How many users do you have (or expect to be found in system_auth.users)? 5 users. What are the current RF for system_auth and consistency level you are using in cqlsh? 135 in one DC and 227 in the other DC. Consistency level one Did you try to obtain a trace of a timing-out query (with TRACING ON)? Tracing timeout even though I increased it to 120 seconds.
From: Oleksandr Shulgin <oleksandr.shul...@zalando.de> Reply-To: "user@cassandra.apache.org" <user@cassandra.apache.org> Date: Wednesday, August 30, 2017 at 10:19 AM To: User <user@cassandra.apache.org> Subject: Re: system_auth replication factor in Cassandra 2.1 On Wed, Aug 30, 2017 at 5:50 PM, Chuck Reynolds <creyno...@ancestry.com<mailto:creyno...@ancestry.com>> wrote: So I’ve read that if your using authentication in Cassandra 2.1 that your replication factor should match the number of nodes in your datacenter. Is that true? I have two datacenter cluster, 135 nodes in datacenter 1 & 227 nodes in an AWS datacenter. Why do I want to replicate the system_auth table that many times? What are the benefits and disadvantages of matching the number of nodes as opposed to the standard replication factor of 3? The reason I’m asking the question is because it seems like I’m getting a lot of authentication errors now and they seem to happen more under load. Also, querying the system_auth table from cqlsh to get the users seems to now timeout. This is surprising. How many users do you have (or expect to be found in system_auth.users)? What are the current RF for system_auth and consistency level you are using in cqlsh? Did you try to obtain a trace of a timing-out query (with TRACING ON)? Regards, -- Oleksandr "Alex" Shulgin | Database Engineer | Zalando SE | Tel: +49 176 127-59-707