+1 2017-07-27 9:26 GMT+02:00 Marco Massenzio <m.massen...@gmail.com>:
> Why not simply have a microservice that does this for you? > > It may expose an API that allows to either store queries and/or conditions > that trigger the queries (maybe time elapsed, an alert generated, > whatever...) and it would then connect to Cassandra and execute the stored > query(ies). > > Given that there is no client waiting for a response, then latency is not > even a (major) issue, so the extra network hop is probably of little > consequence. > > Why would you want this to be an integral part of Cassandra? > (like Jeff I also am struggling to come up with a concrete use case where > this would be desirable) > > -- > *Marco Massenzio* > http://codetrips.com > > On Wed, Jul 26, 2017 at 11:06 PM, Ke Wang <klwan...@gmail.com> wrote: > > > Hi Jeff, > > > > Thanks for the prompt reply. > > > > I'm sorry I wasn't clear about my use case. Let's say I just want the > > server to execute writes that are not directly generated from clients. It > > can be previously stored queries (the case in my last email), or it can > be > > arbitrarily made-up write requests by the server itself. > > > > Can you describe a little bit more on how to implement serializing the > > mutation into the table? > > > > Best, > > Ke > > > > 2017-07-26 22:57 GMT-07:00 Jeff Jirsa <jji...@apache.org>: > > > > > > > > > > > On 2017-07-26 22:19 (-0700), Ke Wang <klwan...@gmail.com> wrote: > > > > Hello all, > > > > > > > > Is there a way to customize Cassandra to execute a query multiple > > times? > > > > > > > > > > There's always a way... > > > > > > > My use case is the following. When the Cassandra server receives > > queries > > > > from remote clients, besides executing those queries, the server also > > > > stores the queries. In the future, the server can re-execute stored > > > queries > > > > under certain circumstances. > > > > > > > > > > Seems like an unusual request. Where are you storing the queries? Are > > > these reads or writes? For writes you could just serialize the > resulting > > > partitionupdate/mutation into a table a la pre-3.0 hints, and then > > re-play > > > as needed (though tbh I don't really get the use case)? > > > > > > > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: dev-unsubscr...@cassandra.apache.org > > > For additional commands, e-mail: dev-h...@cassandra.apache.org > > > > > > > > >
