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Posted to user@cassandra.apache.org by Даниел Симеонов <ds...@gmail.com> on 2010/05/05 12:22:42 UTC
eventuality
Hi,
I have one question about the eventuality, i.e. do you know what are the
variables from which it depends. Well the most obvoius is the
ConsistencyLevel, so lets assume it is set to ONE. The question is that the
eventuallity is the relative time to spread changes across the cassandra
nodes. I suspect that the most important variables are the network latency
and utilization (number of replicas) and number of concurrent requests from
clients, I think the other variables like CPU power and memory are not so
important. Do you have practical observations about this topic. Thank you
very much!
Best regards, Daniel.
Re: eventuality
Posted by Даниел Симеонов <ds...@gmail.com>.
Hi,
You are right, but I have the feeling that this is a different use cases,
i.e. we have a happy case (eventuality when everything is up and working)
and not so happy one to say.
Best regards, Daniel.
2010/5/5 Peter Schüller <sc...@spotify.com>
> > I have one question about the eventuality, i.e. do you know what are
> the
> > variables from which it depends. Well the most obvoius is the
> > ConsistencyLevel, so lets assume it is set to ONE. The question is that
> the
> > eventuallity is the relative time to spread changes across the cassandra
> > nodes. I suspect that the most important variables are the network
> latency
> > and utilization (number of replicas) and number of concurrent requests
> from
> > clients, I think the other variables like CPU power and memory are not so
> > important. Do you have practical observations about this topic. Thank you
> > very much!
>
> Don't forget nodes going down. The "ONE" node that took your write
> could have gone down immediately afterwards. "Eventually" can be a
> significant period into the future.
>
> --
> / Peter Schuller aka scode
>
Re: eventuality
Posted by Peter Schüller <sc...@spotify.com>.
> I have one question about the eventuality, i.e. do you know what are the
> variables from which it depends. Well the most obvoius is the
> ConsistencyLevel, so lets assume it is set to ONE. The question is that the
> eventuallity is the relative time to spread changes across the cassandra
> nodes. I suspect that the most important variables are the network latency
> and utilization (number of replicas) and number of concurrent requests from
> clients, I think the other variables like CPU power and memory are not so
> important. Do you have practical observations about this topic. Thank you
> very much!
Don't forget nodes going down. The "ONE" node that took your write
could have gone down immediately afterwards. "Eventually" can be a
significant period into the future.
--
/ Peter Schuller aka scode