Hey all, Thanks for taking the time to help.
So we have 6 cassandra nodes in 2 Data Centers. Both Data Centers have a replication of 3 - so all nodes have all the data. Over the last 2 days we've noticed that data reads / writes has shifted from balanced to unbalanced (Nodetool status still shows 100% ownership on every node, with similar sizes) For Example We monitor the number of reads / writes of every table via the cassandra JMX metrics. (cassandra.db.read_count) Over the last hour of this run Reads Node 1 (DC1) = 1.79k (seeder) Node 2 (DC1) = 1.92k Node 3 (DC1) = 1.97k Node 1 (DC2) = 2.90k (seeder) Node 2 (DC2) = 1.76k Node 3 (DC2) = 1.19k As you see on DC1, everything is pretty well balanced, but on DC2 the reads favour Node1 over Node 3. I ran a nodetool repair yesterday - ran for 6 hours and when completed didn't change the read balance. Write levels are similar on DC2, but not as bad a reads. Anyone any suggestion on how to rebalance? I'm thinking maybe running a nodetool cleanup in case some of the keys have shifted? Regards Stephen Walsh This email (including any attachments) is proprietary to Aspect Software, Inc. and may contain information that is confidential. If you have received this message in error, please do not read, copy or forward this message. Please notify the sender immediately, delete it from your system and destroy any copies. You may not further disclose or distribute this email or its attachments.
