Summary: Store links to live files in directory on same disk

Test Plan:
Take snapshot and open it. Added a test GetSnapshotLink in
db_test.

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D28713

Summary: It adds lots of code.

Test Plan: compile for iOS, compile for mac. works.

Reviewers: rven, sdong, ljin, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D28857

Summary: So iOS size_t is 32-bit, so we need to static_cast<size_t> any uint64_t :(

Test Plan: TARGET_OS=IOS make static_lib

Reviewers: dhruba, ljin, yhchiang, rven, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D28743

Summary:
This diff adds three sets of APIs to RocksDB.

= GetColumnFamilyMetaData =
* This APIs allow users to obtain the current state of a RocksDB instance on one column family.
* See GetColumnFamilyMetaData in include/rocksdb/db.h

= EventListener =
* A virtual class that allows users to implement a set of
  call-back functions which will be called when specific
  events of a RocksDB instance happens.
* To register EventListener, simply insert an EventListener to ColumnFamilyOptions::listeners

= CompactFiles =
* CompactFiles API inputs a set of file numbers and an output level, and RocksDB
  will try to compact those files into the specified level.

= Example =
* Example code can be found in example/compact_files_example.cc, which implements
  a simple external compactor using EventListener, GetColumnFamilyMetaData, and
  CompactFiles API.

Test Plan:
listener_test
compactor_test
example/compact_files_example
export ROCKSDB_TESTS=CompactFiles
db_test
export ROCKSDB_TESTS=MetaData
db_test

Reviewers: ljin, igor, rven, sdong

Reviewed By: sdong

Subscribers: MarkCallaghan, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D24705

Summary:
Here's a prototype of redesigning pending_outputs_. This way, we don't have to expose pending_outputs_ to other classes (CompactionJob, FlushJob, MemtableList). DBImpl takes care of it.

Still have to write some comments, but should be good enough to start the discussion.

Test Plan: make check, will also run stress test

Reviewers: ljin, sdong, rven, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D28353

Summary: as title

Test Plan: ./db_test

Reviewers: sdong, yhchiang, rven, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D28269

Summary:
Long awaited CompactionJob class! Move most compaction-related things from DBImpl to CompactionJob, making CompactionJob easier to test and understand.

Currently this is just replicating exactly the same functionality with as little as change as possible. As future work, we should:
1. Add CompactionJob tests (I think I'll do that tomorrow)
2. Reduce CompactionJob's state that it inherits from DBImpl
3. Figure out how to do yielding to flush better. Currently I implemented a callback as we agreed yesterday, but I don't think it's a good long term solution.

This reduces db_impl.cc from 5000+ LOC to 3400!

Test Plan: make check, will add CompactionJob-specific tests, probably also move some tests from db_test to compaction_job_test

Reviewers: rven, yhchiang, sdong, ljin

Reviewed By: ljin

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27957

Summary: Decoupling code that deals with archived log files outside of DBImpl. That will make this code easier to reason about and test. It will also make the code easier to improve, because an improver doesn't have to understand DBImpl code in entirety.

Test Plan: added test

Reviewers: ljin, yhchiang, rven, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27873

Summary:
Abstract out FlushProcess and take it out of DBImpl.
This also includes taking DeletionState outside of DBImpl.

Currently this diff is only doing the refactoring. Future work includes:
1. Decoupling flush_process.cc, make it depend on less state
2. Write flush_process_test, which will mock out everything that FlushProcess depends on and test it in isolation

Test Plan: make check

Reviewers: rven, yhchiang, sdong, ljin

Reviewed By: ljin

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D27561

Summary: RocksDB already depends on C++11, so we might as well all the goodness that C++11 provides. This means that we don't need AtomicPointer anymore. The less things in port/, the easier it will be to port to other platforms.

Test Plan: make check + careful visual review verifying that NoBarried got memory_order_relaxed, while Acquire/Release methods got memory_order_acquire and memory_order_release

Reviewers: rven, yhchiang, ljin, sdong

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D27543

Summary: as title

Test Plan: unit test

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D24729

Summary: This might have caused https://github.com/facebook/rocksdb/issues/345. If we're stopping writes and bg_error comes along, we will never unblock the write.

Test Plan: compiles

Reviewers: ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D24807

Summary:
Add two stats to compaction summary:
1. Total input records from previous level
2. Total number of records dropped after compaction

Test Plan: See outputs of printing when runnning locally

Reviewers: ljin, igor, MarkCallaghan

Reviewed By: MarkCallaghan

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D24411

Summary:
make compaction related options changeable. Most of changes are tedious,
following the same convention: grabs MutableCFOptions at the beginning
of compaction under mutex, then pass it throughout the job and register
it in SuperVersion at the end.

Test Plan: make all check

Reviewers: igor, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23349

Summary:
Add a CompactedDBImpl that will enabled when calling OpenForReadOnly()
and the DB only has one level (>0) of files. As a performan comparison,
CuckooTable performs 2.1M/s with CompactedDBImpl vs. 1.78M/s with
ReadOnlyDBImpl.

Test Plan: db_bench

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23553

Summary: as title

Test Plan:
make all check
I will think a way to set up stress test for this

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23055

Summary: This diff just moves the write thread control out of the DBImpl. I will need this as I will control column family data concurrency by only accessing some data in the write thread. That way, we won't have to lock our accesses to column family hash table (mappings from IDs to CFDs).

Test Plan: make check

Reviewers: sdong, yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23301

Summary:
When memtable is full it calls the registered callback. That callback then registers column family as needing the flush. Every write checks if there are some column families that need to be flushed. This completely eliminates the need for MakeRoomForWrite() function and simplifies our Write code-path.

There is some complexity with the concurrency when the column family is dropped. I made it a bit less complex by dropping the column family from the write thread in https://reviews.facebook.net/D22965. Let me know if you want to discuss this.

Test Plan: make check works. I'll also run db_stress with creating and dropping column families for a while.

Reviewers: yhchiang, sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23067

Summary: Avoid creating unnecessary sst files while db opening

Test Plan: make all check

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: zagfox, yhchiang, ljin, leveldb

Differential Revision: https://reviews.facebook.net/D20661

Summary: as title

Test Plan: make release

Reviewers: igor

Differential Revision: https://reviews.facebook.net/D23073

Summary:
Introducing WriteController, which is a source of truth about per-DB write delays. Let's define an DB epoch as a period where there are no flushes and compactions (i.e. new epoch is started when flush or compaction finishes). Each epoch can either:
* proceed with all writes without delay
* delay all writes by fixed time
* stop all writes

The three modes are recomputed at each epoch change (flush, compaction), rather than on every write (which is currently the case).

When we have a lot of column families, our current pull behavior adds a big overhead, since we need to loop over every column family for every write. With new push model, overhead on Write code-path is minimal.

This is just the start. Next step is to also take care of stalls introduced by slow memtable flushes. The final goal is to eliminate function MakeRoomForWrite(), which currently needs to be called for every column family by every write.

Test Plan: make check for now. I'll add some unit tests later. Also, perf test.

Reviewers: dhruba, yhchiang, MarkCallaghan, sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22791

Summary: If we drop column family only from (single) write thread, we can be sure that nobody will drop the column family while we're writing (and our mutex is released). This greatly simplifies my patch that's getting rid of MakeRoomForWrite().

Test Plan: make check, but also running stress test

Reviewers: ljin, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22965

Summary: as title

Test Plan: make release

Reviewers: sdong, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22935

Summary:
Simply code by removing code path which does not use Arena
from NewInternalIterator

Test Plan:
make all check
make valgrind_check

Reviewers: sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22395

Summary:
As a preparation to support updating some options dynamically, I'd like
to first introduce ImmutableOptions, which is a subset of Options that
cannot be changed during the course of a DB lifetime without restart.

ColumnFamily will keep both Options and ImmutableOptions. Any component
below ColumnFamily should only take ImmutableOptions in their
constructor. Other options should be taken from APIs, which will be
allowed to adjust dynamically.

I am yet to make changes to memtable and other related classes to take
ImmutableOptions in their ctor. That can be done in a seprate diff as
this one is already pretty big.

Test Plan: make all check

Reviewers: yhchiang, igor, sdong

Reviewed By: sdong

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D22545

Summary:
Add property 'rocksdb.is-file-deletions-enable'
	 which equals disable_delete_obsole_file_

Test Plan: make all check

Reviewers: sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D22119

Summary:
I will move compression related options in a separate diff since this
diff is already pretty lengthy.
I guess I will also need to change JNI accordingly :(

Test Plan: make all check

Reviewers: yhchiang, igor, sdong

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21915

Summary: 1. write db MANIFEST, CURRENT, IDENTITY, sst files, log files to log before open

Test Plan: run db and check LOG file

Reviewers: ljin, yhchiang, igor, dhruba, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21459

Summary:
Currently DBImpl::Flush() triggers flushes in all column families.
Instead we need to trigger just the column family specified.

Test Plan: make all check

Reviewers: igor, ljin, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D20841

* Script for building the unity.cc file via Makefile
* Unity executable Makefile target for testing builds
* Source code changes to fix compilation of unity build

Summary:
Add a DB Property "rocksdb.estimate-table-readers-mem" to return estimated memory usage by all loaded table readers, other than allocated from block cache.

Refactor the property codes to allow getting property from a version, with DB mutex not acquired.

Test Plan: Add several checks of this new property in existing codes for various cases.

Reviewers: yhchiang, ljin

Reviewed By: ljin

Subscribers: xjin, igor, leveldb

Differential Revision: https://reviews.facebook.net/D20733

Summary: We have quite some properties that are integers and we are adding more. Add a function to directly return them as an integer, instead of a string

Test Plan: Add several unit test checks

Reviewers: yhchiang, igor, dhruba, haobo, ljin

Reviewed By: ljin

Subscribers: yoshinorim, leveldb

Differential Revision: https://reviews.facebook.net/D20637

Summary:
Make StatisticsImpl being able to forward stats to provided statistics
implementation. The main purpose is to allow us to collect internal
stats in the future even when user supplies custom statistics
implementation. It avoids intrumenting 2 sets of stats collection code.
One immediate use case is tuning advisor, which needs to collect some
internal stats, users may not be interested.

Test Plan:
ran db_bench and see stats show up at the end of run
Will run make all check since some tests rely on statistics

Reviewers: yhchiang, sdong, igor

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D20145

Summary: Add a parameter path_id to DB::CompactRange(), to indicate where the output file should be placed to.

Test Plan: add a unit test

Reviewers: yhchiang, ljin

Reviewed By: ljin

Subscribers: xjin, igor, dhruba, MarkCallaghan, leveldb

Differential Revision: https://reviews.facebook.net/D20085

Summary:
also make it aware of column family
output from db_bench

```
** Compaction Stats [default] **
Level Files Size(MB) Score Read(GB)  Rn(GB) Rnp1(GB) Write(GB) Wnew(GB) RW-Amp W-Amp Rd(MB/s) Wr(MB/s)  Rn(cnt) Rnp1(cnt) Wnp1(cnt) Wnew(cnt)  Comp(sec) Comp(cnt) Avg(sec) Stall(sec) Stall(cnt) Avg(ms)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  L0    14      956   0.9      0.0     0.0      0.0       2.7      2.7    0.0   0.0      0.0    111.6        0         0         0         0         24        40    0.612      75.20     492387    0.15
  L1    21     2001   2.0      5.7     2.0      3.7       5.3      1.6    5.4   2.6     71.2     65.7       31        43        55        12         82         2   41.242      43.72      41183    1.06
  L2   217    18974   1.9     16.5     2.0     14.4      15.1      0.7   15.6   7.4     70.1     64.3       17       182       185         3        241        16   15.052       0.00          0    0.00
  L3  1641   188245   1.8      9.1     1.1      8.0       8.5      0.5   15.4   7.4     61.3     57.2        9        75        76         1        152         9   16.887       0.00          0    0.00
  L4  4447   449025   0.4     13.4     4.8      8.6       9.1      0.5    4.7   1.9     77.8     52.7       38        79       100        21        176        38    4.639       0.00          0    0.00
 Sum  6340   659201   0.0     44.7    10.0     34.7      40.6      6.0   32.0  15.2     67.7     61.6       95       379       416        37        676       105    6.439     118.91     533570    0.22
 Int     0        0   0.0      1.2     0.4      0.8       1.3      0.5    5.2   2.7     59.1     65.6        3         7         9         2         20        10    2.003       0.00          0    0.00
Stalls(secs): 75.197 level0_slowdown, 0.000 level0_numfiles, 0.000 memtable_compaction, 43.717 leveln_slowdown
Stalls(count): 492387 level0_slowdown, 0 level0_numfiles, 0 memtable_compaction, 41183 leveln_slowdown

** DB Stats **
Uptime(secs): 202.1 total, 13.5 interval
Cumulative writes: 6291456 writes, 6291456 batches, 1.0 writes per batch, 4.90 ingest GB
Cumulative WAL: 6291456 writes, 6291456 syncs, 1.00 writes per sync, 4.90 GB written
Interval writes: 1048576 writes, 1048576 batches, 1.0 writes per batch, 836.0 ingest MB
Interval WAL: 1048576 writes, 1048576 syncs, 1.00 writes per sync, 0.82 MB written

Test Plan: ran it

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19917

Summary: Browsing through the code, looks like StatsLogger is not used at all!

Test Plan: compiles

Reviewers: ljin, sdong, yhchiang, dhruba

Reviewed By: dhruba

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D19827

Summary:
This diff allows the I/O stats about Flush and Compaction to be reported
in a more accurate way.  Instead of measuring the size of a file, it
measure I/O cost in per read / write basis.

Test Plan: make all check

Reviewers: sdong, igor, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19383

Summary:
This diff adds timeout_hint_us to WriteOptions.  If it's non-zero, then
1) writes associated with this options MAY be aborted when it has been
  waiting for longer than the specified time.  If an abortion happens,
  associated writes will return Status::TimeOut.
2) the stall time of the associated write caused by flush or compaction
  will be limited by timeout_hint_us.

The default value of timeout_hint_us is 0 (i.e., OFF.)

The statistics of timeout writes will be recorded in WRITE_TIMEDOUT.

Test Plan:
export ROCKSDB_TESTS=WriteTimeoutAndDelayTest
make db_test
./db_test

Reviewers: igor, ljin, haobo, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D18837

Summary:
In this patch, we allow RocksDB to support multiple DB paths internally.
No user interface is supported yet so this patch is silent to users.

Test Plan: make all check

Reviewers: igor, haobo, ljin, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D18921

Summary:
Before this diff, we're deciding enable_compression in CompactionPicker and then we're deciding final compression type in DBImpl. This is kind of confusing.

After the diff, the final compression type will be decided in CompactionPicker.

The reason for this is that I want CompactFiles() to specify output compression type, so that people can mix and match compression styles in their compaction algorithms. This diff makes it much easier to do that.

Test Plan: make check

Reviewers: dhruba, haobo, sdong, yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19137