Re: Creating ephemeral nodes: First time returns ZNODEEXISTS

2009-08-31 Thread Leonard Cuff
Hi Patrick, Thank you for your reply. I owe you and the others on this list an apology. It turns out I was creating the node twice, which I discovered after writing a mini-program to demonstrate the problem and the mini-program didn't have the problem. That caused me to go back and look at

Re: Creating ephemeral nodes: First time returns ZNODEEXISTS

2009-08-31 Thread Patrick Hunt
Hi Leonard, Between 00:43:23,035 and 00:43:23,157 I see client session 0x123730dbe6e0001 get 15 "node exists" exceptions in a row. Are you expecting this? (ie are you attempting to create this node 15 times in a row or is this unexpected? I can't tell from the client snippet you included) A

Creating ephemeral nodes: First time returns ZNODEEXISTS

2009-08-31 Thread Leonard Cuff
I've just upgraded to ZooKeeper 3.2.0, testing the fix for ephemeral nodes disappearing correctly when the client process dies. I'm seeing some unexpected behavior: The first time I call zoo_create() to create an ephemeral node, it returns ZNODEEXISTS, even if the node didn't previously exist. It

Re: Runtime Interrogation of the Ensemble

2009-08-31 Thread Mahadev Konar
Hi Todd, You can use jmx to to find such information. Also you can just do this Echo stat | nc localhost clientport To get status from the zookeeper servers. This is all documented in the forrest docs at http://hadoop.apache.org/zookeeper/docs/r3.1.1/zookeeperAdmin.html Hope this helps. > En

Runtime Interrogation of the Ensemble

2009-08-31 Thread Todd Greenwood
Is there a way to query an ensemble and find out who is the current leader? Along those lines, what facilities exist for interrogating the ensemble and the ensemble members? I'm thinking (dreaming) of an API like: Ensemble : object representing a zookeeper ensemble Long Ensemble.getLastT

Re: Watches

2009-08-31 Thread Flavio Junqueira
I forgot to mention this. You may also consider adding more zookeeper servers and setting the weight of such servers to zero. We will be introducing this possibility in 3.2.1 (the upcoming release). Zero- weight servers simulate observers, but they do not behave exactly as a observers, since

Re: Watches

2009-08-31 Thread Flavio Junqueira
I agree with Mahadev that it sounds like a stretch. I just wanted to point out that we have been working on a new feature that would certainly help in this case: Observers (ZOOKEEPER-368). I don't think we have decided yet in which release we will include it, but my current guess is 4.0.0 a