Hi , I'm new in Elastic world , we have a few master nodes , data nodes , logstash nodes and 2 ing nodes , 4 days a go indexes began to be written to the master nodes also , need your advice , what could be the reason and what is the solution ?
Thanks for the answer , I forgot to mention that the master nodes are only master (though on the main master node I see only node.master: true without node.data: false, but on the rest I have node.master: true and node.data: false) , can it be the issue ?
There is no logstash node. logstash is an instance outside the Elasticsearch cluster. And effectively among the roles of an Elasticsearch node, ingest node to pre-process documents before the actual document indexing happens. But you can just use logstash.
these are the parameters which allow you to be able to elect a master in the cluster in a subset of the eligible master. So this will be the list of eligible masters
This is what I did , but due to shards that were created before , service cant be bring ed up , it tells that first of all delete all indexes on the host(doesn't let me bring service with node.data=false).
Indeed - that's why (if your cluster health is green) I suggest wiping the node, i.e. deleting its whole data path. There are other ways forward if you cannot get your cluster health to green but they're much more complicated and risky.