# Understanding shard promotion: how can I tell it occurred/what should I look for?

**URL:** <https://discuss.elastic.co/t/understanding-shard-promotion-how-can-i-tell-it-occurred-what-should-i-look-for/147493>\
**Category:** Elasticsearch\
**Created:** [September 6, 2018, 4:22am UTC](https://discuss.elastic.co/t/understanding-shard-promotion-how-can-i-tell-it-occurred-what-should-i-look-for/147493 "2018-09-06T04:22:30Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![khyron4eva](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/khyron4eva/32/35234_2.png) [@khyron4eva](https://discuss.elastic.co/u/khyron4eva)\
**Post date:** [September 6, 2018, 4:22am UTC](https://discuss.elastic.co/t/understanding-shard-promotion-how-can-i-tell-it-occurred-what-should-i-look-for/147493/1 "2018-09-06T04:22:30Z")

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I've got a few somewhat theoretical questions about replica shard promotion in the face of node failure. All questions are relative to version 2.4.4 **and** 6.2+ (as my next upgrade will be from the former to the latter).

First, what log entries would indicate that a replica was promoted to primary? What log level needs to be enabled to see this, either on the master and/or on a data node? Are there other indications of promotion, successful or otherwise? As things stand now, when I test node failure, I have yet to see in the cluster logs any indication of successful promotion of a replica.

Second, under what configuration conditions should promotion occur? What configuration directives are necessary and sufficient for promotion to occur?

Lastly, I read [this](https://www.elastic.co/guide/en/elasticsearch/reference/current/cluster-reroute.html) recently so I'd like a bit more color here:

`An up-to-date shard copy of the data cannot be found on the current data nodes in the cluster. To prevent data loss, the system does not automatically promote a stale shard copy to primary.`

What is the best way to identify whether I have a stale shard that cannot be promoted? Could slow cluster state updates/propagation cause shards to become stale, especially under load?

I would love to get a bit more clarity around this situation as searches through Github issues found few related to promotion. I'm troubleshooting a situation and trying to discern whether forcing failure of a node in my test environment actually leads to successful replica promotion. I would expect my cluster status to turn RED for up to 30 seconds but not the ~ 120 seconds which really occurs (at which point the "failed" node has re-joined the cluster).

Thank you in advance for any insight offered.

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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:** [October 4, 2018, 4:22am UTC](https://discuss.elastic.co/t/understanding-shard-promotion-how-can-i-tell-it-occurred-what-should-i-look-for/147493/2 "2018-10-04T04:22:39Z")

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Closed on October 4, 2018, 4:22am UTC

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