Failed to read local state, exiting... java.lang.IllegalStateException: ES 2.3.4 upgrade

Hi,
I have upgraded ES cluster with ES 2.3.4. When I start the same, I get following error.
failed to read local state, exiting... java.lang.IllegalStateException: unable to upgrade the mappings for the index

I read somewhere, either I need to delete those indexes if not required or I need re-indexing?
My questions are:
How to do re-indexing? Where is the step by step guide for re-indexing for this case?
If ES is not at all up and running, how can I perform re-indexing?
What is significance of .(dot) in index names?

thanks
Sunil.

I assume you are upgrading from 1.x to 2.3.4?

If ES is not at all up and running, how can I perform re-indexing?

If you do not have the raw data anymore, you will have to start the old elasticsearch version again. Before you do, restore the data folder like it was before the upgrade from a backup and then start elasticsearch with the old version.
(elasticsearch did not really start with the new version so the datafolder is very likely untouched but you should not rely on that.)
If you have not read it yet, here is a blogpost that describes what to take care of before upgrading: https://www.elastic.co/blog/key-point-to-be-aware-of-when-upgrading-from-elasticsearch-1-to-2
. In particular there is a plugin that will tell you what needs to be reindexed.

How to do re-indexing? Where is the step by step guide for re-indexing for this case?

I think logstash has an elasticsearch input and output which should make this easy. A dedicated reindex api is only available from 2.3 onwards.

What is significance of .(dot) in index names?

Having a dot in an index name should not be a problem. Dots in fieldnames are not allowed in 2.3. Is that what you mean?

Hi Britta,
Thanks for the reply.

Can you please explore a bit?

Hi,
Thanks, that helps.
I downloaded migration plugin and found there is conflict because of same field name, same index and same type.
I deleted those mappings.

However, I did not found what to do with closed indexes. Migration checker shows Action needed (in RED) for closed indexes but what action?

br,
Sunil