Cool - yeah we are still on astyanax mode drivers and our own built from scratch 100% non blocking Scala driver that we used in akka like environments
Sent from my iPhone > On Oct 10, 2015, at 12:12 AM, Steve Robenalt <sroben...@highwire.org> wrote: > > Hi Graham, > > I've used the Java driver's DowngradingConsistencyRetryPolicy for that in > cases where it makes sense. > > Ref: > http://docs.datastax.com/en/drivers/java/2.1/com/datastax/driver/core/policies/DowngradingConsistencyRetryPolicy.html > > Steve > > > >> On Fri, Oct 9, 2015 at 6:06 PM, Graham Sanderson <gra...@vast.com> wrote: >> Actually maybe I'll open a JIRA issue for a (local)quorum_or_one consistency >> level... It should be trivial to implement on server side with exist >> timeouts ... I'll need to check the CQL protocol to see if there is a good >> place to indicate you didn't reach quorum (in time) >> >> Sent from my iPhone >> >>> On Oct 9, 2015, at 8:02 PM, Graham Sanderson <gra...@vast.com> wrote: >>> >>> Most of our writes are not user facing so local_quorum is good... We also >>> read at local_quorum because we prefer guaranteed consistency... But we >>> very quickly fall back to local_one in the cases where some data fast is >>> better than a failure. Currently we do that on a per read basis but we >>> could I suppose detect a pattern or just look at the gossip to decide to go >>> en masse into a degraded read mode >>> >>> Sent from my iPhone >>> >>>> On Oct 9, 2015, at 5:39 PM, Steve Robenalt <sroben...@highwire.org> wrote: >>>> >>>> Hi Brice, >>>> >>>> I agree with your nit-picky comment, particularly with respect to the OP's >>>> emphasis, but there are many cases where read at ONE is sufficient and >>>> performance is "better enough" to justify the possibility of a wrong >>>> result. As with anything Cassandra, it's highly dependent on the nature of >>>> the workload. >>>> >>>> Steve >>>> >>>> >>>>> On Fri, Oct 9, 2015 at 12:36 PM, Brice Dutheil <brice.duth...@gmail.com> >>>>> wrote: >>>>>> On Fri, Oct 9, 2015 at 2:27 AM, Steve Robenalt <sroben...@highwire.org> >>>>>> wrote: >>>>>> >>>>>> In general, if you write at QUORUM and read at ONE (or LOCAL variants >>>>>> thereof if you have multiple data centers), your apps will work well >>>>>> despite the theoretical consistency issues. >>>>> >>>>> Nit-picky comment : if consistency is something important then reading at >>>>> QUORUM is important. If read is ONE then the read operation may not see >>>>> important update. The safest option is QUORUM for both write and read. >>>>> Then depending on the business or feature the consistency may be tuned. >>>>> >>>>> — Brice >>>>> >>>> >>>> >>>> >>>> -- >>>> Steve Robenalt >>>> Software Architect >>>> sroben...@highwire.org >>>> (office/cell): 916-505-1785 >>>> >>>> HighWire Press, Inc. >>>> 425 Broadway St, Redwood City, CA 94063 >>>> www.highwire.org >>>> >>>> Technology for Scholarly Communication > > > > -- > Steve Robenalt > Software Architect > sroben...@highwire.org > (office/cell): 916-505-1785 > > HighWire Press, Inc. > 425 Broadway St, Redwood City, CA 94063 > www.highwire.org > > Technology for Scholarly Communication
