When upgrading our elasticsearch cluster to version 7.16.1, we performing a rolling upgarde as described in the documentation. Before the restart we trigger a synced flush and increase
After the shard allocation was enabled the node logs multiple multple warings:
Unable to acquire permit to use snapshot files during recovery, this recovery will recover index files from the source node. Ensure snapshot files can be used during recovery by setting [indices.recovery.max_concurrent_snapshot_file_downloads] to be no greater than 
We did not changed
indices.recovery.max_concurrent_snapshot_file_downloads from the default (
What might cause this warning? Is there a known issue when upgrading to 7.16.1?