Re: BufferPool always allocates on heap?

2016-06-22 Thread Stefania Alborghetti
Sure, if your analysis is correct we can either add the comment to cassandray.yaml or NEWS.txt, or both. Could you leave a comment with your analysis and suggestion to CASSANDRA-11993? When Branimir is back from holiday he can probably confirm easily if that's the case. On Wed, Jun 22, 2016 at

Re: BufferPool always allocates on heap?

2016-06-22 Thread Nimi Wariboko Jr
Hi Stefania, Thanks for the explanation - I think it may be more likely I'm hitting MEMORY_USAGE_THRESHOLD (file_cache_size_in_mb, which is 512mb by default), as the table itself is very large (a couple TB over 12 nodes). In that case, due to the changes outlined

Re: BufferPool always allocates on heap?

2016-06-22 Thread Stefania Alborghetti
Hi Nimi I am not familiar with how CASSANDRA-5863 uses the buffer pool yet, but I do know how the buffer pool works It has a local pool, which is thread local, and takes chunks from a global pool. These are allocated off heap and aligned to the page cache boundaries, see here

BufferPool always allocates on heap?

2016-06-21 Thread Nimi Wariboko Jr
Hi, I'm trying to debug an issue I'm having with Cassandra 3.6+ and Snappy compressed tables - CASSANDRA-11993 (that may be related to CASSANDRA-5863). I'm probably 3% familiar with Cassandra internals, so apologies if I'm wrong here - I was looking at a change in CASSANDRA-5863 where a cache