rocksdb/DEFAULT_OPTIONS_HISTORY.md
sdong 6a14f7a976 Change several option defaults
Summary:
Changing several option defaults:
 options.max_open_files changes from 5000 to -1
 options.base_background_compactions changes from max_background_compactions to 1
 options.wal_recovery_mode changes from kTolerateCorruptedTailRecords to kTolerateCorruptedTailRecords
 options.compaction_pri changes from kByCompensatedSize to kByCompensatedSize

Test Plan: Write unit tests to see OldDefaults() works as expected.

Reviewers: IslamAbdelRahman, yhchiang, igor

Reviewed By: igor

Subscribers: MarkCallaghan, yiwu, kradhakrishnan, leveldb, andrewkr, dhruba

Differential Revision: https://reviews.facebook.net/D56427
2016-04-28 17:50:58 -07:00

15 lines
1.1 KiB
Markdown

## Unreleased
* options.max_open_files changes from 5000 to -1. It improves performance, but users need to set file descriptor limit to be large enough and watch memory usage for index and bloom filters.
* options.base_background_compactions changes from max_background_compactions to 1. When users set higher max_background_compactions but the write throughput is not high, the writes are less spiky to disks.
* options.wal_recovery_mode changes from kTolerateCorruptedTailRecords to kPointInTimeRecovery. Avoid some false positive when file system or hardware reorder the writes for file data and metadata.
# RocksDB default options change log
## 4.7.0 (4/8/2016)
* options.write_buffer_size changes from 4MB to 64MB.
* options.target_file_size_base changes from 2MB to 64MB.
* options.max_bytes_for_level_base changes from 10MB to 256MB.
* options.soft_pending_compaction_bytes_limit changes from 0 (disabled) to 64GB.
* options.hard_pending_compaction_bytes_limit changes from 0 (disabled) to 256GB.
* table_cache_numshardbits changes from 4 to 6.
* max_file_opening_threads changes from 1 to 16.