Have you considered the fantastic DeletingCompactionStrategy? https://github.com/protectwise/cassandra-util/tree/master/deleting-compaction-strategy <https://github.com/protectwise/cassandra-util/tree/master/deleting-compaction-strategy>
> On Sep 21, 2017, at 11:51 AM, Jeff Jirsa <jji...@gmail.com> wrote: > > The major compaction is most efficient but can temporarily double (nearly) > disk usage - if you can afford that, go for it. > > Alternatively you can do a user-defined compaction on each sstable in reverse > generational order (oldest first) and as long as the data is minimally > overlapping it’ll purge tombstones that way as well - takes longer but much > less disk involved. > > > > -- > Jeff Jirsa > > > On Sep 21, 2017, at 11:27 AM, Durity, Sean R <sean_r_dur...@homedepot.com > <mailto:sean_r_dur...@homedepot.com>> wrote: > >> Cassandra version 2.0.17 (yes, it’s old – waiting for new hardware/new OS to >> upgrade) >> >> In a long-running system with billions of rows, TTL was not set. So a >> one-time purge is being planned to reduce disk usage. Records older than a >> certain date will be deleted. The table uses size-tiered compaction. Deletes >> are probably 25-40% of the complete data set. To actually recover the disk >> space, would you recommend a major compaction after the gc_grace_seconds >> time? I expect compaction would then need to be scheduled regularly (ick)… >> >> We also plan to re-insert the remaining data with a calculated TTL, which >> could also benefit from compaction. >> >> >> Sean Durity >> >> >> The information in this Internet Email is confidential and may be legally >> privileged. It is intended solely for the addressee. Access to this Email by >> anyone else is unauthorized. If you are not the intended recipient, any >> disclosure, copying, distribution or any action taken or omitted to be taken >> in reliance on it, is prohibited and may be unlawful. When addressed to our >> clients any opinions or advice contained in this Email are subject to the >> terms and conditions expressed in any applicable governing The Home Depot >> terms of business or client engagement letter. The Home Depot disclaims all >> responsibility and liability for the accuracy and content of this attachment >> and for any damages or losses arising from any inaccuracies, errors, >> viruses, e.g., worms, trojan horses, etc., or other items of a destructive >> nature, which may be contained in this attachment and shall not be liable >> for direct, indirect, consequential or special damages in connection with >> this e-mail message or its attachment.
