1# RocksDB default options change log 2## Unreleased 3* delayed_write_rate takes the rate given by rate_limiter if not specified. 4 5## 5.2 6* Change the default of delayed slowdown value to 16MB/s and further increase the L0 stop condition to 36 files. 7 8## 5.0 (11/17/2016) 9* Options::allow_concurrent_memtable_write and Options::enable_write_thread_adaptive_yield are now true by default 10* Options.level0_stop_writes_trigger default value changes from 24 to 32. 11 12## 4.8.0 (5/2/2016) 13* 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. 14* 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. 15* 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. 16 17## 4.7.0 (4/8/2016) 18* options.write_buffer_size changes from 4MB to 64MB. 19* options.target_file_size_base changes from 2MB to 64MB. 20* options.max_bytes_for_level_base changes from 10MB to 256MB. 21* options.soft_pending_compaction_bytes_limit changes from 0 (disabled) to 64GB. 22* options.hard_pending_compaction_bytes_limit changes from 0 (disabled) to 256GB. 23* table_cache_numshardbits changes from 4 to 6. 24* max_file_opening_threads changes from 1 to 16. 25