[infinispan-issues] [JBoss JIRA] (ISPN-5021) Nodes that finish the rebalance later can see outdated values

Nodes that finish the rebalance later can see outdated values ------------------------------------------------------------- Key: ISPN-5021 URL: https://issues.jboss.org/browse/ISPN-5021 Project: Infinispan Issue Type: Bug Components: Core, State Transfer Affects Versions: 7.0.2.Final Reporter: Dan Berindei Assignee: Pedro Ruivo Priority: Critical Fix For: 7.1.0.Beta1 Copied from [ISPN-4444|https://issues.jboss.org/browse/ISPN-4444?focusedCommentId=1302...] If the CH_UPDATE command is delayed on the old owner, the new owners might update the key without the old owner knowing, and a locality check on the old owner won't help. I remember one thing that struck me when reading the Raft algorithm was that they install configuration changes symmetrically, in 3 phases. We might need to do the same for our rebalance: start a rebalance with read_ch=old, write_ch=old+new, when the new owners have all the data install read_ch=new, write_ch=old+new, and finally read_ch=new, write_ch=new. Old cache entries are removed during the 2nd topology update, and further writes should be ignored, in order for this to work.