Dmitriy Pavlov created IGNITE-7730: -------------------------------------- Summary: Improve WAL history size documentation Key: IGNITE-7730 URL: https://issues.apache.org/jira/browse/IGNITE-7730 Project: Ignite Issue Type: Task Components: documentation Affects Versions: 2.1 Reporter: Dmitriy Pavlov Assignee: Denis Magda Fix For: 2.5
Until IGNITE-6552 is not implemented, we have only ability to configure WAL hist. size in checkpoints. It is needed to improve description for this parameter. I've added draft notes to wiki https://cwiki.apache.org/confluence/display/IGNITE/Ignite+Persistent+Store+-+under+the+hood#IgnitePersistentStore-underthehood-Estimatingdiskspace about ways how wer can estimate WAL sizes without exact bytes/time specification: {panel} WAL Work max used size: walSegmentSize * walSegments = 640Mb (default) in case Default WAL mode - this size is used always, in case other modes best case is 1 segment * walSegmentSize WAL Work+WAL Archive max size may be estimated by average load or by maximum size. 1st way is applicable if checkpoints are triggered mostly by timer trigger. Wal size = 2*Average load(bytes/sec) * trigger interval (sec) * walHistSize (number of checkpoints) Where 2 multiplier coming from physical & logical WAL Records. 2nd way: Checkpoint is triggered by segments max dirty pages percent. Use persisted data regions max sizes: sum(Max configured DataRegionConfiguration.maxSize) * 75% - est. maximum data volume to be writen on 1 checkpoint. Overall WAL size (before archiving) = 2* est. data volume * walHistSize = 1,5 * sum(DataRegionConfiguration.maxSize) * walHistSize Note applying WAL compressor may significiantly reduce archive size. {panel} -- This message was sent by Atlassian JIRA (v7.6.3#76005)