Summary:
In `cf_options_type_info`, the deprecated options are all considered to have offset zero in the `MutableCFOptions` struct. Previously we weren't checking in `GetMutableOptionsFromStrings` whether the provided option was deprecated or not and simply writing the provided value to the offset specified by `cf_options_type_info`. That meant setting any deprecated option would overwrite the first element in the struct, which is `write_buffer_size`. `db_stress` hit this often since it calls `SetOptions` with `soft_rate_limit=0` and `hard_rate_limit=0`, which are both deprecated so cause `write_buffer_size` to be set to zero, which causes it to crash on the following assertion:
```
db_stress: db/memtable.cc:106: rocksdb::MemTable::MemTable(const rocksdb::InternalKeyComparator&, const rocksdb::ImmutableCFOptions&, const rocksdb::MutableCFOptions&, rocksdb::WriteBufferManager*, rocksdb::SequenceNumber, uint32_t): Assertion `!ShouldScheduleFlush()' failed.
```
We fix it by skipping deprecated options (and logging a warning) when users provide them to `SetOptions`. I didn't want to fail the call for compatibility reasons.
Closes https://github.com/facebook/rocksdb/pull/3700
Differential Revision: D7572596
Pulled By: ajkr
fbshipit-source-id: bd5d84e14c0c39f30c5d4c6df7c1503d2c28ecf1
Summary:
1. Remove redundant text.
2. Make terminology consistent across all comments and doc of RocksDB. Also do
our best to conform to conventions. Specifically, use 'callback' instead of
'call-back' [wikipedia](https://en.wikipedia.org/wiki/Callback_(computer_programming)).
Closes https://github.com/facebook/rocksdb/pull/3693
Differential Revision: D7560396
Pulled By: riversand963
fbshipit-source-id: ba8c251c487f4e7d1872a1a8dc680f9e35a6ffb8
Summary:
In this change, an option to set different paths for different column families is added.
This option is set via cf_paths setting of ColumnFamilyOptions. This option will work in a similar fashion to db_paths setting. Cf_paths is a vector of Dbpath values which contains a pair of the absolute path and target size. Multiple levels in a Column family can go to different paths if cf_paths has more than one path.
To maintain backward compatibility, if cf_paths is not specified for a column family, db_paths setting will be used. Note that, if db_paths setting is also not specified, RocksDB already has code to use db_name as the only path.
Changes :
1) A new member "cf_paths" is added to ImmutableCfOptions. This is set, based on cf_paths setting of ColumnFamilyOptions and db_paths setting of ImmutableDbOptions. This member is used to identify the path information whenever files are accessed.
2) Validation checks are added for cf_paths setting based on existing checks for db_paths setting.
3) DestroyDB, PurgeObsoleteFiles etc. are edited to support multiple cf_paths.
4) Unit tests are added appropriately.
Closes https://github.com/facebook/rocksdb/pull/3102
Differential Revision: D6951697
Pulled By: ajkr
fbshipit-source-id: 60d2262862b0a8fd6605b09ccb0da32bb331787d
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:
Provide a block_align option in BlockBasedTableOptions to allow
alignment of SST file data blocks. This will avoid higher
IOPS/throughput load due to < 4KB data blocks spanning 2 4KB pages.
When this option is set to true, the block alignment is set to lower of
block size and 4KB.
Closes https://github.com/facebook/rocksdb/pull/3502
Differential Revision: D7400897
Pulled By: anand1976
fbshipit-source-id: 04cc3bd144e88e3431a4f97604e63ad7a0f06d44
Summary:
enable_pipelined_write was not set in BuildDBOptions() causing its default
value to be dumped in the OPTIONS file
Closes https://github.com/facebook/rocksdb/pull/3585
Differential Revision: D7226395
Pulled By: yiwu-arbug
fbshipit-source-id: 45a659a48d18103ac9ee74bb8805dd0a6ec12474
Summary:
RocksDB should always be able to parse an option file generated using the same or lower version. Unknown option should only happen if it is from a higher version. Change the behavior of RocksDBOptionsParser::Parse()'s behavior with ignore_unknown_options=true so that unknown option from a lower or the same version will never be skipped.
Closes https://github.com/facebook/rocksdb/pull/3527
Differential Revision: D7048851
Pulled By: siying
fbshipit-source-id: e261caea12f6515611a4a29f39acf2b619df2361
Summary:
options/cf_options.cc:
77 memtable_insert_with_hint_prefix_extractor(
CID 1396208 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
2. uninit_member: Non-static class member info_log_level is not initialized in this constructor nor in any functions that it calls.
Closes https://github.com/facebook/rocksdb/pull/3106
Differential Revision: D6874689
Pulled By: sagar0
fbshipit-source-id: b5cd2d13915fd86d87260050f9c5d117615bbe30
Summary:
FIFO and Universal compaction options were recently made dynamic, but I forgot to update these comments. These would mislead anyone who is reading the code.
Closes https://github.com/facebook/rocksdb/pull/3399
Differential Revision: D6786358
Pulled By: sagar0
fbshipit-source-id: 57cfc412f63deaee29bbd82b863304821d60057d
Summary:
Hello and thank you for RocksDB,
While looking into the buffered io used when an `OPTIONS` file is read I noticed the `OPTIONS` files produced by RocksDB 5.8.8 (and head of master) were just over 4096 bytes in size, resulting in the version of glibc I am using (glibc-2.17-196.el7) (on the filesystem used) being passed a 4K buffer for the `fread_unlocked` call and 2 system call reads using a 4096 buffer being used to read the contents of the `OPTIONS` file.
If the buffer size is increased to 8192 then 1 system call read is used to read the contents.
As I think the buffer size is just used for reading `OPTIONS` files, and I thought it likely that `OPTIONS` files have increased in size (as more options are added), I thought I would suggest an increase.
[ If the comments from the top of the `OPTIONS` file are removed, and white space from the start of lines is removed then the size can be reduced to be under 4K, but as more options are added the size seems likely to grow again. ]
Create a new database:
```
> ./ldb --create_if_missing --db=/tmp/rdb_tmp put 1 1
OK
```
The OPTIONS file is 4252 bytes:
```
> stat /tmp/rdb_tmp/OPTIONS* | head -n 2
File: ‘/tmp/rdb_tmp/OPTIONS-000005’
Size: 4252 Blocks: 16 IO Block: 4096 regular file
```
Before, the 4096 byte buffer is used from 2 system read calls:
```
> strace -f ./ldb --try_load_options --db=/tmp/rdb_tmp get DOES_NOT_EXIST 2>&1 |
grep -A 1 'RocksDB option file'
read(3, "# This is a RocksDB option file."..., 4096) = 4096
read(3, "e\n metadata_block_size=4096\n c"..., 4096) = 156
```
ltrace shows 4096 passed to fread_unlocked
```
> ltrace -S -f ./ldb --try_load_options --db=/tmp/rdb_tmp get DOES_NOT_EXIST 2>&1 |
grep -C 3 'RocksDB option file'
[pid 51013] fread_unlocked(0x7ffd5fbf2d50, 1, 4096, 0x7fd2e084e780 <unfinished ...>
[pid 51013] fstat@SYS(3, 0x7ffd5fbf28f0) = 0
[pid 51013] mmap@SYS(nil, 4096, 3, 34, -1, 0) = 0x7fd2e318c000
[pid 51013] read@SYS(3, "# This is a RocksDB option file."..., 4096) = 4096
[pid 51013] <... fread_unlocked resumed> ) = 4096
...
```
After, the 8192 byte buffer is used from 1 system read call:
```
> strace -f ./ldb --try_load_options --db=/tmp/rdb_tmp get DOES_NOT_EXIST 2>&1 | grep -A 1 'RocksDB option file'
read(3, "# This is a RocksDB option file."..., 8192) = 4252
read(3, "", 4096) = 0
```
ltrace shows 8192 passed to fread_unlocked
```
> ltrace -S -f ./ldb --try_load_options --db=/tmp/rdb_tmp get DOES_NOT_EXIST 2>&1 | grep -C 3 'RocksDB option file'
[pid 146611] fread_unlocked(0x7ffcfba382f0, 1, 8192, 0x7fc4e844e780 <unfinished ...>
[pid 146611] fstat@SYS(3, 0x7ffcfba380f0) = 0
[pid 146611] mmap@SYS(nil, 4096, 3, 34, -1, 0) = 0x7fc4eaee0000
[pid 146611] read@SYS(3, "# This is a RocksDB option file."..., 8192) = 4252
[pid 146611] read@SYS(3, "", 4096) = 0
[pid 146611] <... fread_unlocked resumed> ) = 4252
[pid 146611] feof(0x7fc4e844e780) = 1
```
Closes https://github.com/facebook/rocksdb/pull/3294
Differential Revision: D6653684
Pulled By: ajkr
fbshipit-source-id: 222f25f5442fefe1dcec18c700bd9e235bb63491
Summary:
Let me know if more test coverage is needed
Closes https://github.com/facebook/rocksdb/pull/3213
Differential Revision: D6457165
Pulled By: miasantreble
fbshipit-source-id: 3f944abff28aa7775237f1c4f61c64ccbad4eea9
Summary:
The Options header file recommends using max_background_jobs rather than
directly setting max_background_compactions or max_background_flushes.
I've personally seen a performance problem where stalls were happening
because the one background flushing thread was blocked that was fixed
by this change -
https://github.com/cockroachdb/cockroach/issues/19699#issuecomment-347672485
Closes https://github.com/facebook/rocksdb/pull/3208
Differential Revision: D6473178
Pulled By: ajkr
fbshipit-source-id: 67c892ceb7b1909d251492640cb15a0f2262b7ed
Summary:
I started adding gflags support for cmake on linux and got frustrated that I'd need to duplicate the build_detect_platform logic, which determines namespace based on attempting compilation. We can do it differently -- use the GFLAGS_NAMESPACE macro if available, and if not, that indicates it's an old gflags version without configurable namespace so we can simply hardcode "google".
Closes https://github.com/facebook/rocksdb/pull/3212
Differential Revision: D6456973
Pulled By: ajkr
fbshipit-source-id: 3e6d5bde3ca00d4496a120a7caf4687399f5d656
Summary:
Problem: Option string accepts only cache_size as parameter for block_cache which is specified as "block_cache=1M".
It doesn't accept other parameters like num_shards etc.
Changes :
1) ParseBlockBasedTableOption in block_based_table_factory is edited to accept cache options in the format "block_cache=<cache_size>:<num_shard_bits>:<strict_capacity_limit>:<high_pri_pool_ratio>".
Options other than cache_size are optional to maintain backward compatibility. The changes are valid for block_cache_compressed as well.
For example, "block_cache=1M:6:true:0.5", "block_cache=1M:6:true", "block_cache=1M:6" and "block_cache=1M" are all valid option strings.
2) Corresponding unit tests are added.
Closes https://github.com/facebook/rocksdb/pull/3108
Differential Revision: D6420997
Pulled By: sagar0
fbshipit-source-id: cdea8b785688d2802907974af27225ccc1c0cd43
Summary:
Static variables in header files will be instantiated in every file that includes the header file. This patch moves some of them from options_helper.h to its .cc files. It also moves the static variable out of the offset_of since the template function could also lead to multiple instantiation perhaps due to inlining.
Fixes https://github.com/facebook/rocksdb/issues/3176
Closes https://github.com/facebook/rocksdb/pull/3178
Differential Revision: D6363794
Pulled By: maysamyabandeh
fbshipit-source-id: d0a07f061b4d992ab4e0de2706e622131d258fdd
Summary:
The motivation for this PR is to add to RocksDB support for differential (incremental) snapshots, as snapshot of the DB changes between two points in time (one can think of it as diff between to sequence numbers, or the diff D which can be thought of as an SST file or just set of KVs that can be applied to sequence number S1 to get the database to the state at sequence number S2).
This feature would be useful for various distributed storages layers built on top of RocksDB, as it should help reduce resources (time and network bandwidth) needed to recover and rebuilt DB instances as replicas in the context of distributed storages.
From the API standpoint that would like client app requesting iterator between (start seqnum) and current DB state, and reading the "diff".
This is a very draft PR for initial review in the discussion on the approach, i'm going to rework some parts and keep updating the PR.
For now, what's done here according to initial discussions:
Preserving deletes:
- We want to be able to optionally preserve recent deletes for some defined period of time, so that if a delete came in recently and might need to be included in the next incremental snapshot it would't get dropped by a compaction. This is done by adding new param to Options (preserve deletes flag) and new variable to DB Impl where we keep track of the sequence number after which we don't want to drop tombstones, even if they are otherwise eligible for deletion.
- I also added a new API call for clients to be able to advance this cutoff seqnum after which we drop deletes; i assume it's more flexible to let clients control this, since otherwise we'd need to keep some kind of timestamp < -- > seqnum mapping inside the DB, which sounds messy and painful to support. Clients could make use of it by periodically calling GetLatestSequenceNumber(), noting the timestamp, doing some calculation and figuring out by how much we need to advance the cutoff seqnum.
- Compaction codepath in compaction_iterator.cc has been modified to avoid dropping tombstones with seqnum > cutoff seqnum.
Iterator changes:
- couple params added to ReadOptions, to optionally allow client to request internal keys instead of user keys (so that client can get the latest value of a key, be it delete marker or a put), as well as min timestamp and min seqnum.
TableCache changes:
- I modified table_cache code to be able to quickly exclude SST files from iterators heep if creation_time on the file is less then iter_start_ts as passed in ReadOptions. That would help a lot in some DB settings (like reading very recent data only or using FIFO compactions), but not so much for universal compaction with more or less long iterator time span.
What's left:
- Still looking at how to best plug that inside DBIter codepath. So far it seems that FindNextUserKeyInternal only parses values as UserKeys, and iter->key() call generally returns user key. Can we add new API to DBIter as internal_key(), and modify this internal method to optionally set saved_key_ to point to the full internal key? I don't need to store actual seqnum there, but I do need to store type.
Closes https://github.com/facebook/rocksdb/pull/2999
Differential Revision: D6175602
Pulled By: mikhail-antonov
fbshipit-source-id: c779a6696ee2d574d86c69cec866a3ae095aa900
Summary:
GetCommitTimeWriteBatch is currently used to store some state as part of commit in 2PC. In MyRocks it is specifically used to store some data that would be needed only during recovery. So it is not need to be stored in memtable right after each commit.
This patch enables an optimization to write the GetCommitTimeWriteBatch only to the WAL. The batch will be written to memtable during recovery when the WAL is replayed. To cover the case when WAL is deleted after memtable flush, the batch is also buffered and written to memtable right before each memtable flush.
Closes https://github.com/facebook/rocksdb/pull/3071
Differential Revision: D6148023
Pulled By: maysamyabandeh
fbshipit-source-id: 2d09bae5565abe2017c0327421010d5c0d55eaa7
Summary:
228MutableDBOptions::MutableDBOptions()
229 : max_background_jobs(2),
230 base_background_compactions(-1),
231 max_background_compactions(-1),
232 avoid_flush_during_shutdown(false),
233 delayed_write_rate(2 * 1024U * 1024U),
234 max_total_wal_size(0),
235 delete_obsolete_files_period_micros(6ULL * 60 * 60 * 1000000),
236 stats_dump_period_sec(600),
2. uninit_member: Non-static class member bytes_per_sync is not initialized in this constructor nor in any functions that it calls.
CID 1419857 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
4. uninit_member: Non-static class member wal_bytes_per_sync is not initialized in this constructor nor in any functions that it calls.
237 max_open_files(-1) {}
Closes https://github.com/facebook/rocksdb/pull/3069
Differential Revision: D6170424
Pulled By: ajkr
fbshipit-source-id: 1f94e86b87611ad2330b8b1707911150978d68b8
Summary:
- for `SeekToFirst()`, just convert it to a regular `Seek()` if lower bound is specified
- for operations that iterate backwards over user keys (`SeekForPrev`, `SeekToLast`, `Prev`), change `PrevInternal` to check whether user key went below lower bound every time the user key changes -- same approach we use to ensure we stay within a prefix when `prefix_same_as_start=true`.
Closes https://github.com/facebook/rocksdb/pull/3074
Differential Revision: D6158654
Pulled By: ajkr
fbshipit-source-id: cb0e3a922e2650d2cd4d1c6e1c0f1e8b729ff518
Summary:
ColumnFamilyOptions::compaction_options_fifo and all its sub-fields can be set dynamically now.
Some of the ways in which the fifo compaction options can be set are:
- `SetOptions({{"compaction_options_fifo", "{max_table_files_size=1024}"}})`
- `SetOptions({{"compaction_options_fifo", "{ttl=600;}"}})`
- `SetOptions({{"compaction_options_fifo", "{max_table_files_size=1024;ttl=600;}"}})`
- `SetOptions({{"compaction_options_fifo", "{max_table_files_size=51;ttl=49;allow_compaction=true;}"}})`
Most of the code has been made generic enough so that it could be reused later to make universal options (and other such nested defined-types) dynamic with very few lines of parsing/serializing code changes.
Introduced a few new functions like `ParseStruct`, `SerializeStruct` and `GetStringFromStruct`.
The duplicate code in `GetStringFromDBOptions` and `GetStringFromColumnFamilyOptions` has been moved into `GetStringFromStruct`. So they become just simple wrappers now.
Closes https://github.com/facebook/rocksdb/pull/3006
Differential Revision: D6058619
Pulled By: sagar0
fbshipit-source-id: 1e8f78b3374ca5249bb4f3be8a6d3bb4cbc52f92
Summary:
* make `checksum_type_string_map` available for lite
* comment out `FilesPerLevel` in lite mode.
* travis and legocastle lite build also build `all` target and run tests
Closes https://github.com/facebook/rocksdb/pull/3015
Differential Revision: D6069822
Pulled By: yiwu-arbug
fbshipit-source-id: 9fe92ac220e711e9e6ed4e921bd25ef4314796a0
Summary:
Currently, RocksDB does not allow reopening a preexisting DB with no merge operator defined, with a merge operator defined. This means that if a DB ever want to add a merge operator, there's no way to do so currently.
Fix this by adding a new verification type `kByNameAllowFromNull` which will allow old values to be nullptr, and new values to be non-nullptr.
Closes https://github.com/facebook/rocksdb/pull/2958
Differential Revision: D5961131
Pulled By: lth
fbshipit-source-id: 06179bebd0d90db3d43690b5eb7345e2d5bab1eb
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:
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:
Our current implementation of (semi-)copy constructor of DBOptions and ColumnFamilyOptions seems to intend value by value copy, which is what the default copy constructor does anyway. Moreover not using the default constructor has the risk of forgetting to add newly added options.
As an example, allow_2pc seems to be forgotten in the copy constructor which was causing one of the unit tests not seeing its effect.
Closes https://github.com/facebook/rocksdb/pull/2888
Differential Revision: D5846368
Pulled By: maysamyabandeh
fbshipit-source-id: 1ee92a2aeae93886754b7bc039c3411ea2458683
Summary:
test the `DBOptions(const Options&)` and `ColumnFamilyOptions(const Options&)` constructors. Actually this'll work better once we refactor `RandomInitDBOptions` / `RandomInitCFOptions` to use the authoritative sources of struct members: `db_options_type_info` / `cf_options_type_info` (internal task T21804189 for this).
Closes https://github.com/facebook/rocksdb/pull/2873
Differential Revision: D5817141
Pulled By: ajkr
fbshipit-source-id: 8567c20feced9d1751fdf1f4383e2af30f7e3591
Summary:
currently `ImmutableDBOptions::Dump` use default value for `concurrent_prepare` and `manual_wal_flush`, because DBOptions ctor does not init those member variables.
so in LOG file, it will be
```
Options.concurrent_prepare: 0
Options.manual_wal_flush: 0
```
Closes https://github.com/facebook/rocksdb/pull/2864
Differential Revision: D5816240
Pulled By: ajkr
fbshipit-source-id: 82335e8bcae3dceedc6a99224e7998de5fad1e50
Summary:
useful when debugging to tell whether a DB has stats enabled, and whether a stats object is shared across DBs.
Closes https://github.com/facebook/rocksdb/pull/2813
Differential Revision: D5741755
Pulled By: ajkr
fbshipit-source-id: 9b9d51dee77d14d415cd5da985d8d61b5b3837c3
Summary:
Replace dynamic_cast<> so that users can choose to build with RTTI off, so that they can save several bytes per object, and get tiny more memory available.
Some nontrivial changes:
1. Add Comparator::GetRootComparator() to get around the internal comparator hack
2. Add the two experiemental functions to DB
3. Add TableFactory::GetOptionString() to avoid unnecessary casting to get the option string
4. Since 3 is done, move the parsing option functions for table factory to table factory files too, to be symmetric.
Closes https://github.com/facebook/rocksdb/pull/2645
Differential Revision: D5502723
Pulled By: siying
fbshipit-source-id: fd13cec5601cf68a554d87bfcf056f2ffa5fbf7c
Summary:
This reverts the previous commit 1d7048c598, which broke the build.
Did a `git revert 1d7048c`.
Closes https://github.com/facebook/rocksdb/pull/2627
Differential Revision: D5476473
Pulled By: sagar0
fbshipit-source-id: 4756ff5c0dfc88c17eceb00e02c36176de728d06
Summary: This uses `clang-tidy` to comment out unused parameters (in functions, methods and lambdas) in fbcode. Cases that the tool failed to handle are fixed manually.
Reviewed By: igorsugak
Differential Revision: D5454343
fbshipit-source-id: 5dee339b4334e25e963891b519a5aa81fbf627b2
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:
With c7004840d2, it's safe to open a DB with different prefix extractor. So it's safe to skip prefix extractor check.
Closes https://github.com/facebook/rocksdb/pull/2474
Differential Revision: D5294700
Pulled By: siying
fbshipit-source-id: eeb500da795eecb29b8c9c56a14cfd4afda12ecc
Huachao Huang