The most likely explanation is tombstones in files that won’t be collected as they potentially overlap data in other files with a lower timestamp (especially true if your partition key doesn’t change and you’re writing and deleting data within a partition)
-- Jeff Jirsa > On Jun 19, 2018, at 3:28 AM, Abhishek Singh <abh23...@gmail.com> wrote: > > Hi all, > We using Cassandra for storing events which are time series based > for batch processing once a particular batch based on hour is processed we > delete the entries but we were left with almost 18% deletes marked as > Tombstones. > I ran compaction on the particular CF tombstone didn't come > down. > Can anyone suggest what is the optimal tunning/recommended > practice used for compaction strategy and GC_grace period with 100k entries > and deletes every hour. > > Warm Regards > Abhishek Singh --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org For additional commands, e-mail: user-h...@cassandra.apache.org
