Re: Making RF4 useful aka primary and secondary ranges

2018-03-15 Thread Carl Mueller
Close. I'm suggesting that if you have RF4 or 5 or 6, you get to designate a subset of three replicas that are strongly preferred. From this "virtual subset/datacenter" if you do QUORUM against that subset, it just does n/2+1 of the subset. Updates are still sent to the non-primary replicas, and

Re: Making RF4 useful aka primary and secondary ranges

2018-03-14 Thread Jason Brown
I feel like we've had a very similar conversation (not so) recently: https://lists.apache.org/thread.html/9952c419398a1a2f22e2887e3492f9d6899365f0ea7c2b68d6fbe0d4@%3Cuser.cassandra.apache.org%3E Which led to the creation of this JIRA: https://issues.apache.org/jira/browse/CASSANDRA-13645 On

Re: Making RF4 useful aka primary and secondary ranges

2018-03-14 Thread Carl Mueller
Since this is basically driver syntactic sugar... Yes I'll try that. On Wed, Mar 14, 2018 at 5:59 PM, Jonathan Haddad wrote: > You could use a load balancing policy at the driver level to do what you > want, mixed with the existing consistency levels as Jeff suggested. > >

Re: Making RF4 useful aka primary and secondary ranges

2018-03-14 Thread Jonathan Haddad
You could use a load balancing policy at the driver level to do what you want, mixed with the existing consistency levels as Jeff suggested. On Wed, Mar 14, 2018 at 3:47 PM Carl Mueller wrote: > But we COULD have CL2 write (for RF4) > > The extension to this idea

Re: Making RF4 useful aka primary and secondary ranges

2018-03-14 Thread Carl Mueller
But we COULD have CL2 write (for RF4) The extension to this idea is multiple backup/secondary replicas. So you have RF5 or RF6 or higher, but still are performing CL2 against the preferred first three for both read and write. You could also ascertain the general write health of affected ranges

Re: Making RF4 useful aka primary and secondary ranges

2018-03-14 Thread Jeff Jirsa
Write at CL 3 and read at CL 2 -- Jeff Jirsa > On Mar 14, 2018, at 2:40 PM, Carl Mueller > wrote: > > Currently there is little use for RF4. You're getting the requirements of > QUORUM-3 but only one extra backup. > > I'd like to propose something that would

Re: Making RF4 useful aka primary and secondary ranges

2018-03-14 Thread Carl Mueller
I also wonder if the state of hinted handoff can inform the validity of extra replicas. Repair is mentioned in 7168. On Wed, Mar 14, 2018 at 4:55 PM, Carl Mueller wrote: > For my reference: https://issues.apache.org/jira/browse/CASSANDRA-7168 > > > On Wed, Mar 14,

Re: Making RF4 useful aka primary and secondary ranges

2018-03-14 Thread Carl Mueller
For my reference: https://issues.apache.org/jira/browse/CASSANDRA-7168 On Wed, Mar 14, 2018 at 4:46 PM, Ariel Weisberg wrote: > Hi, > > There is a JIRA for decoupling the size of the group size used for > consensus with level of data redundancy. https://issues.apache.org/ >

Re: Making RF4 useful aka primary and secondary ranges

2018-03-14 Thread Ariel Weisberg
Hi, There is a JIRA for decoupling the size of the group size used for consensus with level of data redundancy. https://issues.apache.org/jira/browse/CASSANDRA-13442 It's been discussed quite a bit offline and I did a presentation on it at NGCC. Hopefully we will see some movement on it soon.

Making RF4 useful aka primary and secondary ranges

2018-03-14 Thread Carl Mueller
Currently there is little use for RF4. You're getting the requirements of QUORUM-3 but only one extra backup. I'd like to propose something that would make RF4 a sort of more heavily backed up RF3. A lot of this is probably achievable with strictly driver-level logic, so perhaps it would belong