On 5/29/2018 3:01 PM, Greg Roodt wrote: > What is the best way to perform a backup of a Solr Cloud cluster? Is there > a way to backup only the leader? From my tests with the collections admin > BACKUP command, all nodes in the cluster need to have access to a shared > filesystem. Surely that isn't necessary if you are backing up the leader or > TLOG replica?
If you have more than one Solr instance in your cloud, then all of those instances must have access to the same filesystem accessed from the same mount point. Together, they will write the entire collection to various subdirectories in that location. I can't find any mention of whether backups are load balanced across the cloud, or if they always use leaders. I would assume the former. If that's how it works, then you don't know which machine is going to do the backup of a given shard. Even if the backup always uses leaders, you can't always be sure of where a leader is. It can change from moment to moment, especially if you're having stability problems with your cloud. At restore time, there's a similar situation. You don't know which machine(s) in the cloud are going to be actually loading index data from the backup location. So they all need to have access to the same data. Thanks, Shawn
