Re: Getting a "node exists" code on a sequence create

2010-11-03 Thread Jeremy Stribling
We're building a product for users that aren't used to deploying distributed systems, and we're trying to make it as easy to configure and use as possible. That means not requiring the full list of IP addresses for every node at configuration time; instead, each node can be configured with a s

Re: Getting a "node exists" code on a sequence create

2010-11-03 Thread Benjamin Reed
yes, i think you have summarized the problem nicely jeremy. i'm curious about your reasoning for running servers in standalone mode and then merging. can you explain that a bit more? thanx ben On 11/01/2010 04:51 PM, Jeremy Stribling wrote: I think this is caused by stupid behavior on our ap

Re: Getting a "node exists" code on a sequence create

2010-11-01 Thread Jeremy Stribling
I think this is caused by stupid behavior on our application's part, and the error message just confused me. Here's what I think is happening. 1) 3 servers are up and accepting data, creating sequential znodes under /zkrsm. 2) 1 server dies, the other 2 continue creating sequential znodes. 3)

Re: Getting a "node exists" code on a sequence create

2010-11-01 Thread Jeremy Stribling
Yes, every znode in /zkrsm was created with the sequence flag. We bring up a cluster of three nodes, though we do it in a slightly odd manner to support dynamism: each node starts up as a single-node instance knowing only itself, and then each node is contacted by a coordinator that kills the

Re: Getting a "node exists" code on a sequence create

2010-11-01 Thread Benjamin Reed
how were you able to reproduce it? all the znodes in /zkrsm were created with the sequence flag. right? ben On 11/01/2010 02:28 PM, Jeremy Stribling wrote: We were able to reproduce it. A "stat" on all three servers looks identical: [zk:(CONNECTED) 0] stat /zkrsm cZxid = 9 ctime = Mon Nov 01

Re: Getting a "node exists" code on a sequence create

2010-11-01 Thread Jeremy Stribling
We were able to reproduce it. A "stat" on all three servers looks identical: [zk: (CONNECTED) 0] stat /zkrsm cZxid = 9 ctime = Mon Nov 01 13:01:57 PDT 2010 mZxid = 9 mtime = Mon Nov 01 13:01:57 PDT 2010 pZxid = 12884902218 cversion = 177 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0 dataLen

Re: Getting a "node exists" code on a sequence create

2010-11-01 Thread Jeremy Stribling
Thanks for the reply. It happened every time we called create, not just once. More than that, we tried restarting each of the nodes in the system (one-by-one), including the new master, and the problem continued. Unfortunately we cleaned everything up, and it's not in that state anymore. We

Re: Getting a "node exists" code on a sequence create

2010-11-01 Thread Patrick Hunt
Hi Jeremy, this sounds like a bug to me, I don't think you should be getting the nodeexists when the sequence flag is set. Looking at the code briefly we use the parent's "cversion" (incremented each time the child list is changed, added/removed). Did you see this error each time you called creat