Commit Graph

101 Commits

Author SHA1 Message Date
sdong
22696b0881 Fix uninitlized CompactionJob::SubcompactionState::current_output_file_size
Summary: The new variable introduced in 2149059f910149197d1a0f79ac08cf19465ea2d may be unitialized. Valgrind is failing because of it.

Test Plan: Run valgrind tests

Reviewers: yiwu, andrewkr, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D63201
2016-09-02 17:06:20 -07:00
sdong
32149059f9 Merge options source_compaction_factor, max_grandparent_overlap_bytes and expanded_compaction_factor into max_compaction_bytes
Summary: To reduce number of options, merge source_compaction_factor, max_grandparent_overlap_bytes and expanded_compaction_factor into max_compaction_bytes.

Test Plan: Add two new unit tests. Run all existing tests, including jtest.

Reviewers: yhchiang, igor, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D59829
2016-09-01 14:33:24 -07:00
Anirban Rahut
2fc2fd92a9 Single Delete Mismatch and Fallthrough statistics
Summary:
Added 2 statistics in compaction job statistics, to
identify if single deletes are not meeting a matching key
(fallthrough) or single deletes are meeting a merge, delete or
another single delete (i.e. not the expected case of put).

Test Plan: Tested the statistics using write_stress and compaction_job_stats_test

Reviewers: sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D61749
2016-08-16 08:21:43 -07:00
Aaron Gao
43afd72bee [rocksdb] make more options dynamic
Summary:
make more ColumnFamilyOptions dynamic:
- compression
- soft_pending_compaction_bytes_limit
- hard_pending_compaction_bytes_limit
- min_partial_merge_operands
- report_bg_io_stats
- paranoid_file_checks

Test Plan:
Add sanity check in `db_test.cc` for all above options except for soft_pending_compaction_bytes_limit and hard_pending_compaction_bytes_limit.
All passed.

Reviewers: andrewkr, sdong, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D57519
2016-05-17 13:11:56 -07:00
Islam AbdelRahman
21441c09bd Fix calling GetCurrentMutableCFOptions in CompactionJob::ProcessKeyValueCompaction()
Summary: GetCurrentMutableCFOptions() can only be called when DB mutex is held so we cannot call it in CompactionJob::ProcessKeyValueCompaction() since it's not holding the db mutex

Test Plan: make check -j64

Reviewers: sdong, andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D57471
2016-04-29 17:00:50 -07:00
Yi Wu
a92049e3e7 Added EventListener::OnTableFileCreationStarted() callback
Summary: Added EventListener::OnTableFileCreationStarted. EventListener::OnTableFileCreated will be called on failure case. User can check creation status via TableFileCreationInfo::status.

Test Plan: unit test.

Reviewers: dhruba, yhchiang, ott, sdong

Reviewed By: sdong

Subscribers: sdong, kradhakrishnan, IslamAbdelRahman, andrewkr, yhchiang, leveldb, ott, dhruba

Differential Revision: https://reviews.facebook.net/D56337
2016-04-29 11:35:00 -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
Yueh-Hsuan Chiang
13e6c8e97a Relax an assertion in Compaction::ShouldStopBefore
Summary:
In some case, it is possible to have two concesutive SST files might sharing
same boundary keys.  However, in the assertion in Compaction::ShouldStopBefore,
it exclude such possibility.

This patch fix this issue by relaxing the assertion to allow the equal case.

Test Plan: rocksdb tests

Reviewers: IslamAbdelRahman, kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D55875
2016-04-11 20:15:52 -07:00
Andrew Kryczka
2391ef7214 Embed column family name in SST file
Summary:
Added the column family name to the properties block. This property
is omitted only if the property is unavailable, such as when RepairDB()
writes SST files.

In a next diff, I will change RepairDB to use this new property for
deciding to which column family an existing SST file belongs. If this
property is missing, it will add it to the "unknown" column family (same
as its existing behavior).

Test Plan:
New unit test:

  $ ./db_table_properties_test --gtest_filter=DBTablePropertiesTest.GetColumnFamilyNameProperty

Reviewers: IslamAbdelRahman, yhchiang, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D55605
2016-04-06 23:10:32 -07:00
Yueh-Hsuan Chiang
be9816b3d9 Fix data race issue when sub-compaction is used in CompactionJob
Summary:
When subcompaction is used, all subcompactions share the same Compaction
pointer in CompactionJob while each subcompaction all keeps their mutable
stats in SubcompactionState.  However, there're still some mutable part
that is currently store in the shared Compaction pointer.

This patch makes two changes:

1. Make the shared Compaction pointer const so that it can never be modified
   during the compaction.
2. Move necessary states from Compaction to SubcompactionState.
3. Make functions of Compaction const if the function does not modify
   its internal state.

Test Plan: rocksdb and MyRocks test

Reviewers: sdong, kradhakrishnan, andrewkr, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, yoshinorim, gunnarku, leveldb

Differential Revision: https://reviews.facebook.net/D55923
2016-03-24 19:36:39 -07:00
sdong
19ea40f8b6 Subcompaction boundary keys should not terminate after an empty level
Summary: Now we skip to add boundary keys to subcompaction candidates since we see an empty level. This makes subcompaction almost disabled for universal compaction. We should consider all files instead.

Test Plan: Run existing tests.

Reviewers: IslamAbdelRahman, andrewkr, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D55005
2016-03-02 15:45:07 -08:00
Islam AbdelRahman
df9ba6df62 Introduce SstFileManager::SetMaxAllowedSpaceUsage() to cap disk space usage
Summary:
Introude SstFileManager::SetMaxAllowedSpaceUsage() that can be used to limit the maximum space usage allowed for RocksDB.
When this limit is exceeded WriteImpl() will fail and return Status::Aborted()

Test Plan: unit testing

Reviewers: yhchiang, anthony, andrewkr, sdong

Reviewed By: sdong

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D53763
2016-02-17 15:20:23 -08:00
Baraa Hamodi
21e95811d1 Updated all copyright headers to the new format. 2016-02-09 15:12:00 -08:00
Islam AbdelRahman
d6c838f1e1 Add SstFileManager (component tracking all SST file in DBs and control the deletion rate)
Summary:
Add a new class SstFileTracker that will be notified whenever a DB add/delete/move and sst file, it will also replace DeleteScheduler
SstFileTracker can be used later to abort writes when we exceed a specific size

Test Plan: unit tests

Reviewers: rven, anthony, yhchiang, sdong

Reviewed By: sdong

Subscribers: igor, lovro, march, dhruba

Differential Revision: https://reviews.facebook.net/D50469
2016-01-28 18:35:01 -08:00
Andrew Kryczka
acd7d58695 [directory includes cleanup] Remove util->db dependency for ThreadStatusUtil
Summary:
We can avoid the dependency by forward-declaring ColumnFamilyData and
then treating it as a black box. That means callers of ThreadStatusUtil need to
explicitly provide more options, even if they can be derived from the
ColumnFamilyData, since ThreadStatusUtil doesn't include the definition.

This is part of a series of diffs to eliminate circular dependencies between
directories (e.g., db/* files depending on util/* files and vice-versa).

Test Plan:
  $ ./db_test --gtest_filter=DBTest.GetThreadStatus
  $ make -j32 commit-prereq

Reviewers: sdong, yhchiang, IslamAbdelRahman

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D53361
2016-01-26 10:49:16 -08:00
Siying Dong
298ba27ae2 Merge pull request #846 from yuslepukhin/enble_c4244_lossofdata
Enable MS compiler warning c4244.
2015-12-23 22:59:42 -08:00
Zhipeng Jia
728f944f0d Fix computation of size of last sub-compaction 2015-12-22 18:37:51 +08:00
Zhipeng Jia
e0abec1580 Sorting std::vector instead of using std::set 2015-12-22 14:34:57 +08:00
Dmitri Smirnov
236fe21c92 Enable MS compiler warning c4244.
Mostly due to the fact that there are differences in sizes of int,long
  on 64 bit systems vs GNU.
2015-12-11 16:47:34 -08:00
agiardullo
e5c5f23814 Support marking snapshots for write-conflict checking - Take 2
Summary:
D51183 was reverted due to breaking the LITE build.

This diff is the same as D51183 but with a fix for the LITE BUILD(D51693)

Test Plan: run all unit tests

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51711
2015-12-08 16:47:31 -08:00
sdong
1d63c3d610 Revert "Support marking snapshots for write-conflict checking"
This reverts commit ec704aafdc for it broke RocksDB LITE build.
2015-12-08 09:27:17 -08:00
agiardullo
ec704aafdc Support marking snapshots for write-conflict checking
Summary:
D50475 enables using SST files for transaction write-conflict checking.  In order for this to work, we need to make sure not to compact out SingleDeletes when there is an earlier transaction snapshot(D50295).  If there is a long-held snapshot, this could reduce the benefit of the SingleDelete optimization.

This diff allows Transactions to mark snapshots as being used for write-conflict checking.  Then, during compaction, we will be able to optimize SingleDeletes better in the future.

This diff adds a flag to SnapshotImpl which is used by Transactions.  This diff also passes the earliest write-conflict snapshot's sequence number to CompactionIterator.  This diff does not actually change Compaction (after this diff is pushed, D50295 will be able to use this information).

Test Plan: no behavior change, ran existing tests

Reviewers: rven, kradhakrishnan, yhchiang, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D51183
2015-12-07 19:40:51 -08:00
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
35ad531be3 Seperate InternalIterator from Iterator
Summary:
Separate a new class InternalIterator from class Iterator, when the look-up is done internally, which also means they operate on key with sequence ID and type.

This change will enable potential future optimizations but for now InternalIterator's functions are still the same as Iterator's.
At the same time, separate the cleanup function to a separate class and let both of InternalIterator and Iterator inherit from it.

Test Plan: Run all existing tests.

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

Reviewed By: rven

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D48549
2015-10-13 15:32:13 -07:00
Alexey Maykov
3d07b815f6 Passing table properties to compaction callback
Summary: It would be nice to have and access to table properties in compaction callbacks. In MyRocks project, it will make possible to update optimizer statistics online.

Test Plan: ran the unit test. Ran myrocks with the new way of collecting stats.

Reviewers: igor, rven, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D48267
2015-10-09 18:10:55 -07:00
sdong
776bd8d5eb Pass column family ID to table property collector
Summary: Pass column family ID through TablePropertiesCollectorFactory::CreateTablePropertiesCollector() so that users can identify which column family this file is for and handle it differently.

Test Plan: Add unit test scenarios in tests related to table properties collectors to verify the information passed in is correct.

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

Reviewed By: IslamAbdelRahman

Subscribers: yoshinorim, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D48411
2015-10-09 14:36:51 -07:00
Igor Canadi
d80ce7f99a Compaction filter on merge operands
Summary:
Since Andres' internship is over, I took over https://reviews.facebook.net/D42555 and rebased and simplified it a bit.

The behavior in this diff is a bit simpler than in D42555:
* only merge operators are passed through FilterMergeValue(). If fitler function returns true, the merge operator is ignored
* compaction filter is *not* called on: 1) results of merge operations and 2) base values that are getting merged with merge operands (the second case was also true in previous diff)

Do we also need a compaction filter to get called on merge results?

Test Plan: make && make check

Reviewers: lovro, tnovak, rven, yhchiang, sdong

Reviewed By: sdong

Subscribers: noetzli, kolmike, leveldb, dhruba, sdong

Differential Revision: https://reviews.facebook.net/D47847
2015-10-07 09:30:03 -07:00
Ari Ekmekji
5ba3297d0d Add compaction time to log output
Summary:
Although compaction time is recorded in the statistics,
it is helpful to include this value in the log output corresponding
to the end of compaction.

Test Plan: make all && make check

Reviewers: yhchiang, sdong, igor, noetzli, MarkCallaghan

Reviewed By: MarkCallaghan

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D47007
2015-09-15 17:11:44 -07:00
Ari Ekmekji
03ddce9a01 Add counters for L0 stall while L0-L1 compaction is taking place
Summary:
Although there are currently counters to keep track of the
stall caused by having too many L0 files, there is no distinction as
to whether when that stall occurs either (A) L0-L1 compaction is taking
place to try and mitigate it, or (B) no L0-L1 compaction has been scheduled
at the moment. This diff adds a counter for (A) so that the nature of L0
stalls can be better understood.

Test Plan: make all && make check

Reviewers: sdong, igor, anthony, noetzli, yhchiang

Reviewed By: yhchiang

Subscribers: MarkCallaghan, dhruba

Differential Revision: https://reviews.facebook.net/D46749
2015-09-14 11:03:37 -07:00
Andres Noetzli
8aa1f15197 Refactored common code of Builder/CompactionJob out into a CompactionIterator
Summary:
Builder and CompactionJob share a lot of fairly complex code. This patch
refactors this code into a separate class, the CompactionIterator. Because the
shared code is fairly complex, this patch hopefully improves maintainability.
While there are is a lot of potential for further improvements, the patch is
intentionally pretty close to the original structure because the change is
already complex enough.

Test Plan: make clean all check && ./db_stress

Reviewers: rven, anthony, yhchiang, sdong, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D46197
2015-09-10 14:35:25 -07:00
Ari Ekmekji
3c37b3cccd Determine boundaries of subcompactions
Summary:
Up to this point, the subcompactions that make up a compaction
job have been divided based on the key range of the L1 files, and each
subcompaction has handled the key range of only one file. However
DBOption.max_subcompactions allows the user to designate how many
subcompactions at most to perform. This patch updates the
CompactionJob::GetSubcompactionBoundaries() to determine these
divisions accordingly based on that option and other input/system factors.

The current approach orders the starting and/or ending keys of certain
compaction input files and then generates a histogram to approximate the
size covered by the key range between each consecutive pair of keys. Then
it groups these ranges into groups so that the sizes are approximately equal
to one another. The approach has also been adapted to work for universal
compaction as well instead of just for level-based compaction as it was before.

These subcompactions are then executed in parallel by locally spawning
threads, one for each. The results are then aggregated and the compaction
completed.

Test Plan: make all && make check

Reviewers: yhchiang, anthony, igor, noetzli, sdong

Reviewed By: sdong

Subscribers: MarkCallaghan, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43269
2015-09-10 13:50:00 -07:00
Andres Noetzli
6bdc484fd8 Added Equal method to Comparator interface
Summary:
In some cases, equality comparisons can be done more efficiently than three-way
comparisons. There are quite a few places in the code where we only care about
equality. This patch adds an Equal() method that defaults to using the
Compare() method.

Test Plan: make clean all check

Reviewers: rven, anthony, yhchiang, igor, sdong

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D46233
2015-09-08 15:30:49 -07:00
Ari Ekmekji
2f8d71ec05 Moving sequence number compaction variables from SubCompactionState to CompactionJob
Summary:
It was pointed out to me that the members of SubCompactionState
'earliest_snapshot', 'latest_snapshot' and 'visible_at_tip' are never
modified by the subcompactions, so they can stay as global varaibles
instead to make things simpler.

Test Plan: make all && make check

Reviewers: sdong, igor, noetzli, anthony, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D45477
2015-08-25 14:03:10 -07:00
Ari Ekmekji
b6def58f73 Changed 'num_subcompactions' to the more accurate 'max_subcompactions'
Summary:
Up until this point we had DbOptions.num_subcompactions, but
it is semantically more correct to call this max_subcompactions since
we will schedule *up to* DbOptions.max_subcompactions smaller compactions
at a time during a compaction job.

I also added a --subcompactions option to db_bench

Test Plan: make all   make check

Reviewers: sdong, igor, anthony, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D45069
2015-08-21 14:25:34 -07:00
sdong
c852968465 db_iter_test: add more test cases for the data race bug
Summary: Add more test cases of data race causing wrong iterating results. Tag tests not passing as DISABLED_

Test Plan: Run the tests

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

Reviewed By: yhchiang

Subscribers: tnovak, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D44907
2015-08-21 12:14:12 -07:00
Dmitri Smirnov
5bf8907622 More indent adjustment. 2015-08-20 14:14:02 -07:00
Dmitri Smirnov
e2a9f43d64 Adjust indent 2015-08-20 14:10:51 -07:00
Dmitri Smirnov
1cac89c9b1 Address windows build issues
Intro SubCompactionState move functionality
 =delete copy functionality
 #ifdef SyncPoint in tests for Windows Release builds
2015-08-20 14:08:24 -07:00
Ari Ekmekji
137c376675 Removing variables used only in assertions to prevent build error
Summary:
A couple variables were declared but only used in assertions
which causes issues when building in fbcode.

Test Plan: make dbg  and   make release

Reviewers: yhchiang, sdong, igor, anthony, MarkCallaghan

Reviewed By: MarkCallaghan

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44937
2015-08-19 08:52:22 -07:00
Ari Ekmekji
b47cc58516 Bounding Number of Subcompactions
Summary:
In D43239 (https://reviews.facebook.net/D43239) the number
of subcompactions is set based on the number of L1 files with
unique starting keys. In certain cases when this number is very large
this causes issues, particularly with the overlap between files since
very small output files can be generated. This diff bounds the number
of subcompactions to the user option DBOption.num_subcompactions.

Test Plan: ./db_test ./db_compaction_test

Reviewers: sdong, igor, anthony, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44883
2015-08-18 14:56:31 -07:00
Ari Ekmekji
601b1aaca0 Fixing Failed Assertion in Subcompaction State Diff
Summary:
In D43239 (https://reviews.facebook.net/D43239) there is an
assertion to make sure a subcompaction's output is never empty at the
end of execution. This assertion however breaks the build because some
tests lead to exactly that scenario. So instead I have altered the logic
to handle this case instead of just failing the assertion.

The reason that it is possible for a subcompaction's output to be empty is
that during a sequential execution of subcompactions, if a user aborts the
compaction job then some of the later subcompactions to be executed may
have yet to process any keys and therefore have yet to generate output files.
This becomes very rare once the subcompactions are executed in parallel,
but for now they are still sequential so the case is possible when there is an
early termination, as in some of the tests.

Test Plan: ./db_test  ./db_compaction_test

Reviewers: sdong, igor, anthony, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D44877
2015-08-18 12:27:12 -07:00
Ari Ekmekji
f0da6977a3 [Parallel L0-L1 Compaction Prep]: Giving Subcompactions Their Own State
Summary:
In prepration for running multiple threads at the same time during
a compaction job, this patch assigns each subcompaction its own state
(instead of sharing the one global CompactionState). Each subcompaction then
uses this state to update its statistics, keep track of its snapshots, etc.
during the course of execution. Then at the end of all the executions the
statistics are aggregated across the subcompactions so that the final result
is the same as if only one larger compaction had run.

Test Plan: ./db_test  ./db_compaction_test  ./compaction_job_test

Reviewers: sdong, anthony, igor, noetzli, yhchiang

Reviewed By: yhchiang

Subscribers: MarkCallaghan, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43239
2015-08-18 11:06:23 -07:00
Andres Notzli
f32a572099 Simplify querying of merge results
Summary:
While working on supporting mixing merge operators with
single deletes ( https://reviews.facebook.net/D43179 ),
I realized that returning and dealing with merge results
can be made simpler. Submitting this as a separate diff
because it is not directly related to single deletes.

Before, callers of merge helper had to retrieve the merge
result in one of two ways depending on whether the merge
was successful or not (success = result of merge was single
kTypeValue). For successful merges, the caller could query
the resulting key/value pair and for unsuccessful merges,
the result could be retrieved in the form of two deques of
keys and values. However, with single deletes, a successful merge
does not return a single key/value pair (if merge
operands are merged with a single delete, we have to generate
a value and keep the original single delete around to make
sure that we are not accidentially producing a key overwrite).
In addition, the two existing call sites of the merge
helper were taking the same actions independently from whether
the merge was successful or not, so this patch simplifies that.

Test Plan: make clean all check

Reviewers: rven, sdong, yhchiang, anthony, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D43353
2015-08-17 17:34:38 -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
Andres Notzli
68f934355a Better CompactionJob testing
Summary:
Changed compaction_job_test to support better/more thorough
tests and added two tests. Also changed MockFileContents
to order using InternalKeyComparator.

Test Plan: make compaction_job_test && ./compaction_job_test; make all && make check

Reviewers: sdong, rven, igor, yhchiang, anthony

Reviewed By: anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D42837
2015-08-07 21:59:51 -07:00
sdong
3ae386eafe Add statistic histogram "rocksdb.sst.read.micros"
Summary: Measure read latency histogram and put in statistics. Compaction inputs are excluded from it when possible (unfortunately usually no possible as we usually take table reader from table cache.

Test Plan:
Run db_bench and it shows the stats, like:

rocksdb.sst.read.micros statistics Percentiles :=> 50 : 1.238522 95 : 2.529740 99 : 3.912180

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

Reviewed By: yhchiang

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D43275
2015-08-05 13:02:33 -07:00
Ari Ekmekji
40c64434d4 Parallelize L0-L1 Compaction: Restructure Compaction Job
Summary:
As of now compactions involving files from Level 0 and Level 1 are single
threaded because the files in L0, although sorted, are not range partitioned like
the other levels. This means that during L0-L1 compaction each file from L1
needs to be merged with potentially all the files from L0.

This attempt to parallelize the L0-L1 compaction assigns a thread and a
corresponding iterator to each L1 file that then considers only the key range
found in that L1 file and only the L0 files that have those keys (and only the
specific portion of those L0 files in which those keys are found). In this way
the overlap is minimized and potentially eliminated between different iterators
focusing on the same files.

The first step is to restructure the compaction logic to break L0-L1 compactions
into multiple, smaller, sequential compactions. Eventually each of these smaller
jobs will be run simultaneously. Areas to pay extra attention to are

  # Correct aggregation of compaction job statistics across multiple threads
  # Proper opening/closing of output files (make sure each thread's is unique)
  # Keys that span multiple L1 files
  # Skewed distributions of keys within L0 files

Test Plan: Make and run db_test (newer version has separate compaction tests) and compaction_job_stats_test

Reviewers: igor, noetzli, anthony, sdong, yhchiang

Reviewed By: yhchiang

Subscribers: MarkCallaghan, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D42699
2015-08-03 11:32:14 -07:00
Andres Notzli
d06c82e477 Further cleanup of CompactionJob and MergeHelper
Summary:
Simplified logic in CompactionJob and removed unused parameter in
MergeHelper.

Test Plan: make && make check

Reviewers: rven, igor, sdong, yhchiang

Reviewed By: sdong

Subscribers: aekmekji, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D42687
2015-07-28 19:21:55 -07:00