[infinispan-issues] [Red Hat JIRA] (ISPN-12172) Make the number of segments dynamic

Make the number of segments dynamic ----------------------------------- Key: ISPN-12172 URL: https://issues.redhat.com/browse/ISPN-12172 Project: Infinispan Issue Type: Bug Components: Configuration, Core Affects Versions: 11.0.1.Final Reporter: Dan Berindei Assignee: Dan Berindei Priority: Major Fix For: 12.1.0.Final Now that the data container and stores store segment information, it's becoming harder and harder to change the number of segments to accommodate a growth in the number of nodes and preserve all the data. We should investigate removing the {{numSegments}} configuration attribute and using an {{effectiveNumSegments}} that is the first power of 2 that's bigger than 10 * <cluster size> (customizable, maybe?) and at least as big as the previous {{effectiveNumSegments}}. The number of segments increase would be decided by the coordinator on join and would require state transfer, as {{SyncConsistentHashFactory}} would not assign the split segments to exactly the same owners (although it would have to be pretty close in order to make this practical). We would like to avoid updating the segment of every persisted entry on {{effectiveNumSegments}} changes, so the segment stored in persisted entries should be computed based on the maximum value we will allow for {{effectiveNumSegments}}, e.g. 2^16. We would then use a shift+mask to obtain the "effective segment" of the key, and range queries when obtaining all the keys in a segment.