Hi All, In the link: https://cwiki.apache.org/confluence/display/IGNITE/Ignite+Persistent+Store+-+under+the+hood#IgnitePersistentStore-underthehood-LocalCrashRecovery
Following is mentioned about the Estimation: what is est. maximum data volume to be writen on 1 checkpoint? Is it the size of 1 wal segment or 1 checkpoint buffer size? Estimating disk space WAL Work maximum 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 1. average load or 2. 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. Thanks n Regards, Chal
