I've been using the repository-s3 plugin with Elasticsearch 5.3.3 happily for months. A couple of days ago, our regular snapshot restore process started failing. It shows a timeout attempting to read the list of snapshots in the repository.
I can still see the repository listed when I list repositories using this URL:
but when I try to list the snapshots available in the repository like this:
The request just hangs indefinitely. I see no logging at all on the ES host in /var/log/elasticsearch/elasticsearch.log
Nothing related to S3 permissions or the instance running ES has changed (this is all managed by Terraform so I can be quite certain that the configuration has not changed in months).
Can anyone suggest anything I can do to diagnose the problem? Can I turn on debug logging of some kind for the repository-s3 plugin?