You are viewing a plain text version of this content. The canonical link for it is here.
Posted to user@cassandra.apache.org by Muntasir Raihan Rahman <mu...@gmail.com> on 2013/08/28 22:33:12 UTC
configuring read write quorums in cassandra
Hello,
Are there any tools (e.g like nodetool) that could be used to change
the cassandra read and write quorums at run-time?
In general what is a good strategy of changing these system parameters
while cassandra is running?
Any pointers could be useful!
Thanks
Muntasir.
Re: configuring read write quorums in cassandra
Posted by Muntasir Raihan Rahman <mu...@gmail.com>.
Thanks!
Muntasir.
On Wed, Aug 28, 2013 at 3:52 PM, Robert Coli <rc...@eventbrite.com> wrote:
> On Wed, Aug 28, 2013 at 1:48 PM, Muntasir Raihan Rahman
> <mu...@gmail.com> wrote:
>>
>> Let us say I set read consistency level = ONE, and I am running the
>> system for a while. Then I want to change the read consistency level
>> to TWO so that reads now wait to hear back from 2 replicas instead of
>> 1 before responding to the client.
>
>
> In general, TWO is only for users who really know what they are doing. Most
> users will use ONE or *_QUORUM.
>
> But changing it is just a matter of changing the ConsistencyLevel of your
> new requests, in your application code.
>
> Changing *replication factor* is a bit more involved.
>
> =Rob
>
--
Best Regards
Muntasir Raihan Rahman
Email: muntasir.raihan@gmail.com
Department of Computer Science,
University of Illinois Urbana Champaign,
3111 Siebel Center,
201 N. Goodwin Avenue,
Urbana, IL 61801
Re: configuring read write quorums in cassandra
Posted by Robert Coli <rc...@eventbrite.com>.
On Wed, Aug 28, 2013 at 1:48 PM, Muntasir Raihan Rahman <
muntasir.raihan@gmail.com> wrote:
> Let us say I set read consistency level = ONE, and I am running the
> system for a while. Then I want to change the read consistency level
> to TWO so that reads now wait to hear back from 2 replicas instead of
> 1 before responding to the client.
In general, TWO is only for users who really know what they are doing. Most
users will use ONE or *_QUORUM.
But changing it is just a matter of changing the ConsistencyLevel of your
new requests, in your application code.
Changing *replication factor* is a bit more involved.
=Rob
Re: configuring read write quorums in cassandra
Posted by Muntasir Raihan Rahman <mu...@gmail.com>.
Thanks for clarifying that!
Muntasir.
On Wed, Aug 28, 2013 at 3:51 PM, Andrey Ilinykh <ai...@gmail.com> wrote:
> Each query has its own consistency level. It has nothing to do with
> cassandra.
>
>
> On Wed, Aug 28, 2013 at 1:48 PM, Muntasir Raihan Rahman
> <mu...@gmail.com> wrote:
>>
>> Sorry, let me clarify.
>>
>> Let us say I set read consistency level = ONE, and I am running the
>> system for a while. Then I want to change the read consistency level
>> to TWO so that reads now wait to hear back from 2 replicas instead of
>> 1 before responding to the client. I want to change this consistency
>> level, and then continue running the system.
>>
>> Does that clarify my query?
>>
>> Thanks
>> Muntasir.
>>
>> On Wed, Aug 28, 2013 at 3:39 PM, Andrey Ilinykh <ai...@gmail.com>
>> wrote:
>> > What do you mean "to change the cassandra read and write quorums"?
>> > Quorum is
>> > quorum, 2 of 3 for example. What do you want to change?
>> >
>> > Andrey
>> >
>> >
>> > On Wed, Aug 28, 2013 at 1:33 PM, Muntasir Raihan Rahman
>> > <mu...@gmail.com> wrote:
>> >>
>> >> Hello,
>> >>
>> >> Are there any tools (e.g like nodetool) that could be used to change
>> >> the cassandra read and write quorums at run-time?
>> >>
>> >> In general what is a good strategy of changing these system parameters
>> >> while cassandra is running?
>> >>
>> >> Any pointers could be useful!
>> >>
>> >> Thanks
>> >> Muntasir.
>> >
>> >
>>
>>
>>
>> --
>> Best Regards
>> Muntasir Raihan Rahman
>> Email: muntasir.raihan@gmail.com
>> Department of Computer Science,
>> University of Illinois Urbana Champaign,
>> 3111 Siebel Center,
>> 201 N. Goodwin Avenue,
>> Urbana, IL 61801
>
>
--
Best Regards
Muntasir Raihan Rahman
Email: muntasir.raihan@gmail.com
Department of Computer Science,
University of Illinois Urbana Champaign,
3111 Siebel Center,
201 N. Goodwin Avenue,
Urbana, IL 61801
Re: configuring read write quorums in cassandra
Posted by Andrey Ilinykh <ai...@gmail.com>.
Each query has its own consistency level. It has nothing to do with
cassandra.
On Wed, Aug 28, 2013 at 1:48 PM, Muntasir Raihan Rahman <
muntasir.raihan@gmail.com> wrote:
> Sorry, let me clarify.
>
> Let us say I set read consistency level = ONE, and I am running the
> system for a while. Then I want to change the read consistency level
> to TWO so that reads now wait to hear back from 2 replicas instead of
> 1 before responding to the client. I want to change this consistency
> level, and then continue running the system.
>
> Does that clarify my query?
>
> Thanks
> Muntasir.
>
> On Wed, Aug 28, 2013 at 3:39 PM, Andrey Ilinykh <ai...@gmail.com>
> wrote:
> > What do you mean "to change the cassandra read and write quorums"?
> Quorum is
> > quorum, 2 of 3 for example. What do you want to change?
> >
> > Andrey
> >
> >
> > On Wed, Aug 28, 2013 at 1:33 PM, Muntasir Raihan Rahman
> > <mu...@gmail.com> wrote:
> >>
> >> Hello,
> >>
> >> Are there any tools (e.g like nodetool) that could be used to change
> >> the cassandra read and write quorums at run-time?
> >>
> >> In general what is a good strategy of changing these system parameters
> >> while cassandra is running?
> >>
> >> Any pointers could be useful!
> >>
> >> Thanks
> >> Muntasir.
> >
> >
>
>
>
> --
> Best Regards
> Muntasir Raihan Rahman
> Email: muntasir.raihan@gmail.com
> Department of Computer Science,
> University of Illinois Urbana Champaign,
> 3111 Siebel Center,
> 201 N. Goodwin Avenue,
> Urbana, IL 61801
>
Re: configuring read write quorums in cassandra
Posted by Muntasir Raihan Rahman <mu...@gmail.com>.
Sorry, let me clarify.
Let us say I set read consistency level = ONE, and I am running the
system for a while. Then I want to change the read consistency level
to TWO so that reads now wait to hear back from 2 replicas instead of
1 before responding to the client. I want to change this consistency
level, and then continue running the system.
Does that clarify my query?
Thanks
Muntasir.
On Wed, Aug 28, 2013 at 3:39 PM, Andrey Ilinykh <ai...@gmail.com> wrote:
> What do you mean "to change the cassandra read and write quorums"? Quorum is
> quorum, 2 of 3 for example. What do you want to change?
>
> Andrey
>
>
> On Wed, Aug 28, 2013 at 1:33 PM, Muntasir Raihan Rahman
> <mu...@gmail.com> wrote:
>>
>> Hello,
>>
>> Are there any tools (e.g like nodetool) that could be used to change
>> the cassandra read and write quorums at run-time?
>>
>> In general what is a good strategy of changing these system parameters
>> while cassandra is running?
>>
>> Any pointers could be useful!
>>
>> Thanks
>> Muntasir.
>
>
--
Best Regards
Muntasir Raihan Rahman
Email: muntasir.raihan@gmail.com
Department of Computer Science,
University of Illinois Urbana Champaign,
3111 Siebel Center,
201 N. Goodwin Avenue,
Urbana, IL 61801
Re: configuring read write quorums in cassandra
Posted by Andrey Ilinykh <ai...@gmail.com>.
What do you mean "to change the cassandra read and write quorums"? Quorum
is quorum, 2 of 3 for example. What do you want to change?
Andrey
On Wed, Aug 28, 2013 at 1:33 PM, Muntasir Raihan Rahman <
muntasir.raihan@gmail.com> wrote:
> Hello,
>
> Are there any tools (e.g like nodetool) that could be used to change
> the cassandra read and write quorums at run-time?
>
> In general what is a good strategy of changing these system parameters
> while cassandra is running?
>
> Any pointers could be useful!
>
> Thanks
> Muntasir.
>