# Avoiding unneccessary datashuffling during datanode downtime **URL:** \ **Category:** Elasticsearch\ **Created:** [May 11, 2020, 11:46am UTC](https://discuss.elastic.co/t/avoiding-unneccessary-datashuffling-during-datanode-downtime/231996 "2020-05-11T11:46:59Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![blacksmith](https://avatars.discourse-cdn.com/v4/letter/b/e99b99/32.png) [@blacksmith](https://discuss.elastic.co/u/blacksmith)\ **Post date:** [May 11, 2020, 11:47am UTC](https://discuss.elastic.co/t/avoiding-unneccessary-datashuffling-during-datanode-downtime/231996/1 "2020-05-11T11:47:00Z")
Hey! Running ES 5.6.16 on a three-node cluster (all master-eligible, two data-nodes). Will soon perform maintenance (one node at a time) which will take 2 hours tops per node. When one of the data-nodes will be down, I want to minimize the amount of data-shuffling that occurs and the way I understand it is that if you want availability, you need to at least let the replicas on the remaining data-node be promoted to primaries which is totally understandable and fine. But what I would like to avoid is the creation of new replicas. I'd appreciate your feedback regarding these two options: 1. Setting cluster.routing.allocation.enable to "primaries". I'm guessing this also includes the scope of "new\_primaries" in case some index would roll-over. 2. Setting index.unassigned.node\_left.delayed\_timeout to a high enough value, say 2h. What would the difference between these two be and which one would be more appropriate for my situation? Regards! ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [June 8, 2020, 11:47am UTC](https://discuss.elastic.co/t/avoiding-unneccessary-datashuffling-during-datanode-downtime/231996/2 "2020-06-08T11:47:01Z")
Closed on June 8, 2020, 11:47am UTC This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.