# Getting MasterNotDiscoveredException: null in client nodes

**URL:** <https://discuss.elastic.co/t/getting-masternotdiscoveredexception-null-in-client-nodes/258699>\
**Category:** Elasticsearch\
**Created:** [December 15, 2020, 10:22am UTC](https://discuss.elastic.co/t/getting-masternotdiscoveredexception-null-in-client-nodes/258699 "2020-12-15T10:22:09Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![nchalise](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/nchalise/32/130399_2.png) [@nchalise](https://discuss.elastic.co/u/nchalise)\
**Post date:** [December 15, 2020, 10:22am UTC](https://discuss.elastic.co/t/getting-masternotdiscoveredexception-null-in-client-nodes/258699/1 "2020-12-15T10:22:09Z")

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We have 3 master nodes, 2 client nodes, and 8 data nodes. And client nodes ES logs show below mentioned error even though resource usage(JVM and CPU ) looks fine at that time. And cluster went unresponsive mode. ALL nodes are up are running during that period.  
**ES detail:**  
Version: 7.6  
Disk type: st1  
Instance type: master:c5.2xlarge, client:r5.4xlarge, data: c5.9xlarge

**ES logs Error:**  
'org.elasticsearch.discovery.MasterNotDiscoveredException: null  
at org.elasticsearch.action.support.master.TransportMasterNodeAction$AsyncSingleAction$2.onTimeout(TransportMasterNodeAction.java:220) [elasticsearch-7.6.0.jar:7.6.0]  
at org.elasticsearch.cluster.ClusterStateObserver$ContextPreservingListener.onTimeout(ClusterStateObserver.java:325) [elasticsearch-7.6.0.jar:7.6.0]  
at org.elasticsearch.cluster.ClusterStateObserver$ObserverClusterStateListener.onTimeout(ClusterStateObserver.java:252) [elasticsearch-7.6.0.jar:7.6.0]  
at org.elasticsearch.cluster.service.ClusterApplierService$NotifyTimeout.run(ClusterApplierService.java:598) [elasticsearch-7.6.0.jar:7.6.0]  
at org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingRunnable.run(ThreadContext.java:633) [elasticsearch-7.6.0.jar:7.6.0]  
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0\_232]  
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0\_232]  
at java.lang.Thread.run(Thread.java:748) [?:1.8.0\_232]  
org.elasticsearch.discovery.MasterNotDiscoveredException: null at org.elasticsearch.action.support.master.TransportMasterNodeAction$AsyncSingleAction$2.onTimeout(TransportMasterNodeAction.java:220) [elasticsearch-7.6.0.jar:7.6.0] at org.elasticsearch.cluster.ClusterStateObserver$ContextPreservingListener.onTimeout(ClusterStateObserver.java:325) [elasticsearch-7.6.0.jar:7.6.0] at org.elasticsearch.cluster.ClusterStateObserver$ObserverClusterStateListener.onTimeout(ClusterStateObserver.java:252) [elasticsearch-7.6.0.jar:7.6.0] at org.elasticsearch.cluster.service.ClusterApplierService$NotifyTimeout.run(ClusterApplierService.java:598) [elasticsearch-7.6.0.jar:7.6.0] at org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingRunnable.run(ThreadContext.java:633) [elasticsearch-7.6.0.jar:7.6.0] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0\_232] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0\_232] at java.lang.Thread.run(Thread.java:748) [?:1.8.0\_232]'

Is there any suggestions/solution to resolve this?

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<div class="post-metadata">

**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\
**Post date:** [December 21, 2020, 3:23am UTC](https://discuss.elastic.co/t/getting-masternotdiscoveredexception-null-in-client-nodes/258699/2 "2020-12-21T03:23:43Z")

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Can you please post more of the Elasticsearch log, preferably from startup to after the error occured.

Please also format your code/logs/config using the `</>` button, or markdown style back ticks. It helps to make things easy to read which helps us help you 🙂

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [January 18, 2021, 3:24am UTC](https://discuss.elastic.co/t/getting-masternotdiscoveredexception-null-in-client-nodes/258699/3 "2021-01-18T03:24:10Z")

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