On Monday, 11 August 2014 15:31:28 UTC+2, bitsof...@gmail.com wrote: > > I have 8 data nodes and 6 coordinator nodes in an active cluster running > 1.2.1 > > I want to upgrade to 1.3.1 > > When reading > http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/setup-upgrade.html > > the upgrade docs am I correct to assume: > > a) disable shard allocation before doing anything > > b) proceed to upgrade each node to 1.3.1 > > c) only after ALL nodes are @ 1.3.1 then I can re-enable shard allocation. > > My question is that at some point during the upgrade of all the data > nodes, the shards on them will be "unassigned" and the cluster will not > function... correct? > > So in other words running some nodes as 1.2.1 and others as 1.3.1 with > shard allocation *enabled* is NOT advised and in general cluster > un-availability is expected due to shards being in an unassigned state as > each data node is upgraded. > > At least this is the behavior I see today, (not during an upgrade) when I > disable allocation and restart a node, those shards are unassigned until I > re-enable allocation > > No, the procedure outlined above is not correct and would indeed result in unassigned shards, as you suspect. Instead, you should:
1. Disable allocation 2. Upgrade ONE node 3. Reenable allocation 4. Wait for green 5. Repeat Even when following the above process, you will likely end up with shards being copied over from one node to another (once allocation has been reenabled). After restart, a replica will only reuse the segments that are exactly the same as those in the primary. However, because primaries and replicas refresh, flush, and merge at different times, shards diverge from each other over time. The longer it has been since a replica was copied over from the primary, the fewer identical segments they will have in common. -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to elasticsearch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/elasticsearch/11f7f772-9d86-4a84-a523-a047f4bb88b4%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
