In one of our LCS table auto compaction was disabled. Now after years of > run, range queries using spark-cassandra-connector are failing. Cassandra > version is 2.1.16. > > I suspect due to disabling of autocompaction lots of tombstones got > created. And now while reading those are creating issues and queries are > getting timed out. Am I right in my thinking? What is the possible way to > get out of this? > > I thought of using major compaction but for LCS that was introduced in > Cassandra 2.2. Also user defined compactions dont work on LCS tables. > > > > Regards > > Manish Khandelwal >
If it's tombstones specifically you'll be able to see errors in the logs regarding passing the tombstone limit. However, disabling compactions could cause lots of problems (especially over years). I wouldn't be surprised if your reads are slow purely because of the number of SSTables you're hitting on each read. Given you've been running without compactions for so long you might want to look at just switching to STCS and re-enabling compactions. Note this should be done with care, as it could cause performance/storage issues. Cheers, Kane -- raft.so - Cassandra consulting, support, and managed services
