Commit Graph

1252 Commits

Author SHA1 Message Date
Ding Ma
1a136c1f13 Expose file size
Summary:
add a new function to SstFileWriter that will tell the user how big is there file right now.
Closes https://github.com/facebook/rocksdb/pull/1686

Differential Revision: D4338868

Pulled By: mdyuki1016

fbshipit-source-id: c1ee16a
2016-12-16 18:39:12 -08:00
Daniel Black
816c1e30ca gcc-7 requires include <functional> for std::function
Summary:
Fixes compile error:

In file included from ./util/statistics.h:17:0,
                 from ./util/stop_watch.h:8,
                 from ./util/perf_step_timer.h:9,
                 from ./util/iostats_context_imp.h:8,
                 from ./util/posix_logger.h:27,
                 from ./port/util_logger.h:18,
                 from ./db/auto_roll_logger.h:15,
                 from db/auto_roll_logger.cc:6:
./util/thread_local.h:65:16: error: 'function' in namespace 'std' does not name a template type
   typedef std::function<void(void*, void*)> FoldFunc;
Closes https://github.com/facebook/rocksdb/pull/1656

Differential Revision: D4318702

Pulled By: yiwu-arbug

fbshipit-source-id: 8c5d17a
2016-12-16 11:24:18 -08:00
siddontang
8f5d24ae68 C API: support get usage and pinned_usage for cache
Summary: Closes https://github.com/facebook/rocksdb/pull/1671

Differential Revision: D4327453

Pulled By: yiwu-arbug

fbshipit-source-id: bcdbc65
2016-12-15 17:24:17 -08:00
Daniel Black
bfbcec2339 Gcc 7 error expansion to defined
Summary:
sorry if these gcc-7/clang-4 cleanups are getting tedious.
Closes https://github.com/facebook/rocksdb/pull/1658

Differential Revision: D4318792

Pulled By: yiwu-arbug

fbshipit-source-id: 8e85891
2016-12-13 18:39:14 -08:00
siddontang
b57dd9262a C API: support writebatch delete range
Summary:
Seem that writebatch delete range can work now, so I add C API for later use.

Btw, can we use this feature in production now?
Closes https://github.com/facebook/rocksdb/pull/1647

Differential Revision: D4314534

Pulled By: ajkr

fbshipit-source-id: e835165
2016-12-13 11:24:18 -08:00
Andrew Kryczka
f0c509e2c8 Return finer-granularity status from Env::GetChildren*
Summary:
It'd be nice to use the error status type to distinguish
between user error and system error. For example, GetChildren can fail
listing a backup directory's contents either because a bad path was provided
(user error) or because an operation failed, e.g., a remote storage service
call failed (system error). In the former case, we want to continue and treat
the backup directory as empty; in the latter case, we want to immediately
propagate the error to the caller.

This diff uses NotFound to indicate user error and IOError to indicate
system error. Previously IOError indicated both.
Closes https://github.com/facebook/rocksdb/pull/1644

Differential Revision: D4312157

Pulled By: ajkr

fbshipit-source-id: 51b4f24
2016-12-12 12:54:13 -08:00
zhangjinpeng1987
45c7ce1377 CompactRangeOptions C API
Summary:
Add C API for CompactRangeOptions.
Closes https://github.com/facebook/rocksdb/pull/1596

Differential Revision: D4252339

Pulled By: yiwu-arbug

fbshipit-source-id: f768f93
2016-12-07 17:54:14 -08:00
Islam AbdelRahman
ed8fbdb560 Add EventListener::OnExternalFileIngested() event
Summary:
Add EventListener::OnExternalFileIngested() to allow user to subscribe to external file ingestion events
Closes https://github.com/facebook/rocksdb/pull/1623

Differential Revision: D4285844

Pulled By: IslamAbdelRahman

fbshipit-source-id: 0b95a88
2016-12-06 14:09:17 -08:00
Manuel Ung
2005c88a75 Implement non-exclusive locks
Summary:
This is an implementation of non-exclusive locks for pessimistic transactions. It is relatively simple and does not prevent starvation (ie. it's possible that request for exclusive access will never be granted if there are always threads holding shared access). It is done by changing `KeyLockInfo` to hold an set a transaction ids, instead of just one, and adding a flag specifying whether this lock is currently held with exclusive access or not.

Some implementation notes:
- Some lock diagnostic functions had to be updated to return a set of transaction ids for a given lock, eg. `GetWaitingTxn` and `GetLockStatusData`.
- Deadlock detection is a bit more complicated since a transaction can now wait on multiple other transactions. A BFS is done in this case, and deadlock detection depth is now just a limit on the number of transactions we visit.
- Expirable transactions do not work efficiently with shared locks at the moment, but that's okay for now.
Closes https://github.com/facebook/rocksdb/pull/1573

Differential Revision: D4239097

Pulled By: lth

fbshipit-source-id: da7c074
2016-12-05 17:39:17 -08:00
Islam AbdelRahman
67f37cf198 Allow user to specify a CF for SST files generated by SstFileWriter
Summary:
Allow user to explicitly specify that the generated file by SstFileWriter will be ingested in a specific CF.
This allow us to persist the CF id in the generated file
Closes https://github.com/facebook/rocksdb/pull/1615

Differential Revision: D4270422

Pulled By: IslamAbdelRahman

fbshipit-source-id: 7fb954e
2016-12-05 14:24:16 -08:00
Igor Canadi
3f407b065c Kill flashcache code in RocksDB
Summary:
Now that we have userspace persisted cache, we don't need flashcache anymore.
Closes https://github.com/facebook/rocksdb/pull/1588

Differential Revision: D4245114

Pulled By: igorcanadi

fbshipit-source-id: e2c1c72
2016-12-01 10:09:22 -08:00
Mike Kolupaev
247d0979aa Support for range skips in compaction filter
Summary:
This adds the ability for compaction filter to say "drop this key-value, and also drop everything up to key x". This will cause the compaction to seek input iterator to x, without reading the data. This can make compaction much faster when large consecutive chunks of data are filtered out. See the changes in include/rocksdb/compaction_filter.h for the new API.

Along the way this diff also adds ability for compaction filter changing merge operands, similar to how it can change values; we're not going to use this feature, it just seemed easier and cleaner to implement it than to document that it's not implemented :)

The diff is not as big as it may seem, about half of the lines are a test.
Closes https://github.com/facebook/rocksdb/pull/1599

Differential Revision: D4252092

Pulled By: al13n321

fbshipit-source-id: 41e1e48
2016-12-01 07:09:15 -08:00
Panagiotis Ktistakis
96fcefbf1d c api: expose option for dynamic level size target
Summary: Closes https://github.com/facebook/rocksdb/pull/1587

Differential Revision: D4245923

Pulled By: yiwu-arbug

fbshipit-source-id: 6ee7291
2016-11-30 11:24:14 -08:00
zhangjinpeng1987
00197cff39 Add C API to set base_backgroud_compactions
Summary:
Add C API to set base_backgroud_compactions
Closes https://github.com/facebook/rocksdb/pull/1571

Differential Revision: D4245709

Pulled By: yiwu-arbug

fbshipit-source-id: 792c6b8
2016-11-30 11:09:13 -08:00
Andrew Kryczka
7ffb10fc1a DeleteRange compaction statistics
Summary:
- "rocksdb.compaction.key.drop.range_del" - number of keys dropped during compaction due to a range tombstone covering them
- "rocksdb.compaction.range_del.drop.obsolete" - number of range tombstones dropped due to compaction to bottom level and no snapshot saving them
- s/CompactionIteratorStats/CompactionIterationStats/g since this class is no longer specific to CompactionIterator -- it's also updated for range tombstone iteration during compaction
- Move the above class into a separate .h file to avoid circular dependency.
Closes https://github.com/facebook/rocksdb/pull/1520

Differential Revision: D4187179

Pulled By: ajkr

fbshipit-source-id: 10c2103
2016-11-28 11:54:12 -08:00
Mike Kolupaev
236d4c67e9 Less linear search in DBIter::Seek() when keys are overwritten a lot
Summary:
In one deployment we saw high latencies (presumably from slow iterator operations) and a lot of CPU time reported by perf with this stack:

```
  rocksdb::MergingIterator::Next
  rocksdb::DBIter::FindNextUserEntryInternal
  rocksdb::DBIter::Seek
```

I think what's happening is:
1. we create a snapshot iterator,
2. we do lots of Put()s for the same key x; this creates lots of entries in memtable,
3. we seek the iterator to a key slightly smaller than x,
4. the seek walks over lots of entries in memtable for key x, skipping them because of high sequence numbers.

CC IslamAbdelRahman
Closes https://github.com/facebook/rocksdb/pull/1413

Differential Revision: D4083879

Pulled By: IslamAbdelRahman

fbshipit-source-id: a83ddae
2016-11-28 10:24:11 -08:00
Yi Wu
dfb6fe6755 Unified InlineSkipList::Insert algorithm with hinting
Summary:
This PR is based on nbronson's diff with small
modifications to wire it up with existing interface. Comparing to
previous version, this approach works better for inserting keys in
decreasing order or updating the same key, and impose less restriction
to the prefix extractor.

---- Summary from original diff ----

This diff introduces a single InlineSkipList::Insert that unifies
the existing sequential insert optimization (prev_), concurrent insertion,
and insertion using externally-managed insertion point hints.

There's a deep symmetry between insertion hints (cursors) and the
concurrent algorithm.  In both cases we have partial information from
the recent past that is likely but not certain to be accurate.  This diff
introduces the struct InlineSkipList::Splice, which encodes predecessor
and successor information in the same form that was previously only used
within a single call to InsertConcurrently.  Splice holds information
about an insertion point that can be used to levera
Closes https://github.com/facebook/rocksdb/pull/1561

Differential Revision: D4217283

Pulled By: yiwu-arbug

fbshipit-source-id: 33ee437
2016-11-22 14:09:13 -08:00
Maysam Yabandeh
182b940e70 Add WriteOptions.no_slowdown
Summary:
If the WriteOptions.no_slowdown flag is set AND we need to wait or sleep for
the write request, then fail immediately with Status::Incomplete().
Closes https://github.com/facebook/rocksdb/pull/1527

Differential Revision: D4191405

Pulled By: maysamyabandeh

fbshipit-source-id: 7f3ce3f
2016-11-21 18:09:13 -08:00
Karthikeyan Radhakrishnan
4118e13330 Persistent Cache: Expose stats to user via public API
Summary:
Exposing persistent cache stats (counters) to the user via public API.
Closes https://github.com/facebook/rocksdb/pull/1485

Differential Revision: D4155274

Pulled By: siying

fbshipit-source-id: 30a9f50
2016-11-21 17:39:13 -08:00
Maysam Yabandeh
9d60151b04 Implement PositionedAppend for PosixWritableFile
Summary:
This patch clarifies the contract of PositionedAppend with some unit
tests and also implements it for PosixWritableFile. (Tasks: 14524071)
Closes https://github.com/facebook/rocksdb/pull/1514

Differential Revision: D4204907

Pulled By: maysamyabandeh

fbshipit-source-id: 06eabd2
2016-11-18 17:24:13 -08:00
Islam AbdelRahman
c1038d2837 Release RocksDB 5.0
Summary:
Update HISTORY.md and version.h
Closes https://github.com/facebook/rocksdb/pull/1536

Differential Revision: D4202987

Pulled By: IslamAbdelRahman

fbshipit-source-id: 94985e3
2016-11-17 18:39:15 -08:00
Islam AbdelRahman
f39452e81f Fix heap use after free ASAN/Valgrind
Summary:
Dont use c_str() of temp std::string in RocksLuaCompactionFilter::Name()
Closes https://github.com/facebook/rocksdb/pull/1535

Differential Revision: D4199094

Pulled By: IslamAbdelRahman

fbshipit-source-id: e56ce62
2016-11-17 12:24:12 -08:00
Yi Wu
36e4762ce0 Remove Ticker::SEQUENCE_NUMBER
Summary:
Remove the ticker count because:
* Having to reset the ticker count in WriteImpl is ineffiecent;
* It doesn't make sense to have it as a ticker count if multiple db
  instance share a statistics object.
Closes https://github.com/facebook/rocksdb/pull/1531

Differential Revision: D4194442

Pulled By: yiwu-arbug

fbshipit-source-id: e2110a9
2016-11-16 22:39:09 -08:00
Yueh-Hsuan Chiang
647eafdc21 Introduce Lua Extension: RocksLuaCompactionFilter
Summary:
This diff includes an implementation of CompactionFilter that allows
users to write CompactionFilter in Lua.  With this ability, users can
dynamically change compaction filter logic without requiring building
the rocksdb binary and restarting the database.

To compile, WITH_LUA_PATH must be specified to the base directory
of lua.
Closes https://github.com/facebook/rocksdb/pull/1478

Differential Revision: D4150138

Pulled By: yhchiang

fbshipit-source-id: ed84222
2016-11-16 15:39:12 -08:00
Siying Dong
972e3ff295 Enable allow_concurrent_memtable_write and enable_write_thread_adaptive_yield by default
Summary: Closes https://github.com/facebook/rocksdb/pull/1496

Differential Revision: D4168080

Pulled By: siying

fbshipit-source-id: 056ae62
2016-11-16 09:39:09 -08:00
Andrew Kryczka
489d142808 DeleteRange interface
Summary:
Expose DeleteRange() interface since we think the implementation is functionally correct now.
Closes https://github.com/facebook/rocksdb/pull/1503

Differential Revision: D4171921

Pulled By: ajkr

fbshipit-source-id: 5e21c98
2016-11-15 15:24:16 -08:00
Yi Wu
1ea79a78c9 Optimize sequential insert into memtable - Part 1: Interface
Summary:
Currently our skip-list have an optimization to speedup sequential
inserts from a single stream, by remembering the last insert position.
We extend the idea to support sequential inserts from multiple streams,
and even tolerate small reordering wihtin each stream.

This PR is the interface part adding the following:
- Add `memtable_insert_prefix_extractor` to allow specifying prefix for each key.
- Add `InsertWithHint()` interface to memtable, to allow underlying
  implementation to return a hint of insert position, which can be later
  pass back to optimize inserts.
- Memtable will maintain a map from prefix to hints and pass the hint
  via `InsertWithHint()` if `memtable_insert_prefix_extractor` is non-null.
Closes https://github.com/facebook/rocksdb/pull/1419

Differential Revision: D4079367

Pulled By: yiwu-arbug

fbshipit-source-id: 3555326
2016-11-13 19:09:18 -08:00
Maysam Yabandeh
361010d447 Exporting compaction stats in the form of a map
Summary:
Currently the compaction stats are printed to stdout. We want to export the compaction stats in a map format so that the upper layer apps (e.g., MySQL) could present
the stats in any format required by the them.
Closes https://github.com/facebook/rocksdb/pull/1477

Differential Revision: D4149836

Pulled By: maysamyabandeh

fbshipit-source-id: b3df19f
2016-11-11 20:54:14 -08:00
Jay Lee
a7875272d7 c: support seek_for_prev
Summary:
support seek_for_prev in c abi.
Closes https://github.com/facebook/rocksdb/pull/1457

Differential Revision: D4135360

Pulled By: lightmark

fbshipit-source-id: 61256b0
2016-11-08 12:54:13 -08:00
Andrew Kryczka
f998c9790f DeleteRange Get support
Summary:
During Get()/MultiGet(), build up a RangeDelAggregator with range
tombstones as we search through live memtable, immutable memtables, and
SST files. This aggregator is then used by memtable.cc's SaveValue() and
GetContext::SaveValue() to check whether keys are covered.

added tests for Get on memtables/files; end-to-end tests mainly in https://reviews.facebook.net/D64761
Closes https://github.com/facebook/rocksdb/pull/1456

Differential Revision: D4111271

Pulled By: ajkr

fbshipit-source-id: 6e388d4
2016-11-03 18:54:20 -07:00
zhangjinpeng1987
879f366366 Add C api for RateLimiter
Summary:
Add C api for RateLimiter.
Closes https://github.com/facebook/rocksdb/pull/1455

Differential Revision: D4116362

Pulled By: yiwu-arbug

fbshipit-source-id: cb05a8d
2016-11-03 11:09:17 -07:00
Yi Wu
437942e481 Add avoid_flush_during_shutdown DB option
Summary:
Add avoid_flush_during_shutdown DB option.
Closes https://github.com/facebook/rocksdb/pull/1451

Differential Revision: D4108643

Pulled By: yiwu-arbug

fbshipit-source-id: abdaf4d
2016-11-02 15:39:18 -07:00
Benoit Girard
2b16d664cb Change max_bytes_for_level_multiplier to double
Summary: Closes https://github.com/facebook/rocksdb/pull/1427

Differential Revision: D4094732

Pulled By: yiwu-arbug

fbshipit-source-id: b9b79e9
2016-11-01 21:09:23 -07:00
Jay Lee
16fb04434f expose IngestExternalFile to c abi
Summary:
IngestExternalFile is very useful when doing bulk load. This pr expose this API to c so many bindings can benefit from it too.
Closes https://github.com/facebook/rocksdb/pull/1454

Differential Revision: D4113420

Pulled By: yiwu-arbug

fbshipit-source-id: 307c6ae
2016-11-01 17:09:39 -07:00
Kien-hung Li
eeb27e1bbd Add handy option to turn on direct I/O in db_bench (#1424) 2016-10-28 10:36:05 -07:00
Jan Doms
c6168d13ab removed some declarations from c.h which resulted in undefined symbols (#1407) 2016-10-28 10:33:49 -07:00
Reid Horuff
4dfaa6610a Make IsDeadlockDetect() virtual member of Transaction
Summary: Make `IsDeadlockDetect()` virtual member of base class `Transaction` for ease of use in MyRocks

Test Plan: compiles. compiles into MyRocks call-site.

Reviewers: mung

Reviewed By: mung

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D65385
2016-10-21 14:47:59 -07:00
Islam AbdelRahman
869ae5d786 Support IngestExternalFile (remove AddFile restrictions)
Summary:
Changes in the diff

API changes:
- Introduce IngestExternalFile to replace AddFile (I think this make the API more clear)
- Introduce IngestExternalFileOptions (This struct will encapsulate the options for ingesting the external file)
- Deprecate AddFile() API

Logic changes:
- If our file overlap with the memtable we will flush the memtable
- We will find the first level in the LSM tree that our file key range overlap with the keys in it
- We will find the lowest level in the LSM tree above the the level we found in step 2 that our file can fit in and ingest our file in it
- We will assign a global sequence number to our new file
- Remove AddFile restrictions by using global sequence numbers

Other changes:
- Refactor all AddFile logic to be encapsulated in ExternalSstFileIngestionJob

Test Plan:
unit tests (still need to add more)
addfile_stress (https://reviews.facebook.net/D65037)

Reviewers: yiwu, andrewkr, lightmark, yhchiang, sdong

Reviewed By: sdong

Subscribers: jkedgar, hcz, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D65061
2016-10-20 17:05:32 -07:00
Manuel Ung
4edd39fda2 Implement deadlock detection
Summary: Implement deadlock detection. This is done by maintaining a TxnID -> TxnID map which represents the edges in the wait for graph (this is named `wait_txn_map_`).

Test Plan: transaction_test

Reviewers: IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D64491
2016-10-19 19:45:57 -07:00
Islam AbdelRahman
b88f8e87c5 Support SST files with Global sequence numbers [reland]
Summary:
reland https://reviews.facebook.net/D62523

- Update SstFileWriter to include a property for a global sequence number in the SST file `rocksdb.external_sst_file.global_seqno`
- Update TableProperties to be aware of the offset of each property in the file
- Update BlockBasedTableReader and Block to be able to honor the sequence number in `rocksdb.external_sst_file.global_seqno` property and use it to overwrite all sequence number in the file

Something worth mentioning is that we don't update the seqno in the index block since and when doing a binary search, the reason for that is that it's guaranteed that SST files with global seqno will have only one user_key and each key will have seqno=0 encoded in it, This mean that this key is greater than any other key with seqno> 0. That mean that we can actually keep the current logic for these blocks

Test Plan: unit tests

Reviewers: sdong, yhchiang

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D65211
2016-10-18 16:59:37 -07:00
Yueh-Hsuan Chiang
ab53998372 Bump RocksDB version to 4.13 (#1405)
Summary:
Bump RocksDB version to 4.13

Test Plan:
unit tests

Reviewers: sdong, IslamAbdelRahman, andrewkr, lightmark

Subscribers: leveldb
2016-10-18 15:39:10 -07:00
Aaron Gao
d88dff4ef2 add seeforprev in history
Summary: update new feature in history and avoid breaking mongorocks

Test Plan: make check

Reviewers: sdong, yiwu, andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D64611
2016-10-17 15:34:13 -07:00
Yi Wu
e29d3b67c2 Make max_background_compactions and base_background_compactions dynamic changeable
Summary:
Add DB::SetDBOptions to dynamic change max_background_compactions and base_background_compactions.
I'll add more dynamic changeable options soon.

Test Plan: unit test.

Reviewers: yhchiang, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D64749
2016-10-14 12:25:39 -07:00
Dmitri Smirnov
b9311aa65c Implement WinRandomRW file and improve code reuse (#1388) 2016-10-13 16:36:34 -07:00
Reid Horuff
02b3e3985c Make txn->GetState() const
Summary: makes Transaction::GetState() a const function.

Test Plan: compiles.

Reviewers: mung

Reviewed By: mung

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D64929
2016-10-11 15:48:50 -07:00
Yi Wu
991b585ee0 More block cache tickers
Summary: Adding several missing block cache tickers.

Test Plan:
  make all check

Reviewers: IslamAbdelRahman, yhchiang, lightmark

Reviewed By: lightmark

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D64881
2016-10-11 11:59:05 -07:00
Yi Wu
d6ae6dec69 Add Statistics::getAndResetTickerCount().
Summary: A convience method to atomically get and reset ticker count. I'm wanting to use it to have a thin wrapper to the statistics object to export ticker counts to ODS for LogDevice (since they don't even use fb303).

Test Plan:
test in LogDevice shadow cluster.
https://fburl.com/461868822

Reviewers: andrewkr, yhchiang, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D64869
2016-10-11 10:54:11 -07:00
Islam AbdelRahman
2ad68b971a Support running consistency checks in release mode
Summary:
We always run consistency checks when compiling in debug mode
allow users to set Options::force_consistency_checks to true to be able to run such checks even when compiling in release mode

Test Plan:
make check -j64
make release

Reviewers: lightmark, sdong, yiwu

Reviewed By: yiwu

Subscribers: hermanlee4, andrewkr, yoshinorim, jkedgar, dhruba

Differential Revision: https://reviews.facebook.net/D64701
2016-10-07 17:21:45 -07:00
Islam AbdelRahman
d062328977 Revert "Support SST files with Global sequence numbers"
This reverts commit ab01da5437.
2016-10-07 14:05:12 -07:00
Reid Horuff
37737c3a6b Expose Transaction State Publicly
Summary:
This exposes a transactions state through a public api rather than through a public member variable. I also do some name refactoring.
ExecutionStatus => TransactionState
exec_status_ => trx_state_

Test Plan: It compiles and transaction_test passes.

Reviewers: IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, mung, dhruba, sdong

Differential Revision: https://reviews.facebook.net/D64689
2016-10-07 11:58:53 -07:00
Reid Horuff
2c1f95291d Add facility to write only a portion of WriteBatch to WAL
Summary:
When constructing a write batch a client may now call MarkWalTerminationPoint() on that batch. No batch operations after this call will be added written to the WAL but will still be inserted into the Memtable. This facility is used to remove one of the three WriteImpl calls in 2PC transactions. This produces a ~1% perf improvement.

```
RocksDB - unoptimized 2pc, sync_binlog=1, disable_2pc=off
INFO 2016-08-31 14:30:38,814 [main]: REQUEST PHASE COMPLETED. 75000000 requests done in 2619 seconds. Requests/second = 28628

RocksDB - optimized 2pc , sync_binlog=1, disable_2pc=off
INFO 2016-08-31 16:26:59,442 [main]: REQUEST PHASE COMPLETED. 75000000 requests done in 2581 seconds. Requests/second = 29054
```

Test Plan: Two unit tests added.

Reviewers: sdong, yiwu, IslamAbdelRahman

Reviewed By: yiwu

Subscribers: hermanlee4, dhruba, andrewkr

Differential Revision: https://reviews.facebook.net/D64599
2016-10-07 11:32:10 -07:00
Sage Weil
4985f60fc8 env_mirror: fix a few leaks (#1363)
* env_mirror: fix leak from LockFile

Signed-off-by: Sage Weil <sage@redhat.com>

* env_mirror: instruct EnvMirror whether mirrored Envs should be destroyed

The lifecycle rules for Env are frustrating and undocumented.  Notably,
Env::Default() should *not* be freed, but any Env instances we created
should be.

Explicitly instruct EnvMirror whether to clean up child Env instances.
Default to false so that we do not affect existing callers.

Signed-off-by: Sage Weil <sage@redhat.com>
2016-10-06 10:43:05 -07:00
Igor Mihalik
5aded67ddb update of c.h (#1371)
Added rocksdb_options_set_memtable_prefix_bloom_size_ratio function implemented in c.cc but not exported via c.h
2016-10-06 10:37:19 -07:00
Islam AbdelRahman
ab01da5437 Support SST files with Global sequence numbers
Summary:
- Update SstFileWriter to include a property for a global sequence number in the SST file `rocksdb.external_sst_file.global_seqno`
- Update TableProperties to be aware of the offset of each property in the file
- Update BlockBasedTableReader and Block to be able to honor the sequence number in `rocksdb.external_sst_file.global_seqno` property and use it to overwrite all sequence number in the file

Something worth mentioning is that we don't update the seqno in the index block since and when doing a binary search, the reason for that is that it's guaranteed that SST files with global seqno will have only one user_key and each key will have seqno=0 encoded in it, This mean that this key is greater than any other key with seqno> 0. That mean that we can actually keep the current logic for these blocks

Test Plan: unit tests

Reviewers: andrewkr, yhchiang, yiwu, sdong

Reviewed By: sdong

Subscribers: hcz, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62523
2016-10-03 16:12:39 -07:00
krad
e91b4d0cf6 Add factory method for creating persistent cache that is accessible from public
Summary:
Currently there is no mechanism to create persistent cache from
headers. Adding a simple factory method to create a simple persistent cache with
default or NVM optimized settings.

note: Any idea to test this factory is appreciated.

Test Plan: None

Reviewers: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D64527
2016-10-03 10:55:46 -07:00
Manuel Ung
be1f1092c9 Expose transaction id, lock state information and transaction wait information
Summary:
This diff does 3 things:

Expose TransactionID so that we can identify transactions when we retrieve locking and lock wait information. This is exposed as `Transaction::GetID`.

Expose lock state information by locking all stripes in all column families and copying their contents to a data structure. This is exposed as `TransactionDB::GetLockStatusData`.

Adds support for tracking the transaction and the key being waited on, and exposes this as `Transaction::GetWaitingTxn`.

Test Plan: unit tests

Reviewers: horuff, sdong

Reviewed By: sdong

Subscribers: vasilep, hermanlee4, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D64413
2016-09-30 11:41:21 -07:00
Aaron Gao
f517d9dd09 Add SeekForPrev() to Iterator
Summary:
Add new Iterator API, `SeekForPrev`: find the last key that <= target key
support prefix_extractor
support prefix_same_as_start
support upper_bound
not supported in iterators without Prev()

Also add tests in db_iter_test and db_iterator_test

Pass all tests
Cheers!

Test Plan: make all check -j64

Reviewers: andrewkr, yiwu, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D64149
2016-09-27 18:20:57 -07:00
Yi Wu
9ed928e7a9 Split DBOptions into ImmutableDBOptions and MutableDBOptions
Summary: Use ImmutableDBOptions/MutableDBOptions internally and DBOptions only for user-facing APIs. MutableDBOptions is barely a placeholder for now. I'll start to move options to MutableDBOptions in following diffs.

Test Plan:
  make all check

Reviewers: yhchiang, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D64065
2016-09-23 16:34:04 -07:00
Aaron Gao
0a1bd9c509 add cfh deletion started listener
Summary: add ColumnFamilyHandleDeletionStarted listener which can be called when user deletes handler.

Test Plan: ./listener_test

Reviewers: yiwu, IslamAbdelRahman, sdong, andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D60717
2016-09-22 11:56:18 -07:00
Giuseppe Ottaviano
d45eb6c6d2 Fix typo (#1349) 2016-09-21 20:06:56 -07:00
Yi Wu
17f76fc564 DB::GetOptions() reflect dynamic changed options
Summary: DB::GetOptions() reflect dynamic changed options.

Test Plan: See the new unit test.

Reviewers: yhchiang, sdong, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D63903
2016-09-14 22:10:28 -07:00
Islam AbdelRahman
ba65c816bb Support POSIX RandomRWFile
Summary:
Add Env::RandomRWFile in env.h and implement it for POSIX
RandomRWFile is a file that allow us to read from / write to random offsets in the file

I will implement it for other Envs later after finishing the whole task for AddFile()

Test Plan: unit tests

Reviewers: andrewkr, kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62433
2016-09-13 12:08:22 -07:00
zhangjinpeng1987
b06b191362 add C api for set wal_recovery_mode (#1327)
* add C api for set wal recovery mode

* add test
2016-09-09 10:11:30 -07:00
ammongit
0fcb6dbed7 Remove extraneous function prototypes from c.h (#1326)
* Fix function prototypes from upstream commit 32149059.

* Fix removed function.

* Readd removed function.
2016-09-08 11:31:06 -07:00
Edouard A
66a91e2607 Add NoSpace subcode to IOError (#1320)
Add a sub code to distinguish "out of space" errors from regular I/O errors
2016-09-07 12:37:45 -07:00
wenduo
0e2da497c6 fix typo in option.h's comment (#1321) 2016-09-07 01:36:16 -07:00
sdong
607628d349 Support ZSTD with finalized format
Summary:
ZSTD 1.0.0 is coming. We can finally add a support of ZSTD without worrying about compatibility.
Still keep ZSTDNotFinal for compatibility reason.

Test Plan: Run all tests. Run db_bench with ZSTD version with RocksDB built with ZSTD 1.0 and older.

Reviewers: andrewkr, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: cyan, igor, IslamAbdelRahman, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D63141
2016-09-06 12:22:16 -07:00
Yi Wu
a88677d2cf Remove ImmutableCFOptions from public API
Summary: There's no reference to ImmutableCFOptions elsewhere in /include/rocksdb. ImmutableCFOptions was introduced in this commit (5665e5e285) but later its reference in /include/rocksdb/table.h is removed.

Test Plan:
  make all check

Reviewers: IslamAbdelRahman, sdong, yhchiang

Reviewed By: yhchiang

Subscribers: yhchiang, andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D63177
2016-09-02 14:16:31 -07:00
John Alexander
4fd08f4b8b Ensure Correct Behavior of StatsLevel kExceptDetailedTimers and kExceptTimeForMutex (#1308)
* Fix StatsLevel so that kExceptTimeForMutex leaves compression stats enabled and kExceptDetailedTimers disables mutex lock stats. Also change default stats level to kExceptDetailedTimers (disabling both compression and mutex timing).

* Changed order of StatsLevel enum to simplify logic for determining what stats to record.
2016-09-01 19:57:55 -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
Aaron Gao
4590b53a4b add stats to Cache::LookUp()
Summary: basically for SimCache stats. I find most times it is hard to pass Statistics* to SimCache constructor.

Test Plan: make all check

Reviewers: andrewkr, sdong, yiwu

Reviewed By: yiwu

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62193
2016-09-01 13:50:39 -07:00
Sherlock
85bb308258 Expose Utility function StringToMap() (#1306) 2016-09-01 13:47:21 -07:00
Islam AbdelRahman
b49b92cf28 Introduce Read amplification bitmap (read amp statistics)
Summary:
Add ReadOptions::read_amp_bytes_per_bit option which allow us to create a bitmap for every data block we read
the bitmap will contain (block_size / read_amp_bytes_per_bit) bits.

We will use this bitmap to mark which bytes have been used of the block so we can calculate the read amplification

Test Plan: added new tests

Reviewers: andrewkr, yhchiang, sdong

Reviewed By: sdong

Subscribers: yiwu, leveldb, march, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D58707
2016-08-26 18:55:58 -07:00
Aaron Gao
c7004840d2 store prefix_extractor_name in table
Summary:
Make sure prefix extractor name is stored in SST files and if DB is opened with a prefix extractor of a different name, prefix bloom is skipped when read the file.
Also add unit tests for that.

Test Plan:
before change:
```
Note: Google Test filter = BlockBasedTableTest.SkipPrefixBloomFilter
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from BlockBasedTableTest
[ RUN      ] BlockBasedTableTest.SkipPrefixBloomFilter
table/table_test.cc:1421: Failure
Value of: db_iter->Valid()
Actual: false
Expected: true
[  FAILED  ] BlockBasedTableTest.SkipPrefixBloomFilter (1 ms)
[----------] 1 test from BlockBasedTableTest (1 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (1 ms total)
[  PASSED  ] 0 tests.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] BlockBasedTableTest.SkipPrefixBloomFilter

1 FAILED TEST
```
after:
```
Note: Google Test filter = BlockBasedTableTest.SkipPrefixBloomFilter
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from BlockBasedTableTest
[ RUN      ] BlockBasedTableTest.SkipPrefixBloomFilter
[       OK ] BlockBasedTableTest.SkipPrefixBloomFilter (0 ms)
[----------] 1 test from BlockBasedTableTest (0 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (0 ms total)
[  PASSED  ] 1 test.
```

Reviewers: sdong, andrewkr, yiwu, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61215
2016-08-26 11:46:32 -07:00
Aaron Gao
4ad928e170 add comment to SimCache to estimate actual capacity
Summary: as title

Test Plan: make all check

Reviewers: yiwu

Reviewed By: yiwu

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D62493
2016-08-26 11:36:14 -07:00
Islam AbdelRahman
e9b2af87f8 Expose ThreadPool under include/rocksdb/threadpool.h
Summary:
This diff split ThreadPool to
-ThreadPool (abstract interface exposed in include/rocksdb/threadpool.h)
-ThreadPoolImpl (actual implementation in util/threadpool_imp.h)

This allow us to expose ThreadPool to the user so we can use it as an option later

Test Plan: existing unit tests

Reviewers: andrewkr, yiwu, yhchiang, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D62085
2016-08-26 10:41:35 -07:00
Yi Wu
4a16c32ece Option to cache index/filter blocks with priority
Summary:
Add option to block based table to insert index/filter blocks to block cache with priority. Combined with LRUCache with high_pri_pool_ratio, we can reserved space for index/filter blocks, make them less likely to be evicted.

Depends on D61977.

Test Plan: See unit test.

Reviewers: lightmark, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, march, leveldb

Differential Revision: https://reviews.facebook.net/D62241
2016-08-23 13:44:13 -07:00
Adam Retter
ffdf6eee19 Add Status to RocksDBException so that meaningful function result Status from the C++ API isn't lost (#1273) 2016-08-22 11:01:42 -07:00
Yi Wu
72f8cc703c LRU cache mid-point insertion
Summary:
Add mid-point insertion functionality to LRU cache. Caller of `Cache::Insert()` can set an additional parameter to make a cache entry have higher priority. The LRU cache will reserve at most `capacity * high_pri_pool_pct` bytes for high-pri cache entries. If `high_pri_pool_pct` is zero, the cache degenerates to normal LRU cache.

Context: If we are to put index and filter blocks into RocksDB block cache, index/filter block can be swap out too early. We want to add an option to RocksDB to reserve some capacity in block cache just for index/filter blocks, to mitigate the issue.

In later diffs I'll update block based table reader to use the interface to cache index/filter blocks at high priority, and expose the option to `DBOptions` and make it dynamic changeable.

Test Plan: unit test.

Reviewers: IslamAbdelRahman, sdong, lightmark

Reviewed By: lightmark

Subscribers: andrewkr, dhruba, march, leveldb

Differential Revision: https://reviews.facebook.net/D61977
2016-08-19 16:43:31 -07:00
Wanning Jiang
78837f5d61 TableBuilder / TableReader support for range deletion
Summary: 1. Range Deletion Tombstone structure 2. Modify Add() in table_builder to make it usable for adding range del tombstones 3. Expose NewTombstoneIterator() API in table_reader

Test Plan: table_test.cc (now BlockBasedTableBuilder::Add() only accepts InternalKey. I make table_test only pass InternalKey to BlockBasedTableBuidler. Also test writing/reading range deletion tombstones in table_test )

Reviewers: sdong, IslamAbdelRahman, lightmark, andrewkr

Reviewed By: andrewkr

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61473
2016-08-19 15:10:31 -07:00
Yi Wu
4cc37f59e5 Introduce ClockCache
Summary:
Clock-based cache implemenetation aim to have better concurreny than
default LRU cache. See inline comments for implementation details.

Test Plan:
Update cache_test to run on both LRUCache and ClockCache. Adding some
new tests to catch some of the bugs that I fixed while implementing the
cache.

Reviewers: kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61647
2016-08-19 12:28:19 -07:00
Jay
49d88be021 c abi: allow compaction filter ignore snapshot (#1268)
close #1262
2016-08-17 18:48:43 -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
Andrew Kryczka
3771e37970 WriteBatch support for range deletion
Summary:
Add API to WriteBatch to store range deletions in its buffer
which are later added to memtable. In the WriteBatch buffer, a range
deletion is encoded as "<optype><CF ID (optional)><begin key><end key>".

With this diff, the range tombstones are stored inline with the data in
the memtable. It's useful for now because the test cases rely on the
data being accessible via memtable. My next step is to store range
tombstones in a separate area in the memtable.

Test Plan: unit tests

Reviewers: IslamAbdelRahman, sdong, wanning

Reviewed By: wanning

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61401
2016-08-16 08:16:04 -07:00
Edouard A
a117891b4b Fixed typo (#1279)
Users shouldn't reply on -> users shouldn't rely on
2016-08-15 09:21:01 -07:00
Aaron Gao
e408e98c8c add Name() to Cache
Summary: preparation for detecting Cache type. If SimCache, we then may trigger some command like "setSimCapacity()" with setOptions()

Test Plan: make all check

Reviewers: yiwu, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61953
2016-08-12 14:16:57 -07:00
Dhruba Borthakur
d1be594636 Improve documentation of SliceTransform.
Test Plan: make check

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D61875
2016-08-11 15:10:09 -07:00
Yueh-Hsuan Chiang
6056d6317d Improve comment and bug fix for GetOptionsFromMap functions in convenience.h
Summary:
This diff improves the documentation for GetOptionsFromMap APIs and
fixes a bug in GetOptionsFromMap functions in convenience.h
where new_options will still be changed when the function
call is not successful.

Test Plan: options_test

Reviewers: IslamAbdelRahman, kradhakrishnan, andrewkr, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61731
2016-08-11 14:54:29 -07:00
Aaron Gao
76a67cf741 support stackableDB as the baseDB of transactionDB
Summary: make transactionDB working with StackableDB

Test Plan: make all check -j64

Reviewers: andrewkr, yiwu, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D60705
2016-08-11 14:19:33 -07:00
Aaron Gao
2914de64e8 add sim_cache stats to Statistics
Summary:
add SIM_BLOCK_CACHE_HIT and SIM_BLOCK_CACHE_MISS tickers.
maybe can be combined with Histograms like DB_GET to evaluate the current setting of the size of block cache.

Test Plan: make all check

Reviewers: sdong, andrewkr, IslamAbdelRahman, yiwu

Reviewed By: yiwu

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61803
2016-08-10 17:42:24 -07:00
sdong
5370f44a83 Increase RocksDB version
Summary: RocksDB 4.11 has been branched out. Now need to move to 4.12.

Test Plan: N/A

Reviewers: kradhakrishnan, andrewkr, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D61845
2016-08-10 13:25:31 -07:00
Zongzhi Chen
98d0b78eac Added check_snapshot option in the DB's AddFile function (#1261)
* Added check_snapshot option in the DB's AddFile function

* change check_snapshot to skip_snapshot_check

* add unit test for skip_snapshot_check

* Add skip_snapshot_check comment
2016-08-09 18:14:13 -07:00
omegaga
44f5cc57a5 Add time series database (resubmitted)
Summary: Implement a time series database that supports DateTieredCompactionStrategy. It wraps a db object and separate SST files in different column families (time windows).

Test Plan: Add `date_tiered_test`.

Reviewers: dhruba, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61653
2016-08-05 15:56:22 -07:00
sdong
7c4615cf1f A utility function to help users migrate DB after options change
Summary: Add a utility function that trigger necessary full compaction and put output to the correct level by looking at new options and old options.

Test Plan: Add unit tests for it.

Reviewers: andrewkr, igor, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: muthu, sumeet, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D60783
2016-08-05 15:39:55 -07:00
Aaron Gao
343304e1d3 Use StopWatch to do statistic job in db_impl_add_file.cc
Summary:
patch for diff https://reviews.facebook.net/D58587
Also change StopWatch class to add a fifth param named overwrite which decides whether to overwrite *elapse or add on it.

Test Plan: make all check -j64

Reviewers: sdong, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: andrewkr, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D61239
2016-08-02 14:53:29 -07:00
Jay Edgar
cdc4eb6892 Add a GetComparator() function to the ColumnFamilyHandle base class so that the user's comparator can be retrieved.
Summary: MyRocks is adding support for the user of the SstFileWriter which needs a comparator.  It would be more convenient to get the comparator from the column family (which already has to have it) than to have caller keep track of it.

Test Plan: Standard tests (adding one for the new method)

Reviewers: IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D61155
2016-08-02 14:34:57 -07:00
sdong
e5b5f12b81 Change options memtable_prefix_bloom_huge_page_tlb_size => memtable_huge_page_size and cover huge page to memtable too
Summary: Extend the option memtable_prefix_bloom_huge_page_tlb_size from just putting memtable bloom filter to huge page to memtable itself too.

Test Plan: Run all existing tests.

Reviewers: IslamAbdelRahman, yhchiang, andrewkr

Reviewed By: andrewkr

Subscribers: leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D60513
2016-07-26 18:15:11 -07:00
Islam AbdelRahman
f8061a237e Fix Statistics TickersNameMap miss match with Tickers enum
Summary:
TickersNameMap is not consistent with Tickers enum.
this cause us to report wrong statistics and sometimes to access TickersNameMap outside it's boundary causing crashes (in Fb303 statistics)

Test Plan: added new unit test

Reviewers: sdong, kradhakrishnan

Reviewed By: kradhakrishnan

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D61083
2016-07-25 16:05:50 -07:00
krad
b9a97181aa Bump next release version
Summary: Bump master version to the next potential release version of 4.11

Test Plan: Compile

Reviewers: sdong

Subscribers: andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D60993
2016-07-21 12:22:14 -07:00
ryneli
663afef884 Add EnvLibrados - RocksDB Env of RADOS (#1222)
EnvLibrados is a customized RocksDB Env to use RADOS as the backend file system of RocksDB. It overrides all file system related API of default Env. The easiest way to use it is just like following:

	std::string db_name = "test_db";
	std::string config_path = "path/to/ceph/config";
	DB* db;
	Options options;
	options.env = EnvLibrados(db_name, config_path);
	Status s = DB::Open(options, kDBPath, &db);

Then EnvLibrados will forward all file read/write operation to the RADOS cluster assigned by config_path. Default pool is db_name+"_pool".

There are some options that users could set for EnvLibrados.
- write_buffer_size. This variable is the max buffer size for WritableFile. After reaching the buffer_max_size, EnvLibrados will sync buffer content to RADOS, then clear buffer.
- db_pool. Rather than using default pool, users could set their own db pool name
- wal_dir. The dir for WAL files. Because RocksDB only has 2-level structure (dir_name/file_name), the format of wal_dir is "/dir_name"(CAN'T be "/dir1/dir2"). Default wal_dir is "/wal".
- wal_pool. Corresponding pool name for WAL files. Default value is db_name+"_wal_pool"

The example of setting options looks like following:

	db_name = "test_db";
	db_pool = db_name+"_pool";
	wal_dir = "/wal";
	wal_pool = db_name+"_wal_pool";
	write_buffer_size = 1 << 20;
	env_ = new EnvLibrados(db_name, config, db_pool, wal_dir, wal_pool, write_buffer_size);

	DB* db;
	Options options;
	options.env = env_;
	// The last level dir name should match the dir name in prefix_pool_map
	options.wal_dir = "/tmp/wal";

	// open DB
	Status s = DB::Open(options, kDBPath, &db);

Librados is required to compile EnvLibrados. Then use "$make LIBRADOS=1" to compile RocksDB. If you want to only compile EnvLibrados test, just run "$ make env_librados_test LIBRADOS=1". To run env_librados_test, you need to have a running RADOS cluster with the configure file located in "../ceph/src/ceph.conf" related to "rocksdb/".
2016-07-21 11:16:34 -07:00