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We recently had a disk fail in one of our Cassandra node (its a 5 Cassandra 2.2 cluster with replication factor of 3). It took about a week or more to perform a full repair on that node. Each node contains 3/5 of the data and doing nodetool repair repaired 3/5 of the token ranges across all nodes. Now that its been repaired it will most likely repair faster since it did a incremental repair. I am wondering if its a good idea to perform periodic repairs on all nodes using nodetool repair -pr (We are at 2.2 and I think incremental repair is default in 2.2).

I think its a good idea because if performed periodically it will take less time to repair as it only needs to repair non repaired SStables. We also might've had instances where the nodes may've been down for more than the hinted handoff window and we probably didn't do anything about it.

Danish Shrestha
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Yes, its good practice to run scheduled incremental repair. Run repair frequently enough that every node is repaired before reaching the time specified in the gc_grace_seconds setting.

Brad Schoening
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Also, it would be great if you run incremental repair on a frequent basis, combined with full repair less frequently like once per month/week. incremental repair would repair the SSTable which was not marked as repaired before, but full repair could take care more comprehensive case like SSTable rotting. check the reference from datastax:https://docs.datastax.com/en/cassandra/2.1/cassandra/operations/opsRepairNodesWhen.html

Zhong Hu
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  • You should not run both repair strategies in your cluster. Before changing the strategy certain steps are necessary. https://docs.datastax.com/en/cassandra/3.0/cassandra/operations/changeRepairStrategies.html – Stephan Schielke Oct 02 '18 at 11:52