Re: Does replicate_on_write=true imply that CL.QUORUM for reads is unnecessary?

2013-06-02 Thread Andrew Bialecki
Thanks for the clarifications. For future readers, the details of write requests are well documented at http://www.datastax.com/docs/1.2/cluster_architecture/about_client_requests#about-write-requests . On Fri, May 31, 2013 at 4:20 AM, Sylvain Lebresne sylv...@datastax.comwrote: I agree, the

Re: Does replicate_on_write=true imply that CL.QUORUM for reads is unnecessary?

2013-05-31 Thread Peter Schuller
This is incorrect. IMO that page is misleading. replicate on write should normally always be turned on, or the change will only be recorded on one node. Replicate on write is asynchronous with respect to the request and doesn't affect consistency level at all. On Wed, May 29, 2013 at 7:32 PM,

Re: Does replicate_on_write=true imply that CL.QUORUM for reads is unnecessary?

2013-05-31 Thread Sylvain Lebresne
I agree, the page is clearly misleading in its formulation. However, for the sake of being precise, I'll note that it is not untrue strictly speaking. If replicate_on_write is true (the default that you should probably not change unless you consider yourself an expert in the Cassandra counters

Does replicate_on_write=true imply that CL.QUORUM for reads is unnecessary?

2013-05-29 Thread Andrew Bialecki
Quick question about counter columns. In looking at the replicate_on_write setting, assuming you go with the default of true, my understanding is it writes the increment to all replicas on any increment. If that's the case, doesn't that mean there's no point in using CL.QUORUM for reads because

Re: Does replicate_on_write=true imply that CL.QUORUM for reads is unnecessary?

2013-05-29 Thread Andrew Bialecki
To answer my own question, directly from the docs: http://www.datastax.com/docs/1.0/configuration/storage_configuration#replicate-on-write. It appears the answer to this is: Yes, CL.QUORUM isn't necessary for reads. Essentially, replicate_on_write sets the CL to ALL regardless of what you actually