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From "Hiller, Dean" <Dean.Hil...@nrel.gov>
Subject Revisit with another spin: is there any type of table existing on all nodes?
Date Wed, 18 Sep 2013 13:09:06 GMT
The meta information stored on behalf of CQL must exist on all nodes and must update all nodes
as well.

What table type is that meta information stored in?  And is it possible we can use that same
type of table?

After all, this makes M/R blazingly fast to do local lookups in the database (and we just
have additional meta information that is used by all rows).

Are any of the meta tables writeable by a thrift/CQL client such that we could store info
in there without creating new CF's?

Thanks,
Dean

From: <Hiller>, Nrel <Dean.Hiller@nrel.gov<mailto:Dean.Hiller@nrel.gov>>
Date: Friday, September 13, 2013 3:03 PM
To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
Subject: Re: is there any type of table existing on all nodes(slow to up date, fast to read
in map/reduce)?

That's an interesting idea…..so that would be an RF=1 in each data center…..very interesting.

Dean

From: Jonathan Haddad <jon@jonhaddad.com<mailto:jon@jonhaddad.com>>
Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
Date: Friday, September 13, 2013 1:50 PM
To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
Subject: Re: is there any type of table existing on all nodes(slow to up date, fast to read
in map/reduce)?

You could create a bunch of 1 node DCs if you really wanted it.


On Fri, Sep 13, 2013 at 12:29 PM, Hiller, Dean <Dean.Hiller@nrel.gov<mailto:Dean.Hiller@nrel.gov>>
wrote:
Actually, I have been on a few projects where something like that is
useful.  Gemfire(a grid memory cache) had that feature which we used at
another company.  On every project I encounter, there is usually one small
table somewhereŠ.either meta data or something that is infrequently
changing and nice to duplicate on every node.  I bet eventually nosql
stores may start to add it maybe in a few years, but I guess we are not
there yet.

Thanks,
Dean

On 9/13/13 12:24 PM, "Jon Haddad" <jon@jonhaddad.com<mailto:jon@jonhaddad.com>>
wrote:

>It sounds some something that's only useful in a really limited use case.
> In an 11 node cluster it would be quorum reads / writes would need to
>come from 6 nodes.  It would probably be much slower for both reads &
>writes.
>
>It sounds like what you want is a database with replication, not
>partitioning.
>
>On Sep 13, 2013, at 11:15 AM, "Hiller, Dean" <Dean.Hiller@nrel.gov<mailto:Dean.Hiller@nrel.gov>>
wrote:
>
>> When I add nodes though, I would kind of be screwed there, right?  Is
>>there an RF=${nodecount}Šthat would be neat.
>>
>> Dean
>>
>> From: Robert Coli <rcoli@eventbrite.com<mailto:rcoli@eventbrite.com><mailto:rcoli@eventbrite.com<mailto:rcoli@eventbrite.com>>>
>> Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org><mailto:user@cassandra.apache.org<mailto:user@cassandra.apache.org>>"
>><user@cassandra.apache.org<mailto:user@cassandra.apache.org><mailto:user@cassandra.apache.org<mailto:user@cassandra.apache.org>>>
>> Date: Friday, September 13, 2013 12:06 PM
>> To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org><mailto:user@cassandra.apache.org<mailto:user@cassandra.apache.org>>"
>><user@cassandra.apache.org<mailto:user@cassandra.apache.org><mailto:user@cassandra.apache.org<mailto:user@cassandra.apache.org>>>
>> Subject: Re: is there any type of table existing on all nodes(slow to
>>up date, fast to read in map/reduce)?
>>
>> On Fri, Sep 13, 2013 at 10:47 AM, Hiller, Dean
>><Dean.Hiller@nrel.gov<mailto:Dean.Hiller@nrel.gov><mailto:Dean.Hiller@nrel.gov<mailto:Dean.Hiller@nrel.gov>>>
wrote:
>> I was just wondering if cassandra had any special CF that every row
>>exists on every node for smaller tables that we would want to leverage
>>in map/reduce.  The table row count is less than 500k and we are ok with
>>slow updates to the table, but this would make M/R blazingly fast since
>>for every row, we read into this table.
>>
>> Create a keyspace with replication configured such that RF=N?
>>
>> =Rob
>




--
Jon Haddad
http://www.rustyrazorblade.com
skype: rustyrazorblade

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