# Master up but cluster down **URL:** \ **Category:** Elasticsearch\ **Created:** [August 6, 2020, 6:00pm UTC](https://discuss.elastic.co/t/master-up-but-cluster-down/244078 "2020-08-06T18:00:22Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Musfiqur\_Siddique](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/musfiqur_siddique/32/73048_2.png) [@Musfiqur\_Siddique](https://discuss.elastic.co/u/Musfiqur_Siddique)\ **Post date:** [August 6, 2020, 6:00pm UTC](https://discuss.elastic.co/t/master-up-but-cluster-down/244078/1 "2020-08-06T18:00:23Z")
Is it possible that master node is up but ES cluster is down? ---
**Author:** ![d.silwon](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/d.silwon/32/65853_2.png) [@d.silwon](https://discuss.elastic.co/u/d.silwon)\ **Post date:** [August 6, 2020, 6:29pm UTC](https://discuss.elastic.co/t/master-up-but-cluster-down/244078/2 "2020-08-06T18:29:22Z")
Hi, How do you check the state of cluster? Redgards, Dan ---
**Author:** ![Musfiqur\_Siddique](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/musfiqur_siddique/32/73048_2.png) [@Musfiqur\_Siddique](https://discuss.elastic.co/u/Musfiqur_Siddique)\ **Post date:** [August 6, 2020, 6:32pm UTC](https://discuss.elastic.co/t/master-up-but-cluster-down/244078/3 "2020-08-06T18:32:43Z")
If some nodes of the cluster can still serve request, I would say that it is partially up. What i don't want is the full cluster going down. ---
**Author:** ![d.silwon](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/d.silwon/32/65853_2.png) [@d.silwon](https://discuss.elastic.co/u/d.silwon)\ **Post date:** [August 6, 2020, 6:38pm UTC](https://discuss.elastic.co/t/master-up-but-cluster-down/244078/4 "2020-08-06T18:38:38Z")
The state of cluster you can check in this way: ```auto curl -XGET nodeX:9200 ``` or ```auto curl -XGET nodeX:9200/_cluster/health?pretty ``` if status is green the cluster seems OK. In this way you can check the state of each node of cluster: ```auto curl -XGET nodeX:9200/_cat/nodes ``` where: m – master node, d – data node, i – ingest node, \* - current master node ---
**Author:** ![Musfiqur\_Siddique](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/musfiqur_siddique/32/73048_2.png) [@Musfiqur\_Siddique](https://discuss.elastic.co/u/Musfiqur_Siddique)\ **Post date:** [August 6, 2020, 6:44pm UTC](https://discuss.elastic.co/t/master-up-but-cluster-down/244078/5 "2020-08-06T18:44:02Z")
Thanks for the response. The question is hypothetical. I am trying to understand the value of a "dedicated master node". ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [August 6, 2020, 6:47pm UTC](https://discuss.elastic.co/t/master-up-but-cluster-down/244078/6 "2020-08-06T18:47:15Z")
What is your exact definition of a cluster being down? ---
**Author:** ![d.silwon](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/d.silwon/32/65853_2.png) [@d.silwon](https://discuss.elastic.co/u/d.silwon)\ **Post date:** [August 6, 2020, 6:53pm UTC](https://discuss.elastic.co/t/master-up-but-cluster-down/244078/7 "2020-08-06T18:53:28Z")
> [@Musfiqur\_Siddique](#): > > dedicated master node Hmm, interesting topic. > [@Christian\_Dahlqvist](#): > > What is your exact definition of a cluster being down? In our case we have a cluster with 3 master nodes. If current master mode will down them other will take over his role. ---
**Author:** ![Musfiqur\_Siddique](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/musfiqur_siddique/32/73048_2.png) [@Musfiqur\_Siddique](https://discuss.elastic.co/u/Musfiqur_Siddique)\ **Post date:** [August 6, 2020, 7:12pm UTC](https://discuss.elastic.co/t/master-up-but-cluster-down/244078/8 "2020-08-06T19:12:42Z")
I would consider the cluster is down when none of the nodes are responding and serving any requests. Because of some past mistakes in contracts, we have allowed some bad queries to pass to the cluster. In recent past, we saw multiple ES failures where all nodes went down/became unresponsive. We have 3 dedicated master node now[Previously all nodes were data + master + coordinating]. I want to understand even if some queries are bad, can that bring the whole cluster down in the presence of a dedicated master node? ---
**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\ **Post date:** [August 6, 2020, 7:29pm UTC](https://discuss.elastic.co/t/master-up-but-cluster-down/244078/9 "2020-08-06T19:29:16Z")
In order to serve queries at least some data nodes need to be available. It is potentially possible that all data nodes could be overwhelmed and crash while the dedicated master nodes remain up and available. In such scenario n requests could be served. ---
**Author:** ![Steve\_Mushero](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/steve_mushero/32/22441_2.png) [@Steve\_Mushero](https://discuss.elastic.co/u/Steve_Mushero)\ **Post date:** [August 7, 2020, 2:15am UTC](https://discuss.elastic.co/t/master-up-but-cluster-down/244078/10 "2020-08-07T02:15:57Z")
What is your definition of up or down? You can have a master node up but no data nodes, in which case the cluster status is red and you can't do anything other than get the status, etc. So in that case the cluster is probably 'up', but useless. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [September 4, 2020, 2:16am UTC](https://discuss.elastic.co/t/master-up-but-cluster-down/244078/11 "2020-09-04T02:16:03Z")
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