> When you say that it grows constantly, does that mean up to 30 or even > farther?
My total data size is 2TB Actually, I never see the count stable. When it reached 30 I thinked "I am reaching the default upper limit for a compaction, something went wrong" and I went back to 1GB memtables (also, I saw bigger read latencies). Well, I think you are right: I am CPU bounded on compaction, because I see during compactions a single jvm thread which is almost all the time in running state and the disk is not used beyond 50%. > (A nice future improvement would be to allow for concurrent compaction > so that Cassandra would be able to utilize multiple CPU cores which > may mitigate this if you have left-over CPU. However, this is not > currently supported.) Yes, sure. I'd be happy to test, but I don't dare to alter the code :-) I think that a partial solution would help: if the compaction compacted to 'n' diferents new sstables (not one), the implementation would be easier. I mean, the compaction would compact, for instance, 10 sstables to 2 (being 2 the level of paralelism). In this way, the sstables count would remain eventually stable (although higher). What do you think? Carlos.
