Thanks for your response. On Mon, Aug 26, 2019 at 10:59 PM Anton <[email protected]> wrote:
> Hello, > > > > WAL active folder size calculation is correct, that is walSegmentSize * > walSegment = 64 * 10 = 640Mb. > > > > However, you may completely disregard estimations for WAL archive, as > since latest 2.7 version there is a configuration property to limit WAL > archive size in bytes, which is obviously more precise way to do so. > > > > Ticket for your reference: > https://issues.apache.org/jira/browse/IGNITE-6552 > > Docs link: > https://apacheignite.readme.io/docs/write-ahead-log#section-wal-archive > > > > Though there is the same link is on the under the hood page in WAL > structure part, the ‘estimating disk space’ part has to be updated, thanks > for your question! > > > > Best regards, > > Anton > > *From: *Venkata Bhagavatula <[email protected]> > *Sent: *Monday, August 26, 2019 4:59 PM > *To: *[email protected] > *Subject: *Ignite WAL and WAL archive size estimation > > > > 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 > > >
