Hello. I am testing elasticsearch and I'm plannig to put it in production.
I have read the manual on elasticsearch and also google helped a lot on
figuring out how it works. So,
http://www.elasticsearch.org/guide/en/elasticsearch/guide/current/_scale_horizontally.html
here is the basic scenario on how ES is behaving in H-A, failover, what is
happening with shards and etc. Lets presume, I have 3 nods, node1 is
master, node2 and node3 are data nods and both are eligible to become
master. The settings they all have is discovery.zen.minimum_master_nodes: 2.
If I kill the node1 master(shutdown server or just presume is a network
problem), then one of the other nods would become the master. On the link I
posted we can se that the replica shards of missing primary shards that
were on node1(master) would now be turned into primary. So, what happens if
I turn on node1(previous master) again which I killed? Node1 has a setting
in elasticsearch.xml that he is a master - node.master: true. Will then
node1 become the new master? What whould be with primary shards that he has
in his data? And what would then be with primary shards that where
converted from replicas when master was killed at first, and now those
primary shards are in other nodes? Would that cause the split-brain problem?
Which brings us to how do you reboot server which is a master node in ES
cluster without other nods becoming a master during that period? Should I
shutdown the whole cluster and than do the maintenance of servers or can it
be somehow put in maintenance mode? I mean, if I have Debian servers and
every one of them is a node in ES, and some are master eligible how to you
patch them and reboot them?
And one more question, in another scenario, if I kill a node, the primary
shards which that node held are now not available. The master then decides
which replicas on other nodes are going to become primary shards. And now I
bring that same node back, it will have primary shards which it had before
I killed it. And cluster allready have converted replica shards to primary
shards that are missing... What would happen with the node that was killed
and now brought back and what would happen whit his shards?
Tnx.
--
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+unsubscribe@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/elasticsearch/b55d2abc-12e6-40c1-8cac-cf5be2ed0353%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.