Hello! We had this feature for a few versions, where you could do gnite.cluster(). disableWal() to temporarily disable WAL on a specific cache, involving a PME and checkpoint on every node.
However, it became apparent that you cannot enable or disable WAL on any kind of unstable topology, at all: https://issues.apache.org/jira/browse/IGNITE-13976 You cannot even disable WAL while a baseline node is offline: When it comes back, it will not sync its WAL enabled status with the rest of the cluster, and all subsequent "WAL enable" or "WAL disable" operations will fail on that cache, with no clear way to recover this cache: ignite.close(); client.cluster().disableWal(CACHE_NAME); nodes.add(Ignition.start(igniteCfg(false, consistentId))); client.cluster().enableWal(CACHE_NAME); // will fail Even if this simple scenario is fixed, it seems that there are multiple failure scenarios if you try to add or remove a node in the middle of WAL state change operation. It does not seem that we have any expertise in wal disable/enable implementation right now, and I did not find a simple way of fixing it short of a full rewrite. Therefore, I propose that we should *(a) disable that feature* in 2.10 or* (b) give a clear warning *when it is used, and also mention in the documentation that it may only be used on stable topology. We may also want to re-mark this feature's API as @IgniteExperimental. I have lifted this ticket to be a Blocker. WDYT? Regards,
