Re: High IO and poor read performance on 3.11.2 cassandra cluster

2018-09-09 Thread Laxmikant Upadhyay
Thank you so much Alexander ! Your doubt was right. It was due to the very high value of readahead only (4 mb). Although We had set readahead value to 8kb in our /etc/rc.local but some how this was not working. we are keeping the value to 64 kb as we this is giving better performance than 8kb. No

Re: Stress Test

2018-09-09 Thread Swen Moczarski
Hi, I found this blog quite helpful: https://www.instaclustr.com/deep-diving-into-cassandra-stress-part-1/ on 1, not sure if I understand your question correctly, but I would not start the stress test process on a Cassandra node which will be under test. on 3, the tool has already with an option t

Re: [EXTERNAL] Re: adding multiple node to a cluster, cleanup and num_tokens

2018-09-09 Thread Jonathan Haddad
Your example only really applies if someone is using a 20 node cluster at RF=1, something I've never seen, but I'm sure exists somewhere. Realistically, RF=3 using racks (or AWS regions) and 21 nodes, means you'll have 3 racks with 7 nodes per rack. Adding a single node is an unlikely operation, y

Re: Using CDC Feature to Stream C* to Kafka (Design Proposal)

2018-09-09 Thread Jonathan Haddad
I'll be honest, I'm having a hard time wrapping my head around an architecture where you use CDC to push data into Kafka. I've worked on plenty of systems that use Kafka as a means of communication, and one of the consumers is a process that stores data in Cassandra. That's pretty normal. Sendin

RE: Configuration parameter to reject incremental repair?

2018-09-09 Thread Steinmaurer, Thomas
Kurt, I have created https://issues.apache.org/jira/browse/CASSANDRA-14709 as a request for enhancement. Not sure if/how this gets attention though. Thanks for your support. Thomas From: kurt greaves Sent: Montag, 13. August 2018 13:30 To: User Subject: Re: Configuration parameter to reject