Technote (troubleshooting)
Problem(Abstract)
InfoSphere Replication Server (Q Replication) uses an MQ client to access a remote queue manager running on zOS. Qapply suffers delays in removing messages from the "Receive queue" (RECVQUEUE) and returns ASN0575E with MQ API Error code 2009.
Symptom
Symptoms include high CPU and slow performance.
Error messages that you may see in the QREP error log include:
-
ASN0575E "Q Apply" : "ASN" : "AdminThread" : The program encountered a WebSphere MQ error "2009" while issuing the WebSphere MQ command "MQBACK" on object "*".
ASN0589I "Q Apply" : "ASN" :"AdminThread" The program received return code "510" from routine "pruneDoneMsg".
ASN0575E "Q Apply" : "ASN" : "AdminThread" : The program encountered a WebSphere MQ error "2009" while issuing the WebSphere MQ command "MQDELETE" on object "QREP.UPDATES".
ASN0575E "Q Apply" : "ASN" : "BR00000" : The program encountered a WebSphere MQ error "2009" while issuing the WebSphere MQ command "MQCLOSE" on object "QREP.ADMIN".
ASN0575E "Q Apply" : "ASN" : "BR00000" : The program encountered a WebSphere MQ error "2009" while issuing the WebSphere MQ command "MQDISC" on object "*".
ASN8999D "Q Apply" : "ASN" : "BR00000" : browser 'BR00000' for queue '<qname>' terminating with code 2012
2012 means MQRC_ENVIRONMENT_ERROR
You might also see the following in the AMQERRnn.LOG:
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Process(20578526.58) User(xxx) Program(asnqapp)
AMQ9271: Channel '<channelname>' timed out.
EXPLANATION:
A timeout occurred while waiting to receive from the other end of channel '<channelname>'. The address of the remote end of the connection was '<ipaddr>.
Cause
The queue on the z/OS queue manager used by QRep is not indexed. This means that when QApply does an MQGET operation using the MSGID, the queue has to be scanned for the matching message. If the queue contains thousands of messages, this scan takes so long that the SVRCONN channel is unable to respond to a Heartbeat request from the client.
Resolving the problem
Set INDXTYPE=MSGID on the queues as described in the topic Required settings for WebSphere MQ objects in the Replication Server Information Center. The index improves the performance of the MQGET operations that are looking for a specific message.
| Segment | Product | Component | Platform | Version | Edition |
|---|---|---|---|---|---|
| Information Management | InfoSphere Replication Server | Misc | AIX, HP-UX, i5/OS, Linux, Solaris, Windows, z/OS |
Product Alias/Synonym
WMQ DB2 QRep Q-Rep Q-Replication
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