MQSeries.net :: View topic - Orphaned Channels not dieing off gracefully

hguapluas · Posted: Fri Jan 26, 2007 5:05 pm Post subject:

Hi all,

Sorry to say up front but I do not have full info on this and am only able to include what I do have. Also, I do not have access to the mainframe where this problem is occurring but rather am on the receiving end of this problem.

Background that I do have is:
Mainframe Z/OS 1.4, MQ Ver 5.3 CSD unknown
our system:
2 W2K3 Ent Server, SP1, MQ Ver 5.3 CSD12 (in a clustered config)

Note: Mainframe is using distributed connections to our cluster

Symptoms:
Whenever there is a hard break in the network connection between these systems, the sender channel from the z/OS system gets orphaned and does not gracefully die-off to allow a reconnect on distributed channel connections to Server 2 in our cluster. Connections to Server 1 are always restored without incident.

Actions taken include:
Users on both ends do stops on channels (both sndr/rcvr) on both ends and attempt to restart channels. Connection from W2K3 to z/OS connects fine but connecton from z/OS to W2K3 fails with error on their side. In line traces, we (W2K3 side) see NO traffic flow of any kind.

If they try MQ Ping, it fails with error which is reported as csxq531e (channel in use or wrong type). We (W2K3 side) saw no traffic flow to confirm successful MQ Ping getting to us. Telnet to target MQ port from z/OS was successful proving network layer was in a functional state.

Action to resolve issue:
I had z/OS user do a Force Stop on the channel multiple times. It was on the 3rd attempted Force Stop that an event was logged on the mainframe showing that the orphaned channel was finally killed off and the channel was now in a ready status to be started.

That's all the info I have from the z/OS side...
--

Has anyone seen this behavior before? It was triggered by a break in network service which was over 3 hours prior to the actions taken to resolve the issue were initiated - yeah, they were slow in responding to this... A search on orphaned channels did not reveal any helpful posts on the board.

Thanks.