How to update ElasticSearch 1.3.* to 1.4.* on production?

Question

elasticsearch

There is an elasticsearch (v1.3.6) cluster for 300kk+ documents on three productive machines. What ways to upgrade to v1.4.* without stopping the entire cluster can you suggest?

Answer 1

You've read the documentation carefully , haven't you? Migration from 1.3 to 1.4 does not require a complete restart of the entire cluster and can be performed node by node. You have only three of them, so you can do everything manually.
Of course, if your application uses any functionality that is broken backwards , then you should update the application code first, but this is also quite doable.