Re: Stumped By Cassandra delays

2018-07-22 Thread Gareth Collins
Hi Shalom, Thanks very much for the response! We are only using batches on one Cassandra partition to improve performance. Batches are NEVER used in this app across Cassandra partition. And if you look at the trace messages I showed, there is only one statement per batch anyway. In fact, what I

Re: Stumped By Cassandra delays

2018-07-22 Thread shalom sagges
Hi Gareth, If you're using batches for multiple partitions, this may be the root cause you've been looking for. https://inoio.de/blog/2016/01/13/cassandra-to-batch-or-not-to-batch/ If batches are optimally used and only one node is misbehaving, check if NTP on the node is properly synced. Hope

Stumped By Cassandra delays

2018-07-21 Thread Gareth Collins
Hello, We are running Cassandra 2.1.14 in AWS, with c5.4xlarge machines (initially these were m4.xlarge) for our cassandra servers and m4.xlarge for our application servers. On one of our clusters having problems we have 6 C* nodes and 6 AS nodes (two nodes for C*/AS in each availability zone). I