# Upgrading from 0.19.0 to 0.19.8

**URL:** <https://discuss.elastic.co/t/upgrading-from-0-19-0-to-0-19-8/8342>\
**Category:** Elasticsearch\
**Created:** [July 6, 2012, 5:26pm UTC](https://discuss.elastic.co/t/upgrading-from-0-19-0-to-0-19-8/8342 "2012-07-06T17:26:23Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![VegHead](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/veghead/32/2411_2.png) [@VegHead](https://discuss.elastic.co/u/VegHead)\
**Post date:** [July 6, 2012, 5:26pm UTC](https://discuss.elastic.co/t/upgrading-from-0-19-0-to-0-19-8/8342/1 "2012-07-06T17:26:23Z")

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We have a 10 node cluster out on Amazon EC2 running 0.19.0 and we would  
like to upgrade to 0.19.8 without any down time. Given that it's very easy  
for us to launch new instances, is the easiest approach to simply add new  
nodes running 0.19.8 to the cluster, wait for it to stabilze and then start  
removing the 0.19.0 nodes? Are different minor versions still compatible  
with each other?

And when it comes to major versions (e.g. 0.19.x to 0.20.x, when it comes  
out), we presumably have to maintain two separate clusters and index to  
both of them if we want zero down time?

-Sean

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**Author:** ![drewr](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/drewr/32/7803_2.png) [@drewr](https://discuss.elastic.co/u/drewr)\
**Post date:** [July 6, 2012, 8:00pm UTC](https://discuss.elastic.co/t/upgrading-from-0-19-0-to-0-19-8/8342/2 "2012-07-06T20:00:56Z")

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VegHead wrote:

> We have a 10 node cluster out on Amazon EC2 running 0.19.0 and we  
> would like to upgrade to 0.19.8 without any down time. Given that  
> it's very easy for us to launch new instances, is the easiest  
> approach to simply add new nodes running 0.19.8 to the cluster,  
> wait for it to stabilze and then start removing the 0.19.0 nodes?  
> Are different minor versions still compatible with each other?

There are a few changes in there that would make me nervous. Lucene  
& Netty were both upgraded, not to mention the state changes that led  
up to the dangling index support in 0.19.8 (although Shay may have  
anticipated that in 0.19.0). I don't know if any of that translates  
into inter-node communication issues or not which would be the  
question for a rolling upgrade.

But if you can't afford _any_ downtime, you shouldn't even begin to  
speculate. Copy your cluster as-is (maybe just a subset of nodes)  
and try the upgrade along with a battery of tests. It's the only way  
you'll know for sure.

If you decide you can afford a little bit of downtime, you can  
restart a green cluster with hundreds of large indices in a matter of  
minutes, depending on the hardware. How many indices are we talking  
about here?

> And when it comes to major versions (e.g. 0.19.x to 0.20.x, when it  
> comes out), we presumably have to maintain two separate clusters  
> and index to both of them if we want zero down time?

Yes. Either reindex into the new one and swap it out, or stop  
indexing on the old and leave it up for searching while you get the  
new one up, etc. It sounds like an important enough requirement for  
you that you should put some abstraction above a single ES cluster.

-Drew

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [July 6, 2017, 3:21am UTC](https://discuss.elastic.co/t/upgrading-from-0-19-0-to-0-19-8/8342/3 "2017-07-06T03:21:12Z")

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