Re: CL.ONE reads / RR / badness_threshold interaction

2011-04-12 Thread Chris Burroughs
On 04/12/2011 06:27 PM, Peter Schuller wrote: >> So to increase pinny-ness I'll further reduce RR chance and set a >> badness threshold. Thanks all. > > Just be aware that, assuming I am not missing something, while this > will indeed give you better cache locality under normal circumstances > -

Re: CL.ONE reads / RR / badness_threshold interaction

2011-04-12 Thread Peter Schuller
> To now answer my own question, the critical points that are different > from what I said earlier are: that CL.ONE does prefer *one* node (which > one depending on snitch) and that RR uses digests (which are not > mentioned on the wiki page [1]) instead of comparing raw requests. I updated it to

Re: CL.ONE reads / RR / badness_threshold interaction

2011-04-07 Thread Chris Burroughs
Peter, thank you for the extremely detailed reply. To now answer my own question, the critical points that are different from what I said earlier are: that CL.ONE does prefer *one* node (which one depending on snitch) and that RR uses digests (which are not mentioned on the wiki page [1]) instead

Re: CL.ONE reads / RR / badness_threshold interaction

2011-04-07 Thread aaron morton
Nice explanation. Wanted to add the importance of been the first node in the ordered node list, even for CL ONE, is that this is the node sent the data request and it has to return before the CL is considered satisfied. e.g. CL One with RR running, read sent to all 5 replicas, if 3 digest reque

Re: CL.ONE reads / RR / badness_threshold interaction

2011-04-06 Thread Peter Schuller
Ok, I took this opportunity to look look a bit more on this part of the code. My reading of StorageProxy.fetchRows() and related is as follows, but please allow for others to say I'm wrong/missing something (and sorry, this is more a stream of consciousness that is probably more useful to me for le

CL.ONE reads / RR / badness_threshold interaction

2011-04-06 Thread Chris Burroughs
My understanding for For CL.ONE. For the node that receives the request: (A) If RR is enabled and this node contains the needed row --> return immediately and do RR to remaining replicas in background. (B) If RR is off and this node contains the needed row --> return the needed data immediately.