# ClusterBlockException when master servers(s) return

**URL:** https://discuss.elastic.co/t/clusterblockexception-when-master-servers-s-return/44260
**Category:** Elasticsearch
**Created:** [March 13, 2016, 2:45pm UTC](https://discuss.elastic.co/t/clusterblockexception-when-master-servers-s-return/44260 "2016-03-13T14:45:59Z")
**Posts on this page:** 1
**Showing post:** 2

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### 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: [March 14, 2016, 1:05am UTC](https://discuss.elastic.co/t/clusterblockexception-when-master-servers-s-return/44260/2 "2016-03-14T01:05:29Z")

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> [@Matt\_Chambers](#):
>
> Also, can I catch the ClusterBlockException and then force the unicast discovery to happen, then retry? What Java API call I can make to try and do unicast discovery again?

You can't.

The only option I can think of would be to reduce some of these - [Zen Discovery | Elasticsearch Guide [2.2] | Elastic](https://www.elastic.co/guide/en/elasticsearch/reference/2.2/modules-discovery-zen.html#fault-detection)

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