Record the first parsed sequence number as the minimum
so we can find the true minimum otherwise everything is larger than zero.
Fix the comparator name comparision.
Closes https://github.com/facebook/rocksdb/pull/1858
Differential Revision: D4544365
Pulled By: ajkr
fbshipit-source-id: 439cbc2
Summary:
It was really annoying to have two places (top and bottom of compaction loop) where we cut output files. I had bugs in both DeleteRange and dictionary compression due to updating only one of the two. This diff consolidates the file-cutting logic to the bottom of the compaction loop.
Keep in mind that my goal with input_status is to be consistent with the past behavior, even though I'm not sure it's ideal.
Closes https://github.com/facebook/rocksdb/pull/1832
Differential Revision: D4503038
Pulled By: ajkr
fbshipit-source-id: 7da5213
Summary:
Partition Index blocks and use a Partition-index as a 2nd level index.
The two-level index can be used by setting
BlockBasedTableOptions::kTwoLevelIndexSearch as the index type and
configuring BlockBasedTableOptions::index_per_partition
t15539501
Closes https://github.com/facebook/rocksdb/pull/1814
Differential Revision: D4473535
Pulled By: maysamyabandeh
fbshipit-source-id: bffb87e
Summary:
introduce new methods into a public threadpool interface,
- allow submission of std::functions as they allow greater flexibility.
- add Joining methods to the implementation to join scheduled and submitted jobs with
an option to cancel jobs that did not start executing.
- Remove ugly `#ifdefs` between pthread and std implementation, make it uniform.
- introduce pimpl for a drop in replacement of the implementation
- Introduce rocksdb::port::Thread typedef which is a replacement for std::thread. On Posix Thread defaults as before std::thread.
- Implement WindowsThread that allocates memory in a more controllable manner than windows std::thread with a replaceable implementation.
- should be no functionality changes.
Closes https://github.com/facebook/rocksdb/pull/1823
Differential Revision: D4492902
Pulled By: siying
fbshipit-source-id: c74cb11
Summary:
Added method that returns approx num of entries as well as size for memtables.
Closes https://github.com/facebook/rocksdb/pull/1841
Differential Revision: D4511990
Pulled By: VitaliyLi
fbshipit-source-id: 9a4576e
Summary:
In theory, Get() can get a wrong result, if it races in a special with with flush. The bug can be reproduced in DBTest2.GetRaceFlush. Fix this bug by getting snapshot after referencing the super version.
Closes https://github.com/facebook/rocksdb/pull/1816
Differential Revision: D4475958
Pulled By: siying
fbshipit-source-id: bd9e67a
Summary:
merger.h was always a confusing name for me, simply give the file a better name
Closes https://github.com/facebook/rocksdb/pull/1836
Differential Revision: D4505357
Pulled By: IslamAbdelRahman
fbshipit-source-id: 07b28d8
Summary:
- rocksdb_property_int (so that we don't have to parse strings)
- and rocksdb_set_options (to allow controlling options via strings)
- a few other missing options exposed
- a documentation comment fix
Closes https://github.com/facebook/rocksdb/pull/1793
Differential Revision: D4456569
Pulled By: yiwu-arbug
fbshipit-source-id: 9f1fac1
Summary:
In the patch which LRU cache was made use dynamic shard bits, I changed to 2 shard bits to make the test happy. Look like it is occasionally still unhappy. Change it to 4 shard bits.
Closes https://github.com/facebook/rocksdb/pull/1815
Differential Revision: D4475849
Pulled By: siying
fbshipit-source-id: 575ff00
Summary:
If the users use the NewLRUCache() without passing in the number of shard bits, instead of using hard-coded 6, we'll determine it based on capacity.
Closes https://github.com/facebook/rocksdb/pull/1584
Differential Revision: D4242517
Pulled By: siying
fbshipit-source-id: 86b0f18
Summary:
A current data race issue in Get() and Flush() can cause a Get() to return wrong results when a flush happened in the middle. Disable the test for now.
Closes https://github.com/facebook/rocksdb/pull/1813
Differential Revision: D4472310
Pulled By: siying
fbshipit-source-id: 5755ebd
Summary:
logs_.back() is called out of DB mutex, which can cause data race. We move the access into the DB mutex protection area.
Closes https://github.com/facebook/rocksdb/pull/1774
Reviewed By: AsyncDBConnMarkedDownDBException
Differential Revision: D4417472
Pulled By: AsyncDBConnMarkedDownDBException
fbshipit-source-id: 2da1f1e
Summary:
GetAndRefSuperVersion() should not be called again in the same thread before ReturnAndCleanupSuperVersion() is called.
If we have a compaction filter that is using DB::Get, This will happen
```
CompactFiles() {
GetAndRefSuperVersion() // -- first call
..
CompactionFilter() {
GetAndRefSuperVersion() // -- second call
ReturnAndCleanupSuperVersion()
}
..
ReturnAndCleanupSuperVersion()
}
```
We solve this issue in the same way Iterator is solving it, but using GetReferencedSuperVersion()
This was discovered in https://github.com/facebook/mysql-5.6/issues/427 by alxyang
Closes https://github.com/facebook/rocksdb/pull/1803
Differential Revision: D4460155
Pulled By: IslamAbdelRahman
fbshipit-source-id: 5e54322
Summary:
when writing RangeDelAggregator::AddToBuilder, I forgot that there are sentinel tombstones in the middle of the interval map since gaps between real tombstones are represented with sentinels.
blame: #1614
Closes https://github.com/facebook/rocksdb/pull/1804
Differential Revision: D4460426
Pulled By: ajkr
fbshipit-source-id: 69444b5
Summary:
GetAndRefSuperVersionUnlocked
ReturnAndCleanupSuperVersionUnlocked
GetColumnFamilyHandleUnlocked
Are dead code that are not used any where
Closes https://github.com/facebook/rocksdb/pull/1802
Differential Revision: D4459948
Pulled By: IslamAbdelRahman
fbshipit-source-id: 30fa89d
Summary:
It's a test case for #1797. Also got rid of kTypeDeletion in the conditional since we treat it the same as kTypeRangeDeletion.
Closes https://github.com/facebook/rocksdb/pull/1800
Differential Revision: D4451300
Pulled By: ajkr
fbshipit-source-id: b39dda1
Summary:
This test ensures RangeDelAggregator can still access blocks even if it outlives the table readers that created them (detailed description in comments).
I plan to optimize away the extra cache lookup we currently do in BlockBasedTable::NewRangeTombstoneIterator(), as it is ~5% CPU in my random read benchmark in a database with 1k tombstones. This test will help make sure nothing breaks in the process.
Closes https://github.com/facebook/rocksdb/pull/1739
Differential Revision: D4375954
Pulled By: ajkr
fbshipit-source-id: aef9357
Summary:
change the iterator status to NotSupported as soon as a range tombstone
is encountered by a ForwardIterator.
Closes https://github.com/facebook/rocksdb/pull/1593
Differential Revision: D4246294
Pulled By: ajkr
fbshipit-source-id: aef9f49
Summary:
Fixing GetApproximateSize bug for the case of computing stats for mem tables only.
Closes https://github.com/facebook/rocksdb/pull/1795
Differential Revision: D4445507
Pulled By: IslamAbdelRahman
fbshipit-source-id: 3905846
Summary:
Allow set SavePoint to WriteBatch in C ABI.
Closes https://github.com/facebook/rocksdb/pull/1698
Differential Revision: D4378556
Pulled By: yiwu-arbug
fbshipit-source-id: afca746
Summary:
We should validate this option, otherwise we may see
std::out_of_range thrown at: db/db_impl.cc:1124
1123 for (unsigned int i = 0; i <= end; i++) {
1124 std::string& to_delete = old_info_log_files.at(i);
1125 std::string full_path_to_delete =
1126 (immutable_db_options_.db_log_dir.empty()
Closes https://github.com/facebook/rocksdb/pull/1722
Differential Revision: D4379495
Pulled By: yiwu-arbug
fbshipit-source-id: e136552
Summary:
If users directly call OptimizeForPointLookup(), it is broken as the option isn't compatible with parallel memtable insert. Fix it by using memtable bloomo filter instead.
Closes https://github.com/facebook/rocksdb/pull/1791
Differential Revision: D4442836
Pulled By: siying
fbshipit-source-id: bf6c9cd
Summary:
Added an option to GetApproximateSizes to exclude file stats, as MyRocks has those counted exactly and we need only stats from memtables.
Closes https://github.com/facebook/rocksdb/pull/1787
Differential Revision: D4441111
Pulled By: IslamAbdelRahman
fbshipit-source-id: c11f4c3
Summary:
Fix the bug when sync log fail, FlushJob::Run() will not be execute and
reference to cfd->current() will not be release.
Closes https://github.com/facebook/rocksdb/pull/1792
Differential Revision: D4441316
Pulled By: yiwu-arbug
fbshipit-source-id: 5523e28
Summary:
Consider the following single column family scenario:
prepare in log A
commit in log B
*WAL is too large, flush all CFs to releast log A*
*CFA is on log B so we do not see CFA is depending on log A so no flush is requested*
To fix this we must also consider the log containing the prepare section when determining what log a CF is dependent on.
Closes https://github.com/facebook/rocksdb/pull/1768
Differential Revision: D4403265
Pulled By: reidHoruff
fbshipit-source-id: ce800ff
Summary:
Cockroachdb exposed this bug in #1778. The bug happens when a compaction's output files are ended due to exceeding max_compaction_bytes. In that case we weren't taking into account the next file's start key when deciding how far to extend the current file's max_key. This caused the non-overlapping key-range invariant to be violated.
Note this was correctly handled for the usual case of cutting compaction output, which is file size exceeding max_output_file_size. I am not sure why these are two separate code paths, but we can consider refactoring it to prevent such errors in the future.
Closes https://github.com/facebook/rocksdb/pull/1784
Differential Revision: D4430235
Pulled By: ajkr
fbshipit-source-id: 80af748
Summary:
When debugging tests, it's useful to preserve the DB to investigate it and check the logs
This will allow us to set KEEP_DB=1 to preserve the DB
Closes https://github.com/facebook/rocksdb/pull/1759
Differential Revision: D4393826
Pulled By: IslamAbdelRahman
fbshipit-source-id: 1bff689
Summary:
If concurrent memtable insert is enabled, and one prepare command and a normal command are grouped into a commit group, the sequence ID will be calculated incorrectly.
Closes https://github.com/facebook/rocksdb/pull/1730
Differential Revision: D4371081
Pulled By: siying
fbshipit-source-id: cd40c6d
Summary:
DB shutdown aborts running compactions by setting an atomic shutting_down=true that CompactionJob periodically checks. Without this PR it checks it before processing every _output_ value. If compaction filter filters everything out, the compaction is uninterruptible. This PR adds checks for shutting_down on every _input_ value (in CompactionIterator and MergeHelper).
There's also some minor code cleanup along the way.
Closes https://github.com/facebook/rocksdb/pull/1639
Differential Revision: D4306571
Pulled By: yiwu-arbug
fbshipit-source-id: f050890
Summary:
Enable directIO on WritableFileImpl::Append
with offset being current length of the file.
Enable UniqueID tests on Windows, disable others but
leeting them to compile. Unique tests are valuable to
detect failures on different filesystems and upcoming
ReFS.
Clear output in WinEnv Getchildren.This is different from
previous strategy, do not touch output on failure.
Make sure DBTest.OpenWhenOpen works with windows error message
Closes https://github.com/facebook/rocksdb/pull/1746
Differential Revision: D4385681
Pulled By: IslamAbdelRahman
fbshipit-source-id: c07b702
Summary:
Currently the point lookup values are copied to a string provided by the user.
This incures an extra memcpy cost. This patch allows doing point lookup
via a PinnableSlice which pins the source memory location (instead of
copying their content) and releases them after the content is consumed
by the user. The old API of Get(string) is translated to the new API
underneath.
Here is the summary for improvements:
1. value 100 byte: 1.8% regular, 1.2% merge values
2. value 1k byte: 11.5% regular, 7.5% merge values
3. value 10k byte: 26% regular, 29.9% merge values
The improvement for merge could be more if we extend this approach to
pin the merge output and delay the full merge operation until the user
actually needs it. We have put that for future work.
PS:
Sometimes we observe a small decrease in performance when switching from
t5452014 to this patch but with the old Get(string) API. The difference
is a little and could be noise. More importantly it is safely
cancelled
Closes https://github.com/facebook/rocksdb/pull/1732
Differential Revision: D4374613
Pulled By: maysamyabandeh
fbshipit-source-id: a077f1a
Summary:
When deletion-collapsing mode is enabled (i.e., for DBIter/CompactionIterator), we maintain position in the tombstone maps across calls to ShouldDelete(). Since iterators often access keys sequentially (or reverse-sequentially), scanning forward/backward from the last position can be faster than binary-searching the map for every key.
- When Next() is invoked on an iterator, we use kForwardTraversal to scan forwards, if needed, until arriving at the range deletion containing the next key.
- Similarly for Prev(), we use kBackwardTraversal to scan backwards in the range deletion map.
- When the iterator seeks, we use kBinarySearch for repositioning
- After tombstones are added or before the first ShouldDelete() invocation, the current position is set to invalid, which forces kBinarySearch to be used.
- Non-iterator users (i.e., Get()) use kFullScan, which has the same behavior as before---scan the whole map for every key passed to ShouldDelete().
Closes https://github.com/facebook/rocksdb/pull/1701
Differential Revision: D4350318
Pulled By: ajkr
fbshipit-source-id: 5129b76
Summary:
This fix the issue with tests failing under GCC 481, I am not sure what is the exact reason
Closes https://github.com/facebook/rocksdb/pull/1735
Differential Revision: D4374094
Pulled By: IslamAbdelRahman
fbshipit-source-id: b3625bc
Summary:
Since the backup work as snapshot, we should only copy
the bytes of the wal while we get the alive files.
Closes https://github.com/facebook/rocksdb/pull/1733
Differential Revision: D4373457
Pulled By: ajkr
fbshipit-source-id: 389318f
Summary:
Cleanable objects will perform the registered cleanups when
they are destructed. We however rather to delay this cleaning like when
we are gathering the merge operands. Current approach is to create the
Cleanable object on heap (instead of on stack) and delay deleting it.
By allowing Cleanables to delegate their cleanups to another cleanable
object we can delay the cleaning without however the need to craete the
cleanable object on heap and keeping it around. This patch applies this
technique for the cleanups of BlockIter and shows improved performance
for some in-memory benchmarks:
+1.8% for merge worklaod, +6.4% for non-merge workload when the merge
operator is specified.
https://our.intern.facebook.com/intern/tasks?t=15168163
Non-merge benchmark:
TEST_TMPDIR=/dev/shm/v100nocomp/ ./db_bench --benchmarks=fillrandom
--num=1000000 -value_size=100 -compression_type=none
Reading random with no merge operator specified:
TEST_TMPDIR=/dev/shm/v100nocomp/ ./db_bench
--benchmarks="read
Closes https://github.com/facebook/rocksdb/pull/1711
Differential Revision: D4361163
Pulled By: maysamyabandeh
fbshipit-source-id: 9801e07
Summary:
Add `fadvise_trigger` option to `SstFileWriter`
If fadvise_trigger is passed with a non-zero value, SstFileWriter will invalidate the os page cache every `fadvise_trigger` bytes for the sst file
Closes https://github.com/facebook/rocksdb/pull/1731
Differential Revision: D4371246
Pulled By: IslamAbdelRahman
fbshipit-source-id: 91caff1
Summary:
File copying happens when creating checkpoints and bulkloading files from different FS partition. We should fsync the files when copying them to guarantee durability. A side effect will be that the dirty pages in file system buffers won't grow too large.
Closes https://github.com/facebook/rocksdb/pull/1728
Differential Revision: D4371083
Pulled By: siying
fbshipit-source-id: 579e14c
Summary:
std::unique(beg, end) returns an iterator of unique_end, data behind unique_end should not be accessed.
Closes https://github.com/facebook/rocksdb/pull/1726
Differential Revision: D4371076
Pulled By: IslamAbdelRahman
fbshipit-source-id: 5564450
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:
addfile phase in c_test could fail because in previous steps we did a DeleteRange.
Fix the test by simply moving the addfile phase before DeleteRange
Closes https://github.com/facebook/rocksdb/pull/1672
Differential Revision: D4328896
Pulled By: IslamAbdelRahman
fbshipit-source-id: 1d946df
Summary:
Added a tombstone-collapsing mode to RangeDelAggregator, which eliminates overlap in the TombstoneMap. In this mode, we can check whether a tombstone covers a user key using upper_bound() (i.e., binary search). However, the tradeoff is the overhead to add tombstones is now higher, so at first I've only enabled it for range scans (compaction/flush/user iterators), where we expect a high number of calls to ShouldDelete() for the same tombstones. Point queries like Get() will still use the linear scan approach.
Also in this diff I changed RangeDelAggregator's TombstoneMap to use multimap with user keys instead of map with internal keys. Callers sometimes provided ParsedInternalKey directly, from which it would've required string copying to derive an internal key Slice with which we could search the map.
Closes https://github.com/facebook/rocksdb/pull/1614
Differential Revision: D4270397
Pulled By: ajkr
fbshipit-source-id: 93092c7
Summary:
As suggested by testn in #1650
The Add is at the end of the function. Having a fallthough
will result in it being added twice.
Closes https://github.com/facebook/rocksdb/pull/1676
Differential Revision: D4331906
Pulled By: yiwu-arbug
fbshipit-source-id: 895c4a0
Summary:
add a new function to SstFileWriter that will tell the user how big is there file right now.
Closes https://github.com/facebook/rocksdb/pull/1686
Differential Revision: D4338868
Pulled By: mdyuki1016
fbshipit-source-id: c1ee16a
Summary:
seems it's expensive to check status since the underlying merge iterator checks status of all its children. so only do it when it's really necessary to get the status before invoking Next(), i.e., when we're advancing to get the first key in the next file.
Closes https://github.com/facebook/rocksdb/pull/1691
Differential Revision: D4343446
Pulled By: siying
fbshipit-source-id: 70ab315
Summary:
Fixes compile error:
In file included from ./util/statistics.h:17:0,
from ./util/stop_watch.h:8,
from ./util/perf_step_timer.h:9,
from ./util/iostats_context_imp.h:8,
from ./util/posix_logger.h:27,
from ./port/util_logger.h:18,
from ./db/auto_roll_logger.h:15,
from db/auto_roll_logger.cc:6:
./util/thread_local.h:65:16: error: 'function' in namespace 'std' does not name a template type
typedef std::function<void(void*, void*)> FoldFunc;
Closes https://github.com/facebook/rocksdb/pull/1656
Differential Revision: D4318702
Pulled By: yiwu-arbug
fbshipit-source-id: 8c5d17a
Summary:
Iterator should be in corrupted status if merge operator return false.
Also add test to make sure if max_successive_merges is hit during write,
data will not be lost.
Closes https://github.com/facebook/rocksdb/pull/1665
Differential Revision: D4322695
Pulled By: yiwu-arbug
fbshipit-source-id: b327b05
Summary:
Found by gcc-7 compile error.
This appeared to be a fault as these options seems too different.
Closes https://github.com/facebook/rocksdb/pull/1667
Differential Revision: D4324174
Pulled By: yiwu-arbug
fbshipit-source-id: 0f65383
Summary:
db/memtable.cc: In member function 'void rocksdb::MemTable::Update(rocksdb::SequenceNumber, const rocksdb::Slice&, const rocksdb::Slice&)':
db/memtable.cc:736:11: error: this statement may fall through [-Werror=implicit-fallthrough=]
}
^
db/memtable.cc:738:9: note: here
default:
^~~~~~~
cc1plus: all warnings being treated as errors
closes#1650
Closes https://github.com/facebook/rocksdb/pull/1655
Differential Revision: D4318696
Pulled By: yiwu-arbug
fbshipit-source-id: 1a8981c
Summary:
The two tests keep failing in travis. Disable them and will fix later.
Closes https://github.com/facebook/rocksdb/pull/1648
Differential Revision: D4316389
Pulled By: yiwu-arbug
fbshipit-source-id: 0a370e7
Summary:
Seem that writebatch delete range can work now, so I add C API for later use.
Btw, can we use this feature in production now?
Closes https://github.com/facebook/rocksdb/pull/1647
Differential Revision: D4314534
Pulled By: ajkr
fbshipit-source-id: e835165
Summary:
This PR update IngestExternalFile to return an error if we try to ingest a file into a dropped CF.
Right now if IngestExternalFile want to flush a memtable, and it's ingesting a file into a dropped CF, it will wait forever since flushing is not possible for the dropped CF
Closes https://github.com/facebook/rocksdb/pull/1657
Differential Revision: D4318657
Pulled By: IslamAbdelRahman
fbshipit-source-id: ed6ea2b
Summary:
When compiling with GCC>=7.0.0, "db/internal_stats.cc" fails to compile as the data being written to the buffer potentially exceeds its size.
This fix simply doubles the size of the buffer, thus accommodating the max possible data size.
Closes https://github.com/facebook/rocksdb/pull/1635
Differential Revision: D4302162
Pulled By: yiwu-arbug
fbshipit-source-id: c76ad59
Summary:
Remove "util/testharness.h" from list of includes for "db/db_filesnapshot.cc", as it wasn't being used and thus caused an extraneous dependency on gtest.
Closes https://github.com/facebook/rocksdb/pull/1634
Differential Revision: D4302146
Pulled By: yiwu-arbug
fbshipit-source-id: e900c0b
Summary:
It was doing `&range_del_iters[0]` on an empty vector. Even though the resulting pointer is never dereferenced, it's still bad for two reasons:
* the practical reason: it crashes with `std::out_of_range` exception in our debug build,
* the "C++ standard lawyer" reason: it's undefined behavior because, in `std::vector` implementation, it probably "dereferences" a null pointer, which is invalid even though it doesn't actually read the pointed memory, just converts a pointer into a reference (and then flush_job.cc converts it back to pointer); nullptr references are undefined behavior.
Closes https://github.com/facebook/rocksdb/pull/1612
Differential Revision: D4265625
Pulled By: al13n321
fbshipit-source-id: db26fb9
Summary:
When we Ingest an external file we open it to read some metadata and first/last key
during doing that we insert blocks into the block cache with global_seqno = 0
If we move the file (did not copy it) into the DB, we will use these blocks with the wrong seqno in the read path
Closes https://github.com/facebook/rocksdb/pull/1627
Differential Revision: D4293332
Pulled By: yiwu-arbug
fbshipit-source-id: 3ce5523
Summary:
IsTrivialMove returns true if no input file overlaps with output_level+1 with more than max_compaction_bytes_ bytes.
Closes https://github.com/facebook/rocksdb/pull/1619
Differential Revision: D4278338
Pulled By: yiwu-arbug
fbshipit-source-id: 994c001
Summary:
Embarassingly enough, the first time I tried to use my new feature in logdevice it crashed with this assertion failure:
db/pinned_iterators_manager.h:30: void rocksdb::PinnedIteratorsManager::StartPinning(): Assertion `pinning_enabled == false' failed
The issue was that `pinned_iters_mgr_.StartPinning()` was called but `pinned_iters_mgr_.ReleasePinnedData()` wasn't.
Closes https://github.com/facebook/rocksdb/pull/1611
Differential Revision: D4265622
Pulled By: al13n321
fbshipit-source-id: 747b10f
Summary:
Allow user to explicitly specify that the generated file by SstFileWriter will be ingested in a specific CF.
This allow us to persist the CF id in the generated file
Closes https://github.com/facebook/rocksdb/pull/1615
Differential Revision: D4270422
Pulled By: IslamAbdelRahman
fbshipit-source-id: 7fb954e
Summary:
Made delete_obsolete_files_period_micros option dynamic. It can be updating using DB::SetDBOptions().
Closes https://github.com/facebook/rocksdb/pull/1595
Differential Revision: D4246569
Pulled By: tonek
fbshipit-source-id: d23f560
Summary:
Multi-write thread may update the status of the parallel_group in
WriteThread::CompleteParallelWorker if the status of Writer is not ok!
When copy write status to the paralle_group, the write thread just hold the
mutex of the the writer processed by itself. it is useless. The thread
should held the the leader of the parallel_group instead.
Closes https://github.com/facebook/rocksdb/pull/1598
Differential Revision: D4252335
Pulled By: siying
fbshipit-source-id: 3864cf7
Summary:
This adds the ability for compaction filter to say "drop this key-value, and also drop everything up to key x". This will cause the compaction to seek input iterator to x, without reading the data. This can make compaction much faster when large consecutive chunks of data are filtered out. See the changes in include/rocksdb/compaction_filter.h for the new API.
Along the way this diff also adds ability for compaction filter changing merge operands, similar to how it can change values; we're not going to use this feature, it just seemed easier and cleaner to implement it than to document that it's not implemented :)
The diff is not as big as it may seem, about half of the lines are a test.
Closes https://github.com/facebook/rocksdb/pull/1599
Differential Revision: D4252092
Pulled By: al13n321
fbshipit-source-id: 41e1e48
Summary:
Add C API to set base_backgroud_compactions
Closes https://github.com/facebook/rocksdb/pull/1571
Differential Revision: D4245709
Pulled By: yiwu-arbug
fbshipit-source-id: 792c6b8
Summary:
99c052a34f fixes integer overflow in GetL0ThresholdSpeedupCompaction() by checking if int become -ve.
UBSAN will complain about that since this is still an overflow, we can fix the issue by simply using int64_t
Closes https://github.com/facebook/rocksdb/pull/1582
Differential Revision: D4241525
Pulled By: IslamAbdelRahman
fbshipit-source-id: b3ae21f
Summary:
disable UBSAN for functions with intentional left shift on -ve number / overflow
These functions are
rocksdb:: Hash
FixedLengthColBufEncoder::Append
FaultInjectionTest:: Key
Closes https://github.com/facebook/rocksdb/pull/1577
Differential Revision: D4240801
Pulled By: IslamAbdelRahman
fbshipit-source-id: 3e1caf6
Summary:
Both the single deletion and the value are included in compaction outputs, so no need to update the stat for the value's deletion yet, otherwise it'd be double-counted.
Closes https://github.com/facebook/rocksdb/pull/1574
Differential Revision: D4241181
Pulled By: ajkr
fbshipit-source-id: c9aaa15
Summary:
- "rocksdb.compaction.key.drop.range_del" - number of keys dropped during compaction due to a range tombstone covering them
- "rocksdb.compaction.range_del.drop.obsolete" - number of range tombstones dropped due to compaction to bottom level and no snapshot saving them
- s/CompactionIteratorStats/CompactionIterationStats/g since this class is no longer specific to CompactionIterator -- it's also updated for range tombstone iteration during compaction
- Move the above class into a separate .h file to avoid circular dependency.
Closes https://github.com/facebook/rocksdb/pull/1520
Differential Revision: D4187179
Pulled By: ajkr
fbshipit-source-id: 10c2103
Summary:
In one deployment we saw high latencies (presumably from slow iterator operations) and a lot of CPU time reported by perf with this stack:
```
rocksdb::MergingIterator::Next
rocksdb::DBIter::FindNextUserEntryInternal
rocksdb::DBIter::Seek
```
I think what's happening is:
1. we create a snapshot iterator,
2. we do lots of Put()s for the same key x; this creates lots of entries in memtable,
3. we seek the iterator to a key slightly smaller than x,
4. the seek walks over lots of entries in memtable for key x, skipping them because of high sequence numbers.
CC IslamAbdelRahman
Closes https://github.com/facebook/rocksdb/pull/1413
Differential Revision: D4083879
Pulled By: IslamAbdelRahman
fbshipit-source-id: a83ddae
Summary:
Current write stalling system has the problem of lacking of positive feedback if the restricted rate is already too low. Users sometimes stack in very low slowdown value. With the diff, we add a positive feedback (increasing the slowdown value) if we recover from slowdown state back to normal. To avoid the positive feedback to keep the slowdown value to be to high, we add issue a negative feedback every time we are close to the stop condition. Experiments show it is easier to reach a relative balance than before.
Also increase level0_stop_writes_trigger default from 24 to 32. Since level0_slowdown_writes_trigger default is 20, stop trigger 24 only gives four files as the buffer time to slowdown writes. In order to avoid stop in four files while 20 files have been accumulated, the slowdown value must be very low, which is amost the same as stop. It also doesn't give enough time for the slowdown value to converge. Increase it to 32 will smooth out the system.
Closes https://github.com/facebook/rocksdb/pull/1562
Differential Revision: D4218519
Pulled By: siying
fbshipit-source-id: 95e4088
Summary:
This PR is based on nbronson's diff with small
modifications to wire it up with existing interface. Comparing to
previous version, this approach works better for inserting keys in
decreasing order or updating the same key, and impose less restriction
to the prefix extractor.
---- Summary from original diff ----
This diff introduces a single InlineSkipList::Insert that unifies
the existing sequential insert optimization (prev_), concurrent insertion,
and insertion using externally-managed insertion point hints.
There's a deep symmetry between insertion hints (cursors) and the
concurrent algorithm. In both cases we have partial information from
the recent past that is likely but not certain to be accurate. This diff
introduces the struct InlineSkipList::Splice, which encodes predecessor
and successor information in the same form that was previously only used
within a single call to InsertConcurrently. Splice holds information
about an insertion point that can be used to levera
Closes https://github.com/facebook/rocksdb/pull/1561
Differential Revision: D4217283
Pulled By: yiwu-arbug
fbshipit-source-id: 33ee437
Summary:
When we introduced range deletion block, TableCache::Get() and TableCache::NewIterator() each did two table cache lookups, one for range deletion block iterator and another for getting the table reader to which the Get()/NewIterator() is delegated. This extra cache lookup was very CPU-intensive (about 10% overhead in a read-heavy benchmark). We can avoid it by reusing the Cache::Handle created for range deletion block iterator to get the file reader.
Closes https://github.com/facebook/rocksdb/pull/1537
Differential Revision: D4201167
Pulled By: ajkr
fbshipit-source-id: d33ffd8
Summary:
If the WriteOptions.no_slowdown flag is set AND we need to wait or sleep for
the write request, then fail immediately with Status::Incomplete().
Closes https://github.com/facebook/rocksdb/pull/1527
Differential Revision: D4191405
Pulled By: maysamyabandeh
fbshipit-source-id: 7f3ce3f
Summary:
Exposing persistent cache stats (counters) to the user via public API.
Closes https://github.com/facebook/rocksdb/pull/1485
Differential Revision: D4155274
Pulled By: siying
fbshipit-source-id: 30a9f50
Summary:
- Made RangeDelAggregator's InternalKeyComparator member a reference-to-const so we don't need to copy-construct it. Also added InternalKeyComparator to ImmutableCFOptions so we don't need to construct one for each DBIter.
- Made MemTable::NewRangeTombstoneIterator and the table readers' NewRangeTombstoneIterator() functions return nullptr instead of NewEmptyInternalIterator to avoid the allocation. Updated callers accordingly.
Closes https://github.com/facebook/rocksdb/pull/1548
Differential Revision: D4208169
Pulled By: ajkr
fbshipit-source-id: 2fd65cf
Summary:
The Arena construction/destruction introduced significant overhead to read-heavy workload just by creating empty vectors for its blocks, so avoid it in RangeDelAggregator.
Closes https://github.com/facebook/rocksdb/pull/1547
Differential Revision: D4207781
Pulled By: ajkr
fbshipit-source-id: 9d1c130
Summary:
Since a RangeDelAggregator is created for each read request, these heap-allocating member variables were consuming significant CPU (~3% total) which slowed down request throughput. The map and pinning manager are only necessary when range deletions exist, so we can defer their initialization until the first range deletion is encountered. Currently lazy initialization is done for reads only since reads pass us a single snapshot, which is easier to store on the stack for later insertion into the map than the vector passed to us by flush or compaction.
Note the Arena member variable is still expensive, I will figure out what to do with it in a subsequent diff. It cannot be lazily initialized because we currently use this arena even to allocate empty iterators, which is necessary even when no range deletions exist.
Closes https://github.com/facebook/rocksdb/pull/1539
Differential Revision: D4203488
Pulled By: ajkr
fbshipit-source-id: 3b36279
Summary:
these functions were too complicated to change with exit points everywhere, so refactored them.
btw, please review urgently, this is a prereq to fix the 5.0 perf regression
Closes https://github.com/facebook/rocksdb/pull/1534
Differential Revision: D4198972
Pulled By: ajkr
fbshipit-source-id: 04ebfb7
Summary:
Remove the ticker count because:
* Having to reset the ticker count in WriteImpl is ineffiecent;
* It doesn't make sense to have it as a ticker count if multiple db
instance share a statistics object.
Closes https://github.com/facebook/rocksdb/pull/1531
Differential Revision: D4194442
Pulled By: yiwu-arbug
fbshipit-source-id: e2110a9
Summary:
pinned_iters_mgr_ pins iterators allocated with arena_, so we should order the
instance variable declarations such that the pinned iterators have their destructors
executed before the arena is destroyed.
Closes https://github.com/facebook/rocksdb/pull/1528
Differential Revision: D4191984
Pulled By: ajkr
fbshipit-source-id: 1386f20
Summary:
It is hard to measure acutal memory usage by std containers. Even
providing a custom allocator will miss count some of the usage. Here we
only do a wild guess on its memory usage.
Closes https://github.com/facebook/rocksdb/pull/1511
Differential Revision: D4179945
Pulled By: yiwu-arbug
fbshipit-source-id: 32ab929
Summary:
Previously we used TableCache::NewIterator() for multiple purposes (data
block iterator and range deletion iterator), and returned non-ok status in
the data block iterator. In one case where the caller only used the range
deletion block iterator (9e7cf3469b/db/version_set.cc (L965-L973)),
we didn't check/free the data block iterator containing non-ok status, which
caused a valgrind error.
So, this diff decouples creation of data block and range deletion block iterators,
and updates the callers accordingly. Both functions can return non-ok status
in an InternalIterator. Since the non-ok status is returned in an iterator that the
callers will definitely use, it should be more usable/less error-prone.
Closes https://github.com/facebook/rocksdb/pull/1513
Differential Revision: D4181423
Pulled By: ajkr
fbshipit-source-id: 835b8f5
Summary:
Return an error from DeleteRange() (or Write() if the user is using the
low-level WriteBatch API) if an unsupported table type is configured.
Closes https://github.com/facebook/rocksdb/pull/1519
Differential Revision: D4185933
Pulled By: ajkr
fbshipit-source-id: abcdf84
Summary:
It's possible that we set min_write_buffer_number_to_merge to 0.
This should never happen
Closes https://github.com/facebook/rocksdb/pull/1515
Differential Revision: D4183356
Pulled By: yiwu-arbug
fbshipit-source-id: c9d39d7
Summary:
Adjusted AddToBuilder() to take lower_bound and upper_bound, which serve two purposes: (1) only range deletions overlapping with the interval [lower_bound, upper_bound) will be added to the output file, and (2) the output file's boundaries will not be extended before lower_bound or after upper_bound. Our computation of lower_bound/upper_bound consider both subcompaction boundaries and previous/next files within the subcompaction.
Test cases are here (level subcompactions: https://gist.github.com/ajkr/63c7eae3e9667c5ebdc0a7efb74ac332, and universal subcompactions: https://gist.github.com/ajkr/5a62af77c4ebe4052a1955c496d51fdb) but can't be included in this diff as they depend on committing the API first. They fail before this change and pass after.
Closes https://github.com/facebook/rocksdb/pull/1501
Reviewed By: yhchiang
Differential Revision: D4171685
Pulled By: ajkr
fbshipit-source-id: ee99db8
Summary:
This conditional should only open a new file that's dedicated to range deletions when it's the sole output of the subcompaction. Previously, we created such a file whenever the table builder was nullptr, which would've also been the case whenever the CompactionIterator's final key coincided with the final output table becoming full.
Closes https://github.com/facebook/rocksdb/pull/1507
Differential Revision: D4174613
Pulled By: ajkr
fbshipit-source-id: 9ffacea
Summary:
This makes it easier to implement future optimizations like range collapsing.
Closes https://github.com/facebook/rocksdb/pull/1504
Differential Revision: D4172214
Pulled By: ajkr
fbshipit-source-id: ac4942f
Summary:
Currently our skip-list have an optimization to speedup sequential
inserts from a single stream, by remembering the last insert position.
We extend the idea to support sequential inserts from multiple streams,
and even tolerate small reordering wihtin each stream.
This PR is the interface part adding the following:
- Add `memtable_insert_prefix_extractor` to allow specifying prefix for each key.
- Add `InsertWithHint()` interface to memtable, to allow underlying
implementation to return a hint of insert position, which can be later
pass back to optimize inserts.
- Memtable will maintain a map from prefix to hints and pass the hint
via `InsertWithHint()` if `memtable_insert_prefix_extractor` is non-null.
Closes https://github.com/facebook/rocksdb/pull/1419
Differential Revision: D4079367
Pulled By: yiwu-arbug
fbshipit-source-id: 3555326
Summary:
Implement a insert hint into skip-list to hint insert position. This is
to optimize for the write workload where there are multiple stream of
sequential writes. For example, there is a stream of keys of a1, a2,
a3... but also b1, b2, b2... Each stream are not neccessary strictly
sequential, but can get reorder a little bit. User can specify a prefix
extractor and the `SkipListRep` can thus maintan a hint for each of the
stream for fast insert into memtable.
This is the internal implementation part. See #1419 for the interface part.
See inline comments for details.
Closes https://github.com/facebook/rocksdb/pull/1449
Differential Revision: D4106781
Pulled By: yiwu-arbug
fbshipit-source-id: f4d48c4
Summary:
If user did not call SstFileWriter::Finish() or called Finish() but it failed.
We need to abandon the builder, to avoid destructing it while it's open
Closes https://github.com/facebook/rocksdb/pull/1502
Differential Revision: D4171660
Pulled By: IslamAbdelRahman
fbshipit-source-id: ab6f434
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:
This is a previous fix that has a typo
Closes https://github.com/facebook/rocksdb/pull/1487
Differential Revision: D4157381
Pulled By: lightmark
fbshipit-source-id: f079be8
Summary:
Originally sequence ids were calculated, in recovery, based off of the first seqid found if the first log recovered. The working seqid was then incremented from that value based on every insertion that took place. This was faulty because of the potential for missing log files or inserts that skipped the WAL. The current recovery scheme grabs sequence from current recovering batch and increments using memtableinserter to track how many actual inserts take place. This works for 2PC batches as well scenarios where some logs are missing or inserts that skip the WAL.
Closes https://github.com/facebook/rocksdb/pull/1486
Differential Revision: D4156064
Pulled By: reidHoruff
fbshipit-source-id: a6da8d9
Summary:
This fixes a correctness issue where ranges with same begin key would overwrite each other.
This diff uses InternalKey as TombstoneMap's key such that all tombstones have unique keys even when their start keys overlap. We also update TombstoneMap to use an internal key comparator.
End-to-end tests pass and are here (https://gist.github.com/ajkr/851ffe4c1b8a15a68d33025be190a7d9) but cannot be included yet since the DeleteRange() API is yet to be checked in. Note both tests failed before this fix.
Closes https://github.com/facebook/rocksdb/pull/1484
Differential Revision: D4155248
Pulled By: ajkr
fbshipit-source-id: 304b4b9
Summary:
Fix the following RocksDB Lite build failure in c_test.cc
db/c_test.c:1051:3: error: implicit declaration of function 'fprintf' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
fprintf(stderr, "SKIPPED\n");
^
db/c_test.c:1051:3: error: declaration of built-in function 'fprintf' requires inclusion of the header <stdio.h> [-Werror,-Wbuiltin-requires-header]
db/c_test.c:1051:11: error: use of undeclared identifier 'stderr'
fprintf(stderr, "SKIPPED\n");
^
3 errors generated.
Closes https://github.com/facebook/rocksdb/pull/1479
Differential Revision: D4151160
Pulled By: yhchiang
fbshipit-source-id: a471a30
Summary:
copied from: 5ebfd2623a
Opening existing RocksDB attempts recovery from log files, which uses
wrong sequence number to create the memtable. This is a regression
introduced in change a400336.
This change includes a test demonstrating the problem, without the fix
the test fails with "Operation failed. Try again.: Transaction could not
check for conflicts for operation at SequenceNumber 1 as the MemTable
only contains changes newer than SequenceNumber 2. Increasing the value
of the max_write_buffer_number_to_maintain option could reduce the
frequency of this error"
This change is a joint effort by Peter 'Stig' Edwards thatsafunnyname
and me.
Closes https://github.com/facebook/rocksdb/pull/1458
Differential Revision: D4143791
Pulled By: reidHoruff
fbshipit-source-id: 5a25033
Summary:
A deadlock is possible if this happen
(1) Writer thread is stopped because it's waiting for compaction to finish
(2) Compaction is waiting for current IngestExternalFile() calls to finish
(3) IngestExternalFile() is waiting to be able to acquire the writer thread
(4) WriterThread is held by stopped writes that are waiting for compactions to finish
This patch fix the issue by not incrementing num_running_ingest_file_ except when we acquire the writer thread.
This patch include a unittest to reproduce the described scenario
Closes https://github.com/facebook/rocksdb/pull/1480
Differential Revision: D4151646
Pulled By: IslamAbdelRahman
fbshipit-source-id: 09b39db
Summary:
In ForwardIterator::SeekInternal(), we may end up passing empty Slice representing an internal key to InternalKeyComparator::Compare.
and when we try to extract the user key from this empty Slice, we will create a slice with size = 0 - 8 ( which will overflow and cause us to read invalid memory as well )
Scenarios to reproduce these issues are in the unit tests
Closes https://github.com/facebook/rocksdb/pull/1467
Differential Revision: D4136660
Pulled By: lightmark
fbshipit-source-id: 151e128
Summary:
Note: reviewed in https://reviews.facebook.net/D65115
- DBIter maintains a range tombstone accumulator. We don't cleanup obsolete tombstones yet, so if the user seeks back and forth, the same tombstones would be added to the accumulator multiple times.
- DBImpl::NewInternalIterator() (used to make DBIter's underlying iterator) adds memtable/L0 range tombstones, L1+ range tombstones are added on-demand during NewSecondaryIterator() (see D62205)
- DBIter uses ShouldDelete() when advancing to check whether keys are covered by range tombstones
Closes https://github.com/facebook/rocksdb/pull/1464
Differential Revision: D4131753
Pulled By: ajkr
fbshipit-source-id: be86559
Summary:
During Get()/MultiGet(), build up a RangeDelAggregator with range
tombstones as we search through live memtable, immutable memtables, and
SST files. This aggregator is then used by memtable.cc's SaveValue() and
GetContext::SaveValue() to check whether keys are covered.
added tests for Get on memtables/files; end-to-end tests mainly in https://reviews.facebook.net/D64761
Closes https://github.com/facebook/rocksdb/pull/1456
Differential Revision: D4111271
Pulled By: ajkr
fbshipit-source-id: 6e388d4
Summary:
IngestExternalFile is very useful when doing bulk load. This pr expose this API to c so many bindings can benefit from it too.
Closes https://github.com/facebook/rocksdb/pull/1454
Differential Revision: D4113420
Pulled By: yiwu-arbug
fbshipit-source-id: 307c6ae
Summary:
Changed BuildTable() (used for flush) to (1) add range
tombstones to the aggregator, which is used by CompactionIterator to
determine which keys can be removed; and (2) add aggregator's range
tombstones to the table that is output for the flush.
Closes https://github.com/facebook/rocksdb/pull/1438
Differential Revision: D4100025
Pulled By: ajkr
fbshipit-source-id: cb01a70
Summary:
Passing std::atomic<uint64_t> variables to ASSERT_EQ()
results in compile error
C2718 'const T1': actual parameter with requested alignment of 8 won't be aligned.
VS2015 defines std::atomic as specially aligned type ( with 'alignas'),
however the compiler does not like declspec(align)ed function
arguments.
Worked around by casting std::atomic<uint64_t> types to uint64_t
in ASSERT_EQ.
Closes https://github.com/facebook/rocksdb/pull/1450
Differential Revision: D4106788
Pulled By: yiwu-arbug
fbshipit-source-id: 5fb42c3
Summary:
Currently the compression suppport and fast CRC support information is printed as info level. They should be in the same level as options, which is header level.
Also add ZSTD to this printing.
Closes https://github.com/facebook/rocksdb/pull/1448
Differential Revision: D4106608
Pulled By: yiwu-arbug
fbshipit-source-id: cb9a076
Summary:
DB Stats now are truncated if there are too many CFs. Extend the buffer size to allow more to be printed out. Also, separate out malloc to another log line.
Closes https://github.com/facebook/rocksdb/pull/1439
Differential Revision: D4100943
Pulled By: yiwu-arbug
fbshipit-source-id: 79f7218
Summary:
The current 10 millisecond waiting for test results may not be sufficient in some test environments. Increase it to 60 seconds and check the results for every 1 milliseond.
Already reviewed: https://reviews.facebook.net/D65457
Closes https://github.com/facebook/rocksdb/pull/1437
Differential Revision: D4099443
Pulled By: siying
fbshipit-source-id: cf1f205
Summary:
A bug that tailingIterator->Seek(target) skips records.
I think the bug is in the SeekInternal starting at lines 387:
search_left_bound > search_right_bound
There are only 2 cases this can happen:
(1) target key is smaller than left most file
(2) target key is larger than right most file
The comment is wrong, there is another possibility that at the higher level there is a big gap such that the file in the lower level fits completely in the gap and then
indexer->GetNextLevelIndex returns search_left_bound > search_right_bound I think pointing on the files after and before the gap.
details: https://github.com/facebook/rocksdb/issues/1372
fixed this bug with test case added.
Closes https://github.com/facebook/rocksdb/pull/1436
Reviewed By: IslamAbdelRahman
Differential Revision: D4099313
Pulled By: lightmark
fbshipit-source-id: 6a675b3
Summary:
Currently, we don't use options.compression_per_level[0] as the compression style for L0 compression type, unless it is None. This behavior
doesn't look like on purpose. This diff will make sure L0 compress using the style of options.compression_per_level[0].
Reviewed and accepted in: https://reviews.facebook.net/D65607
Closes https://github.com/facebook/rocksdb/pull/1435
Differential Revision: D4099368
Pulled By: siying
fbshipit-source-id: cfbbdcd
Summary: As offline discussion with Siying, revert this since it has bug with seek.
Test Plan: make check -j64
Reviewers: yiwu, andrewkr, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D65559
Summary:
The verification condition of the test DBTest.RepeatedWritesToSameKey doesn't hold anymore after 3ce3bb3da2.
Disable the test for now before we find a way to replace it.
Test Plan: Run the test and make sure it is disabled.
Summary: Siying suggested to keep old code for normal mode prev() for safety
Test Plan: make check -j64
Reviewers: yiwu, andrewkr, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D65439
Summary: Using real clock causes failures of DBSSTTest.RateLimitedDelete in some cases. Turn away from the real time. Use fake time instead.
Test Plan: Run the tests and all existing tests.
Reviewers: yiwu, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D65145
Summary:
The previous fix of reappearing of a deleted row 0ce258f9b3 missed a corner case, which can be reproduced using test CompactionPickerTest.OverlappingUserKeys7. Consider such an example:
input level file: 1[B E] 2[F H]
output level file: 3[A C] 4[D I] 5[I K]
First file 2 is picked, which overlaps to file 4. 4 expands to 5. Now the all range is [D K] with 2 output level files. When we try to expand that, [D K] overlaps with file 1 and 2 in the input level, and 1 and 2 overlaps with 3 and 4 in the output level. So we end up with picking 3 and 4 in the output level. Without expanding, it also has 2 files, so we determine the output level doesn't change, although they are the different two files.
The fix is to expand the output level files after we picked 3 and 4. In that case, there will be three output level files so we will abort the expanding.
I also added two unit tests related to marked_for_compaction and being_compacted. They have been passing though.
Test Plan: Run the new unit test, as well as all other tests.
Reviewers: andrewkr, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: yoshinorim, leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D65373
Summary:
change ioptions.comparator to user_comparator instread of internal_comparator.
Also change Comparator* to InternalKeyComparator* to make its type explicitly.
Test Plan: make all check -j64
Reviewers: andrewkr, sdong, yiwu
Reviewed By: yiwu
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D65121
Summary:
Changes in the diff
API changes:
- Introduce IngestExternalFile to replace AddFile (I think this make the API more clear)
- Introduce IngestExternalFileOptions (This struct will encapsulate the options for ingesting the external file)
- Deprecate AddFile() API
Logic changes:
- If our file overlap with the memtable we will flush the memtable
- We will find the first level in the LSM tree that our file key range overlap with the keys in it
- We will find the lowest level in the LSM tree above the the level we found in step 2 that our file can fit in and ingest our file in it
- We will assign a global sequence number to our new file
- Remove AddFile restrictions by using global sequence numbers
Other changes:
- Refactor all AddFile logic to be encapsulated in ExternalSstFileIngestionJob
Test Plan:
unit tests (still need to add more)
addfile_stress (https://reviews.facebook.net/D65037)
Reviewers: yiwu, andrewkr, lightmark, yhchiang, sdong
Reviewed By: sdong
Subscribers: jkedgar, hcz, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D65061
Summary: DBTestUniversalCompaction.UniversalCompactionTrivialMoveTest2 verifies non-trivial move is not triggered if we load data in sequential order. However, if there are multiple compaction threads, this conditon may not hold. Restrict the running condition to 1 compaction thread to make the test more robust.
Test Plan: Run the test and make sure at least it doesn't regress normally.
Reviewers: yhchiang, andrewkr, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D65277
Summary: Some tests in column_family_test depend on functions that are not available in LITE build, which sometimes cause flakiness. Disable them.
Test Plan: Run those tests in LITE build.
Reviewers: yiwu, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D65271
Summary:
reland https://reviews.facebook.net/D62523
- Update SstFileWriter to include a property for a global sequence number in the SST file `rocksdb.external_sst_file.global_seqno`
- Update TableProperties to be aware of the offset of each property in the file
- Update BlockBasedTableReader and Block to be able to honor the sequence number in `rocksdb.external_sst_file.global_seqno` property and use it to overwrite all sequence number in the file
Something worth mentioning is that we don't update the seqno in the index block since and when doing a binary search, the reason for that is that it's guaranteed that SST files with global seqno will have only one user_key and each key will have seqno=0 encoded in it, This mean that this key is greater than any other key with seqno> 0. That mean that we can actually keep the current logic for these blocks
Test Plan: unit tests
Reviewers: sdong, yhchiang
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D65211
Summary: we should not split file on level 0 in compaction because it will fail the following verification of seqno order on level 0
Test Plan: check with filldeterministic in db_bench
Reviewers: yhchiang, andrewkr
Reviewed By: andrewkr
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D65193
Summary: in rocksdb::DBIter::FindValueForCurrentKey(), last_not_merge_type could also be SingleDelete() which is omitted
Test Plan: db_iter_test
Reviewers: yhchiang, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D65187
Summary: SamePrefixTest.InDomainTest may fail if the previous run of some test cases in prefix_test fail.
Test Plan: Run the test
Reviewers: lightmark, yhchiang, IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: leveldb, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D65163
Summary:
MyRocks hit a regression, @mung generated perf reports showing that the reason is the cost of calling `GetDBOptions()` inside `GetFromBatchAndDB()`
This diff avoid calling `GetDBOptions` and use the `ImmutableDBOptions` instead
Test Plan: make check -j64
Reviewers: sdong, yiwu
Reviewed By: yiwu
Subscribers: andrewkr, dhruba, mung
Differential Revision: https://reviews.facebook.net/D65151
Summary:
This diff introduces RangeDelAggregator, which takes ownership of iterators
provided to it via AddTombstones(). The tombstones are organized in a two-level
map (snapshot stripe -> begin key -> tombstone). Tombstone creation avoids data
copy by holding Slices returned by the iterator, which remain valid thanks to pinning.
For compaction, we create a hierarchical range tombstone iterator with structure
matching the iterator over compaction input data. An aggregator based on that
iterator is used by CompactionIterator to determine which keys are covered by
range tombstones. In case of merge operand, the same aggregator is used by
MergeHelper. Upon finishing each file in the compaction, relevant range tombstones
are added to the output file's range tombstone metablock and file boundaries are
updated accordingly.
To check whether a key is covered by range tombstone, RangeDelAggregator::ShouldDelete()
considers tombstones in the key's snapshot stripe. When this function is used outside of
compaction, it also checks newer stripes, which can contain covering tombstones. Currently
the intra-stripe check involves a linear scan; however, in the future we plan to collapse ranges
within a stripe such that binary search can be used.
RangeDelAggregator::AddToBuilder() adds all range tombstones in the table's key-range
to a new table's range tombstone meta-block. Since range tombstones may fall in the gap
between files, we may need to extend some files' key-ranges. The strategy is (1) first file
extends as far left as possible and other files do not extend left, (2) all files extend right
until either the start of the next file or the end of the last range tombstone in the gap,
whichever comes first.
One other notable change is adding release/move semantics to ScopedArenaIterator
such that it can be used to transfer ownership of an arena-allocated iterator, similar to
how unique_ptr is used for malloc'd data.
Depends on D61473
Test Plan: compaction_iterator_test, mock_table, end-to-end tests in D63927
Reviewers: sdong, IslamAbdelRahman, wanning, yhchiang, lightmark
Reviewed By: lightmark
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D62205
Summary:
Previously the WAL files that were avoided during recovery would never
be considered for deletion. That was because alive_log_files_ was only
populated when log files are created. This diff further populates
alive_log_files_ with existing log files that aren't flushed during recovery,
such that FindObsoleteFiles() can find them later.
Depends on D64053.
Test Plan: new unit test, verifies it fails before this change and passes after
Reviewers: sdong, IslamAbdelRahman, yiwu
Reviewed By: yiwu
Subscribers: leveldb, dhruba, andrewkr
Differential Revision: https://reviews.facebook.net/D64059
Summary:
Previously we have an assertion which triggers when we issue Merges
after a single delete. However, merges after a single delete are
unrelated to that single delete. Thus this behavior should be
allowed.
This will address a flakyness of db_stress.
Test Plan: db_stress
Reviewers: IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D64923
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: I accidentally left out these changes from my commit of D64053 due to
messing up the merge conflict resolution.
Test Plan: ./db_wal_test
Reviewers:
Subscribers:
Tasks:
Blame Revision: D64053
Summary:
This reverts commit 9e4aa798c3,
which doesn't handle all cases (see inline comment).
I reimplemented the logic as suggested in the initial PR: https://github.com/facebook/rocksdb/pull/1313.
This approach has two benefits:
- All the parsing/filtering of full_scan_candidate_files is kept together in PurgeObsoleteFiles.
- We only need to check whether log file is recycled in one place where we've already determined it's a log file
Test Plan:
new unit test, verified fails before the original fix, still passes
now.
Reviewers: IslamAbdelRahman, yiwu, sdong
Reviewed By: yiwu, sdong
Subscribers: leveldb, dhruba, andrewkr
Differential Revision: https://reviews.facebook.net/D64053
Summary:
1) The previous solution for Prev() prefix support is not clean.
Since I add api SeekForPrev(), now the Prev() can be symmetric to Next().
and we do not need SeekToLast() to be called in Prev() any more.
Also, Next() will Seek(prefix_seek_key_) to solve the problem of possible inconsistency between db_iter and merge_iter when
there is merge_operator. And prefix_seek_key is only refreshed when change direction to forward.
2) This diff also solves the bug of Iterator::SeekToLast() with iterate_upper_bound_ with prefix extractor.
add test cases for the above two cases.
There are some tests for the SeekToLast() in Prev(), I will clean them later.
Test Plan: make all check
Reviewers: IslamAbdelRahman, andrewkr, yiwu, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D63933
Summary:
We always run consistency checks when compiling in debug mode
allow users to set Options::force_consistency_checks to true to be able to run such checks even when compiling in release mode
Test Plan:
make check -j64
make release
Reviewers: lightmark, sdong, yiwu
Reviewed By: yiwu
Subscribers: hermanlee4, andrewkr, yoshinorim, jkedgar, dhruba
Differential Revision: https://reviews.facebook.net/D64701
Summary:
When constructing a write batch a client may now call MarkWalTerminationPoint() on that batch. No batch operations after this call will be added written to the WAL but will still be inserted into the Memtable. This facility is used to remove one of the three WriteImpl calls in 2PC transactions. This produces a ~1% perf improvement.
```
RocksDB - unoptimized 2pc, sync_binlog=1, disable_2pc=off
INFO 2016-08-31 14:30:38,814 [main]: REQUEST PHASE COMPLETED. 75000000 requests done in 2619 seconds. Requests/second = 28628
RocksDB - optimized 2pc , sync_binlog=1, disable_2pc=off
INFO 2016-08-31 16:26:59,442 [main]: REQUEST PHASE COMPLETED. 75000000 requests done in 2581 seconds. Requests/second = 29054
```
Test Plan: Two unit tests added.
Reviewers: sdong, yiwu, IslamAbdelRahman
Reviewed By: yiwu
Subscribers: hermanlee4, dhruba, andrewkr
Differential Revision: https://reviews.facebook.net/D64599
Summary:
- Update SstFileWriter to include a property for a global sequence number in the SST file `rocksdb.external_sst_file.global_seqno`
- Update TableProperties to be aware of the offset of each property in the file
- Update BlockBasedTableReader and Block to be able to honor the sequence number in `rocksdb.external_sst_file.global_seqno` property and use it to overwrite all sequence number in the file
Something worth mentioning is that we don't update the seqno in the index block since and when doing a binary search, the reason for that is that it's guaranteed that SST files with global seqno will have only one user_key and each key will have seqno=0 encoded in it, This mean that this key is greater than any other key with seqno> 0. That mean that we can actually keep the current logic for these blocks
Test Plan: unit tests
Reviewers: andrewkr, yhchiang, yiwu, sdong
Reviewed By: sdong
Subscribers: hcz, andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D62523
Summary:
- Store range tombstones in a separate MemTableRep instantiated with ColumnFamilyOptions::memtable_factory
- MemTable::NewRangeTombstoneIterator() returns a MemTableIterator over the separate MemTableRep
- Part of the read path is not implemented yet (i.e., MemTable::Get())
Test Plan: see unit tests
Reviewers: wanning
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D62217
Summary:
Fix the conflict bug between AddFile() and CompactRange() by
- Make sure that no AddFile calls are running when asking CompactionPicker to pick compaction for manual compaction
- If AddFile() run after we pick the compaction for the manual compaction it will be aware of it since we will add the manual compaction to running_compactions_ after picking it
This will solve these 2 scenarios
- If AddFile() is running, we will wait for it to finish before we pick a compaction for the manual compaction
- If we already picked a manual compaction and then AddFile() started ... we ensure that it never ingest a file in a level that will overlap with the manual compaction
Test Plan: unit tests
Reviewers: sdong
Reviewed By: sdong
Subscribers: andrewkr, yoshinorim, jkedgar, dhruba
Differential Revision: https://reviews.facebook.net/D64449
Summary:
Add new Iterator API, `SeekForPrev`: find the last key that <= target key
support prefix_extractor
support prefix_same_as_start
support upper_bound
not supported in iterators without Prev()
Also add tests in db_iter_test and db_iterator_test
Pass all tests
Cheers!
Test Plan: make all check -j64
Reviewers: andrewkr, yiwu, IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D64149
Summary: We didn't recompute compaction score on SetOptions, and end up not having compaction if no flush happens afterward. The PR fixing it.
Test Plan: See unit test.
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D64167
Summary:
Since AddFile unlock/lock the mutex inside LogAndApply() we need to ensure that during this period other compactions cannot run since such compactions are not aware of the file we are ingesting and could create a compaction that overlap wit this file
this diff add
- WaitForAddFile() call that will ensure that no AddFile() calls are being processed right now
- Call `WaitForAddFile()` in 3 locations
-- When doing manual Compaction
-- When starting automatic Compaction
-- When doing CompactFiles()
Test Plan: unit test
Reviewers: lightmark, yiwu, andrewkr, sdong
Reviewed By: sdong
Subscribers: andrewkr, yoshinorim, jkedgar, dhruba
Differential Revision: https://reviews.facebook.net/D64383
Summary: we should not call ShouldStopBefore() in compaction when the compaction targets level 0. Otherwise, CheckConsistency will fail the assertion of seq number check on level 0.
Test Plan:
make all check -j64
I also manully test that using db_bench to compact files to level 0. Without this line change, the assertion files and multiple files are generated on level 0 after compaction.
Reviewers: yhchiang, andrewkr, yiwu, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D64269
Summary: Use ImmutableDBOptions/MutableDBOptions internally and DBOptions only for user-facing APIs. MutableDBOptions is barely a placeholder for now. I'll start to move options to MutableDBOptions in following diffs.
Test Plan:
make all check
Reviewers: yhchiang, IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D64065
Summary:
Revert the behavior where we don't read sequence id from WAL, but increase it as we replay the log. We still keep the behave for 2PC for now but will fix later.
This change fixes github issue 1339, where some writes come with WAL disabled and we may recover records with wrong sequence id.
Test Plan: Added unit test.
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D64275
Summary: add ColumnFamilyHandleDeletionStarted listener which can be called when user deletes handler.
Test Plan: ./listener_test
Reviewers: yiwu, IslamAbdelRahman, sdong, andrewkr
Reviewed By: andrewkr
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D60717
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:
Mitigate regression bug of options.max_successive_merges hit during DB Recovery
For https://reviews.facebook.net/D62625
Test Plan: make all check
Reviewers: horuff, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D62655
