Re: data modeling question

2009-12-03 Thread Jonathan Ellis
On Thu, Dec 3, 2009 at 3:22 PM, Coe, Robin robin@bluecoat.com wrote:
 I seem to recall some talk about dynamically setting a key space or maybe it 
 was dynamically loading column families?  Is this already a feature request, 
 to your knowledge, or should I open a Jira issue?

https://issues.apache.org/jira/browse/CASSANDRA-44 maybe?

 If yes to opening a Jira issue, should it be the feature of dynamically 
 reloading the config or dynamically creating CFs?

Well, it's sort of the same thing, in that you need the latter and the
former is the simplest way to actually interface with it.

-Jonathan


RE: data modeling question

2009-12-03 Thread Coe, Robin
Yup, this looks like pretty good coverage of the topic.

I *think* I like the idea of Cassandra pushing a CF change to its peers, as 
opposed to managing it by a separate admin task, simply because I wouldn't want 
a change managed by an application admin to be missed because of bad 
communication, forgetfulness, etc., with the Ops team.

So, considering that I currently have to take down a node to make a CF change, 
I'm wondering how to perform automatic failover from my application?  Is there 
a mechanism by which I can request from Cassandra all the destination IP:ports 
for the nodes in a cluster, so I can adapt dynamically?  For example, if I ramp 
up/down Cassandra instances based on server load, I would like my application 
to automatically know what servers are available, to execute automatic 
reconnection when the node I'm connected to goes down.

Thanks,
Robin.


-Original Message-
From: Jonathan Ellis [mailto:jbel...@gmail.com] 
Sent: December 3, 2009 4:32 PM
To: cassandra-user@incubator.apache.org
Subject: Re: data modeling question

On Thu, Dec 3, 2009 at 3:22 PM, Coe, Robin robin@bluecoat.com wrote:
 I seem to recall some talk about dynamically setting a key space or maybe it 
 was dynamically loading column families?  Is this already a feature request, 
 to your knowledge, or should I open a Jira issue?

https://issues.apache.org/jira/browse/CASSANDRA-44 maybe?

 If yes to opening a Jira issue, should it be the feature of dynamically 
 reloading the config or dynamically creating CFs?

Well, it's sort of the same thing, in that you need the latter and the
former is the simplest way to actually interface with it.

-Jonathan


Re: data modeling question

2009-12-03 Thread Jonathan Ellis
On Thu, Dec 3, 2009 at 4:23 PM, Coe, Robin robin@bluecoat.com wrote:
 I *think* I like the idea of Cassandra pushing a CF change to its peers, as 
 opposed to managing it by a separate admin task, simply because I wouldn't 
 want a change managed by an application admin to be missed because of bad 
 communication, forgetfulness, etc., with the Ops team.

Managing this w/in cassandra is bad separation of concerns.

If your ops team really can't be trusted with push this new config
file out then that should be a separate tool.

 So, considering that I currently have to take down a node to make a CF 
 change, I'm wondering how to perform automatic failover from my application?  
 Is there a mechanism by which I can request from Cassandra all the 
 destination IP:ports for the nodes in a cluster, so I can adapt dynamically?

Again, there are standard solutions for this.  Use one. :)  round
robin dns, haproxy, ...

-Jonathan