Hi Rob,

1) 1.2.2 on 6 to 12 EC2 m1.xlarge 
2) Quorum R&W . Almost no deletes (just some TTL)
3) Yes
4) On each node once a week (rolling repairs using crontab)
5) The only behavior that is quite odd or unexplained to me is why a repair doesn't fix a counter mismatch between 2 nodes. I mean when I read my counters with a CL.One I have inconsistency (the counter value may change anytime I read it, depending, I guess, on what node I read from. Reading with CL.Quorum fixes this bug, but the data is still wrong on some nodes. About performance, it's quite expensive to run a repair but doing it in a low charge period and in a rolling fashion works quite well and has no impact on the service.

Hope this will help somehow. Let me know if you need more information.


2013/5/10 Robert Coli <rcoli@eventbrite.com>

I have been wondering how Repair is actually used by operators. If
people operating Cassandra in production could answer the following
questions, I would greatly appreciate it.

1) What version of Cassandra do you run, on what hardware?
2) What consistency level do you write at? Do you do DELETEs?
3) Do you run a regularly scheduled repair?
4) If you answered "yes" to 3, what is the frequency of the repair?
5) What has been your subjective experience with the performance of
repair? (Does it work as you would expect? Does its overhead have a
significant impact on the performance of your cluster?)