Commit Graph

74 Commits

Author SHA1 Message Date
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
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
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
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
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
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
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
Levi Tamasi 98094f6cac Add some comments for BlockContents
Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/5354

Differential Revision: D15496645

Pulled By: ltamasi

fbshipit-source-id: 1282b1ce11fbc412d3d87b2688fd0586e7bb6b85
2019-05-24 11:20:09 -07:00
Siying Dong 89ab1381f8 Apply automatic formatting to some files (#5114)
Summary:
Following files were run through automatic formatter:
db/db_impl.cc
db/db_impl.h
db/db_impl_compaction_flush.cc
db/db_impl_debug.cc
db/db_impl_files.cc
db/db_impl_readonly.h
db/db_impl_write.cc
db/dbformat.cc
db/dbformat.h
table/block.cc
table/block.h
table/block_based_filter_block.cc
table/block_based_filter_block.h
table/block_based_filter_block_test.cc
table/block_based_table_builder.cc
table/block_based_table_reader.cc
table/block_based_table_reader.h
table/block_builder.cc
table/block_builder.h
table/block_fetcher.cc
table/block_prefix_index.cc
table/block_prefix_index.h
table/block_test.cc
table/format.cc
table/format.h

I could easily run all the files, but I don't want people to feel that
I'm doing it for lines of code changes :)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5114

Differential Revision: D14633040

Pulled By: siying

fbshipit-source-id: 3f346cb53bf21e8c10704400da548dfce1e89a52
2019-03-27 16:24:45 -07:00
Andrew Kryczka 01013ae766 Digest ZSTD compression dictionary once when writing SST file (#4849)
Summary:
This is essentially a re-submission of #4251 with a few improvements:

- Split `CompressionDict` into two separate classes: `CompressionDict` and `UncompressionDict`
- Eliminated `Init` functions. Instead do all initialization work in constructors.
- Added test case for parallel DB open, which is the scenario where #4251 failed under TSAN.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4849

Differential Revision: D13606039

Pulled By: ajkr

fbshipit-source-id: 08c236059798c710db9cbf545fce0f371232d447
2019-01-18 19:12:57 -08:00
Siying Dong b82e57d425 Remove two variables from BlockContents class and don't use class Block for compressed block (#4650)
Summary:
We carry compression type and "cachable" variables for every block in the block cache, while they take well-known values. 8-byte is wasted for each block (2-byte for useful information but it takes 8 bytes because of padding). With this change, these two variables are removed.

The cachable information is only useful in the process of reading the block. We use other information to infer from it. For compressed blocks, the compression type is a part of the block content itself so we can get it from there.

Some code is slightly refactored so that the cachable information can flow better.

Another change is to only use class BlockContents for compressed block, and narrow the class Block to only be used for uncompressed blocks, including blocks in compressed block cache. This can make the Block class less confusing. It also saves tens of bytes for each block in compressed block cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4650

Differential Revision: D12969070

Pulled By: siying

fbshipit-source-id: 548b62724e9eb66993026429fd9c7c3acd1f95ed
2018-11-13 17:02:55 -08:00
Yi Wu f560c8f5c8 s/CacheAllocator/MemoryAllocator/g (#4590)
Summary:
Rename the interface, as it is mean to be a generic interface for memory allocation.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4590

Differential Revision: D10866340

Pulled By: yiwu-arbug

fbshipit-source-id: 85cb753351a40cb856c046aeaa3f3b369eef3d16
2018-10-26 14:30:30 -07:00
Zhongyi Xie ce1fc5af09 fix unused param `allocator` in compression.h (#4453)
Summary:
this should fix currently failing contrun test: rocksdb-contrun-no_compression, rocksdb-contrun-tsan, rocksdb-contrun-tsan_crash
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4453

Differential Revision: D10202626

Pulled By: miasantreble

fbshipit-source-id: 850b07f14f671b5998c22d8239e2a55b2fc1e355
2018-10-04 13:24:22 -07:00
Igor Canadi 1cf5deb8fd Introduce CacheAllocator, a custom allocator for cache blocks (#4437)
Summary:
This is a conceptually simple change, but it touches many files to
pass the allocator through function calls.

We introduce CacheAllocator, which can be used by clients to configure
custom allocator for cache blocks. Our motivation is to hook this up
with folly's `JemallocNodumpAllocator`
(f43ce6d686/folly/experimental/JemallocNodumpAllocator.h),
but there are many other possible use cases.

Additionally, this commit cleans up memory allocation in
`util/compression.h`, making sure that all allocations are wrapped in a
unique_ptr as soon as possible.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4437

Differential Revision: D10132814

Pulled By: yiwu-arbug

fbshipit-source-id: be1343a4b69f6048df127939fea9bbc96969f564
2018-10-02 17:24:58 -07:00
Maysam Yabandeh 65ac72edd9 Fix bug in partition filters with format_version=4 (#4381)
Summary:
Value delta encoding in format_version 4 requires the differences between the size of two consecutive handles to be sent to BlockBuilder::Add. This applies not only to indexes on blocks but also the indexes on indexes and filters in partitioned indexes and filters respectively. The patch fixes a bug where the partitioned filters would encode the entire size of the handle rather than the difference of the size with the last size.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4381

Differential Revision: D9879505

Pulled By: maysamyabandeh

fbshipit-source-id: 27a22e49b482b927fbd5629dc310c46d63d4b6d1
2018-09-17 17:28:15 -07:00
Andrew Kryczka 2c14662213 Revert "Digest ZSTD compression dictionary once per SST file (#4251)" (#4347)
Summary:
Reverting is needed to unblock a user building against master, who is blocked for multiple days due to a thread-safety issue in `GetEmptyDict`. We haven't been able to fix it quickly, so reverting.

Simply ran `git revert 6c40806e51a89386d2b066fddf73d3fd03a36f65`. There were no merge conflicts.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4347

Differential Revision: D9668365

Pulled By: ajkr

fbshipit-source-id: 0c56334f0a23cf5ee0233d4e4679eae6709739cd
2018-09-06 09:58:34 -07:00
Andrew Kryczka 6c40806e51 Digest ZSTD compression dictionary once per SST file (#4251)
Summary:
In RocksDB, for a given SST file, all data blocks are compressed with the same dictionary. When we compress a block using the dictionary's raw bytes, the compression library first has to digest the dictionary to get it into a usable form. This digestion work is redundant and ideally should be done once per file.

ZSTD offers APIs for the caller to create and reuse a digested dictionary object (`ZSTD_CDict`). In this PR, we call `ZSTD_createCDict` once per file to digest the raw bytes. Then we use `ZSTD_compress_usingCDict` to compress each data block using the pre-digested dictionary. Once the file's created `ZSTD_freeCDict` releases the resources held by the digested dictionary.

There are a couple other changes included in this PR:

- Changed the parameter object for (un)compression functions from `CompressionContext`/`UncompressionContext` to `CompressionInfo`/`UncompressionInfo`. This avoids the previous pattern, where `CompressionContext`/`UncompressionContext` had to be mutated before calling a (un)compression function depending on whether dictionary should be used. I felt that mutation was error-prone so eliminated it.
- Added support for digested uncompression dictionaries (`ZSTD_DDict`) as well. However, this PR does not support reusing them across uncompression calls for the same file. That work is deferred to a later PR when we will store the `ZSTD_DDict` objects in block cache.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4251

Differential Revision: D9257078

Pulled By: ajkr

fbshipit-source-id: 21b8cb6bbdd48e459f1c62343780ab66c0a64438
2018-08-23 19:28:18 -07:00
Maysam Yabandeh caf0f53a74 Index value delta encoding (#3983)
Summary:
Given that index value is a BlockHandle, which is basically an <offset, size> pair we can apply delta encoding on the values. The first value at each index restart interval encoded the full BlockHandle but the rest encode only the size. Refer to IndexBlockIter::DecodeCurrentValue for the detail of the encoding. This reduces the index size which helps using the  block cache more efficiently. The feature is enabled with using format_version 4.

The feature comes with a bit of cpu overhead which should be paid back by the higher cache hits due to smaller index block size.
Results with sysbench read-only using 4k blocks and using 16 index restart interval:
Format 2:
19585   rocksdb read-only range=100
Format 3:
19569   rocksdb read-only range=100
Format 4:
19352   rocksdb read-only range=100
Pull Request resolved: https://github.com/facebook/rocksdb/pull/3983

Differential Revision: D8361343

Pulled By: maysamyabandeh

fbshipit-source-id: f882ee082322acac32b0072e2bdbb0b5f854e651
2018-08-09 16:58:40 -07:00
Maysam Yabandeh eb8885a08a Return correct usable_size for BlockContents (#4246)
Summary:
If jemalloc is disabled or the API is incorrectly referenced (jemalloc api on windows have a prefix je_) memory usage is incorrectly reported for all block sizes. This is because sizeof(char) is always 1. sizeof() is calculated at compile time and *(char*) is char. The patch uses the size of the slice to fix that.
Fixes #4245
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4246

Differential Revision: D9233958

Pulled By: maysamyabandeh

fbshipit-source-id: 9646933b24504e2814c7379f06a31148829c6b4e
2018-08-08 17:43:00 -07:00
Maysam Yabandeh 29ffbb8a50 Charging block cache more accurately (#4073)
Summary:
Currently the block cache is charged only by the size of the raw data block and excludes the overhead of the c++ objects that contain the raw data block. The patch improves the accuracy of the charge by including the c++ object overhead into it.
Closes https://github.com/facebook/rocksdb/pull/4073

Differential Revision: D8686552

Pulled By: maysamyabandeh

fbshipit-source-id: 8472f7fc163c0644533bc6942e20cdd5725f520f
2018-06-29 08:57:20 -07:00
Zhongyi Xie f1592a06c2 run make format for PR 3838 (#3954)
Summary:
PR https://github.com/facebook/rocksdb/pull/3838 made some changes that triggers lint warnings.
Run `make format` to fix formatting as suggested by siying .
Also piggyback two changes:
1) fix singleton destruction order for windows and posix env
2) fix two clang warnings
Closes https://github.com/facebook/rocksdb/pull/3954

Differential Revision: D8272041

Pulled By: miasantreble

fbshipit-source-id: 7c4fd12bd17aac13534520de0c733328aa3c6c9f
2018-06-05 12:58:02 -07:00
Maysam Yabandeh d0c38c0c8c Extend some tests to format_version=3 (#3942)
Summary:
format_version=3 changes the format of SST index. This is however not being tested currently since tests only work with the default format_version which is currently 2. The patch extends the most related tests to also test for format_version=3.
Closes https://github.com/facebook/rocksdb/pull/3942

Differential Revision: D8238413

Pulled By: maysamyabandeh

fbshipit-source-id: 915725f55753dd8e9188e802bf471c23645ad035
2018-06-04 20:13:00 -07:00
Dmitri Smirnov f4b72d7056 Provide a way to override windows memory allocator with jemalloc for ZSTD
Summary:
Windows does not have LD_PRELOAD mechanism to override all memory allocation functions and ZSTD makes use of C-tuntime calloc. During flushes and compactions default system allocator fragments and the system slows down considerably.

For builds with jemalloc we employ an advanced ZSTD context creation API that re-directs memory allocation to jemalloc. To reduce the cost of context creation on each block we cache ZSTD context within the block based table builder while a new SST file is being built, this will help all platform builds including those w/o jemalloc. This avoids system allocator fragmentation and improves the performance.

The change does not address random reads and currently on Windows reads with ZSTD regress as compared with SNAPPY compression.
Closes https://github.com/facebook/rocksdb/pull/3838

Differential Revision: D8229794

Pulled By: miasantreble

fbshipit-source-id: 719b622ab7bf4109819bc44f45ec66f0dd3ee80d
2018-06-04 12:12:48 -07:00
David Lai 3be9b36453 comment unused parameters to turn on -Wunused-parameter flag
Summary:
This PR comments out the rest of the unused arguments which allow us to turn on the -Wunused-parameter flag. This is the second part of a codemod relating to https://github.com/facebook/rocksdb/pull/3557.
Closes https://github.com/facebook/rocksdb/pull/3662

Differential Revision: D7426121

Pulled By: Dayvedde

fbshipit-source-id: 223994923b42bd4953eb016a0129e47560f7e352
2018-04-12 17:59:16 -07:00
Siying Dong 2f1a3a4d74 Refactor ReadBlockContents()
Summary:
Divide ReadBlockContents() to multiple sub-functions. Maintaining the input and intermediate data in a new class BlockFetcher.
I hope in general it makes the code easier to maintain.
Another motivation to do it is to clearly divide the logic before file reading and after file reading. The refactor will help us evaluate how can we make I/O async in the future.
Closes https://github.com/facebook/rocksdb/pull/3244

Differential Revision: D6520983

Pulled By: siying

fbshipit-source-id: 338d90bc0338472d46be7a7682028dc9114b12e9
2017-12-11 15:27:32 -08:00
Siying Dong 666a005f9b Support prefetch last 512KB with direct I/O in block based file reader
Summary:
Right now, if direct I/O is enabled, prefetching the last 512KB cannot be applied, except compaction inputs or readahead is enabled for iterators. This can create a lot of I/O for HDD cases. To solve the problem, the 512KB is prefetched in block based table if direct I/O is enabled. The prefetched buffer is passed in totegher with random access file reader, so that we try to read from the buffer before reading from the file. This can be extended in the future to support flexible user iterator readahead too.
Closes https://github.com/facebook/rocksdb/pull/2708

Differential Revision: D5593091

Pulled By: siying

fbshipit-source-id: ee36ff6d8af11c312a2622272b21957a7b5c81e7
2017-08-11 12:16:45 -07:00
Siying Dong 3c327ac2d0 Change RocksDB License
Summary: Closes https://github.com/facebook/rocksdb/pull/2589

Differential Revision: D5431502

Pulled By: siying

fbshipit-source-id: 8ebf8c87883daa9daa54b2303d11ce01ab1f6f75
2017-07-15 16:11:23 -07:00
Siying Dong d616ebea23 Add GPLv2 as an alternative license.
Summary: Closes https://github.com/facebook/rocksdb/pull/2226

Differential Revision: D4967547

Pulled By: siying

fbshipit-source-id: dd3b58ae1e7a106ab6bb6f37ab5c88575b125ab4
2017-04-27 18:06:12 -07:00
Siying Dong d2dce5611a Move some files under util/ to separate dirs
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
2017-04-05 19:09:16 -07:00
Maysam Yabandeh a2f7a514d1 Refactoring
Summary:
This is the first split of https://github.com/facebook/rocksdb/pull/1891 and will be needed for the upcoming partitioned filter patch.
Closes https://github.com/facebook/rocksdb/pull/1949

Differential Revision: D4652152

Pulled By: maysamyabandeh

fbshipit-source-id: 9801778
2017-03-03 18:24:12 -08:00
Andrew Kryczka 815f54afad Insert range deletion meta-block into block cache
Summary:
This handles two issues: (1) range deletion iterator sometimes outlives
the table reader that created it, in which case the block must not be destroyed
during table reader destruction; and (2) we prefer to read these range tombstone
meta-blocks from file fewer times.

- Extracted cache-populating logic from NewDataBlockIterator() into a separate function: MaybeLoadDataBlockToCache()
- Use MaybeLoadDataBlockToCache() to load range deletion meta-block and pin it through the reader's lifetime. This code reuse works since range deletion meta-block has same format as data blocks.
- Use NewDataBlockIterator() to create range deletion iterators, which uses block cache if enabled, otherwise reads the block from file. Either way, the underlying block won't disappear until after the iterator is destroyed.
Closes https://github.com/facebook/rocksdb/pull/1459

Differential Revision: D4123175

Pulled By: ajkr

fbshipit-source-id: 8f64281
2016-11-05 09:24:26 -07:00
Yi Wu a88677d2cf Remove ImmutableCFOptions from public API
Summary: There's no reference to ImmutableCFOptions elsewhere in /include/rocksdb. ImmutableCFOptions was introduced in this commit (5665e5e285) but later its reference in /include/rocksdb/table.h is removed.

Test Plan:
  make all check

Reviewers: IslamAbdelRahman, sdong, yhchiang

Reviewed By: yhchiang

Subscribers: yhchiang, andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D63177
2016-09-02 14:16:31 -07:00
John Alexander 9430333f84 New Statistics to track Compression/Decompression (#1197)
* Added new statistics and refactored to allow ioptions to be passed around as required to access environment and statistics pointers (and, as a convenient side effect, info_log pointer).

* Prevent incrementing compression counter when compression is turned off in options.

* Prevent incrementing compression counter when compression is turned off in options.

* Added two more supported compression types to test code in db_test.cc

* Prevent incrementing compression counter when compression is turned off in options.

* Added new StatsLevel that excludes compression timing.

* Fixed casting error in coding.h

* Fixed CompressionStatsTest for new StatsLevel.

* Removed unused variable that was breaking the Linux build
2016-07-19 09:44:03 -07:00
Nadav Rotem 7360db39e6 Add a check mode to verify compressed block can be decompressed back
Summary:
Try to decompress compressed blocks when a special flag is set.
assert and crash in debug builds if we can't decompress the just-compressed input.

Test Plan: Run unit-tests.

Reviewers: dhruba, andrewkr, sdong, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D59145
2016-06-10 18:20:54 -07:00
krad a08c8c851a Added PersistentCache abstraction
Summary:
Added a new abstraction to cache page to RocksDB designed for the read
cache use.

RocksDB current block cache is more of an object cache. For the persistent read cache
project, what we need is a page cache equivalent. This changes adds a cache
abstraction to RocksDB to cache pages called PersistentCache. PersistentCache can cache
uncompressed pages or raw pages (content as in filesystem). The user can
choose to operate PersistentCache either in  COMPRESSED or UNCOMPRESSED mode.

Blame Rev:

Test Plan: Run unit tests

Reviewers: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D55707
2016-05-15 22:17:18 -07:00
Dmitri Smirnov e7899c6618 Fix build issue. (#1103) 2016-04-28 11:39:12 -07:00
Andrew Kryczka 843d2e3137 Shared dictionary compression using reference block
Summary:
This adds a new metablock containing a shared dictionary that is used
to compress all data blocks in the SST file. The size of the shared dictionary
is configurable in CompressionOptions and defaults to 0. It's currently only
used for zlib/lz4/lz4hc, but the block will be stored in the SST regardless of
the compression type if the user chooses a nonzero dictionary size.

During compaction, computes the dictionary by randomly sampling the first
output file in each subcompaction. It pre-computes the intervals to sample
by assuming the output file will have the maximum allowable length. In case
the file is smaller, some of the pre-computed sampling intervals can be beyond
end-of-file, in which case we skip over those samples and the dictionary will
be a bit smaller. After the dictionary is generated using the first file in a
subcompaction, it is loaded into the compression library before writing each
block in each subsequent file of that subcompaction.

On the read path, gets the dictionary from the metablock, if it exists. Then,
loads that dictionary into the compression library before reading each block.

Test Plan: new unit test

Reviewers: yhchiang, IslamAbdelRahman, cyan, sdong

Reviewed By: sdong

Subscribers: andrewkr, yoshinorim, kradhakrishnan, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D52287
2016-04-27 17:36:03 -07:00
Dmitri Smirnov ee221d2de0 Introduce XPRESS compresssion on Windows. (#1081)
Comparable with Snappy on comp ratio.
  Implemented using Windows API, does not require external package.
  Avaiable since Windows 8 and server 2012.
  Use -DXPRESS=1 with CMake to enable.
2016-04-19 22:54:24 -07:00
Baraa Hamodi 21e95811d1 Updated all copyright headers to the new format. 2016-02-09 15:12:00 -08:00
sdong 6e9fbeb27c Move rate_limiter, write buffering, most perf context instrumentation and most random kill out of Env
Summary: We want to keep Env a think layer for better portability. Less platform dependent codes should be moved out of Env. In this patch, I create a wrapper of file readers and writers, and put rate limiting, write buffering, as well as most perf context instrumentation and random kill out of Env. It will make it easier to maintain multiple Env in the future.

Test Plan: Run all existing unit tests.

Reviewers: anthony, kradhakrishnan, IslamAbdelRahman, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D42321
2015-07-17 16:58:18 -07:00
sdong f9728640f3 "make format" against last 10 commits
Summary: This helps Windows port to format their changes, as discussed. Might have formatted some other codes too becasue last 10 commits include more.

Test Plan: Build it.

Reviewers: anthony, IslamAbdelRahman, kradhakrishnan, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D41961
2015-07-13 13:50:18 -07:00
Dmitri Smirnov ef4b87f1b2 Commit both PR and internal code review changes 2015-07-07 16:58:20 -07:00
Dmitri Smirnov 18285c1e2f Windows Port from Microsoft
Summary: Make RocksDb build and run on Windows to be functionally
 complete and performant. All existing test cases run with no
 regressions. Performance numbers are in the pull-request.

 Test plan: make all of the existing unit tests pass, obtain perf numbers.

 Co-authored-by: Praveen Rao praveensinghrao@outlook.com
 Co-authored-by: Sherlock Huang baihan.huang@gmail.com
 Co-authored-by: Alex Zinoviev alexander.zinoviev@me.com
 Co-authored-by: Dmitri Smirnov dmitrism@microsoft.com
2015-07-01 16:13:56 -07:00
Igor Canadi 9ab5adfc59 New BlockBasedTable version -- better compressed block format
Summary:
This diff adds BlockBasedTable format_version = 2. New format version brings better compressed block format for these compressions:
1) Zlib -- encode decompressed size in compressed block header
2) BZip2 -- encode decompressed size in compressed block header
3) LZ4 and LZ4HC -- instead of doing memcpy of size_t encode size as varint32. memcpy is very bad because the DB is not portable accross big/little endian machines or even platforms where size_t might be 8 or 4 bytes.

It does not affect format for snappy.

If you write a new database with format_version = 2, it will not be readable by RocksDB versions before 3.10. DB::Open() will return corruption in that case.

Test Plan:
Added a new test in db_test.
I will also run db_bench and verify VSIZE when block_cache == 1GB

Reviewers: yhchiang, rven, MarkCallaghan, dhruba, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D31461
2015-01-14 16:24:24 -08:00
Igor Canadi 96b8240bc5 Support footer versions bigger than 1
Summary:
In this diff I add another parameter to BlockBasedTableOptions that will let users specify block based table's format. This will greatly simplify block based table's format changes in the future.

First format change that this will support is encoding decompressed size in Zlib and BZip2 blocks. This diff is blocking https://reviews.facebook.net/D31311.

Test Plan: Added a unit tests. More tests to come as part of https://reviews.facebook.net/D31311.

Reviewers: dhruba, MarkCallaghan, yhchiang, rven, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D31383
2015-01-13 14:33:04 -08:00
Manish Patil 7ea7bdf04d Dump routine to BlockBasedTableReader
Summary: Added necessary routines for dumping block based SST with block filter

Test Plan: Added "raw" mode to utility sst_dump

Reviewers: sdong, rven

Reviewed By: rven

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D29679
2014-12-23 13:24:07 -08:00
Igor Canadi 9f20395cd6 Turn -Wshadow back on
Summary: It turns out that -Wshadow has different rules for gcc than clang. Previous commit fixed clang. This commits fixes the rest of the warnings for gcc.

Test Plan: compiles

Reviewers: ljin, yhchiang, rven, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D28131
2014-11-06 11:14:28 -08:00
Igor Canadi 54cada92b1 Run make format on PR #249 2014-09-17 15:08:50 -07:00
Torrie Fischer fb6456b00d Replace naked calls to operator new and delete (Fixes #222)
This replaces a mishmash of pointers in the Block and BlockContents classes with
std::unique_ptr. It also changes the semantics of BlockContents to be limited to
use as a constructor parameter for Block objects, as it owns any block buffers
handed to it.
2014-09-17 13:50:07 -07:00