Changing the datadrives to SSD would help to speed up the repairs. Also don't run 3 node, RF2. That makes Quorum = All.
Regards, Carlos Juzarte Rolo Cassandra Consultant / Datastax Certified Architect / Cassandra MVP Pythian - Love your data rolo@pythian | Twitter: @cjrolo | Skype: cjr2k3 | Linkedin: *linkedin.com/in/carlosjuzarterolo <http://linkedin.com/in/carlosjuzarterolo>* Mobile: +351 918 918 100 www.pythian.com On Fri, Apr 20, 2018 at 4:42 PM, Nuno Cervaens - Hoist Group - Portugal < nuno.cerva...@hoistgroup.com> wrote: > Hello, > > I have a 3 node cluster with RF 2 and using STCS. I use SSDs for > commitlogs and HDDs for data. Apache Cassandra version is 3.11.2. > I basically have a huge keyspace ('newts' from opennms) and a big keyspace > ('opspanel'). Here's a summary of the 'du' output for one node (which is > more or less the same for each node): > > 51G ./data/opspanel > 776G ./data/newts/samples-00ae9420ea0711e5a39bbd7839a19930 > 776G ./data/newts > > My issue is that running a 'nodetool repair -pr' takes one day an a half > per node and as I want to store daily snapshots (for the past 7 days), I > dont see how I can do this as repairs take too long. > For example I see huge compactions and validations that take lots of hours > (compactionstats taken at different times): > > id compaction type keyspace > table completed total unit progress > 7125eb20-446b-11e8-a57d-f36e88375e31 Compaction newts samples > 294177987449 835153786347 bytes 35,22% > > id compaction type keyspace > table completed total unit progress > 6aa5ce51-4425-11e8-a7c1-572dede7e4d6 Anticompaction after repair > newts samples 581839334815 599408876344 bytes 97,07% > > id compaction type keyspace > table completed total unit progress > 69976700-43e2-11e8-a7c1-572dede7e4d6 Validation newts samples > 63249761990 826302170493 bytes 7,65% > 69973ff0-43e2-11e8-a7c1-572dede7e4d6 Validation newts samples > 102513762816 826302170600 bytes 12,41% > > Is there something I can do to improve the situation? > > Also, is an incremental repair (apparently nodetool's default) safe? As I > see in the datastax documentation that the incremental should not be used, > only the full. Can you please clarify? > > Thanks for the feedback. > Nuno > -- --
