Summary:
MyRocks currently sets `max_write_buffer_number_to_maintain` in order to maintain enough history for transaction conflict checking. The effectiveness of this approach depends on the size of memtables. When memtables are small, it may not keep enough history; when memtables are large, this may consume too much memory.
We are proposing a new way to configure memtable list history: by limiting the memory usage of immutable memtables. The new option is `max_write_buffer_size_to_maintain` and it will take precedence over the old `max_write_buffer_number_to_maintain` if they are both set to non-zero values. The new option accounts for the total memory usage of flushed immutable memtables and mutable memtable. When the total usage exceeds the limit, RocksDB may start dropping immutable memtables (which is also called trimming history), starting from the oldest one.
The semantics of the old option actually works both as an upper bound and lower bound. History trimming will start if number of immutable memtables exceeds the limit, but it will never go below (limit-1) due to history trimming.
In order the mimic the behavior with the new option, history trimming will stop if dropping the next immutable memtable causes the total memory usage go below the size limit. For example, assuming the size limit is set to 64MB, and there are 3 immutable memtables with sizes of 20, 30, 30. Although the total memory usage is 80MB > 64MB, dropping the oldest memtable will reduce the memory usage to 60MB < 64MB, so in this case no memtable will be dropped.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5022
Differential Revision: D14394062
Pulled By: miasantreble
fbshipit-source-id: 60457a509c6af89d0993f988c9b5c2aa9e45f5c5
Summary:
Top-level index in partitioned index/filter blocks are small and could be pinned in memory. So far we use that by cache_index_and_filter_blocks to false. This however make it difficult to keep account of the total memory usage. This patch introduces pin_top_level_index_and_filter which in combination with cache_index_and_filter_blocks=true keeps the top-level index in cache and yet pinned them to avoid cache misses and also cache lookup overhead.
Closes https://github.com/facebook/rocksdb/pull/4037
Differential Revision: D8596218
Pulled By: maysamyabandeh
fbshipit-source-id: 3a5f7f9ca6b4b525b03ff6bd82354881ae974ad2
Summary:
This option is needed to be enabled for Direct IO
and I cannot think of a reason where we need to disable it
remove it and default it to true
Closes https://github.com/facebook/rocksdb/pull/1944
Differential Revision: D4641088
Pulled By: IslamAbdelRahman
fbshipit-source-id: d7085b9
Summary:
Remove disableDataSync, and another similarly named disable_data_sync options.
This is being done to simplify options, and also because the performance gains of this feature can be achieved by other methods.
Closes https://github.com/facebook/rocksdb/pull/1859
Differential Revision: D4541292
Pulled By: sagar0
fbshipit-source-id: 5b3a6ca
Summary: Add mutable options info into `OptionsTypeInfo` and use it to parse mutable options map. Also support `max_bytes_for_level_multiplier_additional` in option file.
Test Plan: unit test
Reviewers: yhchiang, IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D63843
Summary:
When a block based table file is opened, if prefetch_index_and_filter is true, it will prefetch the index and filter blocks, putting them into the block cache.
What this feature adds: when a L0 block based table file is opened, if pin_l0_filter_and_index_blocks_in_cache is true in the options (and prefetch_index_and_filter is true), then the filter and index blocks aren't released back to the block cache at the end of BlockBasedTableReader::Open(). Instead the table reader takes ownership of them, hence pinning them, ie. the LRU cache will never push them out. Meanwhile in the table reader, further accesses will not hit the block cache, thus avoiding lock contention.
Test Plan:
'export TEST_TMPDIR=/dev/shm/ && DISABLE_JEMALLOC=1 OPT=-g make all valgrind_check -j32' is OK.
I didn't run the Java tests, I don't have Java set up on my devserver.
Reviewers: sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56133
Summary:
When a block based table file is opened, if prefetch_index_and_filter is true, it will prefetch the index and filter blocks, putting them into the block cache.
What this feature adds: when a L0 block based table file is opened, if pin_l0_filter_and_index_blocks_in_cache is true in the options (and prefetch_index_and_filter is true), then the filter and index blocks aren't released back to the block cache at the end of BlockBasedTableReader::Open(). Instead the table reader takes ownership of them, hence pinning them, ie. the LRU cache will never push them out. Meanwhile in the table reader, further accesses will not hit the block cache, thus avoiding lock contention.
When the table reader is destroyed, it releases the pinned blocks (if there were any). This has to happen before the cache is destroyed, so I had to introduce a TableReader::Close(), to guarantee the order of destruction.
Test Plan:
Added two unit tests for this. Existing unit tests run fine (default is pin_l0_filter_and_index_blocks_in_cache=false).
DISABLE_JEMALLOC=1 OPT=-g make all valgrind_check -j32
Mac: OK.
Linux: with D55287 patched in it's OK.
Reviewers: sdong
Reviewed By: sdong
Subscribers: andrewkr, leveldb, dhruba
Differential Revision: https://reviews.facebook.net/D54801
Summary:
Update examples/rocksdb_option_file_example.ini to use the options file
generated by the db_bench readwhilewriting benchmark.
Test Plan: no code change.
Reviewers: igor, IslamAbdelRahman, rven, kradhakrishnan, sdong, anthony
Reviewed By: anthony
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D51567
Summary: Fixed some typos in the comments of rocksdb options file example
Test Plan: No code change.
Reviewers: igor, anthony, IslamAbdelRahman, rven, kradhakrishnan, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D51393
Summary:
Introduce TableOptions section and support BlockBasedTable in RocksDB
options file. A TableOptions section has the following format:
[TableOptions/<FactoryClassName> "<ColumnFamily Name>"]
which includes information about its TableFactory class and belonging
column family. Below is an example TableOptions section of a
BlockBasedTableOptions that belongs to the default column family:
[TableOptions/BlockBasedTable "default"]
format_version=0
whole_key_filtering=true
block_size_deviation=10
block_size=4096
block_restart_interval=16
filter_policy=nullptr
no_block_cache=false
checksum=kCRC32c
cache_index_and_filter_blocks=false
index_type=kBinarySearch
hash_index_allow_collision=true
flush_block_policy_factory=FlushBlockBySizePolicyFactory
Currently, Cache-type options (i.e., block_cache and block_cache_compressed)
are not supported.
Test Plan: options_test
Reviewers: igor, anthony, IslamAbdelRahman, sdong
Reviewed By: sdong
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D48435
Summary:
This patch defines the format of RocksDB options file, which
follows the INI file format, and implements functions for its
serialization and deserialization. An example RocksDB options
file can be found in examples/rocksdb_option_file_example.ini.
A typical RocksDB options file has three sections, which are
Version, DBOptions, and more than one CFOptions. The RocksDB
options file in general follows the basic INI file format
with the following extensions / modifications:
* Escaped characters
We escaped the following characters:
- \n -- line feed - new line
- \r -- carriage return
- \\ -- backslash \
- \: -- colon symbol :
- \# -- hash tag #
* Comments
We support # style comments. Comments can appear at the ending
part of a line.
* Statements
A statement is of the form option_name = value.
Each statement contains a '=', where extra white-spaces
are supported. However, we don't support multi-lined statement.
Furthermore, each line can only contain at most one statement.
* Section
Sections are of the form [SecitonTitle "SectionArgument"],
where section argument is optional.
* List
We use colon-separated string to represent a list.
For instance, n1:n2:n3:n4 is a list containing four values.
Below is an example of a RocksDB options file:
[Version]
rocksdb_version=4.0.0
options_file_version=1.0
[DBOptions]
max_open_files=12345
max_background_flushes=301
[CFOptions "default"]
[CFOptions "the second column family"]
[CFOptions "the third column family"]
Test Plan: Added many tests in options_test.cc
Reviewers: igor, IslamAbdelRahman, sdong, anthony
Reviewed By: anthony
Subscribers: maykov, dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D46059
Zhongyi Xie