About index.unassigned.node_left.delayed_timeout setting

Per ES reference, we can delay the allocation when node leaves with following setting:

PUT /_all/_settings
"settings": {
"index.unassigned.node_left.delayed_timeout": "5m"

My questions is,
If I put this setting in elasticsearch.yml, does it work?

I tried to add this setting to yml config, the ES could be started successfully, but I don't know if it really works.

Yes, it will work on Elasticsearch 2.x but not on 5.x (see discussion here: https://github.com/elastic/elasticsearch/issues/18073). This is an index-level setting and should be set on the index. If you want this to apply to all newly created indices as well, you should define an index template that applies this setting.

Thanks a lot!
So it is better put this setting in template to be forward compatible to 5.x

yes :slight_smile: