use_adaptive_mutex=false enable_thread_tracking=false allow_fallocate=true error_if_exists=false recycle_log_file_num=0 db_log_dir= skip_log_error_on_recovery=false new_table_reader_for_compaction_inputs=true allow_mmap_reads=false allow_mmap_writes=false use_direct_reads=false use_direct_wr...
可以通过设置 RocksDB 的 use_direct_reads 参数来使用 direct io 读，这样就绕过系统的 page cache，...
--use_direct_reads=0 --use_direct_io_for_flush_and_compaction=0 \ --disable_wal=1 --verify_checksum=1 \ --stats_per_interval=1 --stats_interval_seconds=60 --histogram=1 The readrandom workload The readrandom workload randomly reads data from an existing database. The numb...
//创建迭代器 rocksdb::Iterator* it = db->NewIterator(option); //Seek与Next移动迭代器 for (...
LSM-Tree点查流程（LSM-Tree与rocksdb的差异暂时忽略）•先查找MemTable、ImmuMemTable，读取到数据则...
DB大小为86G,HDD存储,在一个具有100TB数据的node上模拟小内存,使用Direct IO(关闭OS file cache),block cache大小设置为60MB。分片后吞吐提升了11倍( 5 op/s提升到55 op/s)。 /db_bench--benchmarks="readwhilewriting[X3],stats"--use_direct_reads=1-compaction_readahead_size1048576--use_existing_db...
406 // disabled (ReadOptions::fill_cache = false) and direct IO is 407 // enabled (DBOptions::use_direct_reads = true). 408 // The default mode is the best tradeoff for most use cases. 409 // This option only affects newly written tables. 410 // 411 // The index contains a...
DIO tests were executed with the options --use_direct_io_for_flush_and_compaction --use_direct_reads. All other parameters used the default values, unless explicitly mentioned here. Tests were executed sequentially against the same database instance. The db_bench tool was generated via make ...
.setWriteBufferSize(writeBufferSizeMB*1024L*1024L) .setMaxWriteBufferNumber(MAX_WRITE_BUFFER_NUMBER) .setMinWriteBufferNumberToMerge(MIN_WRITE_BUFFER_NUMBER_TO_MERGE) .setTableFormatConfig(tableFormatConfig) .setOptimizeFiltersForHits(true) .setUseDirectReads(true); }...
Now, DBOptions::use_direct_io_for_flush_and_compaction only applies to background writes, and DBOptions::use_direct_reads applies to both user reads and background reads. This conforms with Linux's open(2) manpage, which advises against simultaneously reading a file in buffered and direct ...