# SERVICE\_UNAVAILABLE/2/no master

**URL:** <https://discuss.elastic.co/t/service-unavailable-2-no-master/44219>\
**Category:** Elasticsearch\
**Created:** [March 12, 2016, 3:27am UTC](https://discuss.elastic.co/t/service-unavailable-2-no-master/44219 "2016-03-12T03:27:31Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![wangyz2015](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@wangyz2015](https://discuss.elastic.co/u/wangyz2015)\
**Post date:** [March 12, 2016, 3:27am UTC](https://discuss.elastic.co/t/service-unavailable-2-no-master/44219/1 "2016-03-12T03:27:31Z")

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hi,all  
my cluster has 24 nodes 6 machines(4 nodes per machine), one server seem not work yesterday,  
but my client print this error frequency:"org.elasticsearch.cluster.block.ClusterBlockException: blocked by: [SERVICE\_UNAVAILABLE/2/no master]",it is confused to me,because my cluster works well.

```
how can ti be ?
```

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<div class="post-metadata">

**Author:** ![wangyz2015](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@wangyz2015](https://discuss.elastic.co/u/wangyz2015)\
**Post date:** [March 15, 2016, 1:31am UTC](https://discuss.elastic.co/t/service-unavailable-2-no-master/44219/2 "2016-03-15T01:31:12Z")

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supplement：  
esVersion:1.7  
status:green  
elasticsearch.yml:  
action.disable\_delete\_all\_indices: true  
bootstrap.mlockall: true

index.refresh\_interval: 10s  
index.number\_of\_shards: 32  
index.number\_of\_replicas: 13  
index.query.bool.max\_clause\_count: 65535  
index.translog.flush\_threshold\_ops: 100000  
index.store.throttle.type: none  
index.merge.scheduler.max\_thread\_count: 1  
index.cache.field.type: soft  
indices.memory.index\_buffer\_size: 30%  
indices.memory.min\_shard\_index\_buffer\_size: 256mb  
indices.recovery.max\_bytes\_per\_sec: 400mb  
indices.fielddata.cache.size: -1

cluster.routing.allocation.cluster\_concurrent\_rebalance: 4  
cluster.routing.allocation.node\_initial\_primaries\_recoveries: 18

discovery.zen.ping.multicast.enabled: false  
discovery.zen.ping.unicast.hosts: [XXXXXX]

discovery.zen.minimum\_master\_nodes: 15  
gateway.recover\_after\_time: 5m

only when index, the problem occurs.

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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:** [July 5, 2017, 11:08pm UTC](https://discuss.elastic.co/t/service-unavailable-2-no-master/44219/3 "2017-07-05T23:08:33Z")

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