Commit Graph

1622 Commits

Author SHA1 Message Date
Andrew Kryczka
b6280d01f9 Require ZSTD 1.1.3+ to use dictionary trainer (#4295)
Summary:
ZSTD's dynamic library exports `ZDICT_trainFromBuffer` symbol since v1.1.3, and its static library exports it since v0.6.1. We don't know whether linkage is static or dynamic, so just require v1.1.3 to use dictionary trainer.

Fixes the issue reported here: https://jira.mariadb.org/browse/MDEV-16525.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4295

Differential Revision: D9417183

Pulled By: ajkr

fbshipit-source-id: 0e89d2f48d9e7f6eee73e7f4572660a9f7122db8
2018-08-22 18:27:52 -07:00
Yi Wu
4f12d49daf Suppress clang analyzer error (#4299)
Summary:
Suppress multiple clang-analyzer error. All of them are clang false-positive.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4299

Differential Revision: D9430740

Pulled By: yiwu-arbug

fbshipit-source-id: fbdd575bdc214d124826d61d35a117995c509279
2018-08-21 16:43:05 -07:00
Siying Dong
d5612b43de Two code changes to make "clang analyze" happy (#4292)
Summary:
Clang analyze is not happy in two pieces of code, with "Potential memory leak". No idea what the problem but slightly changing the code makes clang happy.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4292

Differential Revision: D9413555

Pulled By: siying

fbshipit-source-id: 9428c9d3664530c72129feefd135ee63d8386137
2018-08-20 17:43:41 -07:00
Fenggang Wu
19ec44fd39 Improve point-lookup performance using a data block hash index (#4174)
Summary:
Add hash index support to data blocks, which helps to reduce the CPU utilization of point-lookup operations. This feature is backward compatible with the data block created without the hash index. It is disabled by default unless `BlockBasedTableOptions::data_block_index_type` is set to `data_block_index_type = kDataBlockBinaryAndHash.`

The DB size would be bigger with the hash index option as a hash table is added at the end of each data block. If the hash utilization ratio is 1:1, the space overhead is one byte per key. The hash table utilization ratio is adjustable using `BlockBasedTableOptions::data_block_hash_table_util_ratio`. A lower utilization ratio will improve more on the point-lookup efficiency, but take more space too.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4174

Differential Revision: D8965914

Pulled By: fgwu

fbshipit-source-id: 1c6bae5d1fc39c80282d8890a72e9e67bc247198
2018-08-15 14:30:03 -07:00
jsteemann
33ad9060d3 fix compilation with g++ option -Wsuggest-override (#4272)
Summary:
Fixes compilation warnings (which are turned into compilation errors by default) when compiling with g++ option `-Wsuggest-override`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4272

Differential Revision: D9322556

Pulled By: siying

fbshipit-source-id: abd57a29ec8f544bee77c0bb438f31be830b7244
2018-08-14 15:13:10 -07:00
Zhichao Cao
999d955e4f RocksDB Trace Analyzer (#4091)
Summary:
A framework of trace analyzing for RocksDB

After collecting the trace by using the tool of [PR #3837](https://github.com/facebook/rocksdb/pull/3837). User can use the Trace Analyzer to interpret, analyze, and characterize the collected workload.
**Input:**
1. trace file
2. Whole keys space file

**Statistics:**
1. Access count of each operation (Get, Put, Delete, SingleDelete, DeleteRange, Merge) in each column family.
2. Key hotness (access count) of each one
3. Key space separation based on given prefix
4. Key size distribution
5. Value size distribution if appliable
6. Top K accessed keys
7. QPS statistics including the average QPS and peak QPS
8. Top K accessed prefix
9. The query correlation analyzing, output the number of X after Y and the corresponding average time
    intervals

**Output:**
1. key access heat map (either in the accessed key space or whole key space)
2. trace sequence file (interpret the raw trace file to line base text file for future use)
3. Time serial (The key space ID and its access time)
4. Key access count distritbution
5. Key size distribution
6. Value size distribution (in each intervals)
7. whole key space separation by the prefix
8. Accessed key space separation by the prefix
9. QPS of each operation and each column family
10. Top K QPS and their accessed prefix range

**Test:**
1. Added the unit test of analyzing Get, Put, Delete, SingleDelete, DeleteRange, Merge
2. Generated the trace and analyze the trace

**Implemented but not tested (due to the limitation of trace_replay):**
1. Analyzing Iterator, supporting Seek() and SeekForPrev() analyzing
2. Analyzing the number of Key found by Get

**Future Work:**
1.  Support execution time analyzing of each requests
2.  Support cache hit situation and block read situation of Get
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4091

Differential Revision: D9256157

Pulled By: zhichao-cao

fbshipit-source-id: f0ceacb7eedbc43a3eee6e85b76087d7832a8fe6
2018-08-13 11:44:02 -07:00
Zhichao Cao
6d75319d95 Add tracing function of Seek() and SeekForPrev() to trace_replay (#4228)
Summary:
In the current trace_and replay, Get an WriteBatch are traced. This pull request track down the Seek() and SeekForPrev() to the trace file. <target_key, timestamp, column_family_id> are write to the file.

Replay of Iterator is not supported in the current implementation.

Tested with trace_analyzer.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4228

Differential Revision: D9201381

Pulled By: zhichao-cao

fbshipit-source-id: 6f9cc9cb3c20260af741bee065ec35c5c96354ab
2018-08-10 17:57:40 -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
Jingguo Yao
ceb5fea1e3 Improve FullFilterBitsReader::HashMayMatch's doc (#4202)
Summary:
HashMayMatch is related to AddKey() instead of CreateFilter().
Also applies some minor Fixes #4191 #4200 #3910
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4202

Differential Revision: D9180945

Pulled By: maysamyabandeh

fbshipit-source-id: 6f07b81c5bb9bda5c0273475b486ba8a030471e6
2018-08-06 11:13:18 -07:00
Gustav Davidsson
a15354d04e Expose GetTotalTrashSize in SstFileManager interface (#4206)
Summary:
Hi, it would be great if we could expose this API, so that LogDevice can use it to track the total size of trash files and alarm if it grows too large in relation to disk size. There's probably other customers that would be interested in this as well. :)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4206

Differential Revision: D9115516

Pulled By: gdavidsson

fbshipit-source-id: f34993a940e39cb0a0b544ae8298546499b7e047
2018-08-04 17:57:48 -07:00
Sagar Vemuri
12b6cdeed3 Trace and Replay for RocksDB (#3837)
Summary:
A framework for tracing and replaying RocksDB operations.

A binary trace file is created by capturing the DB operations, and it can be replayed back at the same rate using db_bench.

- Column-families are supported
- Multi-threaded tracing is supported.
- TraceReader and TraceWriter are exposed to the user, so that tracing to various destinations can be enabled (say, to other messaging/logging services). By default, a FileTraceReader and FileTraceWriter are implemented to capture to a file and replay from it.
- This is not yet ideal to be enabled in production due to large performance overhead, but it can be safely tried out in a shadow setup, say, for analyzing RocksDB operations.

Currently supported DB operations:
- Writes:
-- Put
-- Merge
-- Delete
-- SingleDelete
-- DeleteRange
-- Write
- Reads:
-- Get (point lookups)
Pull Request resolved: https://github.com/facebook/rocksdb/pull/3837

Differential Revision: D7974837

Pulled By: sagar0

fbshipit-source-id: 8ec65aaf336504bc1f6ed0feae67f6ed5ef97a72
2018-08-01 00:27:08 -07:00
Andrew Kryczka
a1a546a634 Avoid integer division in filter probing (#4071)
Summary:
The cache line size was computed dynamically based on the length of the filter bits, and the number of cache-lines encoded in the footer. This calculation had to be dynamic in case users migrate their data between platforms with different cache line sizes. The downside, though, was bloom filter probing became expensive as it did integer mod and division.

However, since we know all possible cache line sizes are powers of two, we should be able to use bit shift to find the cache line, and bitwise-and to find the bit within the cache line. To do this, we compute the log-base-two of cache line size in the constructor, and use that in bitwise operations to replace division/mod.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4071

Differential Revision: D8684067

Pulled By: ajkr

fbshipit-source-id: 50298872fba5acd01e8269cd7abcc51a095e0f61
2018-07-30 17:57:44 -07:00
Manuel Ung
ea212e5316 WriteUnPrepared: Implement unprepared batches for transactions (#4104)
Summary:
This adds support for writing unprepared batches based on size defined in `TransactionOptions::max_write_batch_size`. This is done by overriding methods that modify data (Put/Delete/SingleDelete/Merge) and checking first if write batch size has exceeded threshold. If so, the write batch is written to DB as an unprepared batch.

Support for Commit/Rollback for unprepared batch is added as well. This has been done by simply extending the WritePrepared Commit/Rollback logic to take care of all unprep_seq numbers either when updating prepare heap, or adding to commit map. For updating the commit map, this logic exists inside `WriteUnpreparedCommitEntryPreReleaseCallback`.

A test change was also made to have transactions unregister themselves when committing without prepare. This is because with write unprepared, there may be unprepared entries (which act similarly to prepared entries) already when a commit is done without prepare.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4104

Differential Revision: D8785717

Pulled By: lth

fbshipit-source-id: c02006e281ec1ce00f628e2a7beec0ee73096a91
2018-07-24 00:13:18 -07:00
Chang Su
374c37da5b move static msgs out of Status class (#4144)
Summary:
The member msgs of class Status contains all types of status messages.
When users dump a Status object, msgs will confuse users. So move it out
of class Status by making it as file-local static variable.

Closes #3831 .
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4144

Differential Revision: D8941419

Pulled By: sagar0

fbshipit-source-id: 56b0510258465ff26db15aa6b04e01532e053e3d
2018-07-23 15:44:16 -07:00
Siying Dong
a5e851e113 Reformatting some recent changes (#4161)
Summary:
Lint is not happy with some new code recently committed. Format them.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4161

Differential Revision: D8940582

Pulled By: siying

fbshipit-source-id: c9b43b1ef8c88b5e923911058b44eb77234b36b7
2018-07-20 14:43:38 -07:00
Siying Dong
8425c8bd4d BlockBasedTableReader: automatically adjust tail prefetch size (#4156)
Summary:
Right now we use one hard-coded prefetch size to prefetch data from the tail of the SST files. However, this may introduce a waste for some use cases, while not efficient for others.
Introduce a way to adjust this prefetch size by tracking 32 recent times, and pick a value with which the wasted read is less than 10%
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4156

Differential Revision: D8916847

Pulled By: siying

fbshipit-source-id: 8413f9eb3987e0033ed0bd910f83fc2eeaaf5758
2018-07-20 14:43:37 -07:00
Dmitri Smirnov
78ab11cd71 Return new operator for Status allocations for Windows (#4128)
Summary: Windows requires new/delete for memory allocations to be overriden. Refactor to be less intrusive.

Differential Revision: D8878047

Pulled By: siying

fbshipit-source-id: 35f2b5fec2f88ea48c9be926539c6469060aab36
2018-07-19 15:09:06 -07:00
Siying Dong
4bb1e239b5 Cap concurrent arena's shard block size to 128KB (#4147)
Summary:
Users sometime see their memtable size far smaller than expected. They probably have hit a fragementation of shard blocks. Cap their size anyway to reduce the impact of problem. 128KB is conservative so I don't imagine it can cause any performance problem.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4147

Differential Revision: D8886706

Pulled By: siying

fbshipit-source-id: 8528a2a4196aa4457274522e2565fd3ff28f621e
2018-07-18 10:43:54 -07:00
Fenggang Wu
5a59ce4149 Coding.h: Added Fixed16 support (#4142)
Summary:
Added Get Put Encode Decode support for Fixed16 (uint16_t). Unit test added in `coding_test.cc`
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4142

Differential Revision: D8873516

Pulled By: fgwu

fbshipit-source-id: 331913e0a9a8fe9c95606a08e856e953477d64d3
2018-07-16 23:43:41 -07:00
Zhongyi Xie
91d7c03cdc Exclude time waiting for rate limiter from rocksdb.sst.read.micros (#4102)
Summary:
Our "rocksdb.sst.read.micros" stat includes time spent waiting for rate limiter. It probably only affects people rate limiting compaction reads, which is fairly rare.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4102

Differential Revision: D8848506

Pulled By: miasantreble

fbshipit-source-id: 01258ac5ae56e4eee372978cfc9143a6869f8bfc
2018-07-13 18:44:14 -07:00
Maysam Yabandeh
8581a93a6b Per-thread unique test db names (#4135)
Summary:
The patch makes sure that two parallel test threads will operate on different db paths. This enables using open source tools such as gtest-parallel to run the tests of a file in parallel.
Example: ``` ~/gtest-parallel/gtest-parallel ./table_test```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4135

Differential Revision: D8846653

Pulled By: maysamyabandeh

fbshipit-source-id: 799bad1abb260e3d346bcb680d2ae207a852ba84
2018-07-13 17:27:39 -07:00
Fosco Marotto
8527012bb6 Converted db/merge_test.cc to use gtest (#4114)
Summary:
Picked up a task to convert this to use the gtest framework.  It can't be this simple, can it?

It works, but should all the std::cout be removed?

```
[$] ~/git/rocksdb [gft !]: ./merge_test
[==========] Running 2 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 2 tests from MergeTest
[ RUN      ] MergeTest.MergeDbTest
Test read-modify-write counters...
a: 3
1
2
a: 3
b: 1225
3
Compaction started ...
Compaction ended
a: 3
b: 1225
Test merge-based counters...
a: 3
1
2
a: 3
b: 1225
3
Test merge in memtable...
a: 3
1
2
a: 3
b: 1225
3
Test Partial-Merge
Test merge-operator not set after reopen
[       OK ] MergeTest.MergeDbTest (93 ms)
[ RUN      ] MergeTest.MergeDbTtlTest
Opening database with TTL
Test read-modify-write counters...
a: 3
1
2
a: 3
b: 1225
3
Compaction started ...
Compaction ended
a: 3
b: 1225
Test merge-based counters...
a: 3
1
2
a: 3
b: 1225
3
Test merge in memtable...
Opening database with TTL
a: 3
1
2
a: 3
b: 1225
3
Test Partial-Merge
Opening database with TTL
Opening database with TTL
Opening database with TTL
Opening database with TTL
Test merge-operator not set after reopen
[       OK ] MergeTest.MergeDbTtlTest (97 ms)
[----------] 2 tests from MergeTest (190 ms total)

[----------] Global test environment tear-down
[==========] 2 tests from 1 test case ran. (190 ms total)
[  PASSED  ] 2 tests.
```
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4114

Differential Revision: D8822886

Pulled By: gfosco

fbshipit-source-id: c299d008e883c3bb911d2b357a2e9e4423f8e91a
2018-07-13 14:13:07 -07:00
Tamir Duberstein
7bee48bdbd Add GCC 8 to Travis (#3433)
Summary:
- Avoid `strdup` to use jemalloc on Windows
- Use `size_t` for consistency
- Add GCC 8 to Travis
- Add CMAKE_BUILD_TYPE=Release to Travis
Pull Request resolved: https://github.com/facebook/rocksdb/pull/3433

Differential Revision: D6837948

Pulled By: sagar0

fbshipit-source-id: b8543c3a4da9cd07ee9a33f9f4623188e233261f
2018-07-13 10:58:06 -07:00
Sagar Vemuri
1c912196de Remove external tracking of AlignedBuffer's size (#4105)
Summary:
Remove external tracking of AlignedBuffer's size in `ReadaheadRandomAccessFile` and `FilePrefetchBuffer`.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4105

Differential Revision: D8805724

Pulled By: sagar0

fbshipit-source-id: d61d8c203c7c500e3f36e912132d7852026ed023
2018-07-11 15:57:49 -07:00
Sagar Vemuri
440621aab8 Fix Copying of data between buffers in FilePrefetchBuffer (#4100)
Summary:
Copy data between buffers inside FilePrefetchBuffer only when chunk length is greater than 0. Otherwise AlignedBuffer was accessing memory out of its range causing crashes.

Removing the tracking of buffer length outside of `AlignedBuffer`, i.e. in `FilePrefetchBuffer` and `ReadaheadRandomAccessFile`, will follow in a separate PR, as it is not the root cause of the crash reported in #4051. (`FilePrefetchBuffer` itself has been this way from its inception, and `ReadaheadRandomAccessFile` was updated to add the buffer length at some point).

Comprehensive tests for `FilePrefetchBuffer` also to follow in a separate PR.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4100

Differential Revision: D8792590

Pulled By: sagar0

fbshipit-source-id: 3578f45761cf6884243e767f749db4016ccc93e1
2018-07-11 12:28:13 -07:00
Siying Dong
926f3a78a6 In delete scheduler, before ftruncate file for slow delete, check whether there is other hard links (#4093)
Summary:
Right now slow deletion with ftruncate doesn't work well with checkpoints because it ruin hard linked files in checkpoints. To fix it, check the file has no other hard link before ftruncate it.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4093

Differential Revision: D8730360

Pulled By: siying

fbshipit-source-id: 756eea5bce8a87b9a2ea3a5bfa190b2cab6f75df
2018-07-09 15:28:12 -07:00
Andrew Kryczka
25403c2265 Prefetch cache lines for filter lookup (#4068)
Summary:
Since the filter data is unaligned, even though we ensure all probes are within a span of `cache_line_size` bytes, those bytes can span two cache lines. In that case I doubt hardware prefetching does a great job considering we don't necessarily access those two cache lines in order. This guess seems correct since adding explicit prefetch instructions reduced filter lookup overhead by 19.4%.
Closes https://github.com/facebook/rocksdb/pull/4068

Differential Revision: D8674189

Pulled By: ajkr

fbshipit-source-id: 747427d9a17900151c17820488e3f7efe06b1871
2018-06-28 13:20:29 -07:00
Anand Ananthabhotla
52d4c9b7f6 Allow DB resume after background errors (#3997)
Summary:
Currently, if RocksDB encounters errors during a write operation (user requested or BG operations), it sets DBImpl::bg_error_ and fails subsequent writes. This PR allows the DB to be resumed for certain classes of errors. It consists of 3 parts -
1. Introduce Status::Severity in rocksdb::Status to indicate whether a given error can be recovered from or not
2. Refactor the error handling code so that setting bg_error_ and deciding on severity is in one place
3. Provide an API for the user to clear the error and resume the DB instance

This whole change is broken up into multiple PRs. Initially, we only allow clearing the error for Status::NoSpace() errors during background flush/compaction. Subsequent PRs will expand this to include more errors and foreground operations such as Put(), and implement a polling mechanism for out-of-space errors.
Closes https://github.com/facebook/rocksdb/pull/3997

Differential Revision: D8653831

Pulled By: anand1976

fbshipit-source-id: 6dc835c76122443a7668497c0226b4f072bc6afd
2018-06-28 12:34:40 -07:00
Daniel Black
e5ae1bb465 Remove bogus gcc-8.1 warning (#3870)
Summary:
Various rearrangements of the cch maths failed or replacing = '\0' with
memset failed to convince the compiler it was nul terminated. So took
the perverse option of changing strncpy to strcpy.

Return null if memory couldn't be allocated.

util/status.cc: In static member function ‘static const char* rocksdb::Status::CopyState(const char*)’:
util/status.cc:28:15: error: ‘char* strncpy(char*, const char*, size_t)’ output truncated before terminating nul copying as many bytes from a string as its length [-Werror=stringop-truncation]
   std::strncpy(result, state, cch - 1);
   ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
util/status.cc:19:18: note: length computed here
       std::strlen(state) + 1; // +1 for the null terminator
       ~~~~~~~~~~~^~~~~~~
cc1plus: all warnings being treated as errors
make: *** [Makefile:645: shared-objects/util/status.o] Error 1

closes #2705
Closes https://github.com/facebook/rocksdb/pull/3870

Differential Revision: D8594114

Pulled By: anand1976

fbshipit-source-id: ab20f3a456a711e4d29144ebe630e4fe3c99ec25
2018-06-27 12:23:07 -07:00
Zhongyi Xie
408205a36b use user_key and iterate_upper_bound to determine compatibility of bloom filters (#3899)
Summary:
Previously in https://github.com/facebook/rocksdb/pull/3601 bloom filter will only be checked if `prefix_extractor` in the mutable_cf_options matches the one found in the SST file.
This PR relaxes the requirement by checking if all keys in the range [user_key, iterate_upper_bound) all share the same prefix after transforming using the BF in the SST file. If so, the bloom filter is considered compatible and will continue to be looked at.
Closes https://github.com/facebook/rocksdb/pull/3899

Differential Revision: D8157459

Pulled By: miasantreble

fbshipit-source-id: 18d17cba56a1005162f8d5db7a27aba277089c41
2018-06-26 15:57:26 -07:00
Maysam Yabandeh
80ade9ad83 Pin top-level index on partitioned index/filter blocks (#4037)
Summary:
Top-level index in partitioned index/filter blocks are small and could be pinned in memory. So far we use that by cache_index_and_filter_blocks to false. This however make it difficult to keep account of the total memory usage. This patch introduces pin_top_level_index_and_filter which in combination with cache_index_and_filter_blocks=true keeps the top-level index in cache and yet pinned them to avoid cache misses and also cache lookup overhead.
Closes https://github.com/facebook/rocksdb/pull/4037

Differential Revision: D8596218

Pulled By: maysamyabandeh

fbshipit-source-id: 3a5f7f9ca6b4b525b03ff6bd82354881ae974ad2
2018-06-22 15:27:46 -07:00
Sagar Vemuri
7103559f49 Improve direct IO range scan performance with readahead (#3884)
Summary:
This PR extends the improvements in #3282 to also work when using Direct IO.
We see **4.5X performance improvement** in seekrandom benchmark doing long range scans, when using direct reads, on flash.

**Description:**
This change improves the performance of iterators doing long range scans (e.g. big/full index or table scans in MyRocks) by using readahead and prefetching additional data on each disk IO, and storing in a local buffer. This prefetching is automatically enabled on noticing more than 2 IOs for the same table file during iteration. The readahead size starts with 8KB and is exponentially increased on each additional sequential IO, up to a max of 256 KB. This helps in cutting down the number of IOs needed to complete the range scan.

**Implementation Details:**
- Used `FilePrefetchBuffer` as the underlying buffer to store the readahead data. `FilePrefetchBuffer` can now take file_reader, readahead_size and max_readahead_size as input to the constructor, and automatically do readahead.
- `FilePrefetchBuffer::TryReadFromCache` can now call `FilePrefetchBuffer::Prefetch` if readahead is enabled.
- `AlignedBuffer` (which is the underlying store for `FilePrefetchBuffer`) now takes a few additional args in `AlignedBuffer::AllocateNewBuffer` to allow copying data from the old buffer.
- Made sure not to re-read partial chunks of data that were already available in the buffer, from device again.
- Fixed a couple of cases where `AlignedBuffer::cursize_` was not being properly kept up-to-date.

**Constraints:**
- Similar to #3282, this gets currently enabled only when ReadOptions.readahead_size = 0 (which is the default value).
- Since the prefetched data is stored in a temporary buffer allocated on heap, this could increase the memory usage if you have many iterators doing long range scans simultaneously.
- Enabled only for user reads, and disabled for compactions. Compaction reads are controlled by the options `use_direct_io_for_flush_and_compaction` and `compaction_readahead_size`, and the current feature takes precautions not to mess with them.

**Benchmarks:**
I used the same benchmark as used in #3282.
Data fill:
```
TEST_TMPDIR=/data/users/$USER/benchmarks/iter ./db_bench -benchmarks=fillrandom -num=1000000000 -compression_type="none" -level_compaction_dynamic_level_bytes
```

Do a long range scan: Seekrandom with large number of nexts
```
TEST_TMPDIR=/data/users/$USER/benchmarks/iter ./db_bench -benchmarks=seekrandom -use_direct_reads -duration=60 -num=1000000000 -use_existing_db -seek_nexts=10000 -statistics -histogram
```

```
Before:
seekrandom   :   37939.906 micros/op 26 ops/sec;   29.2 MB/s (1636 of 1999 found)
With this change:
seekrandom   :   8527.720 micros/op 117 ops/sec;  129.7 MB/s (6530 of 7999 found)
```
~4.5X perf improvement. Taken on an average of 3 runs.
Closes https://github.com/facebook/rocksdb/pull/3884

Differential Revision: D8082143

Pulled By: sagar0

fbshipit-source-id: 4d7a8561cbac03478663713df4d31ad2620253bb
2018-06-21 11:13:08 -07:00
Yanqin Jin
524c6e6b72 Add file name info to SequentialFileReader. (#4026)
Summary:
We potentially need this information for tracing, profiling and diagnosis.
Closes https://github.com/facebook/rocksdb/pull/4026

Differential Revision: D8555214

Pulled By: riversand963

fbshipit-source-id: 4263e06c00b6d5410b46aa46eb4e358ff2161dd2
2018-06-21 08:42:24 -07:00
Tomas Kolda
906a602c2c Build and tests fixes for Solaris Sparc (#4000)
Summary:
Here are some fixes for build on Solaris Sparc.

It is also fixing CRC test on BigEndian platforms.
Closes https://github.com/facebook/rocksdb/pull/4000

Differential Revision: D8455394

Pulled By: ajkr

fbshipit-source-id: c9289a7b541a5628139c6b77e84368e14dc3d174
2018-06-15 12:42:53 -07:00
Andrew Kryczka
1f32dc7d2b Check with PosixEnv before opening LOCK file (#3993)
Summary:
Rebased and resubmitting #1831 on behalf of stevelittle.

The problem is when a single process attempts to open the same DB twice, the second attempt fails due to LOCK file held. If the second attempt had opened the LOCK file, it'll now need to close it, and closing causes the file to be unlocked. Then, any subsequent attempt to open the DB will succeed, which is the wrong behavior.

The solution was to track which files a process has locked in PosixEnv, and check those before opening a LOCK file.

Fixes #1780.
Closes https://github.com/facebook/rocksdb/pull/3993

Differential Revision: D8398984

Pulled By: ajkr

fbshipit-source-id: 2755fe66950a0c9de63075f932f9e15768041918
2018-06-13 17:32:04 -07:00
Andrew Kryczka
a720401877 Avoid acquiring SyncPoint mutex when it is disabled (#3991)
Summary:
In `db_stress` profile the vast majority of CPU time is spent acquiring the `SyncPoint` mutex. I mistakenly assumed #3939 had fixed this mutex contention problem by disabling `SyncPoint` processing. But actually the lock was still being acquired just to check whether processing is enabled. We can avoid that overhead by using an atomic to track whether it's enabled.
Closes https://github.com/facebook/rocksdb/pull/3991

Differential Revision: D8393825

Pulled By: ajkr

fbshipit-source-id: 5bc4e3c722ee7304e7a9c2439998c456b05a6897
2018-06-13 13:13:18 -07:00
Zhongyi Xie
45b6bcca98 ZSTD compression: should also expect type = kZSTDNotFinalCompression (#3964)
Summary:
Depending on the compression type, `CompressBlock` calls the compress method for each compression type. It calls ZSTD_Compress for both kZSTD and kZSTDNotFinalCompression (https://github.com/facebook/rocksdb/blob/master/table/block_based_table_builder.cc#L169).
However currently ZSTD_Compress only expects the type to be kZSTD and this is causing assert failures and crashes. The same also applies to ZSTD_Uncompress.
Closes https://github.com/facebook/rocksdb/pull/3964

Differential Revision: D8308715

Pulled By: miasantreble

fbshipit-source-id: e5125f53edb829c9c33733167bec74e4793d0782
2018-06-06 23:42:29 -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
Andrew Kryczka
2210152947 Fix singleton destruction order of PosixEnv and SyncPoint (#3951)
Summary:
Ensure the PosixEnv singleton is destroyed first since its destructor waits for background threads to all complete. This ensures background threads cannot hit sync points after the SyncPoint singleton is destroyed, which was previously possible.
Closes https://github.com/facebook/rocksdb/pull/3951

Differential Revision: D8265295

Pulled By: ajkr

fbshipit-source-id: 7738dd458c5d993a78377dd0420e82badada81ab
2018-06-04 15:58:46 -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
Maysam Yabandeh
402b7aa07f Exclude seq from index keys
Summary:
Index blocks have the same format as data blocks. The keys therefore similarly to the keys in the data blocks are internal keys, which means that in addition to the user key it also has 8 bytes that encodes sequence number and value type. This extra 8 bytes however is not necessary in index blocks since the index keys act as an separator between two data blocks. The only exception is when the last key of a block and the first key of the next block share the same user key, in which the sequence number is required to act as a separator.
The patch excludes the sequence from index keys only if the above special case does not happen for any of the index keys. It then records that in the property block. The reader looks at the property block to see if it should expect sequence numbers in the keys of the index block.s
Closes https://github.com/facebook/rocksdb/pull/3894

Differential Revision: D8118775

Pulled By: maysamyabandeh

fbshipit-source-id: 915479f028b5799ca91671d67455ecdefbd873bd
2018-05-25 18:42:43 -07:00
Andrew Kryczka
01bcc34896 Introduce library-independent default compression level
Summary:
Previously we were using -1 as the default for every library, which was legacy from our zlib options. That worked for a while, but after zstd introduced a146ee04ae, it started giving poor compression ratios by default in zstd.

This PR adds a constant to RocksDB public API, `CompressionOptions::kDefaultCompressionLevel`, which will get translated to the default value specific to the compression library being used in "util/compression.h". The constant uses a number that appears to be larger than any library's maximum compression level.
Closes https://github.com/facebook/rocksdb/pull/3895

Differential Revision: D8125780

Pulled By: ajkr

fbshipit-source-id: 2db157a89118cd4f94577c2f4a0a5ff31c8391c6
2018-05-23 18:42:08 -07:00
Andrew Kryczka
7b655214d2 Assert keys/values pinned by range deletion meta-block iterators
Summary:
`RangeDelAggregator` holds the pointers returned by `BlockIter::key()` and `BlockIter::value()` so requires the data to which they point is pinned. `BlockIter::key()` points into block memory and is guaranteed to be pinned if and only if prefix encoding is disabled (or, equivalently, restart interval is set to one). I think `BlockIter::value()` is always pinned. Added an assert for these and removed the wrong TODO about increasing restart interval, which would enable key prefix encoding and break the assertion.
Closes https://github.com/facebook/rocksdb/pull/3875

Differential Revision: D8063667

Pulled By: ajkr

fbshipit-source-id: 60b5ebcc0cdd610dd6aad9e74a23378793672c41
2018-05-21 09:57:00 -07:00
Siying Dong
17af09fcce Implement key shortening functions in ReverseBytewiseComparator
Summary:
Right now ReverseBytewiseComparator::FindShortestSeparator() doesn't really shorten key, and ReverseBytewiseComparator::FindShortestSuccessor() seems to return wrong results. The code is confusing too as it uses BytewiseComparatorImpl::FindShortestSeparator() but the function actually won't do anything if the the first key is larger than the second.

Implement ReverseBytewiseComparator::FindShortestSeparator() and override ReverseBytewiseComparator::FindShortestSuccessor() to be empty.
Closes https://github.com/facebook/rocksdb/pull/3836

Differential Revision: D7959762

Pulled By: siying

fbshipit-source-id: 93acb621c16ce6f23e087ae4e19f7d84d1254683
2018-05-17 18:27:16 -07:00
Maysam Yabandeh
718c1c9c1f Pass manual_wal_flush also to the first wal file
Summary:
Currently manual_wal_flush if set in the options will be used only for the wal files created during wal switch. The configuration thus does not affect the first wal file. The patch fixes that and also update the related unit tests.
This PR is built on top of https://github.com/facebook/rocksdb/pull/3756
Closes https://github.com/facebook/rocksdb/pull/3824

Differential Revision: D7909153

Pulled By: maysamyabandeh

fbshipit-source-id: 024ed99d2555db06bf096c902b998e432bb7b9ce
2018-05-14 10:57:56 -07:00
Andrew Kryczka
072ae671a7 Apply use_direct_io_for_flush_and_compaction to writes only
Summary:
Previously `DBOptions::use_direct_io_for_flush_and_compaction=true` combined with `DBOptions::use_direct_reads=false` could cause RocksDB to simultaneously read from two file descriptors for the same file, where background reads used direct I/O and foreground reads used buffered I/O. Our measurements found this mixed-mode I/O negatively impacted foreground read perf, compared to when only buffered I/O was used.

This PR makes the mixed-mode I/O situation impossible by repurposing `DBOptions::use_direct_io_for_flush_and_compaction` to only apply to background writes, and `DBOptions::use_direct_reads` to apply to all reads. There is no risk of direct background direct writes happening simultaneously with buffered reads since we never read from and write to the same file simultaneously.
Closes https://github.com/facebook/rocksdb/pull/3829

Differential Revision: D7915443

Pulled By: ajkr

fbshipit-source-id: 78bcbf276449b7e7766ab6b0db246f789fb1b279
2018-05-09 19:42:58 -07:00
Andrew Kryczka
4bf169f07e Disable readahead when using mmap for reads
Summary:
`ReadaheadRandomAccessFile` had an unwritten assumption, which was that its wrapped file's `Read()` function always copies into the provided scratch buffer. Actually this was not true when the wrapped file was `PosixMmapReadableFile`, whose `Read()` implementation does no copying and instead returns a `Slice` pointing directly into the  `mmap`'d memory region. This PR:

- prevents `ReadaheadRandomAccessFile` from ever wrapping mmap readable files
- adds an assert for the assumption `ReadaheadRandomAccessFile` makes about the wrapped file's use of scratch buffer
Closes https://github.com/facebook/rocksdb/pull/3813

Differential Revision: D7891513

Pulled By: ajkr

fbshipit-source-id: dc64a55222d6af280c39a1852ee39e9e9d7cde7d
2018-05-08 12:13:18 -07:00
Maysam Yabandeh
cfb86659bf WritePrepared Txn: enable rollback in stress test
Summary:
Rollback was disabled in stress test since there was a concurrency issue in WritePrepared rollback algorithm. The issue is fixed by caching the column family handles in WritePrepared to skip getting them from the db when needed for rollback.

Tested by running transaction stress test under tsan.
Closes https://github.com/facebook/rocksdb/pull/3785

Differential Revision: D7793727

Pulled By: maysamyabandeh

fbshipit-source-id: d81ab6fda0e53186ca69944cfe0712ce4869451e
2018-05-02 18:13:05 -07:00
Siying Dong
63c965cdb4 Sync parent directory after deleting a file in delete scheduler
Summary:
sync parent directory after deleting a file in delete scheduler. Otherwise, trim speed may not be as smooth as what we want.
Closes https://github.com/facebook/rocksdb/pull/3767

Differential Revision: D7760136

Pulled By: siying

fbshipit-source-id: ec131d53b61953f09c60d67e901e5eeb2716b05f
2018-04-26 13:58:20 -07:00