Hi, In normal circumstances checkpoint is triggered on timeout, e.g. every 3 minutes (controlled by checkpointFrequency). So, the size of the checkpoint is the amount of data written/updated in a 3-minute interval. The best way to estimate it in your system is to enable data storage metrics (DataStorageMetrics.setMetricsEnabled(true)) and check the metric getLastCheckpointTotalPagesNumber().
Stan On Mon, Aug 26, 2019 at 4:59 PM Venkata Bhagavatula <venkat.cha...@gmail.com> wrote: > 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 >
