quick recovery after node restart in elasticsearch

elasticsearch

Solution

For Elasticsearch version >= 1.0.0:

curl -XPUT localhost:9200/_cluster/settings -d '{"transient":{"cluster.routing.allocation.enable": "none"}}'
/etc/init.d/elasticsearch restart
curl -XPUT localhost:9200/_cluster/settings -d '{"transient":{"cluster.routing.allocation.enable": "all"}}'

For earlier version of ES:

curl -XPUT localhost:9200/_cluster/settings -d '{"transient":{"cluster.routing.allocation.disable_allocation": true}}'
/etc/init.d/elasticsearch restart
curl -XPUT localhost:9200/_cluster/settings -d '{"transient":{"cluster.routing.allocation.disable_allocation": false}}'

Shard keep unallocated until "cluster.routing.allocation.disable_allocation": false, then shards recover on the server just restarted (starting at size they were before shutdown) It is very quick.

Reference: http://elasticsearch-users.115913.n3.nabble.com/quick-recovery-after-node-restart-in-elasticsearch-td4033876.html#a4034211

Problem

Consider the below settings in the elasticsearch.yml ``` gateway.recover_after_data_nodes: 3 gateway.recover_after_time: 5m gateway.expected_data_nodes: 3 ``` Current setting: Say, I have 3 data nodes. Now if I decide to restart a data node(due to a small change in setting), the recovery will start immediately after node restart as per the expected_data_nodes setting. There will be many unassigned shards, which will get allocated slowly depending on the data it contains. In order to avoid that, is there any way to allocate all the unassigned shards to a specific node?(in my case the restarted node) and once that is done, ES should take over the rebalancing. Mainly I want to avoid the heavy timelag of the cluster state from yellow to green.(it is in the range of hours in my case) Can I use the cluster reroute api for this purpose? or is there any other api to transfer all the unassigned shards to specific node at one go?

Original source