What is 'Retry failed shards'? (Cluster Reroute)

Elastic Stack Elasticsearch
1

Hi,

I'm looking for a way to prevent the loss of shard data piled up during ES shutdown.

Is this document relevant? ↓

'Cluster Reroute' >> 'Retry failed shards'
(https://www.elastic.co/guide/en/elasticsearch/reference/5.0/cluster-reroute.html#_retry_failed_shards)

This document is too short.

What exactly is this document about?
And, how do you use it?

2

Can you elaborate on what you mean by this please?