Rolling Upgrade: use of Remote Store in mode read-only causes data inconsistencies ---------------------------------------------------------------------------------- Key: ISPN-7586 URL: https://issues.jboss.org/browse/ISPN-7586 Project: Infinispan Issue Type: Bug Reporter: Gustavo Fernandes Assignee: Gustavo Fernandes Fix For: 9.0.0.CR4 We recommend to do rolling upgrades with the target cluster with a remote-store pointing to the source cluster, in mode ready-only. Clients are switched to point to the target cluster. This cause situations like this in the client: {code:java} client.put("K","value") // will get "V" back client.get("K") // Deletes will not propagate to the source cluster, // the RemoteStore is in 'read-only' mode. client.remove("K") // Returns "V". Although deleted, value will be retrieved // from the remote store cache.get("K") {code} This can break existing applications that expect a consistent access to data during a Rolling Upgrade process. Clearly the remote store should not be in read only mode, but at the same time, as the Rolling Upgrade does a put in the target cache reading data from the source cache, it should not trigger a write back to the source cluster.