# Reindexing indices between clusters

**URL:** <https://discuss.elastic.co/t/reindexing-indices-between-clusters/109316>\
**Category:** Elasticsearch\
**Created:** [November 28, 2017, 6:39am UTC](https://discuss.elastic.co/t/reindexing-indices-between-clusters/109316 "2017-11-28T06:39:58Z")\
**Posts on this page:** 1\
**Showing post:** 31

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**Author:** ![Itay\_Bittan](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/itay_bittan/32/23527_2.png) [@Itay\_Bittan](https://discuss.elastic.co/u/Itay_Bittan)\
**Post date:** [December 11, 2017, 6:40am UTC](https://discuss.elastic.co/t/reindexing-indices-between-clusters/109316/31 "2017-12-11T06:40:41Z")

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One cluster, 16 nodes, two 'logical' zones: worker (indexing) and server (serving); 8 nodes each.  
This cluster will also be separated into two availability zones A & B.  
Till now we have 4 node groups:  
(1) 4 nodes in worker zone, availability zone A  
(2) 4 nodes in worker zone, availability zone B  
(3) 4 nodes in server zone, availability zone A  
(4) 4 nodes in server zone, availability zone B

- full rebuild will be done via group (1) since our builder process runs there.
- delta updates will be done directly on the server zone via group (3).

1. I assume that if group (3) is completely unavailable, group (4) can serve and vice versa. That's why I want to ensure that each set of shared (aka replica) is available in each availability zone. Is it right?
2. How can I ensure that?
3. I don't care which shard is primary, I care about the performance when using two AZ in the same cluster. Can you list the cons please?

Thank you!

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_[View the full topic](https://discuss.elastic.co/t/reindexing-indices-between-clusters/109316)._