Dynamic adding/removing ZK servers on client

2010-05-03 Thread Dave Wright
I've got a situation where I essentially need dynamic cluster membership, which has been talked about in ZOOKEEPER-107 but doesn't look like it's going to happen any time soon. For now, I'm planning on working around this by having a simple coordinator service on the server nodes that will re-writ

Re: Dynamic adding/removing ZK servers on client

2010-05-03 Thread Gustavo Niemeyer
> I've got a situation where I essentially need dynamic cluster > membership, which has been talked about in ZOOKEEPER-107 but doesn't > look like it's going to happen any time soon. Wow, perfect timing! Vishal K just commented in the ticket moments ago that he's interested in writing it. :-) I'

Re: Dynamic adding/removing ZK servers on client

2010-05-03 Thread Patrick Hunt
On 05/03/2010 07:03 AM, Dave Wright wrote: I've got a situation where I essentially need dynamic cluster membership, which has been talked about in ZOOKEEPER-107 but doesn't look like it's going to happen any time soon. Could you provide some insight into why you need this? Just so we have a

Re: Dynamic adding/removing ZK servers on client

2010-05-03 Thread Mahadev Konar
Hi Dave, Just a question on how do you see it being used, meaning who would call addserver and removeserver? It does seem useful to be able to do this. This is definitely worth working on. You can link it as a subtask of ZOOKEEPER-107. Thanks mahadev On 5/3/10 7:03 AM, "Dave Wright" wrote: >

Re: Dynamic adding/removing ZK servers on client

2010-05-03 Thread Patrick Hunt
Another benefit of ZOOKEEPER-146 - we could use this for some sort of load balancing amongst the ensemble members. The first version could return a static list, however I can see where the HTTPD might be updated to monitor the load on the servers/ensemble and prioritize the list for each client

Re: Dynamic adding/removing ZK servers on client

2010-05-03 Thread Dave Wright
> Hi Dave, > Just a question on how do you see it being used, meaning who would call > addserver and removeserver? It does seem useful to be able to do this. This > is definitely worth working on. You can link it as a subtask of > ZOOKEEPER-107. > In my case, it would be my client application - I

Re: Dynamic adding/removing ZK servers on client

2010-05-03 Thread Ted Dunning
Should this be a znode in the privileged namespace? On Mon, May 3, 2010 at 1:45 PM, Dave Wright wrote: > > Hi Dave, > > Just a question on how do you see it being used, meaning who would call > > addserver and removeserver? It does seem useful to be able to do this. > This > > is definitely wor

Re: Dynamic adding/removing ZK servers on client

2010-05-03 Thread Mahadev Konar
Yeah, that was one of the ideas, I think its been on the jira somewhere ( I forget)... But could be and would definitely be one soln for it. Thanks mahadev On 5/3/10 2:12 PM, "Ted Dunning" wrote: > Should this be a znode in the privileged namespace? > > On Mon, May 3, 2010 at 1:45 PM, Dave Wr

Re: Dynamic adding/removing ZK servers on client

2010-05-03 Thread Dave Wright
> Should this be a znode in the privileged namespace? > I think having a znode for the current cluster members is part of the ZOOKEEPER-107 proposal, with the idea being that you could get/set the membership just by writing to that node. On the client side, you could watch that znode and update yo

Re: Dynamic adding/removing ZK servers on client

2010-05-03 Thread Henry Robinson
On 3 May 2010 16:40, Dave Wright wrote: > > Should this be a znode in the privileged namespace? > > > > I think having a znode for the current cluster members is part of the > ZOOKEEPER-107 proposal, with the idea being that you could get/set the > membership just by writing to that node. On the

Re: Dynamic adding/removing ZK servers on client

2010-05-03 Thread Dave Wright
> > > This is tricky: what happens if the server your client is connected to is > decommissioned by a view change, and you are unable to locate another server > to connect to because other view changes committed while you are > reconnecting have removed all the servers you knew about. We'd need to

avoiding deadlocks on client handle close w/ python/c api

2010-05-03 Thread Kapil Thangavelu
Hi Folks, I'm constructing an async api on top of the zookeeper python bindings for twisted. The intent was to make a thin wrapper that would wrap the existing async api with one that allows for integration with the twisted python event loop (http://www.twistedmatrix.com) primarily using the async