I was hoping to use synced flush to speed up recovery after a node restart, but I have not been able to make it work. Is it possible to make sure that sync_id does not change for any shards, to avoid copying indices across the network?
I have tried the following without any success:
cluster.routing.allocation.enableis set to
cluster.blocks.read_onlyis set to
- synced flush has been performed successfully on all indices
- Shut down all external processes trying to index, delete or change anything.
Some properties of the cluster:
- 5TB of data
- 10 nodes
- 4000 indices of uneven size.
- 50-100 writes (indexing+delete) per second
- Elasticsearch 5.5
Recovery of just one node takes several hours. I know that it is possible to tune recovery speed by various settings, but it will always be much slower to copy than to use local files.
Is this working as expected? Are there anything else I can do to avoid copying indices across the network when a node is restarted?