Summary:
Level Compaction with TTL.
As of today, a file could exist in the LSM tree without going through the compaction process for a really long time if there are no updates to the data in the file's key range. For example, in certain use cases, the keys are not actually "deleted"; instead they are just set to empty values. There might not be any more writes to this "deleted" key range, and if so, such data could remain in the LSM for a really long time resulting in wasted space.
Introducing a TTL could solve this problem. Files (and, in turn, data) older than TTL will be scheduled for compaction when there is no other background work. This will make the data go through the regular compaction process and get rid of old unwanted data.
This also has the (good) side-effect of all the data in the non-bottommost level being newer than ttl, and all data in the bottommost level older than ttl. It could lead to more writes while reducing space.
This functionality can be controlled by the newly introduced column family option -- ttl.
TODO for later:
- Make ttl mutable
- Extend TTL to Universal compaction as well? (TTL is already supported in FIFO)
- Maybe deprecate CompactionOptionsFIFO.ttl in favor of this new ttl option.
Closes https://github.com/facebook/rocksdb/pull/3591
Differential Revision: D7275442
Pulled By: sagar0
fbshipit-source-id: dcba484717341200d419b0953dafcdf9eb2f0267
Summary:
This patch record the deleted WAL numbers in the manifest to ignore them and any WAL older than them during recovery. This is to avoid scenarios when we have a gap between the WAL files are fed to the recovery procedure. The gap could happen by for example out-of-order WAL deletion. Such gap could cause problems in 2PC recovery where the prepared and commit entry are placed into two separate WAL and gap in the WALs could result into not processing the WAL with the commit entry and hence breaking the 2PC recovery logic.
Closes https://github.com/facebook/rocksdb/pull/3488
Differential Revision: D6967893
Pulled By: maysamyabandeh
fbshipit-source-id: 13119feb155a08ab6d4909f437c7a750480dc8a1
Summary:
Before:
> $ TEST_TMPDIR=/dev/shm ./db_bench -use_direct_reads=true -benchmarks=readrandomwriterandom -num=10000000 -reads=100000 -write_buffer_size=1048576 -target_file_size_base=1048576 -max_bytes_for_level_base=4194304 -max_background_jobs=12 -readwritepercent=50 -key_size=16 -value_size=48 -threads=32
DB path: [/dev/shm/dbbench]
put error: IO error: While open a file for random read: /dev/shm/dbbench/000007.sst: Invalid argument
put error: IO error: While open a file for random read: /dev/shm/dbbench/000007.sst: Invalid argument
put error: IO error: While open a file for random read: /dev/shm/dbbench/000007.sst: Invalid argument
put error: IO error: While open a file for random read: /dev/shm/dbbench/000007.sst: Invalid argument
put error: IO error: While open a file for random read: /dev/shm/dbbench/000007.sst: Invalid argument
put error: IO error: While open a file for random read: /dev/shm/dbbench/000007.sst: Invalid argument
put error: IO error: While open a file for random read: /dev/shm/dbbench/000007.sst: Invalid argument
put error: IO error: While open a file for random read: /dev/shm/dbbench/000007.sst: Invalid argument
put error: IO error: While open a file for random read: /dev/shm/dbbench/000007.sst: Invalid argument
db_bench: tpp.c:84: __pthread_tpp_change_priority: Assertion `new_prio == -1 || (new_prio >= fifo_min_prio && new_prio <= fifo_max_prio)' failed.
put error: IO error: While open a file for random read: /dev/shm/dbbench/000007.sst: Invalid argument
put error: IO error: While open a file for random read: /dev/shm/dbbench/000007.sst: Invalid argument
After:
> TEST_TMPDIR=/dev/shm ./db_bench -use_direct_reads=true -benchmarks=readrandomwriterandom -num=10000000 -reads=100000 -write_buffer_size=1048576 -target_file_size_base=1048576 -max_bytes_for_level_base=4194304 -max_background_jobs=12 -readwritepercent=50 -key_size=16 -value_size=48 -threads=32
Initializing RocksDB Options from the specified file
Initializing RocksDB Options from command-line flags
open error: Not implemented: Direct I/O is not supported by the specified DB.
Closes https://github.com/facebook/rocksdb/pull/3539
Differential Revision: D7082658
Pulled By: miasantreble
fbshipit-source-id: f9d9c6ec3b5e9e049cab52154940ee101ba4d342
Summary:
Add PreReleaseCallback to be called at the end of WriteImpl but before publishing the sequence number. The callback is used in WritePrepareTxn to i) update the commit map, ii) update the last published sequence number in the 2nd write queue. It also ensures that all the commits will go to the 2nd queue.
These changes will ensure that the commit map is updated before the sequence number is published and used by reading snapshots. If we use two write queues, the snapshots will use the seq number published by the 2nd queue. If we use one write queue (the default, the snapshots will use the last seq number in the memtable, which also indicates the last published seq number.
Closes https://github.com/facebook/rocksdb/pull/3205
Differential Revision: D6438959
Pulled By: maysamyabandeh
fbshipit-source-id: f8b6c434e94bc5f5ab9cb696879d4c23e2577ab9
Summary:
Add tests to ensure that WritePrepared and WriteCommitted policies are cross compatible when the db WAL is empty. This is important when the admin want to switch between the policies. In such case, before the switch the admin needs to empty the WAL by i) committing/rollbacking all the pending transactions, ii) FlushMemTables
Closes https://github.com/facebook/rocksdb/pull/3118
Differential Revision: D6227247
Pulled By: maysamyabandeh
fbshipit-source-id: bcde3d92c1e89cda3b9cfa69f6a20af5d8993db7
Summary:
Add a simple policy for NVMe write time life hint
Closes https://github.com/facebook/rocksdb/pull/3095
Differential Revision: D6298030
Pulled By: shligit
fbshipit-source-id: 9a72a42e32e92193af11599eb71f0cf77448e24d
Summary:
SstFileManager move files that need to be deleted into a trash directory.
Deprecate this behaviour and instead add ".trash" extension to files that need to be deleted
Closes https://github.com/facebook/rocksdb/pull/2970
Differential Revision: D5976805
Pulled By: IslamAbdelRahman
fbshipit-source-id: 27374ece4315610b2792c30ffcd50232d4c9a343
Summary:
Enable concurrent_prepare flag for WritePrepared transactions and extend the existing transaction tests with this config.
Closes https://github.com/facebook/rocksdb/pull/3046
Differential Revision: D6106534
Pulled By: maysamyabandeh
fbshipit-source-id: 88c8d21d45bc492beb0a131caea84a2ac5e7d38c
Summary:
The file numbers assigned post-repair were sometimes smaller than older files' numbers due to `LogAndApply` saving the wrong next file number in the manifest.
- Mark the highest file seen during repair as used before `LogAndApply` so the correct next file number will be stored.
- Renamed `MarkFileNumberUsedDuringRecovery` to `MarkFileNumberUsed` since now it's used during repair in addition to during recovery
- Added `TEST_Current_Next_FileNo` to expose the next file number for the unit test.
Closes https://github.com/facebook/rocksdb/pull/2988
Differential Revision: D6018083
Pulled By: ajkr
fbshipit-source-id: 3f25cbf74439cb8f16dd12af90b67f9f9f75e718
Summary:
Update Compaction/Flush to support WritePreparedTxnDB: Add SnapshotChecker which is a proxy to query WritePreparedTxnDB::IsInSnapshot. Pass SnapshotChecker to DBImpl on WritePreparedTxnDB open. CompactionIterator use it to check if a key has been committed and if it is visible to a snapshot. In CompactionIterator:
* check if key has been committed. If not, output uncommitted keys AS-IS.
* use SnapshotChecker to check if key is visible to a snapshot when in need.
* do not output key with seq = 0 if the key is not committed.
Closes https://github.com/facebook/rocksdb/pull/2926
Differential Revision: D5902907
Pulled By: yiwu-arbug
fbshipit-source-id: 945e037fdf0aa652dc5ba0ad879461040baa0320
Summary:
Add a new function in Listener to let the caller know when rocksdb
is stalling writes.
Closes https://github.com/facebook/rocksdb/pull/2897
Differential Revision: D5860124
Pulled By: schischi
fbshipit-source-id: ee791606169aa64f772c86f817cebf02624e05e1
Summary:
SUMMARY
Moves the bytes_per_sync and wal_bytes_per_sync options from immutableoptions to mutable options. Also if wal_bytes_per_sync is changed, the wal file and memtables are flushed.
TEST PLAN
ran make check
all passed
Two new tests SetBytesPerSync, SetWalBytesPerSync check that after issuing setoptions with a new value for the var, the db options have the new value.
Closes https://github.com/facebook/rocksdb/pull/2893
Reviewed By: yiwu-arbug
Differential Revision: D5845814
Pulled By: TheRushingWookie
fbshipit-source-id: 93b52d779ce623691b546679dcd984a06d2ad1bd
Summary:
Context/problem:
- CFs may be flushed at different times
- A WAL can only be deleted after all CFs have flushed beyond end of that WAL.
- Point-in-time recovery might stop upon reaching the first corruption.
- Some CFs may have already flushed beyond that point, while others haven't. We should fail the Open() instead of proceeding with inconsistent CFs.
Closes https://github.com/facebook/rocksdb/pull/2900
Differential Revision: D5863281
Pulled By: miasantreble
fbshipit-source-id: 180dbaf83d96c804cff49b3c406312a4ae61313e
Summary:
By default the seq number in DB is increased once per written key. WritePrepared txns requires the seq to be increased once per the entire batch so that the seq would be used as the prepare timestamp by which the transaction is identified. Also we need to increase seq for the commit marker since it would give a unique id to the commit timestamp of transactions.
Two unit tests are added to verify our understanding of how the seq should be increased. The recovery path requires much more work and is left to another patch.
Closes https://github.com/facebook/rocksdb/pull/2885
Differential Revision: D5837843
Pulled By: maysamyabandeh
fbshipit-source-id: a08960b93d727e1cf438c254d0c2636fb133cc1c
Summary:
Valgrind had false positive complaints about the initialization pattern for `GetCurrentTime()`'s argument in #2480. We can instead have the client initialize the time variable before calling `GetCurrentTime()`, and have `GetCurrentTime()` promise to only overwrite it in success case.
Closes https://github.com/facebook/rocksdb/pull/2526
Differential Revision: D5358689
Pulled By: ajkr
fbshipit-source-id: 857b189f24c19196f6bb299216f3e23e7bc4be42
Summary:
Adding/Correcting inline comments and clarify the sync rules. To make it simple to reason, the rules are a big general which ended up to some extra synchronizations. However such synchronizations are not on the fast path, and they are worth the simplicity.
Closes https://github.com/facebook/rocksdb/pull/2517
Differential Revision: D5348239
Pulled By: maysamyabandeh
fbshipit-source-id: ff2e59fb1e568c122d2cdbf598310f3613b7d212
Summary:
Introducing FIFO compactions with TTL.
FIFO compaction is based on size only which makes it tricky to enable in production as use cases can have organic growth. A user requested an option to drop files based on the time of their creation instead of the total size.
To address that request:
- Added a new TTL option to FIFO compaction options.
- Updated FIFO compaction score to take TTL into consideration.
- Added a new table property, creation_time, to keep track of when the SST file is created.
- Creation_time is set as below:
- On Flush: Set to the time of flush.
- On Compaction: Set to the max creation_time of all the files involved in the compaction.
- On Repair and Recovery: Set to the time of repair/recovery.
- Old files created prior to this code change will have a creation_time of 0.
- FIFO compaction with TTL is enabled when ttl > 0. All files older than ttl will be deleted during compaction. i.e. `if (file.creation_time < (current_time - ttl)) then delete(file)`. This will enable cases where you might want to delete all files older than, say, 1 day.
- FIFO compaction will fall back to the prior way of deleting files based on size if:
- the creation_time of all files involved in compaction is 0.
- the total size (of all SST files combined) does not drop below `compaction_options_fifo.max_table_files_size` even if the files older than ttl are deleted.
This feature is not supported if max_open_files != -1 or with table formats other than Block-based.
**Test Plan:**
Added tests.
**Benchmark results:**
Base: FIFO with max size: 100MB ::
```
svemuri@dev15905 ~/rocksdb (fifo-compaction) $ TEST_TMPDIR=/dev/shm ./db_bench --benchmarks=readwhilewriting --num=5000000 --threads=16 --compaction_style=2 --fifo_compaction_max_table_files_size_mb=100
readwhilewriting : 1.924 micros/op 519858 ops/sec; 13.6 MB/s (1176277 of 5000000 found)
```
With TTL (a low one for testing) ::
```
svemuri@dev15905 ~/rocksdb (fifo-compaction) $ TEST_TMPDIR=/dev/shm ./db_bench --benchmarks=readwhilewriting --num=5000000 --threads=16 --compaction_style=2 --fifo_compaction_max_table_files_size_mb=100 --fifo_compaction_ttl=20
readwhilewriting : 1.902 micros/op 525817 ops/sec; 13.7 MB/s (1185057 of 5000000 found)
```
Example Log lines:
```
2017/06/26-15:17:24.609249 7fd5a45ff700 (Original Log Time 2017/06/26-15:17:24.609177) [db/compaction_picker.cc:1471] [default] FIFO compaction: picking file 40 with creation time 1498515423 for deletion
2017/06/26-15:17:24.609255 7fd5a45ff700 (Original Log Time 2017/06/26-15:17:24.609234) [db/db_impl_compaction_flush.cc:1541] [default] Deleted 1 files
...
2017/06/26-15:17:25.553185 7fd5a61a5800 [DEBUG] [db/db_impl_files.cc:309] [JOB 0] Delete /dev/shm/dbbench/000040.sst type=2 #40 -- OK
2017/06/26-15:17:25.553205 7fd5a61a5800 EVENT_LOG_v1 {"time_micros": 1498515445553199, "job": 0, "event": "table_file_deletion", "file_number": 40}
```
SST Files remaining in the dbbench dir, after db_bench execution completed:
```
svemuri@dev15905 ~/rocksdb (fifo-compaction) $ ls -l /dev/shm//dbbench/*.sst
-rw-r--r--. 1 svemuri users 30749887 Jun 26 15:17 /dev/shm//dbbench/000042.sst
-rw-r--r--. 1 svemuri users 30768779 Jun 26 15:17 /dev/shm//dbbench/000044.sst
-rw-r--r--. 1 svemuri users 30757481 Jun 26 15:17 /dev/shm//dbbench/000046.sst
```
Closes https://github.com/facebook/rocksdb/pull/2480
Differential Revision: D5305116
Pulled By: sagar0
fbshipit-source-id: 3e5cfcf5dd07ed2211b5b37492eb235b45139174
Summary:
Throughput: 46k tps in our sysbench settings (filling the details later)
The idea is to have the simplest change that gives us a reasonable boost
in 2PC throughput.
Major design changes:
1. The WAL file internal buffer is not flushed after each write. Instead
it is flushed before critical operations (WAL copy via fs) or when
FlushWAL is called by MySQL. Flushing the WAL buffer is also protected
via mutex_.
2. Use two sequence numbers: last seq, and last seq for write. Last seq
is the last visible sequence number for reads. Last seq for write is the
next sequence number that should be used to write to WAL/memtable. This
allows to have a memtable write be in parallel to WAL writes.
3. BatchGroup is not used for writes. This means that we can have
parallel writers which changes a major assumption in the code base. To
accommodate for that i) allow only 1 WriteImpl that intends to write to
memtable via mem_mutex_--which is fine since in 2PC almost all of the memtable writes
come via group commit phase which is serial anyway, ii) make all the
parts in the code base that assumed to be the only writer (via
EnterUnbatched) to also acquire mem_mutex_, iii) stat updates are
protected via a stat_mutex_.
Note: the first commit has the approach figured out but is not clean.
Submitting the PR anyway to get the early feedback on the approach. If
we are ok with the approach I will go ahead with this updates:
0) Rebase with Yi's pipelining changes
1) Currently batching is disabled by default to make sure that it will be
consistent with all unit tests. Will make this optional via a config.
2) A couple of unit tests are disabled. They need to be updated with the
serial commit of 2PC taken into account.
3) Replacing BatchGroup with mem_mutex_ got a bit ugly as it requires
releasing mutex_ beforehand (the same way EnterUnbatched does). This
needs to be cleaned up.
Closes https://github.com/facebook/rocksdb/pull/2345
Differential Revision: D5210732
Pulled By: maysamyabandeh
fbshipit-source-id: 78653bd95a35cd1e831e555e0e57bdfd695355a4
Summary:
- `max_background_flushes` and `max_background_compactions` are still supported for backwards compatibility
- `base_background_compactions` is completely deprecated. Now we just throttle to one background compaction when there's no pressure.
- `max_background_jobs` is added to automatically partition the concurrent background jobs into flushes vs compactions. Currently it's very simple as we just allocate one-fourth of the jobs to flushes, and the remaining can be used for compactions.
- The test cases that set `base_background_compactions > 1` needed to be updated. I just grab the pressure token such that the desired number of compactions can be scheduled.
Closes https://github.com/facebook/rocksdb/pull/2205
Differential Revision: D4937461
Pulled By: ajkr
fbshipit-source-id: df52cbbd497e13bbc9a60560a5ac2a2526b3f1f9
Summary:
It's hard for RocksDB to come up with a good default of delayed write rate. Use rate given by rate limiter if it is availalbe. This provides the I/O order of magnitude.
Closes https://github.com/facebook/rocksdb/pull/2357
Differential Revision: D5115324
Pulled By: siying
fbshipit-source-id: 341065ad2211c981fc804011c0f0e59a50c7e754
Summary:
Disable direct reads for log and manifest. Direct reads should not affect sequential_file
Also add kDirectIO for option_config_ in db_test_util
Closes https://github.com/facebook/rocksdb/pull/2337
Differential Revision: D5100261
Pulled By: lightmark
fbshipit-source-id: 0ebfd13b93fa1b8f9acae514ac44f8125a05868b
Summary:
Adding DB::CreateColumnFamilie() and DB::DropColumnFamilies() to bulk create/drop column families. This is to address the problem creating/dropping 1k column families takes minutes. The bottleneck is we persist options files for every single column family create/drop, and it parses the persisted options file for verification, which take a lot CPU time.
The new APIs simply create/drop column families individually, and persist options file once at the end. This improves create 1k column families to within ~0.1s. Further improvement can be merge manifest write to one IO.
Closes https://github.com/facebook/rocksdb/pull/2248
Differential Revision: D5001578
Pulled By: yiwu-arbug
fbshipit-source-id: d4e00bda671451e0b314c13e12ad194b1704aa03
Summary:
Makes max_open_files db option dynamically set-able by SetDBOptions. During the call of SetDBOptions we call SetCapacity on the table cache, which is a LRUCache.
Closes https://github.com/facebook/rocksdb/pull/2185
Differential Revision: D4979189
Pulled By: yiwu-arbug
fbshipit-source-id: ca7e8dc5e3619c79434f579be4847c0f7e56afda
Summary:
Replace Options::use_direct_writes with Options::use_direct_io_for_flush_and_compaction
Now if Options::use_direct_io_for_flush_and_compaction = true, we will enable direct io for both reads and writes for flush and compaction job. Whereas Options::use_direct_reads controls user reads like iterator and Get().
Closes https://github.com/facebook/rocksdb/pull/2117
Differential Revision: D4860912
Pulled By: lightmark
fbshipit-source-id: d93575a8a5e780cf7e40797287edc425ee648c19
Summary:
1. Move universal compaction picker to separate files compaction_picker_universal.cc and compaction_picker_universal.h.
2. Rename some functions to make the code easier to understand.
3. Move leveled compaction picking code to a dedicated class, so that we we don't need to pass some common variable around when calling functions. It also allowed us to break down LevelCompactionPicker::PickCompaction() to smaller functions.
Closes https://github.com/facebook/rocksdb/pull/2100
Differential Revision: D4845948
Pulled By: siying
fbshipit-source-id: efa0ab4
Summary:
Move some files under util/ to new directories env/, monitoring/ options/ and cache/
Closes https://github.com/facebook/rocksdb/pull/2090
Differential Revision: D4833681
Pulled By: siying
fbshipit-source-id: 2fd8bef
Summary:
db_impl.cc is too large to manage. Divide db_impl.cc into db/db_impl.cc, db/db_impl_compaction_flush.cc, db/db_impl_files.cc, db/db_impl_open.cc and db/db_impl_write.cc.
Closes https://github.com/facebook/rocksdb/pull/2095
Differential Revision: D4838188
Pulled By: siying
fbshipit-source-id: c5f3059
