# Cluster Rolling Upgrade : Necessary to disable replica shard allocation for each node?

**URL:** <https://discuss.elastic.co/t/cluster-rolling-upgrade-necessary-to-disable-replica-shard-allocation-for-each-node/219399>\
**Category:** Elasticsearch\
**Created:** [February 14, 2020, 3:19pm UTC](https://discuss.elastic.co/t/cluster-rolling-upgrade-necessary-to-disable-replica-shard-allocation-for-each-node/219399 "2020-02-14T15:19:50Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Travis](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/travis/32/54079_2.png) [@Travis](https://discuss.elastic.co/u/Travis)\
**Post date:** [February 14, 2020, 3:19pm UTC](https://discuss.elastic.co/t/cluster-rolling-upgrade-necessary-to-disable-replica-shard-allocation-for-each-node/219399/1 "2020-02-14T15:19:51Z")

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Hello Elasticers,

I'm asking if it's really necessary to disable replica shard allocation for each node as described in the [documentation](https://www.elastic.co/guide/en/elasticsearch/reference/current/rolling-upgrades.html#_upgrading_your_cluster)

As this is a cluster setting, why not disable replica shard allocation one time, upgrade all nodes and then re-enable replicas shard allocation at the end ?

Thanks for your feedback ! 🙂

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**Author:** ![DavidTurner](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/davidturner/32/22453_2.png) [@DavidTurner](https://discuss.elastic.co/u/DavidTurner)\
**Post date:** [February 14, 2020, 3:23pm UTC](https://discuss.elastic.co/t/cluster-rolling-upgrade-necessary-to-disable-replica-shard-allocation-for-each-node/219399/2 "2020-02-14T15:23:01Z")

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You should re-enable it and allow the cluster to recover to `green` health after each node if possible. If you do not, your cluster health may end up `red` (i.e. some shards are completely unavailable) during the process, which rather defeats the purpose of doing a rolling upgrade.

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**Author:** ![Travis](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/travis/32/54079_2.png) [@Travis](https://discuss.elastic.co/u/Travis)\
**Post date:** [February 14, 2020, 3:33pm UTC](https://discuss.elastic.co/t/cluster-rolling-upgrade-necessary-to-disable-replica-shard-allocation-for-each-node/219399/3 "2020-02-14T15:33:58Z")

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Ok. So very few chances that someting like that arrive but as this is possible, it's recommended to do it for each node to reduce the risk.

That sounds logic. Thanks @DavidTurner

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**Author:** ![DavidTurner](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/davidturner/32/22453_2.png) [@DavidTurner](https://discuss.elastic.co/u/DavidTurner)\
**Post date:** [February 14, 2020, 4:07pm UTC](https://discuss.elastic.co/t/cluster-rolling-upgrade-necessary-to-disable-replica-shard-allocation-for-each-node/219399/4 "2020-02-14T16:07:07Z")

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I think it's pretty likely to be honest, unless you have stopped all write traffic for the duration of the upgrade. Again, this rather defeats the purpose of doing a rolling upgrade.

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [March 13, 2020, 4:07pm UTC](https://discuss.elastic.co/t/cluster-rolling-upgrade-necessary-to-disable-replica-shard-allocation-for-each-node/219399/5 "2020-03-13T16:07:08Z")

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