This is an informative piece on (anti-entropy) repairs: https://cassandra-zone.com/understanding-repairs/
2016-11-18 8:12 GMT-02:00 wxn...@zjqunshuo.com <wxn...@zjqunshuo.com>: > Thanks Ben for the response. It's very helpfull and it's really what I > want. > > > *From:* Ben Dalling <b.dall...@locp.co.uk> > *Date:* 2016-11-18 18:07 > *To:* user <user@cassandra.apache.org> > *Subject:* Re: Is it a must to run Cassandra repair in scheduled time > Hi Simon, > > See http://www.datastax.com/dev/blog/repair-in-cassandra for a good > explanation. Basically repair is not a good word because it suggests it is > fixing something that is broken. This is not the case. It ensures the > consistency across your cluster. Not running repairs is a VERY BAD THING. > Key things to check are how long do your repairs take and do they affect > the operation of your cluster. Decide how often and when to run them based > on this. The general rule of thumb is to run them within > the gc_grace_seconds. Another good article is *Cassandra’s “Repair” > Should Be Called “Required Maintenance”* which is available at > https://lostechies.com/ryansvihla/2015/09/25/cassandras-repair-should-be- > called-required-maintenance/ > > Best wishes, > > Ben > > On 18 November 2016 at 09:41, wxn...@zjqunshuo.com <wxn...@zjqunshuo.com> > wrote: > >> Hi All, >> I'm new to Cassandra and from the mail chain seemed repair is an >> important thing to do. To avoid trouble in putting Cassandra in production >> environment, I have some questions. >> 1. What exactly does Cassandra repair do? >> 2. I saw someone do repair in scheduled time, daily or weekly. Is it a >> must to do this? >> 3. In which cases do I need to do repair? >> >> Cheers, >> -Simon Wu >> >
