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By default WAL history size is 20 to increase probability that rebalancing can be done using logical deltas from WAL.

Estimating disk space

 

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

  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.