I'm running a Tornado webserver and using ZooKeeper to store some metadata and
occasionally the ZooKeeper connection will error out irrevocably. Any
subsequent calls to ZooKeeper from this process will result in a SystemError.
Here is the relevant portion of the Python traceback:
<snip>...
File "/usr/lib/pymodules/python2.5/zuul/storage/zoo.py", line 69, in call
return getattr(zookeeper, name)(self.handle, *args)
SystemError: NULL result without error in PyObject_Call
I found this in the ZooKeeper server logs:
2010-07-13 06:52:46,488 - INFO
[NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:nioservercnxn$fact...@251] -
Accepted socket connection from /10.2.128.233:54779
2010-07-13 06:52:46,489 - INFO
[NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:nioserverc...@742] - Client
attempting to renew session 0x429b865a6270003 at /10.2.128.233:54779
2010-07-13 06:52:46,489 - INFO
[NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:lear...@95] - Revalidating client:
299973596915630083
2010-07-13 06:52:46,793 - INFO
[QuorumPeer:/0:0:0:0:0:0:0:0:2181:nioserverc...@1424] - Invalid session
0x429b865a6270003 for client /10.2.128.233:54779, probably expired
2010-07-13 06:52:46,794 - INFO
[NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:nioserverc...@1286] - Closed socket
connection for client /10.2.128.233:54779 which had sessionid 0x429b865a6270003
The ZooKeeper ensemble is healthy; each node responds as expected to the four
letter word commands and a simple restart of the Tornado processes "fixes" this.
My question is, if this really is due to session expiration why is a
SessionExpiredException not raised? Another question, is there an easy way to
determine the version of the ZooKeeper Python bindings I'm using? I built the
3.3.0 bindings but I just want to be able to verify that.
Thanks for the help,
Rich
