Commit Graph

56 Commits

Author SHA1 Message Date
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
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
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
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
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
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
Anand Ananthabhotla
f9f4d40f93 Align SST file data blocks to avoid spanning multiple pages
Summary:
Provide a block_align option in BlockBasedTableOptions to allow
alignment of SST file data blocks. This will avoid higher
IOPS/throughput load due to < 4KB data blocks spanning 2 4KB pages.
When this option is set to true, the block alignment is set to lower of
block size and 4KB.
Closes https://github.com/facebook/rocksdb/pull/3502

Differential Revision: D7400897

Pulled By: anand1976

fbshipit-source-id: 04cc3bd144e88e3431a4f97604e63ad7a0f06d44
2018-03-26 20:26:10 -07:00
Fosco Marotto
d518fe1da6 uint64_t and size_t changes to compile for iOS
Summary:
In attempting to build a static lib for use in iOS, I ran in to lots of type errors between uint64_t and size_t.  This PR contains the changes I made to get `TARGET_OS=IOS make static_lib` to succeed while also getting Xcode to build successfully with the resulting `librocksdb.a` library imported.

This also compiles for me on macOS and tests fine, but I'm really not sure if I made the correct decisions about where to `static_cast` and where to change types.

Also up for discussion: is iOS worth supporting?  Getting the static lib is just part one, we aren't providing any bridging headers or wrappers like the ObjectiveRocks project, it won't be a great experience.
Closes https://github.com/facebook/rocksdb/pull/3503

Differential Revision: D7106457

Pulled By: gfosco

fbshipit-source-id: 82ac2073de7e1f09b91f6b4faea91d18bd311f8e
2018-03-06 12:43:51 -08:00
Siying Dong
b3c5351335 Direct I/O writable file should do fsync in Close()
Summary:
We don't do fsync() after truncate in direct I/O writeable file (in fact we don't do any fsync ever). This can cause metadata not persistent to disk after the file is generated. We call it instead.
Closes https://github.com/facebook/rocksdb/pull/3500

Differential Revision: D6981482

Pulled By: siying

fbshipit-source-id: 7e2b591b7e5dd1b96fc0775515b8b9e6092980ef
2018-02-13 16:27:11 -08:00
Andrew Kryczka
b78ed0460b fix ReadaheadRandomAccessFile/iterator prefetch bug
Summary:
`ReadaheadRandomAccessFile` is used by iterators for file reads in several cases, like in compaction when `compaction_readahead_size > 0` or `use_direct_io_for_flush_and_compaction == true`, or in user iterator when `ReadOptions::readahead_size > 0`. `ReadaheadRandomAccessFile` maintains an internal buffer for readahead data. It assumes that, if the buffer's length is less than `ReadaheadRandomAccessFile::readahead_size_`, which is fixed in the constructor, then EOF has been reached so it doesn't try reading further.

Recently, d938226af4 started calling `RandomAccessFile::Prefetch` with various lengths: 8KB, 16KB, etc. When the `RandomAccessFile` is a `ReadaheadRandomAccessFile`, it triggers the above condition and incorrectly determines EOF. If a block is partially in the readahead buffer and EOF is incorrectly decided, the result is a truncated data block.

The problem is reproducible:

```
TEST_TMPDIR=/data/compaction_bench ./db_bench -benchmarks=fillrandom -write_buffer_size=1048576 -target_file_size_base=1048576 -block_size=18384 -use_direct_io_for_flush_and_compaction=true
...
put error: Corruption: truncated block read from /data/compaction_bench/dbbench/000014.sst offset 20245, expected 10143 bytes, got 8427
```
Closes https://github.com/facebook/rocksdb/pull/3454

Differential Revision: D6869405

Pulled By: ajkr

fbshipit-source-id: 87001c299e7600a37c0dcccbd0368e0954c929cf
2018-02-01 09:42:09 -08:00
Maysam Yabandeh
4927b4e662 Rounddown in FilePrefetchBuffer::Prefetch
Summary:
FilePrefetchBuffer::Prefetch is currently rounds the offset up which does not fit its new use cases in prefetching index/filter blocks, as it would skips over some the offsets that were requested to be prefetched. This patch rounds down instead.

Fixes #3180
Closes https://github.com/facebook/rocksdb/pull/3413

Differential Revision: D6816392

Pulled By: maysamyabandeh

fbshipit-source-id: 3aaeaf59c55d72b61dacfae6d4a8e65eccb3c553
2018-01-26 12:57:25 -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
Andrew Kryczka
c217e0b9c7 Call RateLimiter for compaction reads
Summary:
Allow users to rate limit background work based on read bytes, written bytes, or sum of read and written bytes. Support these by changing the RateLimiter API, so no additional options were needed.
Closes https://github.com/facebook/rocksdb/pull/2433

Differential Revision: D5216946

Pulled By: ajkr

fbshipit-source-id: aec57a8357dbb4bfde2003261094d786d94f724e
2017-06-13 14:56:46 -07:00
Siying Dong
0175d58c3c Make direct I/O write use incremental buffer
Summary:
Currently for direct I/O, the large maximum buffer is always allocated. This will be wasteful if users flush the data in much smaller chunks. This diff fix this by changing the behavior of incremental buffer works. When we enlarge buffer, we try to copy the existing data in the buffer to the enlarged buffer, rather than flush the buffer first. This can make sure that no extra I/O is introduced because of buffer enlargement.
Closes https://github.com/facebook/rocksdb/pull/2403

Differential Revision: D5178403

Pulled By: siying

fbshipit-source-id: a8fe1e7304bdb8cab2973340022fe80ff83449fd
2017-06-13 04:41:37 -07:00
Aaron Gao
a36220ccfb fix unity test
Summary:
unity test will fail even if we have the same function names in different anonymous namespaces in different files.
Closes https://github.com/facebook/rocksdb/pull/2321

Differential Revision: D5083783

Pulled By: lightmark

fbshipit-source-id: 1347aaf866900af30d23cdd4f29c1b96f17352af
2017-05-17 18:56:55 -07:00
Aaron Gao
2d42cf5ea9 Roundup read bytes in ReadaheadRandomAccessFile
Summary:
Fix alignment in ReadaheadRandomAccessFile
Closes https://github.com/facebook/rocksdb/pull/2253

Differential Revision: D5012336

Pulled By: lightmark

fbshipit-source-id: 10d2c829520cb787227ef653ef63d5d701725778
2017-05-05 12:14:14 -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
Dmitri Smirnov
cdad04b051 Remove double buffering on RandomRead on Windows.
Summary:
Remove double buffering on RandomRead on Windows.
  With more logic appear in file reader/write Read no longer
  obeys forwarding calls to Windows implementation.
  Previously direct_io (unbuffered) was only available on Windows
  but now is supported as generic.
  We remove intermediate buffering on Windows.
  Remove random_access_max_buffer_size option which was windows specific.
  Non-zero values for that opton introduced unnecessary lock contention.
  Remove Env::EnableReadAhead(), Env::ShouldForwardRawRequest() that are
  no longer necessary.
  Add aligned buffer reads for cases when requested reads exceed read ahead size.
Closes https://github.com/facebook/rocksdb/pull/2105

Differential Revision: D4847770

Pulled By: siying

fbshipit-source-id: 8ab48f8e854ab498a4fd398a6934859792a2788f
2017-04-27 12:30:05 -07:00
Aaron Gao
6e8d6f429d readahead backwards from sst end
Summary:
prefetch some data from the end of the file for each compaction to reduce IO.
Closes https://github.com/facebook/rocksdb/pull/2149

Differential Revision: D4880576

Pulled By: lightmark

fbshipit-source-id: aa767cd1afc84c541837fbf1ad6c0d45b34d3932
2017-04-14 18:56:14 -07:00
Aaron Gao
10d7546961 set readahead buffer size from roundup(user_size) + 4k to roundup(use…
Summary:
Users usually set readahead buffer to a multiple of 4k, more than that, usually a multiple of blocks.
So previously we set real buffer size 512 * n + 4k, which may introduce an additional block reading.
Closes https://github.com/facebook/rocksdb/pull/2138

Differential Revision: D4871504

Pulled By: lightmark

fbshipit-source-id: b070faa51d92e976e8e8468c00692699e585e243
2017-04-11 17:13:33 -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
Aaron Gao
9272e12f19 avoid ftruncate twice in buffered io
Summary:
in buffered io, the filesize_ is the real size.
Closes https://github.com/facebook/rocksdb/pull/1991

Differential Revision: D4711433

Pulled By: lightmark

fbshipit-source-id: ad604b9
2017-03-17 11:39:13 -07:00
Aaron Gao
d525718a93 cleanup direct io flag in WritableFileWriter
Summary:
remove unnecessary field `direct_io_`, use `use_direct_io()` instead.
Closes https://github.com/facebook/rocksdb/pull/1992

Differential Revision: D4712195

Pulled By: lightmark

fbshipit-source-id: 57d34f9
2017-03-14 22:39:09 -07:00
Andrew Kryczka
7c80a6d7d1 Statistic for how often rate limiter is drained
Summary:
This is the metric I plan to use for adaptive rate limiting. The statistics are updated only if the rate limiter is drained by flush or compaction. I believe (but am not certain) that this is the normal case.

The Statistics object is passed in RateLimiter::Request() to avoid requiring changes to client code, which would've been necessary if we passed it in the RateLimiter constructor.
Closes https://github.com/facebook/rocksdb/pull/1946

Differential Revision: D4646489

Pulled By: ajkr

fbshipit-source-id: d8e0161
2017-03-02 17:54:15 -08:00
Aaron Gao
f206af56fc add use_direct_io() to ReadaheadRandomAccessFile
Summary:
Missing this function will cause RandomAccessFileReader not doing alignment in Direct IO mode, which introduce an IOError: invalid argument.
Closes https://github.com/facebook/rocksdb/pull/1900

Differential Revision: D4601261

Pulled By: lightmark

fbshipit-source-id: c3eadf1
2017-02-22 14:54:11 -08:00
Yulia Kartseva
ebc8a79980 alignment is on in ReadaheadRandomAccessFile::Read()
Summary: Closes https://github.com/facebook/rocksdb/pull/1857

Differential Revision: D4534518

Pulled By: wat-ze-hex

fbshipit-source-id: b456946
2017-02-18 12:09:12 -08:00
Aaron Gao
db2b4eb50e avoid direct io in rocksdb_lite
Summary:
fix lite bugs
disable direct io in lite mode
Closes https://github.com/facebook/rocksdb/pull/1870

Differential Revision: D4559866

Pulled By: yiwu-arbug

fbshipit-source-id: 3761c51
2017-02-16 10:39:13 -08:00
Aaron Gao
3e6899d116 change UseDirectIO() to use_direct_io()
Summary:
also change variable name `direct_io_` to `use_direct_io_` in WritableFile to make it consistent with read path.
Closes https://github.com/facebook/rocksdb/pull/1770

Differential Revision: D4416435

Pulled By: lightmark

fbshipit-source-id: 4143c53
2017-01-13 12:09:15 -08:00
Aaron Gao
dc2584eea0 direct reads refactor
Summary:
direct IO reads refactoring
remove unnecessary classes and unified interfaces
tested with db_bench

need more change for options and ON/OFF for different files.
Since disabled is default, it should be fine now
Closes https://github.com/facebook/rocksdb/pull/1636

Differential Revision: D4307189

Pulled By: lightmark

fbshipit-source-id: 6991e22
2017-01-11 16:54:12 -08:00
Aaron Gao
972f96b3fb direct io write support
Summary:
rocksdb direct io support

```
[gzh@dev11575.prn2 ~/rocksdb] ./db_bench -benchmarks=fillseq --num=1000000
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
RocksDB:    version 5.0
Date:       Wed Nov 23 13:17:43 2016
CPU:        40 * Intel(R) Xeon(R) CPU E5-2660 v2 @ 2.20GHz
CPUCache:   25600 KB
Keys:       16 bytes each
Values:     100 bytes each (50 bytes after compression)
Entries:    1000000
Prefix:    0 bytes
Keys per prefix:    0
RawSize:    110.6 MB (estimated)
FileSize:   62.9 MB (estimated)
Write rate: 0 bytes/second
Compression: Snappy
Memtablerep: skip_list
Perf Level: 1
WARNING: Assertions are enabled; benchmarks unnecessarily slow
------------------------------------------------
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
DB path: [/tmp/rocksdbtest-112628/dbbench]
fillseq      :       4.393 micros/op 227639 ops/sec;   25.2 MB/s

[gzh@dev11575.prn2 ~/roc
Closes https://github.com/facebook/rocksdb/pull/1564

Differential Revision: D4241093

Pulled By: lightmark

fbshipit-source-id: 98c29e3
2016-12-22 13:09:19 -08:00
Dhruba Borthakur
34723b4c4a Cleanup unused variable pending_fsync_.
Summary: Cleanup unused variable pending_fsync_.

Test Plan: make check

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D61581
2016-08-05 10:31:41 -07:00
Baraa Hamodi
21e95811d1 Updated all copyright headers to the new format. 2016-02-09 15:12:00 -08:00
Dmitri Smirnov
5270b33bd3 Make use of portable uint64_t type to make possible file access
in 64-bit.

  Currently, a signed off_t type is being used for the following
  interfaces for both offset and the length in bytes:
  * `Allocate`
  * `RangeSync`

  On Linux `off_t` is automatically either 32 or 64-bit depending on
  the platform. On Windows it is always a 32-bit signed long which
  limits file access and in particular space pre-allocation
  to effectively 2 Gb.

  Proposal is to replace off_t with uint64_t as a portable type
  always access files with 64-bit interfaces.

  May need to modify posix code but lack resources to test it.
2015-11-10 17:03:42 -08:00
SherlockNoMad
a6dd0831d5 Add Option to Skip Flushing in TableBuilder 2015-10-29 22:10:25 -07:00
sdong
296c3a1f94 "make format" in some recent commits
Summary: Run "make format" for some recent commits.

Test Plan: Build and run tests

Reviewers: IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D49707
2015-10-29 17:11:14 -07:00
Siying Dong
6388e7f4e2 Merge pull request #798 from yuslepukhin/readahead_buffermanagement
Implement smart buffer management in Windows Env.
2015-10-29 15:02:59 -07:00
Islam AbdelRahman
72d6e758b4 Fix WritableFileWriter::Append() return
Summary: It looks like WritableFileWriter::Append() was returning OK() even when there is an error

Test Plan: make check

Reviewers: sdong, yhchiang, anthony, rven, kradhakrishnan, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D49569
2015-10-27 21:04:00 -07:00
Dmitri Smirnov
6fbc4f9f3e Implement smart buffer management.
introduce a new DBOption random_access_max_buffer_size to limit
  the size of the random access buffer used for unbuffered access.
  Implement read ahead buffering when enabled.
  To that effect propagate compaction_readahead_size and the new option
  to the env options to make it available for the implementation.
  Add Hint() override so SetupForCompaction() call would call Hint()
  readahead can now be setup from both Hint() and EnableReadAhead()
  Add new option random_access_max_buffer_size support
  db_bench, options_helper to make it string parsable
  and the unit test.
2015-10-27 14:44:16 -07:00
Igor Canadi
4e07c99a9a Fix iOS build
Summary: We don't yet have a CI build for iOS, so our iOS compile gets broken sometimes. Most of the errors are from assumption that size_t is 64-bit, while it's actually 32-bit on some (all?) iOS platforms. This diff fixes the compile.

Test Plan:
TARGET_OS=IOS make static_lib

Observe there are no warnings

Reviewers: sdong, anthony, IslamAbdelRahman, kradhakrishnan, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D49029
2015-10-19 13:40:44 -07:00
sdong
277dea78f0 Add more kill points
Summary:
Add kill points in:
1. after creating a file
2. before writing a manifest record
3. before syncing manifest
4. before creating a new current file
5. after creating a new current file

Test Plan: Run all current tests.

Reviewers: yhchiang, igor, anthony, IslamAbdelRahman, rven, kradhakrishnan

Reviewed By: kradhakrishnan

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D48855
2015-10-16 14:35:12 -07:00
sdong
e1a5ff857b Allow users to disable some kill points in db_stress
Summary:
Give a name for every kill point, and allow users to disable some kill points based on prefixes. The kill points can be passed by db_stress through a command line paramter. This provides a way for users to boost the chance of triggering low frequency kill points
This allow follow up changes in crash test scripts to improve crash test coverage.

Test Plan:
Manually run db_stress with variable values of --kill_random_test and --kill_prefix_blacklist. Like this:
 --kill_random_test=2 --kill_prefix_blacklist=Posix,WritableFileWriter::Append,WritableFileWriter::WriteBuffered,WritableFileWriter::Sync

Reviewers: igor, kradhakrishnan, rven, IslamAbdelRahman, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D48735
2015-10-15 14:33:13 -07:00
Dmitri Smirnov
ddc8b44998 Address code review comments both GH and internal
Fix compilation issues on GCC/CLANG
 Address Windows Release test build issues due to Sync
2015-09-11 17:36:48 -07:00
Dmitri Smirnov
30e82d5c41 Refactor to support file_reader_writer on Windows.
Summary. A change https://reviews.facebook.net/differential/diff/224721/
  Has attempted to move common functionality out of platform dependent
  code to a new facility called file_reader_writer.
  This includes:
  - perf counters
  - Buffering
  - RateLimiting

  However, the change did not attempt to refactor Windows code.
  To mitigate, we introduce new quering interfaces such as UseOSBuffer(),
  GetRequiredBufferAlignment() and ReaderWriterForward()
  for pure forwarding where required.
  Introduce WritableFile got a new method Truncate(). This is to communicate
  to the file as to how much data it has on close.
   - When space is pre-allocated on Linux it is filled with zeros implicitly,
    no such thing exist on Windows so we must truncate file on close.
   - When operating in unbuffered mode the last page is filled with zeros but we still want to truncate.

   Previously, Close() would take care of it but now buffer management is shifted to the wrappers and the file has
   no idea about the file true size.

   This means that Close() on the wrapper level must always include
   Truncate() as well as wrapper __dtor should call Close() and
   against double Close().
   Move buffered/unbuffered write logic to the wrapper.
   Utilize Aligned buffer class.
   Adjust tests and implement Truncate() where necessary.
   Come up with reasonable defaults for new virtual interfaces.
   Forward calls for RandomAccessReadAhead class to avoid double
   buffering and locking (double locking in unbuffered mode on WIndows).
2015-09-11 09:57:02 -07:00
Javier González
0886f4f66a Helper functions to support direct IO
Summary:
This patch adds the helper functions and variables to allow a backend
implementing WritableFile to support direct IO when persisting a
memtable.

Test Plan:
Since there is no upstream implementation of WritableFile supporting
direct IO, the new behavior is disabled.

Tests should be provided by the backend implementing WritableFile.
2015-08-27 08:36:56 +02:00
Igor Canadi
5f4166c90e ReadaheadRandomAccessFile -- userspace readahead
Summary:
ReadaheadRandomAccessFile acts as a transparent layer on top of RandomAccessFile. When a Read() request is issued, it issues a much bigger request to the OS and caches the result. When a new request comes in and we already have the data cached, it doesn't have to issue any requests to the OS.

We add ReadaheadRandomAccessFile layer only when file is read during compactions.

D45105 was incorrectly closed by Phabricator because I committed it to a separate branch (not master), so I'm resubmitting the diff.

Test Plan: make check

Reviewers: MarkCallaghan, sdong

Reviewed By: sdong

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D45123
2015-08-26 15:25:59 -07:00
sdong
72613657f0 Measure file read latency histogram per level
Summary: In internal stats, remember read latency histogram, if statistics is enabled. It can be retrieved from DB::GetProperty() with "rocksdb.dbstats" property, if it is enabled.

Test Plan: Manually run db_bench and prints out "rocksdb.dbstats" by hand and make sure it prints out as expected

Reviewers: igor, IslamAbdelRahman, rven, kradhakrishnan, anthony, yhchiang

Reviewed By: yhchiang

Subscribers: MarkCallaghan, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D44193
2015-08-14 17:32:42 -07:00
sdong
603b6da8b8 Add options.compaction_measure_io_stats to print write I/O stats in compactions
Summary:
Add options.compaction_measure_io_stats to print out / pass to listener accumulated time spent on write calls. Example outputs in info logs:

2015/08/12-16:27:59.463944 7fd428bff700 (Original Log Time 2015/08/12-16:27:59.463922) EVENT_LOG_v1 {"time_micros": 1439422079463897, "job": 6, "event": "compaction_finished", "output_level": 1, "num_output_files": 4, "total_output_size": 6900525, "num_input_records": 111483, "num_output_records": 106877, "file_write_nanos": 15663206, "file_range_sync_nanos": 649588, "file_fsync_nanos": 349614797, "file_prepare_write_nanos": 1505812, "lsm_state": [2, 4, 0, 0, 0, 0, 0]}

Add two more counters in iostats_context.

Also add a parameter of db_bench.

Test Plan: Add a unit test. Also manually verify LOG outputs in db_bench

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D44115
2015-08-13 16:52:26 -07:00