On Wed, Jun 11, 2014 at 10:12 AM, Jeremy Jongsma <jer...@barchart.com> wrote:
> The big problem seems to have been requesting a large number of row keys > combined with a large number of named columns in a query. 20K rows with 20K > columns destroyed my cluster. Splitting it into slices of 100 sequential > queries fixed the performance issue. > > When updating 20K rows at a time, I saw a different issue - > BrokenPipeException from all nodes. Splitting into slices of 1000 fixed > that issue. > > Is there any documentation on this? Obviously these limits will vary by > cluster capacity, but for new users it would be great to know that you can > run into problems with large queries, and how they present themselves when > you hit them. The errors I saw are pretty opaque, and took me a couple days > to track down. > > The first thing that comes to mind is the Multiget section on the Datastax anti-patterns page: http://www.datastax.com/documentation/cassandra/1.2/cassandra/architecture/architecturePlanningAntiPatterns_c.html?scroll=concept_ds_emm_hwl_fk__multiple-gets -psanford
