Commit Graph

318 Commits

Author SHA1 Message Date
Peter Dillinger
6db57bc37f Disable new Bloom filter assertion (#6128)
Summary:
A longstanding bug in our C interface can trigger this
assertion; see issue https://github.com/facebook/rocksdb/issues/6129. Disabling the assertion for now
(for 6.6.0) and will re-enable on fix of that bug.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6128

Differential Revision: D18854899

Pulled By: pdillinger

fbshipit-source-id: 9eb5294b9f11b208dc1a8cc148aaa31e47ff892b
2019-12-06 10:28:02 -08:00
Peter Dillinger
ca3b6c28c9 Expose and elaborate FilterBuildingContext (#6088)
Summary:
This change enables custom implementations of FilterPolicy to
wrap a variety of NewBloomFilterPolicy and select among them based on
contextual information such as table level and compaction style.

* Moves FilterBuildingContext to public API and elaborates it with more
useful data. (It would be nice to put more general options-like data,
but at the time this object is constructed, we are using internal APIs
ImmutableCFOptions and MutableCFOptions and don't have easy access to
ColumnFamilyOptions that I can tell.)

* Renames BloomFilterPolicy::GetFilterBitsBuilderInternal to
GetBuilderWithContext, because it's now public.

* Plumbs through the table's "level_at_creation" for filter building
context.

* Simplified some tests by adding GetBuilder() to
MockBlockBasedTableTester.

* Adds test as DBBloomFilterTest.ContextCustomFilterPolicy, including
sample wrapper class LevelAndStyleCustomFilterPolicy.

* Fixes a cross-test bug in DBBloomFilterTest.OptimizeFiltersForHits
where it does not reset perf context.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6088

Test Plan: make check, valgrind on db_bloom_filter_test

Differential Revision: D18697817

Pulled By: pdillinger

fbshipit-source-id: 5f987a2d7b07cc7a33670bc08ca6b4ca698c1cf4
2019-11-26 18:24:10 -08:00
Peter Dillinger
57f3032285 Allow fractional bits/key in BloomFilterPolicy (#6092)
Summary:
There's no technological impediment to allowing the Bloom
filter bits/key to be non-integer (fractional/decimal) values, and it
provides finer control over the memory vs. accuracy trade-off. This is
especially handy in using the format_version=5 Bloom filter in place
of the old one, because bits_per_key=9.55 provides the same accuracy as
the old bits_per_key=10.

This change not only requires refining the logic for choosing the best
num_probes for a given bits/key setting, it revealed a flaw in that logic.
As bits/key gets higher, the best num_probes for a cache-local Bloom
filter is closer to bpk / 2 than to bpk * 0.69, the best choice for a
standard Bloom filter. For example, at 16 bits per key, the best
num_probes is 9 (FP rate = 0.0843%) not 11 (FP rate = 0.0884%).
This change fixes and refines that logic (for the format_version=5
Bloom filter only, just in case) based on empirical tests to find
accuracy inflection points between each num_probes.

Although bits_per_key is now specified as a double, the new Bloom
filter converts/rounds this to "millibits / key" for predictable/precise
internal computations. Just in case of unforeseen compatibility
issues, we round to the nearest whole number bits / key for the
legacy Bloom filter, so as not to unlock new behaviors for it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6092

Test Plan: unit tests included

Differential Revision: D18711313

Pulled By: pdillinger

fbshipit-source-id: 1aa73295f152a995328cb846ef9157ae8a05522a
2019-11-26 15:59:34 -08:00
Peter Dillinger
f059c7d9b9 New Bloom filter implementation for full and partitioned filters (#6007)
Summary:
Adds an improved, replacement Bloom filter implementation (FastLocalBloom) for full and partitioned filters in the block-based table. This replacement is faster and more accurate, especially for high bits per key or millions of keys in a single filter.

Speed

The improved speed, at least on recent x86_64, comes from
* Using fastrange instead of modulo (%)
* Using our new hash function (XXH3 preview, added in a previous commit), which is much faster for large keys and only *slightly* slower on keys around 12 bytes if hashing the same size many thousands of times in a row.
* Optimizing the Bloom filter queries with AVX2 SIMD operations. (Added AVX2 to the USE_SSE=1 build.) Careful design was required to support (a) SIMD-optimized queries, (b) compatible non-SIMD code that's simple and efficient, (c) flexible choice of number of probes, and (d) essentially maximized accuracy for a cache-local Bloom filter. Probes are made eight at a time, so any number of probes up to 8 is the same speed, then up to 16, etc.
* Prefetching cache lines when building the filter. Although this optimization could be applied to the old structure as well, it seems to balance out the small added cost of accumulating 64 bit hashes for adding to the filter rather than 32 bit hashes.

Here's nominal speed data from filter_bench (200MB in filters, about 10k keys each, 10 bits filter data / key, 6 probes, avg key size 24 bytes, includes hashing time) on Skylake DE (relatively low clock speed):

$ ./filter_bench -quick -impl=2 -net_includes_hashing # New Bloom filter
Build avg ns/key: 47.7135
Mixed inside/outside queries...
  Single filter net ns/op: 26.2825
  Random filter net ns/op: 150.459
    Average FP rate %: 0.954651
$ ./filter_bench -quick -impl=0 -net_includes_hashing # Old Bloom filter
Build avg ns/key: 47.2245
Mixed inside/outside queries...
  Single filter net ns/op: 63.2978
  Random filter net ns/op: 188.038
    Average FP rate %: 1.13823

Similar build time but dramatically faster query times on hot data (63 ns to 26 ns), and somewhat faster on stale data (188 ns to 150 ns). Performance differences on batched and skewed query loads are between these extremes as expected.

The only other interesting thing about speed is "inside" (query key was added to filter) vs. "outside" (query key was not added to filter) query times. The non-SIMD implementations are substantially slower when most queries are "outside" vs. "inside". This goes against what one might expect or would have observed years ago, as "outside" queries only need about two probes on average, due to short-circuiting, while "inside" always have num_probes (say 6). The problem is probably the nastily unpredictable branch. The SIMD implementation has few branches (very predictable) and has pretty consistent running time regardless of query outcome.

Accuracy

The generally improved accuracy (re: Issue https://github.com/facebook/rocksdb/issues/5857) comes from a better design for probing indices
within a cache line (re: Issue https://github.com/facebook/rocksdb/issues/4120) and improved accuracy for millions of keys in a single filter from using a 64-bit hash function (XXH3p). Design details in code comments.

Accuracy data (generalizes, except old impl gets worse with millions of keys):
Memory bits per key: FP rate percent old impl -> FP rate percent new impl
6: 5.70953 -> 5.69888
8: 2.45766 -> 2.29709
10: 1.13977 -> 0.959254
12: 0.662498 -> 0.411593
16: 0.353023 -> 0.0873754
24: 0.261552 -> 0.0060971
50: 0.225453 -> ~0.00003 (less than 1 in a million queries are FP)

Fixes https://github.com/facebook/rocksdb/issues/5857
Fixes https://github.com/facebook/rocksdb/issues/4120

Unlike the old implementation, this implementation has a fixed cache line size (64 bytes). At 10 bits per key, the accuracy of this new implementation is very close to the old implementation with 128-byte cache line size. If there's sufficient demand, this implementation could be generalized.

Compatibility

Although old releases would see the new structure as corrupt filter data and read the table as if there's no filter, we've decided only to enable the new Bloom filter with new format_version=5. This provides a smooth path for automatic adoption over time, with an option for early opt-in.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6007

Test Plan: filter_bench has been used thoroughly to validate speed, accuracy, and correctness. Unit tests have been carefully updated to exercise new and old implementations, as well as the logic to select an implementation based on context (format_version).

Differential Revision: D18294749

Pulled By: pdillinger

fbshipit-source-id: d44c9db3696e4d0a17caaec47075b7755c262c5f
2019-11-13 16:44:01 -08:00
Peter Dillinger
42b5494ec8 Fix BloomFilterPolicy changes for unsigned char (ARM) (#6024)
Summary:
Bug in PR https://github.com/facebook/rocksdb/issues/5941 when char is unsigned that should only affect
assertion on unused/invalid filter metadata.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6024

Test Plan: on ARM: ./bloom_test && ./db_bloom_filter_test && ./block_based_filter_block_test && ./full_filter_block_test && ./partitioned_filter_block_test

Differential Revision: D18461206

Pulled By: pdillinger

fbshipit-source-id: 68a7c813a0b5791c05265edc03cdf52c78880e9a
2019-11-12 15:29:15 -08:00
anand76
03ce7fb292 Fix a buffer overrun problem in BlockBasedTable::MultiGet (#6014)
Summary:
The calculation in BlockBasedTable::MultiGet for the required buffer length for reading in compressed blocks is incorrect. It needs to take the 5-byte block trailer into account.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6014

Test Plan: Add a unit test DBBasicTest.MultiGetBufferOverrun that fails in asan_check before the fix, and passes after.

Differential Revision: D18412753

Pulled By: anand1976

fbshipit-source-id: 754dfb66be1d5f161a7efdf87be872198c7e3b72
2019-11-11 16:59:15 -08:00
anand76
9836a1fa33 Fix MultiGet crash when no_block_cache is set (#5991)
Summary:
This PR fixes https://github.com/facebook/rocksdb/issues/5975. In ```BlockBasedTable::RetrieveMultipleBlocks()```, we were calling ```MaybeReadBlocksAndLoadToCache()```, which is a no-op if neither uncompressed nor compressed block cache are configured.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5991

Test Plan:
1. Add unit tests that fail with the old code and pass with the new
2. make check and asan_check

Cc spetrunia

Differential Revision: D18272744

Pulled By: anand1976

fbshipit-source-id: e62fa6090d1a6adf84fcd51dfd6859b03c6aebfe
2019-11-07 12:02:21 -08:00
Yanqin Jin
67e735dbf9 Rename BlockBasedTable::ReadMetaBlock (#6009)
Summary:
According to
https://github.com/facebook/rocksdb/wiki/Rocksdb-BlockBasedTable-Format,
the block read by BlockBasedTable::ReadMetaBlock is actually the meta index
block. Therefore, it is better to rename the function to ReadMetaIndexBlock.

This PR also applies some format change to existing code.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6009

Test Plan: make check

Differential Revision: D18333238

Pulled By: riversand963

fbshipit-source-id: 2c4340a29b3edba53d19c132cbfd04caf6242aed
2019-11-05 17:19:11 -08:00
Peter Dillinger
685e895652 Prepare filter tests for more implementations (#5967)
Summary:
This change sets up for alternate implementations underlying
BloomFilterPolicy:

* Refactor BloomFilterPolicy and expose in internal .h file so that it's easy to iterate over / select implementations for testing, regardless of what the best public interface will look like. Most notably updated db_bloom_filter_test to use this.
* Hide FullFilterBitsBuilder from unit tests (alternate derived classes planned); expose the part important for testing (CalculateSpace), as abstract class BuiltinFilterBitsBuilder. (Also cleaned up internally exposed interface to CalculateSpace.)
* Rename BloomTest -> BlockBasedBloomTest for clarity (despite ongoing confusion between block-based table and block-based filter)
* Assert that block-based filter construction interface is only used on BloomFilterPolicy appropriately constructed. (A couple of tests updated to add ", true".)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5967

Test Plan: make check

Differential Revision: D18138704

Pulled By: pdillinger

fbshipit-source-id: 55ef9273423b0696309e251f50b8c1b5e9ec7597
2019-10-31 14:12:33 -07:00
Peter Dillinger
013babc685 Clean up some filter tests and comments (#5960)
Summary:
Some filtering tests were unfriendly to new implementations of
FilterBitsBuilder because of dynamic_cast to FullFilterBitsBuilder. Most
of those have now been cleaned up, worked around, or at least changed
from crash on dynamic_cast failure to individual test failure.

Also put some clarifying comments on filter-related APIs.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5960

Test Plan: make check

Differential Revision: D18121223

Pulled By: pdillinger

fbshipit-source-id: e83827d9d5d96315d96f8e25a99cd70f497d802c
2019-10-24 18:48:16 -07:00
Peter Dillinger
ca7ccbe2ea Misc hashing updates / upgrades (#5909)
Summary:
- Updated our included xxhash implementation to version 0.7.2 (== the latest dev version as of 2019-10-09).
- Using XXH_NAMESPACE (like other fb projects) to avoid potential name collisions.
- Added fastrange64, and unit tests for it and fastrange32. These are faster alternatives to hash % range.
- Use preview version of XXH3 instead of MurmurHash64A for NPHash64
-- Had to update cache_test to increase probability of passing for any given hash function.
- Use fastrange64 instead of % with uses of NPHash64
-- Had to fix WritePreparedTransactionTest.CommitOfDelayedPrepared to avoid deadlock apparently caused by new hash collision.
- Set default seed for NPHash64 because specifying a seed rarely makes sense for it.
- Removed unnecessary include xxhash.h in a popular .h file
- Rename preview version of XXH3 to XXH3p for clarity and to ease backward compatibility in case final version of XXH3 is integrated.

Relying on existing unit tests for NPHash64-related changes. Each new implementation of fastrange64 passed unit tests when manipulating my local build to select it. I haven't done any integration performance tests, but I consider the improved performance of the pieces being swapped in to be well established.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5909

Differential Revision: D18125196

Pulled By: pdillinger

fbshipit-source-id: f6bf83d49d20cbb2549926adf454fd035f0ecc0d
2019-10-24 17:16:46 -07:00
Peter Dillinger
ec11eff3bc FilterPolicy consolidation, part 2/2 (#5966)
Summary:
The parts that are used to implement FilterPolicy /
NewBloomFilterPolicy and not used other than for the block-based table
should be consolidated under table/block_based/filter_policy*.

This change is step 2 of 2:
mv util/bloom.cc table/block_based/filter_policy.cc
This gets its own PR so that git has the best chance of following the
rename for blame purposes. Note that low-level shared implementation
details of Bloom filters remain in util/bloom_impl.h, and
util/bloom_test.cc remains where it is for now.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5966

Test Plan: make check

Differential Revision: D18124930

Pulled By: pdillinger

fbshipit-source-id: 823bc09025b3395f092ef46a46aa5ba92a914d84
2019-10-24 15:44:51 -07:00
Peter Dillinger
dd19014a7a FilterPolicy consolidation, part 1/2 (#5963)
Summary:
The parts that are used to implement FilterPolicy /
NewBloomFilterPolicy and not used other than for the block-based table
should be consolidated under table/block_based/filter_policy*. I don't
foresee sharing these APIs with e.g. the Plain Table because they don't
expose hashes for reuse in indexing.

This change is step 1 of 2:
(a) mv table/full_filter_bits_builder.h to
table/block_based/filter_policy_internal.h which I expect to expand
soon to internally reveal more implementation details for testing.
(b) consolidate eventual contents of table/block_based/filter_policy.cc
in util/bloom.cc, which has the most elaborate revision history
(see step 2 ...)

Step 2 soon to follow:
mv util/bloom.cc table/block_based/filter_policy.cc
This gets its own PR so that git has the best chance of following the
rename for blame purposes. Note that low-level shared implementation
details of Bloom filters are in util/bloom_impl.h.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5963

Test Plan: make check

Differential Revision: D18121199

Pulled By: pdillinger

fbshipit-source-id: 8f21732c3d8909777e3240e4ac3123d73140326a
2019-10-24 13:20:35 -07:00
sdong
30e2dc02f0 Fix VerifyChecksum readahead with mmap mode (#5945)
Summary:
A recent change introduced readahead inside VerifyChecksum(). However it is not compatible with mmap mode and generated wrong checksum verification failure. Fix it by not enabling readahead in mmap
 mode.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5945

Test Plan: Add a unit test that used to fail.

Differential Revision: D18021443

fbshipit-source-id: 6f2eb600f81b26edb02222563a4006869d576bff
2019-10-21 11:38:30 -07:00
Levi Tamasi
29ccf2075c Store the filter bits reader alongside the filter block contents (#5936)
Summary:
Amongst other things, PR https://github.com/facebook/rocksdb/issues/5504 refactored the filter block readers so that
only the filter block contents are stored in the block cache (as opposed to the
earlier design where the cache stored the filter block reader itself, leading to
potentially dangling pointers and concurrency bugs). However, this change
introduced a performance hit since with the new code, the metadata fields are
re-parsed upon every access. This patch reunites the block contents with the
filter bits reader to eliminate this overhead; since this is still a self-contained
pure data object, it is safe to store it in the cache. (Note: this is similar to how
the zstd digest is handled.)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5936

Test Plan:
make asan_check

filter_bench results for the old code:

```
$ ./filter_bench -quick
WARNING: Assertions are enabled; benchmarks unnecessarily slow
Building...
Build avg ns/key: 26.7153
Number of filters: 16669
Total memory (MB): 200.009
Bits/key actual: 10.0647
----------------------------
Inside queries...
  Dry run (46b) ns/op: 33.4258
  Single filter ns/op: 42.5974
  Random filter ns/op: 217.861
----------------------------
Outside queries...
  Dry run (25d) ns/op: 32.4217
  Single filter ns/op: 50.9855
  Random filter ns/op: 219.167
    Average FP rate %: 1.13993
----------------------------
Done. (For more info, run with -legend or -help.)

$ ./filter_bench -quick -use_full_block_reader
WARNING: Assertions are enabled; benchmarks unnecessarily slow
Building...
Build avg ns/key: 26.5172
Number of filters: 16669
Total memory (MB): 200.009
Bits/key actual: 10.0647
----------------------------
Inside queries...
  Dry run (46b) ns/op: 32.3556
  Single filter ns/op: 83.2239
  Random filter ns/op: 370.676
----------------------------
Outside queries...
  Dry run (25d) ns/op: 32.2265
  Single filter ns/op: 93.5651
  Random filter ns/op: 408.393
    Average FP rate %: 1.13993
----------------------------
Done. (For more info, run with -legend or -help.)
```

With the new code:

```
$ ./filter_bench -quick
WARNING: Assertions are enabled; benchmarks unnecessarily slow
Building...
Build avg ns/key: 25.4285
Number of filters: 16669
Total memory (MB): 200.009
Bits/key actual: 10.0647
----------------------------
Inside queries...
  Dry run (46b) ns/op: 31.0594
  Single filter ns/op: 43.8974
  Random filter ns/op: 226.075
----------------------------
Outside queries...
  Dry run (25d) ns/op: 31.0295
  Single filter ns/op: 50.3824
  Random filter ns/op: 226.805
    Average FP rate %: 1.13993
----------------------------
Done. (For more info, run with -legend or -help.)

$ ./filter_bench -quick -use_full_block_reader
WARNING: Assertions are enabled; benchmarks unnecessarily slow
Building...
Build avg ns/key: 26.5308
Number of filters: 16669
Total memory (MB): 200.009
Bits/key actual: 10.0647
----------------------------
Inside queries...
  Dry run (46b) ns/op: 33.2968
  Single filter ns/op: 58.6163
  Random filter ns/op: 291.434
----------------------------
Outside queries...
  Dry run (25d) ns/op: 32.1839
  Single filter ns/op: 66.9039
  Random filter ns/op: 292.828
    Average FP rate %: 1.13993
----------------------------
Done. (For more info, run with -legend or -help.)
```

Differential Revision: D17991712

Pulled By: ltamasi

fbshipit-source-id: 7ea205550217bfaaa1d5158ebd658e5832e60f29
2019-10-18 19:32:59 -07:00
Maysam Yabandeh
4e729f9095 Fix SeekForPrev bug with Partitioned Filters and Prefix (#5907)
Summary:
Partition Filters make use of a top-level index to find the partition that might have the bloom hash of the key. The index is with internal key format (before format version 3). Each partition contains the i) blooms of the keys in that range ii) bloom of prefixes of keys in that range, iii) the bloom of the prefix of the last key in the previous partition.
When ::SeekForPrev(key), we first perform a prefix bloom test on the SST file. The partition however is identified using the full internal key, rather than the prefix key. The reason is to be compatible with the internal key format of the top-level index. This creates a corner case. Example:
- SST k, Partition N: P1K1, P1K2
- SST k, top-level index: P1K2
- SST k+1, Partition 1: P2K1, P3K1
- SST k+1 top-level index: P3K1
When SeekForPrev(P1K3), it should point us to P1K2. However SST k top-level index would reject P1K3 since it is out of range.
One possible fix would be to search with the prefix P1 (instead of full internal key P1K3) however the details of properly comparing prefix with full internal key might get complicated. The fix we apply in this PR is to look into the last partition anyway even if the key is out of range.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5907

Differential Revision: D17889918

Pulled By: maysamyabandeh

fbshipit-source-id: 169fd7b3c71dbc08808eae5a8340611ebe5bdc1e
2019-10-11 20:30:00 -07:00
Andrew Kryczka
b00761eea6 Fix block cache ID uniqueness for Windows builds (#5844)
Summary:
Since we do not evict a file's blocks from block cache before that file
is deleted, we require a file's cache ID prefix is both unique and
non-reusable. However, the Windows functionality we were relying on only
guaranteed uniqueness. That meant a newly created file could be assigned
the same cache ID prefix as a deleted file. If the newly created file
had block offsets matching the deleted file, full cache keys could be
exactly the same, resulting in obsolete data blocks returned from cache
when trying to read from the new file.

We noticed this when running on FAT32 where compaction was writing out
of order keys due to reading obsolete blocks from its input files. The
functionality is documented as behaving the same on NTFS, although I
wasn't able to repro it there.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5844

Test Plan:
we had a reliable repro of out-of-order keys on FAT32 that
was fixed by this change

Differential Revision: D17752442

fbshipit-source-id: 95d983f9196cf415f269e19293b97341edbf7e00
2019-10-11 18:19:31 -07:00
Peter Dillinger
46ca51d430 filter_bench - a prelim tool for SST filter benchmarking (#5825)
Summary:
Example: using the tool before and after PR https://github.com/facebook/rocksdb/issues/5784 shows that
the refactoring, presumed performance-neutral, actually sped up SST
filters by about 3% to 8% (repeatable result):

Before:
-  Dry run ns/op: 22.4725
-  Single filter ns/op: 51.1078
-  Random filter ns/op: 120.133

After:
+  Dry run ns/op: 22.2301
+  Single filter run ns/op: 47.4313
+  Random filter ns/op: 115.9

Only tests filters for the block-based table (full filters and
partitioned filters - same implementation; not block-based filters),
which seems to be the recommended format/implementation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5825

Differential Revision: D17804987

Pulled By: pdillinger

fbshipit-source-id: 0f18a9c254c57f7866030d03e7fa4ba503bac3c5
2019-10-07 20:10:53 -07:00
anand76
19a97dd139 Fix data block upper bound checking for iterator reseek case (#5883)
Summary:
When an iterator reseek happens with the user specifying a new iterate_upper_bound in ReadOptions, and the new seek position is at the end of the same data block, the Seek() ends up using a stale value of data_block_within_upper_bound_ and may return incorrect results.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5883

Test Plan: Added a new test case DBIteratorTest.IterReseekNewUpperBound. Verified that it failed due to the assertion failure without the fix, and passes with the fix.

Differential Revision: D17752740

Pulled By: anand1976

fbshipit-source-id: f9b635ff5d6aeb0e1bef102cf8b2f900efd378e3
2019-10-03 20:53:29 -07:00
Yanqin Jin
9f31df8679 Fix compilation error (#5872)
Summary:
Without this fix, compiler complains.
```
$ROCKSDB_NO_FBCODE=1 USE_CLANG=1 make ldb
table/block_based/full_filter_block.cc: In constructor ‘rocksdb::FullFilterBlockBuilder::FullFilterBlockBuilder(const rocksdb::SliceTransform*, bool, rocksdb::FilterBitsBuilder*)’:
table/block_based/full_filter_block.cc:20:43: error: declaration of ‘prefix_extractor’ shadows a member of 'this' [-Werror=shadow]
FilterBitsBuilder* filter_bits_builder)
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5872

Test Plan:
```
$ROCKSDB_NO_FBCODE=1 make all
```

Differential Revision: D17690058

Pulled By: riversand963

fbshipit-source-id: 19e3d9bd86e1123847095240e73d30da5d66240e
2019-10-01 14:07:13 -07:00
sdong
846e05005d Revert "Merging iterator to avoid child iterator reseek for some cases (#5286)" (#5871)
Summary:
This reverts commit 9fad3e21eb.

Iterator verification in stress tests sometimes fail for assertion
table/block_based/block_based_table_reader.cc:2973: void rocksdb::BlockBasedTableIterator<TBlockIter, TValue>::FindBlockForward() [with TBlockIter = rocksdb::DataBlockIter; TValue = rocksdb::Slice]: Assertion `!next_block_is_out_of_bound || user_comparator_.Compare(*read_options_.iterate_upper_bound, index_iter_->user_key()) <= 0' failed.

It is likely to be linked to https://github.com/facebook/rocksdb/pull/5286 together with https://github.com/facebook/rocksdb/pull/5468 as the former PR makes some child iterator's seek being avoided, so that upper bound condition fails to be updated there. Strictly speaking, the former PR was merged before the latter one, but the latter one feels a more important improvement so I choose to revert the former one for now.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5871

Differential Revision: D17689196

fbshipit-source-id: 4ded5be68f67bee2782d31a29cb72ea68f59dd8c
2019-10-01 11:22:41 -07:00
Maysam Yabandeh
6652c94f59 Fix a bug in format_version 3 + partition filters + prefix search (#5835)
Summary:
Partitioned filters make use of a top-level index to find the partition in which the filter resides. The top-level index has a key per partition. The key is guaranteed to be larger or equal than any key in that partition. When used with format_version 3, which excludes the sequence number form index keys, the separator key in the index could be equal to the prefix of the keys in the next partition. In this way, when searching for the key, the top-level index will lead us to the previous partition, which has no key with that prefix. The prefix bloom test thus returns false, although the prefix exists in the bloom of the next partition.
The patch fixes that by a hack: It always adds the prefix of the first key of the next partition to the bloom of the current partition. In this way, in the corner cases that the index will lead us to the previous partition, we still can find the bloom filter there.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5835

Differential Revision: D17513585

Pulled By: maysamyabandeh

fbshipit-source-id: e2d1ff26c759e6e03875c4d57f4228316ecf50e9
2019-09-24 14:00:11 -07:00
Levi Tamasi
c9932d18cc Add class comment for Block
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5832

Differential Revision: D17550773

Pulled By: ltamasi

fbshipit-source-id: 66972bb008516e55b6fbba58ddd10234346d5d11
2019-09-24 11:02:11 -07:00
sdong
e8263dbdaa Apply formatter to recent 200+ commits. (#5830)
Summary:
Further apply formatter to more recent commits.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5830

Test Plan: Run all existing tests.

Differential Revision: D17488031

fbshipit-source-id: 137458fd94d56dd271b8b40c522b03036943a2ab
2019-09-20 12:04:26 -07:00
Maysam Yabandeh
638d239507 Charge block cache for cache internal usage (#5797)
Summary:
For our default block cache, each additional entry has extra memory overhead. It include LRUHandle (72 bytes currently) and the cache key (two varint64, file id and offset). The usage is not negligible. For example for block_size=4k, the overhead accounts for an extra 2% memory usage for the cache. The patch charging the cache for the extra usage, reducing untracked memory usage outside block cache. The feature is enabled by default and can be disabled by passing kDontChargeCacheMetadata to the cache constructor.
This PR builds up on https://github.com/facebook/rocksdb/issues/4258
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5797

Test Plan:
- Existing tests are updated to either disable the feature when the test has too much dependency on the old way of accounting the usage or increasing the cache capacity to account for the additional charge of metadata.
- The Usage tests in cache_test.cc are augmented to test the cache usage under kFullChargeCacheMetadata.

Differential Revision: D17396833

Pulled By: maysamyabandeh

fbshipit-source-id: 7684ccb9f8a40ca595e4f5efcdb03623afea0c6f
2019-09-16 15:26:21 -07:00
sdong
b931f84e56 Divide file_reader_writer.h and .cc (#5803)
Summary:
file_reader_writer.h and .cc contain several files and helper function, and it's hard to navigate. Separate it to multiple files and put them under file/
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5803

Test Plan: Build whole project using make and cmake.

Differential Revision: D17374550

fbshipit-source-id: 10efca907721e7a78ed25bbf74dc5410dea05987
2019-09-16 10:33:51 -07:00
Shylock Hg
9eb3e1f77d Use delete to disable automatic generated methods. (#5009)
Summary:
Use delete to disable automatic generated methods instead of private, and put the constructor together for more clear.This modification cause the unused field warning, so add unused attribute to disable this warning.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5009

Differential Revision: D17288733

fbshipit-source-id: 8a767ce096f185f1db01bd28fc88fef1cdd921f3
2019-09-11 18:09:00 -07:00
Wilfried Goesgens
fbab9913e2 upgrade gtest 1.7.0 => 1.8.1 for json result writing
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5332

Differential Revision: D17242232

fbshipit-source-id: c0d4646556a1335e51ac7382b986ca7f6ced7b64
2019-09-09 11:24:11 -07:00
Levi Tamasi
df8c307d63 Revert to storing UncompressionDicts in the cache (#5645)
Summary:
PR https://github.com/facebook/rocksdb/issues/5584 decoupled the uncompression dictionary object from the underlying block data; however, this defeats the purpose of the digested ZSTD dictionary, since the whole point
of the digest is to create it once and reuse it over and over again. This patch goes back to
storing the uncompression dictionary itself in the cache (which should be now safe to do,
since it no longer includes a Statistics pointer), while preserving the rest of the refactoring.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5645

Test Plan: make asan_check

Differential Revision: D16551864

Pulled By: ltamasi

fbshipit-source-id: 2a7e2d34bb16e70e3c816506d5afe1d842057800
2019-08-23 08:27:30 -07:00
Maysam Yabandeh
244e6f2002 Refactor MultiGet names in BlockBasedTable (#5726)
Summary:
To improve code readability, since RetrieveBlock already calls MaybeReadBlockAndLoadToCache, we avoid name similarity of the functions that call RetrieveBlock with MaybeReadBlockAndLoadToCache. The patch thus renames MaybeLoadBlocksToCache to RetrieveMultipleBlock and deletes GetDataBlockFromCache, which contains only two lines.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5726

Differential Revision: D16962535

Pulled By: maysamyabandeh

fbshipit-source-id: 99e8946808ce4eb7857592b9003812e3004f92d6
2019-08-22 08:49:00 -07:00
anand76
9046bdc5d3 Fix MultiGet() bug when whole_key_filtering is disabled (#5665)
Summary:
The batched MultiGet() implementation was not correctly handling bloom filter lookups when whole_key_filtering is disabled. It was incorrectly skipping keys not in the prefix_extractor domain, and not calling transform for keys in domain. This PR fixes both problems by moving the domain check and transformation to the FilterBlockReader.

Tests:
Unit test (confirmed failed before the fix)
make check
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5665

Differential Revision: D16902380

Pulled By: anand1976

fbshipit-source-id: a6be81ad68a6e37134a65246aec7a2c590eccf00
2019-08-21 10:23:23 -07:00
sdong
e1c468d16f Do readahead in VerifyChecksum() (#5713)
Summary:
Right now VerifyChecksum() doesn't do read-ahead. In some use cases, users won't be able to achieve good performance. With this change, by default, RocksDB will do a default readahead, and users will be able to overwrite the readahead size by passing in a ReadOptions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5713

Test Plan: Add a new unit test.

Differential Revision: D16860874

fbshipit-source-id: 0cff0fe79ac855d3d068e6ccd770770854a68413
2019-08-16 16:42:56 -07:00
Zhongyi Xie
e89b1c9c6e add missing check for hash index when calling BlockBasedTableIterator (#5712)
Summary:
Previous PR https://github.com/facebook/rocksdb/pull/3601 added support for making prefix_extractor dynamically mutable. However, there was a missing check for hash index when creating new BlockBasedTableIterator. While the check may be redundant because no other types of IndexReader makes uses of the flag, it is less error-prone to add the missing check so that future index reader implementation will not worry about violating the contract.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5712

Differential Revision: D16842052

Pulled By: miasantreble

fbshipit-source-id: aef11c0ff7a690ed248f5b8fe23481cac486b381
2019-08-16 16:39:49 -07:00
Eli Pozniansky
c2404d9928 Optimizing ApproximateSize to create index iterator just once (#5693)
Summary:
VersionSet::ApproximateSize doesn't need to create two separate index iterators and do binary search for each in BlockBasedTable. So BlockBasedTable::ApproximateSize was added that creates the iterator once and uses it to calculate the data size between start and end keys.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5693

Differential Revision: D16774056

Pulled By: elipoz

fbshipit-source-id: 53ce262e1a057788243bf30cd9b8aa6581df1a18
2019-08-16 14:18:28 -07:00
Levi Tamasi
d92a59b6f2 Fix regression affecting partitioned indexes/filters when cache_index_and_filter_blocks is false (#5705)
Summary:
PR https://github.com/facebook/rocksdb/issues/5298 (and subsequent related patches) unintentionally changed the
semantics of cache_index_and_filter_blocks: historically, this option
only affected the main index/filter block; with the changes, it affects
index/filter partitions as well. This can cause performance issues when
cache_index_and_filter_blocks is false since in this case, partitions are
neither cached nor preloaded (i.e. they are loaded on demand upon each
access). The patch reverts to the earlier behavior, that is, partitions
are cached similarly to data blocks regardless of the value of the above
option.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5705

Test Plan:
make check
./db_bench -benchmarks=fillrandom --statistics --stats_interval_seconds=1 --duration=30 --num=500000000 --bloom_bits=20 --partition_index_and_filters=true --cache_index_and_filter_blocks=false
./db_bench -benchmarks=readrandom --use_existing_db --statistics --stats_interval_seconds=1 --duration=10 --num=500000000 --bloom_bits=20 --partition_index_and_filters=true --cache_index_and_filter_blocks=false --cache_size=8000000000

Relevant statistics from the readrandom benchmark with the old code:

rocksdb.block.cache.index.miss COUNT : 0
rocksdb.block.cache.index.hit COUNT : 0
rocksdb.block.cache.index.add COUNT : 0
rocksdb.block.cache.index.bytes.insert COUNT : 0
rocksdb.block.cache.index.bytes.evict COUNT : 0
rocksdb.block.cache.filter.miss COUNT : 0
rocksdb.block.cache.filter.hit COUNT : 0
rocksdb.block.cache.filter.add COUNT : 0
rocksdb.block.cache.filter.bytes.insert COUNT : 0
rocksdb.block.cache.filter.bytes.evict COUNT : 0

With the new code:

rocksdb.block.cache.index.miss COUNT : 2500
rocksdb.block.cache.index.hit COUNT : 42696
rocksdb.block.cache.index.add COUNT : 2500
rocksdb.block.cache.index.bytes.insert COUNT : 4050048
rocksdb.block.cache.index.bytes.evict COUNT : 0
rocksdb.block.cache.filter.miss COUNT : 2500
rocksdb.block.cache.filter.hit COUNT : 4550493
rocksdb.block.cache.filter.add COUNT : 2500
rocksdb.block.cache.filter.bytes.insert COUNT : 10331040
rocksdb.block.cache.filter.bytes.evict COUNT : 0

Differential Revision: D16817382

Pulled By: ltamasi

fbshipit-source-id: 28a516b0da1f041a03313e0b70b28cf5cf205d00
2019-08-14 18:16:06 -07:00
Vijay Nadimpalli
d150e01474 New API to get all merge operands for a Key (#5604)
Summary:
This is a new API added to db.h to allow for fetching all merge operands associated with a Key. The main motivation for this API is to support use cases where doing a full online merge is not necessary as it is performance sensitive. Example use-cases:
1. Update subset of columns and read subset of columns -
Imagine a SQL Table, a row is encoded as a K/V pair (as it is done in MyRocks). If there are many columns and users only updated one of them, we can use merge operator to reduce write amplification. While users only read one or two columns in the read query, this feature can avoid a full merging of the whole row, and save some CPU.
2. Updating very few attributes in a value which is a JSON-like document -
Updating one attribute can be done efficiently using merge operator, while reading back one attribute can be done more efficiently if we don't need to do a full merge.
----------------------------------------------------------------------------------------------------
API :
Status GetMergeOperands(
      const ReadOptions& options, ColumnFamilyHandle* column_family,
      const Slice& key, PinnableSlice* merge_operands,
      GetMergeOperandsOptions* get_merge_operands_options,
      int* number_of_operands)

Example usage :
int size = 100;
int number_of_operands = 0;
std::vector<PinnableSlice> values(size);
GetMergeOperandsOptions merge_operands_info;
db_->GetMergeOperands(ReadOptions(), db_->DefaultColumnFamily(), "k1", values.data(), merge_operands_info, &number_of_operands);

Description :
Returns all the merge operands corresponding to the key. If the number of merge operands in DB is greater than merge_operands_options.expected_max_number_of_operands no merge operands are returned and status is Incomplete. Merge operands returned are in the order of insertion.
merge_operands-> Points to an array of at-least merge_operands_options.expected_max_number_of_operands and the caller is responsible for allocating it. If the status returned is Incomplete then number_of_operands will contain the total number of merge operands found in DB for key.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5604

Test Plan:
Added unit test and perf test in db_bench that can be run using the command:
./db_bench -benchmarks=getmergeoperands --merge_operator=sortlist

Differential Revision: D16657366

Pulled By: vjnadimpalli

fbshipit-source-id: 0faadd752351745224ee12d4ae9ef3cb529951bf
2019-08-06 14:26:44 -07:00
Levi Tamasi
092f417037 Move the uncompression dictionary object out of the block cache (#5584)
Summary:
RocksDB has historically stored uncompression dictionary objects in the block
cache as opposed to storing just the block contents. This neccesitated
evicting the object upon table close. With the new code, only the raw blocks
are stored in the cache, eliminating the need for eviction.

In addition, the patch makes the following improvements:

1) Compression dictionary blocks are now prefetched/pinned similarly to
index/filter blocks.
2) A copy operation got eliminated when the uncompression dictionary is
retrieved.
3) Errors related to retrieving the uncompression dictionary are propagated as
opposed to silently ignored.

Note: the patch temporarily breaks the compression dictionary evicition stats.
They will be fixed in a separate phase.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5584

Test Plan: make asan_check

Differential Revision: D16344151

Pulled By: ltamasi

fbshipit-source-id: 2962b295f5b19628f9da88a3fcebbce5a5017a7b
2019-07-23 16:01:44 -07:00
Eli Pozniansky
6b7fcc0d5f Improve CPU Efficiency of ApproximateSize (part 1) (#5613)
Summary:
1. Avoid creating the iterator in order to call BlockBasedTable::ApproximateOffsetOf(). Instead, directly call into it.
2. Optimize BlockBasedTable::ApproximateOffsetOf() keeps the index block iterator in stack.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5613

Differential Revision: D16442660

Pulled By: elipoz

fbshipit-source-id: 9320be3e918c139b10e758cbbb684706d172e516
2019-07-23 15:34:33 -07:00
haoyuhuang
8a008d4170 Block access tracing: Trace referenced key for Get on non-data blocks. (#5548)
Summary:
This PR traces the referenced key for Get for all types of blocks. This is useful when evaluating hybrid row-block caches.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5548

Test Plan: make clean && USE_CLANG=1 make check -j32

Differential Revision: D16157979

Pulled By: HaoyuHuang

fbshipit-source-id: f6327411c9deb74e35e22a35f66cdbae09ab9d87
2019-07-17 13:05:58 -07:00
Levi Tamasi
3bde41b5a3 Move the filter readers out of the block cache (#5504)
Summary:
Currently, when the block cache is used for the filter block, it is not
really the block itself that is stored in the cache but a FilterBlockReader
object. Since this object is not pure data (it has, for instance, pointers that
might dangle, including in one case a back pointer to the TableReader), it's not
really sharable. To avoid the issues around this, the current code erases the
cache entries when the TableReader is closed (which, BTW, is not sufficient
since a concurrent TableReader might have picked up the object in the meantime).
Instead of doing this, the patch moves the FilterBlockReader out of the cache
altogether, and decouples the filter reader object from the filter block.
In particular, instead of the TableReader owning, or caching/pinning the
FilterBlockReader (based on the customer's settings), with the change the
TableReader unconditionally owns the FilterBlockReader, which in turn
owns/caches/pins the filter block. This change also enables us to reuse the code
paths historically used for data blocks for filters as well.

Note:
Eviction statistics for filter blocks are temporarily broken. We plan to fix this in a
separate phase.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5504

Test Plan: make asan_check

Differential Revision: D16036974

Pulled By: ltamasi

fbshipit-source-id: 770f543c5fb4ed126fd1e04bfd3809cf4ff9c091
2019-07-16 13:14:58 -07:00
haoyuhuang
6ca3feed5c Fix -Werror=shadow (#5546)
Summary:
This PR fixes shadow errors.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5546

Test Plan: make clean && make check -j32 && make clean && USE_CLANG=1 make check -j32 && make clean && COMPILE_WITH_ASAN=1 make check -j32

Differential Revision: D16147841

Pulled By: HaoyuHuang

fbshipit-source-id: 1043500d70c134185f537ab4c3900452752f1534
2019-07-08 00:12:43 -07:00
sdong
2de61d9129 Assert get_context not null in BlockBasedTable::Get() (#5542)
Summary:
clang analyze fails after https://github.com/facebook/rocksdb/pull/5514 for this failure:
table/block_based/block_based_table_reader.cc:3450:16: warning: Called C++ object pointer is null
          if (!get_context->SaveValue(
               ^~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.

The reaon is that a branching is added earlier in the function on get_context is null or not, CLANG analyze thinks that it can be null and we make the function call withou the null checking.
Fix the issue by removing the branch and add an assert.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5542

Test Plan: "make all check" passes and CLANG analyze failure goes away.

Differential Revision: D16133988

fbshipit-source-id: d4627d03c4746254cc11926c523931086ccebcda
2019-07-05 12:34:13 -07:00
haoyuhuang
6edc5d0719 Block cache tracing: Associate a unique id with Get and MultiGet (#5514)
Summary:
This PR associates a unique id with Get and MultiGet. This enables us to track how many blocks a Get/MultiGet request accesses. We can also measure the impact of row cache vs block cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5514

Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32

Differential Revision: D16032681

Pulled By: HaoyuHuang

fbshipit-source-id: 775b05f4440badd58de6667e3ec9f4fc87a0af4c
2019-07-03 19:35:41 -07:00
Yi Wu
662ce62044 Reduce iterator key comparison for upper/lower bound check (2nd attempt) (#5468)
Summary:
This is a second attempt for https://github.com/facebook/rocksdb/issues/5111, with the fix to redo iterate bounds check after `SeekXXX()`. This is because MyRocks may change iterate bounds between seek.

See https://github.com/facebook/rocksdb/issues/5111 for original benchmark result and discussion.

Closes https://github.com/facebook/rocksdb/issues/5463.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5468

Test Plan: Existing rocksdb tests, plus myrocks test `rocksdb.optimizer_loose_index_scans` and `rocksdb.group_min_max`.

Differential Revision: D15863332

fbshipit-source-id: ab4aba5899838591806b8673899bd465f3f53e18
2019-07-02 11:48:46 -07:00
anand76
7259e28d91 MultiGet parallel IO (#5464)
Summary:
Enhancement to MultiGet batching to read data blocks required for keys in a batch in parallel from disk. It uses Env::MultiRead() API to read multiple blocks and reduce latency.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5464

Test Plan:
1. make check
2. make asan_check
3. make asan_crash

Differential Revision: D15911771

Pulled By: anand1976

fbshipit-source-id: 605036b9af0f90ca0020dc87c3a86b4da6e83394
2019-06-30 20:56:04 -07:00
sdong
15fd3be07b LRU Cache to enable mid-point insertion by default (#5508)
Summary:
Mid-point insertion is a useful feature and is mature now. Make it default. Also changed cache_index_and_filter_blocks_with_high_priority=true as default accordingly, so that we won't evict index and filter blocks easier after the change, to avoid too many surprises to users.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5508

Test Plan: Run all existing tests.

Differential Revision: D16021179

fbshipit-source-id: ce8456e8d43b3bfb48df6c304b5290a9d19817eb
2019-06-27 10:20:57 -07:00
haoyuhuang
a8975b6245 Block cache tracer: Do not populate block cache trace record when tracing is disabled. (#5510)
Summary:
This PR makes sure that trace record is not populated when tracing is disabled.

Before this PR:
DB path: [/data/mysql/rocks_regression_tests/OPTIONS-myrocks-40-33-10000000/2019-06-26-13-04-41/db]
readwhilewriting :       9.803 micros/op 1550408 ops/sec;  107.9 MB/s (5000000 of 5000000 found)
Microseconds per read:
Count: 80000000 Average: 9.8045  StdDev: 12.64
Min: 1  Median: 7.5246  Max: 25343
Percentiles: P50: 7.52 P75: 12.10 P99: 37.44 P99.9: 75.07 P99.99: 133.60

After this PR:
DB path: [/data/mysql/rocks_regression_tests/OPTIONS-myrocks-40-33-10000000/2019-06-26-14-08-21/db]
readwhilewriting :       8.723 micros/op 1662882 ops/sec;  115.8 MB/s (5000000 of 5000000 found)
Microseconds per read:
Count: 80000000 Average: 8.7236  StdDev: 12.19
Min: 1  Median: 6.7262  Max: 25229
Percentiles: P50: 6.73 P75: 10.50 P99: 31.54 P99.9: 74.81 P99.99: 132.82
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5510

Differential Revision: D16016428

Pulled By: HaoyuHuang

fbshipit-source-id: 3b3d11e6accf207d18ec2545b802aa01ee65901f
2019-06-27 08:34:08 -07:00
Mike Kolupaev
9dbcda9e3b Fix uninitialized prev_block_offset_ in BlockBasedTableReader (#5507)
Summary:
Found by valgrind_check.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5507

Differential Revision: D16002612

Pulled By: miasantreble

fbshipit-source-id: 13c11c183190e0a0571844635457d434da3ac59a
2019-06-25 23:02:01 -07:00
Mike Kolupaev
b4d7209428 Add an option to put first key of each sst block in the index (#5289)
Summary:
The first key is used to defer reading the data block until this file gets to the top of merging iterator's heap. For short range scans, most files never make it to the top of the heap, so this change can reduce read amplification by a lot sometimes.

Consider the following workload. There are a few data streams (we'll be calling them "logs"), each stream consisting of a sequence of blobs (we'll be calling them "records"). Each record is identified by log ID and a sequence number within the log. RocksDB key is concatenation of log ID and sequence number (big endian). Reads are mostly relatively short range scans, each within a single log. Writes are mostly sequential for each log, but writes to different logs are randomly interleaved. Compactions are disabled; instead, when we accumulate a few tens of sst files, we create a new column family and start writing to it.

So, a typical sst file consists of a few ranges of blocks, each range corresponding to one log ID (we use FlushBlockPolicy to cut blocks at log boundaries). A typical read would go like this. First, iterator Seek() reads one block from each sst file. Then a series of Next()s move through one sst file (since writes to each log are mostly sequential) until the subiterator reaches the end of this log in this sst file; then Next() switches to the next sst file and reads sequentially from that, and so on. Often a range scan will only return records from a small number of blocks in small number of sst files; in this case, the cost of initial Seek() reading one block from each file may be bigger than the cost of reading the actually useful blocks.

Neither iterate_upper_bound nor bloom filters can prevent reading one block from each file in Seek(). But this PR can: if the index contains first key from each block, we don't have to read the block until this block actually makes it to the top of merging iterator's heap, so for short range scans we won't read any blocks from most of the sst files.

This PR does the deferred block loading inside value() call. This is not ideal: there's no good way to report an IO error from inside value(). As discussed with siying offline, it would probably be better to change InternalIterator's interface to explicitly fetch deferred value and get status. I'll do it in a separate PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5289

Differential Revision: D15256423

Pulled By: al13n321

fbshipit-source-id: 750e4c39ce88e8d41662f701cf6275d9388ba46a
2019-06-24 20:54:04 -07:00
haoyuhuang
705b8eecb4 Add more callers for table reader. (#5454)
Summary:
This PR adds more callers for table readers. These information are only used for block cache analysis so that we can know which caller accesses a block.
1. It renames the BlockCacheLookupCaller to TableReaderCaller as passing the caller from upstream requires changes to table_reader.h and TableReaderCaller is a more appropriate name.
2. It adds more table reader callers in table/table_reader_caller.h, e.g., kCompactionRefill, kExternalSSTIngestion, and kBuildTable.

This PR is long as it requires modification of interfaces in table_reader.h, e.g., NewIterator.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5454

Test Plan: make clean && COMPILE_WITH_ASAN=1 make check -j32.

Differential Revision: D15819451

Pulled By: HaoyuHuang

fbshipit-source-id: b6caa704c8fb96ddd15b9a934b7e7ea87f88092d
2019-06-20 14:31:48 -07:00
Zhongyi Xie
24f73436fb sanitize and limit block_size under 4GB (#5492)
Summary:
`Block::restart_index_`, `Block::restarts_`, and `Block::current_` are defined as uint32_t but  `BlockBasedTableOptions::block_size` is defined as a size_t so user might see corruption as in https://github.com/facebook/rocksdb/issues/5486.
This PR adds a check in `BlockBasedTableFactory::SanitizeOptions` to disallow such configurations.
yiwu-arbug
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5492

Differential Revision: D15914047

Pulled By: miasantreble

fbshipit-source-id: c943f153d967e15aee7f2795730ab8259e2be201
2019-06-20 11:45:08 -07:00
Vijay Nadimpalli
24b118ad98 Combine the read-ahead logic for user reads and compaction reads (#5431)
Summary:
Currently the read-ahead logic for user reads and compaction reads go through different code paths where compaction reads create new table readers and use `ReadaheadRandomAccessFile`. This change is to unify read-ahead logic to use read-ahead in BlockBasedTableReader::InitDataBlock(). As a result of the change  `ReadAheadRandomAccessFile` class and `new_table_reader_for_compaction_inputs` option will no longer be used.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5431

Test Plan:
make check

Here is the benchmarking - https://gist.github.com/vjnadimpalli/083cf423f7b6aa12dcdb14c858bc18a5

Differential Revision: D15772533

Pulled By: vjnadimpalli

fbshipit-source-id: b71dca710590471ede6fb37553388654e2e479b9
2019-06-19 14:10:46 -07:00
Levi Tamasi
5355e527d9 Make the 'block read count' performance counters consistent (#5484)
Summary:
The patch brings the semantics of per-block-type read performance
context counters in sync with the generic block_read_count by only
incrementing the counter if the block was actually read from the file.
It also fixes index_block_read_count, which fell victim to the
refactoring in PR https://github.com/facebook/rocksdb/issues/5298.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5484

Test Plan: Extended the unit tests.

Differential Revision: D15887431

Pulled By: ltamasi

fbshipit-source-id: a3889759d0ac5759d56625d692cd828d1b9207a6
2019-06-18 19:03:24 -07:00
Levi Tamasi
d0c6aea192 Revert to respecting only the read_tier read option for index blocks (#5481)
Summary:
PR https://github.com/facebook/rocksdb/issues/5298 subtly changed how read options are applied to the index block
during a Get, MultiGet, or iteration. Earlier, only the read_tier option
applied to the index block read; since PR https://github.com/facebook/rocksdb/issues/5298, fill_cache and
verify_checksums also have an effect. This patch restores the earlier
behavior to prevent surprise memory increases for clients due to the
index block not being cached.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5481

Test Plan: make check

Differential Revision: D15883082

Pulled By: ltamasi

fbshipit-source-id: 9a065ec3a6db5a365cf6dd5e95190a20c5756356
2019-06-18 15:02:09 -07:00
haoyuhuang
7a8d7358bb Integrate block cache tracer in block based table reader. (#5441)
Summary:
This PR integrates the block cache tracer into block based table reader. The tracer will write the block cache accesses using the trace_writer. The tracer is null in this PR so that nothing will be logged.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5441

Differential Revision: D15772029

Pulled By: HaoyuHuang

fbshipit-source-id: a64adb92642cd23222e0ba8b10d86bf522b42f9b
2019-06-14 17:40:31 -07:00
haoyuhuang
bb4178066d Integrate block cache tracer into db_impl (#5433)
Summary:
This PR integrates the block cache tracer class into db_impl.cc.
db_impl.cc contains a member variable of AtomicBlockCacheTraceWriter class and passes its reference to the block_based_table_reader.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5433

Differential Revision: D15728016

Pulled By: HaoyuHuang

fbshipit-source-id: 23d5659e8c82d556833dcc1a5558aac8c1f7db71
2019-06-13 15:43:10 -07:00
Levi Tamasi
ba64a4cf52 Revert "Reduce iterator key comparison for upper/lower bound check (#5111)" (#5440)
Summary:
This reverts commit f3a7847598.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5440

Differential Revision: D15765967

Pulled By: ltamasi

fbshipit-source-id: d027fe24132e3729289cd7c01857a7eb449d9dd0
2019-06-11 16:23:41 -07:00
haoyuhuang
5efa0d6b0d Create a BlockCacheLookupContext to enable fine-grained block cache tracing. (#5421)
Summary:
BlockCacheLookupContext only contains the caller for now.
We will trace block accesses at five places:
1. BlockBasedTable::GetFilter.
2. BlockBasedTable::GetUncompressedDict.
3. BlockBasedTable::MaybeReadAndLoadToCache. (To trace access on data, index, and range deletion block.)
4. BlockBasedTable::Get. (To trace the referenced key and whether the referenced key exists in a fetched data block.)
5. BlockBasedTable::MultiGet. (To trace the referenced key and whether the referenced key exists in a fetched data block.)

We create the context at:
1. BlockBasedTable::Get. (kUserGet)
2. BlockBasedTable::MultiGet. (kUserMGet)
3. BlockBasedTable::NewIterator. (either kUserIterator, kCompaction, or external SST ingestion calls this function.)
4. BlockBasedTable::Open. (kPrefetch)
5. Index/Filter::CacheDependencies. (kPrefetch)
6. BlockBasedTable::ApproximateOffsetOf. (kCompaction or kUserApproximateSize).

I loaded 1 million key-value pairs into the database and ran the readrandom benchmark with a single thread. I gave the block cache 10 GB to make sure all reads hit the block cache after warmup. The throughput is comparable.
Throughput of this PR: 231334 ops/s.
Throughput of the master branch: 238428 ops/s.

Experiment setup:
RocksDB:    version 6.2
Date:       Mon Jun 10 10:42:51 2019
CPU:        24 * Intel Core Processor (Skylake)
CPUCache:   16384 KB
Keys:       20 bytes each
Values:     100 bytes each (100 bytes after compression)
Entries:    1000000
Prefix:    20 bytes
Keys per prefix:    0
RawSize:    114.4 MB (estimated)
FileSize:   114.4 MB (estimated)
Write rate: 0 bytes/second
Read rate: 0 ops/second
Compression: NoCompression
Compression sampling rate: 0
Memtablerep: skip_list
Perf Level: 1

Load command: ./db_bench --benchmarks="fillseq" --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --statistics --cache_index_and_filter_blocks --cache_size=10737418240 --disable_auto_compactions=1 --disable_wal=1 --compression_type=none --min_level_to_compress=-1 --compression_ratio=1 --num=1000000

Run command: ./db_bench --benchmarks="readrandom,stats" --use_existing_db --threads=1 --duration=120 --key_size=20 --prefix_size=20 --keys_per_prefix=0 --value_size=100 --statistics --cache_index_and_filter_blocks --cache_size=10737418240 --disable_auto_compactions=1 --disable_wal=1 --compression_type=none --min_level_to_compress=-1 --compression_ratio=1 --num=1000000 --duration=120

TODOs:
1. Create a caller for external SST file ingestion and differentiate the callers for iterator.
2. Integrate tracer to trace block cache accesses.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5421

Differential Revision: D15704258

Pulled By: HaoyuHuang

fbshipit-source-id: 4aa8a55f8cb1576ffb367bfa3186a91d8f06d93a
2019-06-10 15:33:27 -07:00
anand76
63ace8ef0e Reuse data block iterator in BlockBasedTableReader::MultiGet() (#5314)
Summary:
Instead of creating a new DataBlockIterator for every key in a MultiGet batch, reuse it if the next key is in the same block. This results in a small 1-2% cpu improvement.

TEST_TMPDIR=/dev/shm/multiget numactl -C 10  ./db_bench.tmp -use_existing_db=true -benchmarks="readseq,multireadrandom" -write_buffer_size=4194304 -target_file_size_base=4194304 -max_bytes_for_level_base=16777216 -num=12000000 -reads=12000000 -duration=90 -threads=1 -compression_type=none -cache_size=4194304000 -batch_size=32 -disable_auto_compactions=true -bloom_bits=10 -cache_index_and_filter_blocks=true -pin_l0_filter_and_index_blocks_in_cache=true -multiread_batched=true -multiread_stride=4

Without the change -
multireadrandom :       3.066 micros/op 326122 ops/sec; (29375968 of 29375968 found)

With the change -
multireadrandom :       3.003 micros/op 332945 ops/sec; (29983968 of 29983968 found)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5314

Differential Revision: D15742108

Pulled By: anand1976

fbshipit-source-id: 220fb0b8eea9a0d602ddeb371528f7af7936d771
2019-06-10 13:31:19 -07:00
Levi Tamasi
0f48e56f96 Revert to checking the upper bound on a per-key basis in BlockBasedTableIterator (#5428)
Summary:
PR #5111 reduced the number of key comparisons when iterating with
upper/lower bounds; however, this caused a regression for MyRocks.
Reverting to the previous behavior in BlockBasedTableIterator as a hotfix.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5428

Differential Revision: D15721038

Pulled By: ltamasi

fbshipit-source-id: 5450106442f1763bccd17f6cfd648697f2ae8b6c
2019-06-07 15:17:05 -07:00
Zhongyi Xie
d68f9f4580 simplify include directive involving inttypes (#5402)
Summary:
When using `PRIu64` type of printf specifier, current code base does the following:
```
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
```
However, this can be simplified to
```
#include <cinttypes>
```
as long as flag `-std=c++11` is used.
This should solve issues like https://github.com/facebook/rocksdb/issues/5159
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5402

Differential Revision: D15701195

Pulled By: miasantreble

fbshipit-source-id: 6dac0a05f52aadb55e9728038599d3d2e4b59d03
2019-06-06 13:56:07 -07:00
Levi Tamasi
bee2f48a66 Refactor the handling of cache related counters and statistics (#5408)
Summary:
The patch cleans up the handling of cache hit/miss/insertion related
performance counters, get context counters, and statistics by
eliminating some code duplication and factoring out the affected logic
into separate methods. In addition, it makes the semantics of cache hit
metrics more consistent by changing the code so that accessing a
partition of partitioned indexes/filters through a pinned reference no
longer counts as a cache hit.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5408

Differential Revision: D15610883

Pulled By: ltamasi

fbshipit-source-id: ee749c18965077aca971d8f8bee8b24ed8fa76f1
2019-06-06 11:36:40 -07:00
Yanqin Jin
340ed4fac7 Add support for timestamp in Get/Put (#5079)
Summary:
It's useful to be able to (optionally) associate key-value pairs with user-provided timestamps. This PR is an early effort towards this goal and continues the work of facebook#4942. A suite of new unit tests exist in DBBasicTestWithTimestampWithParam. Support for timestamp requires the user to provide timestamp as a slice in `ReadOptions` and `WriteOptions`. All timestamps of the same database must share the same length, format, etc. The format of the timestamp is the same throughout the same database, and the user is responsible for providing a comparator function (Comparator) to order the <key, timestamp> tuples. Once created, the format and length of the timestamp cannot change (at least for now).

Test plan (on devserver):
```
$COMPILE_WITH_ASAN=1 make -j32 all
$./db_basic_test --gtest_filter=Timestamp/DBBasicTestWithTimestampWithParam.PutAndGet/*
$make check
```
All tests must pass.

We also run the following db_bench tests to verify whether there is regression on Get/Put while timestamp is not enabled.
```
$TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillseq,readrandom -num=1000000
$TEST_TMPDIR=/dev/shm ./db_bench -benchmarks=fillrandom -num=1000000
```
Repeat for 6 times for both versions.

Results are as follows:
```
|        | readrandom | fillrandom |
| master | 16.77 MB/s | 47.05 MB/s |
| PR5079 | 16.44 MB/s | 47.03 MB/s |
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5079

Differential Revision: D15132946

Pulled By: riversand963

fbshipit-source-id: 833a0d657eac21182f0f206c910a6438154c742c
2019-06-05 23:10:47 -07:00
haoyuhuang
349db90497 Make GetEntryFromCache a member function. (#5394)
Summary:
The commit makes GetEntryFromCache become a member function. It also makes all its callers become member functions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5394

Differential Revision: D15579222

Pulled By: HaoyuHuang

fbshipit-source-id: 07509c42ee9022dcded54950012bd3bd562aa1ae
2019-06-03 12:34:59 -07:00
Siying Dong
000b9ec217 Move some logging related files to logging/ (#5387)
Summary:
Many logging related source files are under util/. It will be more structured if they are together.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5387

Differential Revision: D15579036

Pulled By: siying

fbshipit-source-id: 3850134ed50b8c0bb40a0c8ae1f184fa4081303f
2019-05-31 17:23:59 -07:00
Levi Tamasi
a3609b7dde Improve const correctness in BlockBasedTableReader (#5383)
Summary:
Many methods are passing around pointers to non-const objects when in fact
they do not/should not modify said objects. The patch makes the semantics
clearer and also helps from a thread safety point-of-view by changing some
pointers to pointers-to-const and marking some instance methods as const.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5383

Differential Revision: D15562770

Pulled By: ltamasi

fbshipit-source-id: 89361dadbb8b25bbe54d17e8da28fee24a2419af
2019-05-31 11:41:35 -07:00
Siying Dong
8843129ece Move some memory related files from util/ to memory/ (#5382)
Summary:
Move arena, allocator, and memory tools under util to a separate memory/ directory.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5382

Differential Revision: D15564655

Pulled By: siying

fbshipit-source-id: 9cd6b5d0d3d52b39606e19221fa154596e5852a5
2019-05-30 17:44:09 -07:00
Vijay Nadimpalli
50e470791d Organizing rocksdb/table directory by format
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5373

Differential Revision: D15559425

Pulled By: vjnadimpalli

fbshipit-source-id: 5d6d6d615582bedd96a4b879bb25d429a6de8b55
2019-05-30 14:51:11 -07:00