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Posted to user@cassandra.apache.org by mo...@gmail.com on 2009/07/14 17:17:59 UTC
replica on in the beginning or added later
as a followup question
the items we are storing are extremely valuable and we are using cassandra
as a sql replacement tool.. ie no more postgres and all data from cassandra,
given cassandra scalability
as we hit limits on postgres and found pgpool-II horizontal partitioning too
clunky and skype, plproxy requires too much rewiring the client code.
should we start with a replica factor 1 and then increase replica factor to
2
or is is prudent to start with a replica factor of 2
Can cassandra replicate even after running for a long time with a replica
factor of 1, if we change the replica factor to say 2 after 2months when we
add more nodes and figure there is enough space now to replicate
thanks
--
Bidegg worlds best auction site
http://bidegg.com
Re: replica on in the beginning or added later
Posted by mo...@gmail.com.
what is quorum for a key?
On Tue, Jul 14, 2009 at 8:25 AM, Jonathan Ellis <jb...@gmail.com> wrote:
> Note that for N=2, quorum write is the same as block-for-all. That is
> why N=3 is more popular, because it allows for one node to be down but
> still give you a quorum for any key.
>
> -Jonathan
>
> On Tue, Jul 14, 2009 at 10:22 AM, <mo...@gmail.com> wrote:
> > starting with replica count 2 is more prudent thanks
> >
> > On Tue, Jul 14, 2009 at 8:21 AM, Jonathan Ellis <jb...@gmail.com>
> wrote:
> >>
> >> although the repair code Stu is working on
> >> (https://issues.apache.org/jira/browse/CASSANDRA-193) could handle
> >> increasing the replica count, IMO there's little sense in relying any
> >> more on features that don't yet exist than necessary. :)
> >>
> >> On Tue, Jul 14, 2009 at 10:17 AM, <mo...@gmail.com> wrote:
> >> > as a followup question
> >> > the items we are storing are extremely valuable and we are using
> >> > cassandra
> >> > as a sql replacement tool.. ie no more postgres and all data from
> >> > cassandra,
> >> > given cassandra scalability
> >> > as we hit limits on postgres and found pgpool-II horizontal
> partitioning
> >> > too
> >> > clunky and skype, plproxy requires too much rewiring the client code.
> >> > should we start with a replica factor 1 and then increase replica
> factor
> >> > to
> >> > 2
> >> > or is is prudent to start with a replica factor of 2
> >> > Can cassandra replicate even after running for a long time with a
> >> > replica
> >> > factor of 1, if we change the replica factor to say 2 after 2months
> when
> >> > we
> >> > add more nodes and figure there is enough space now to replicate
> >> > thanks
> >> >
> >> > --
> >> > Bidegg worlds best auction site
> >> > http://bidegg.com
> >> >
> >
> >
> >
> > --
> > Bidegg worlds best auction site
> > http://bidegg.com
> >
>
--
Bidegg worlds best auction site
http://bidegg.com
Re: replica on in the beginning or added later
Posted by Jonathan Ellis <jb...@gmail.com>.
Note that for N=2, quorum write is the same as block-for-all. That is
why N=3 is more popular, because it allows for one node to be down but
still give you a quorum for any key.
-Jonathan
On Tue, Jul 14, 2009 at 10:22 AM, <mo...@gmail.com> wrote:
> starting with replica count 2 is more prudent thanks
>
> On Tue, Jul 14, 2009 at 8:21 AM, Jonathan Ellis <jb...@gmail.com> wrote:
>>
>> although the repair code Stu is working on
>> (https://issues.apache.org/jira/browse/CASSANDRA-193) could handle
>> increasing the replica count, IMO there's little sense in relying any
>> more on features that don't yet exist than necessary. :)
>>
>> On Tue, Jul 14, 2009 at 10:17 AM, <mo...@gmail.com> wrote:
>> > as a followup question
>> > the items we are storing are extremely valuable and we are using
>> > cassandra
>> > as a sql replacement tool.. ie no more postgres and all data from
>> > cassandra,
>> > given cassandra scalability
>> > as we hit limits on postgres and found pgpool-II horizontal partitioning
>> > too
>> > clunky and skype, plproxy requires too much rewiring the client code.
>> > should we start with a replica factor 1 and then increase replica factor
>> > to
>> > 2
>> > or is is prudent to start with a replica factor of 2
>> > Can cassandra replicate even after running for a long time with a
>> > replica
>> > factor of 1, if we change the replica factor to say 2 after 2months when
>> > we
>> > add more nodes and figure there is enough space now to replicate
>> > thanks
>> >
>> > --
>> > Bidegg worlds best auction site
>> > http://bidegg.com
>> >
>
>
>
> --
> Bidegg worlds best auction site
> http://bidegg.com
>
Re: replica on in the beginning or added later
Posted by mo...@gmail.com.
starting with replica count 2 is more prudent thanks
On Tue, Jul 14, 2009 at 8:21 AM, Jonathan Ellis <jb...@gmail.com> wrote:
> although the repair code Stu is working on
> (https://issues.apache.org/jira/browse/CASSANDRA-193) could handle
> increasing the replica count, IMO there's little sense in relying any
> more on features that don't yet exist than necessary. :)
>
> On Tue, Jul 14, 2009 at 10:17 AM, <mo...@gmail.com> wrote:
> > as a followup question
> > the items we are storing are extremely valuable and we are using
> cassandra
> > as a sql replacement tool.. ie no more postgres and all data from
> cassandra,
> > given cassandra scalability
> > as we hit limits on postgres and found pgpool-II horizontal partitioning
> too
> > clunky and skype, plproxy requires too much rewiring the client code.
> > should we start with a replica factor 1 and then increase replica factor
> to
> > 2
> > or is is prudent to start with a replica factor of 2
> > Can cassandra replicate even after running for a long time with a replica
> > factor of 1, if we change the replica factor to say 2 after 2months when
> we
> > add more nodes and figure there is enough space now to replicate
> > thanks
> >
> > --
> > Bidegg worlds best auction site
> > http://bidegg.com
> >
>
--
Bidegg worlds best auction site
http://bidegg.com
Re: replica on in the beginning or added later
Posted by Jonathan Ellis <jb...@gmail.com>.
although the repair code Stu is working on
(https://issues.apache.org/jira/browse/CASSANDRA-193) could handle
increasing the replica count, IMO there's little sense in relying any
more on features that don't yet exist than necessary. :)
On Tue, Jul 14, 2009 at 10:17 AM, <mo...@gmail.com> wrote:
> as a followup question
> the items we are storing are extremely valuable and we are using cassandra
> as a sql replacement tool.. ie no more postgres and all data from cassandra,
> given cassandra scalability
> as we hit limits on postgres and found pgpool-II horizontal partitioning too
> clunky and skype, plproxy requires too much rewiring the client code.
> should we start with a replica factor 1 and then increase replica factor to
> 2
> or is is prudent to start with a replica factor of 2
> Can cassandra replicate even after running for a long time with a replica
> factor of 1, if we change the replica factor to say 2 after 2months when we
> add more nodes and figure there is enough space now to replicate
> thanks
>
> --
> Bidegg worlds best auction site
> http://bidegg.com
>