We’ve found with incremental repairs that more frequent repairs are generally better. Our current standard for incremental repairs is once per day. I imagine that the exact optimum frequency is dependant on the ratio of reads to write in your cluster.
Turning on incremental repairs from the get-go works OK if your data load is increment. If you do a big load before your first incremental repair then it’s not much different to migrating to incremental repairs so worth following the procedures for migration to avoid a big impact. Cheers Ben On Tue, 17 May 2016 at 16:50 Ashic Mahtab <as...@live.com> wrote: > Hi All, > My previous cassandra clusters had moderate loads, and I'd simply schedule > full repairs at different times in the week (but on the same day). That > seemed to work ok, but was redundant. In my current project, I'm going to > need to care about repair times a lot more, and was wondering what would be > the best way to go about it. I have a few questions around this: > > * This would be a brand new cluster, and as such, was wondering if I could > simply turn on incremental repair from the get go. > * I would then run nodetool repair -pr -par -inc once a week on every node > at (roughly) the same time once a week. I'd do this with a cron job / > external scheduler. > * If I were to replace a node, or one rejoins after being absent for > longer than the grace period, I'd run a full repair on that node. > > Does this sound reasonable? Are there any pitfalls I should be aware of? > > Thanks, > Ashic. > -- ———————— Ben Slater Chief Product Officer, Instaclustr +61 437 929 798
