On Tue, Nov 25, 2014 at 10:45 AM, Dan Kinder <dkin...@turnitin.com> wrote:
> To be clear, I expect this range query to take a long time and perform > relatively heavy I/O. What I expected Cassandra to do was use auto-paging ( > https://issues.apache.org/jira/browse/CASSANDRA-4415, > http://stackoverflow.com/questions/17664438/iterating-through-cassandra-wide-row-with-cql3) > so that we aren't literally pulling the entire thing in. Am I > misunderstanding this use case? Could you clarify why exactly it would slow > way down? It seems like with each read it should be doing a simple range > read from one or two sstables. > If you're paging through a single partition, that's likely to be fine. When you said "range reads ... over rows" my impression was you were talking about attempting to page through millions of partitions. With that confusion cleared up, the likely explanation for lack of availability in your case is heap pressure/GC time. Look for GCs around that time. Also, if you're using authentication, make sure that your authentication keyspace has a replication factor greater than 1. =Rob
