I am fairly new to Cassandra. We have a 9 node cluster, 5 in one DC and 4 in another.
Running a repair on a large column family seems to be moving much slower than I expect. Looking at nodetool compaction stats it indicates the Validation phase is running that the total bytes is 4.5T (4505336278756). This is a very large CF. The process has been running for 2.5 hours and has processed 71G (71950433062). That rate is about 28.4 GB per hour. At this rate it will take 158 hours, just shy of 1 week. Is this reasonable? This is my first large repair and I am wondering if this is normal for a CF of this size. Seems like a long time to me. Is it possible to tune this process to speed it up? Is there something in my configuration that could be causing this slow performance? I am running HDDs, not SSDs in a JBOD configuration. Gene Robichaux Manager, Database Operations Match.com 8300 Douglas Avenue I Suite 800 I Dallas, TX 75225 Phone: 214-576-3273
