APAR status
Closed as program error.
Error description
Customer observes 2 issues: - A large number of FDCs being generated by the MQ Telemetry channel, with probeID XR051002, and Exception cause "java.lang.Exception: mqcd<mqsc>:json at com.ibm.mq.MQXRService.MQTransmitQueueMessage parseRfh2(MQTransmitQueueMessage.java:798)" - A build up of messages on the SYSTEM.MQTT.TRANSMIT.QUEUE and very slow performances.
Local fix
n/a
Problem summary
**************************************************************** USERS AFFECTED: This issue affects users of: - The MQ V8 Telemetry channel. - The MQ V9 Telemetry channel. who have: - MQ TT clients which publish messages on a topic, where the messages have the "Msd" field within the <mcd> folder within the MQRFH2 header set to a value other than the ones shown below: - jms_bytes - jms_map - jms_none - jms_object - jms_stream - jms_text - mrm - xmlnsc - xmlns - xml - mime - idoc - none - And MQ TT clients that subscribe to the same topic. Platforms affected: MultiPlatform **************************************************************** PROBLEM DESCRIPTION: When the MQ Telemetry channel is given a message to forward on to an MQTT subscriber, it looks at the Msd field within the <mcd> folder in the MQRFH2 header for the message to determine how to treat the message payload. The MQ Telemetry channel expects this field to have one of the following values: - jms_bytes - jms_map - jms_none - jms_object - jms_stream - jms_text - mrm - xmlnsc - xmlns - xml - mime - idoc - none If the Msd field was set to a different value, then the MQ Telemetry channel would treat the message payload as bytes when forwarding it on to an MQ TT subscriber. However, the channel would also generate an FDC containing probe identifier XR051002. If every message that was processed by the MQ Telemetry channel had the Msd field set to an unexpected value, then it would generate an FDC for every message. As well as filling up the file system on the machine where the queue manager was running, this also affected the performance of the MQ Telemetry channel (generating an FDC is quite a performance intensive operation) which resulted in messages building up on the system queue SYSTEM.MQTT.TRANSMIT.QUEUE used by the channel.
Problem conclusion
The MQ Telemetry channel has been updated so that it does not generate an FDC if it is asked to process a message where the Msd field within the <msd>folder within the MQRFH2 header of a message is set to an unexpected value. FDCs should only be generated for errors that are severe, and potentially unrecoverable, and they usually indicate either a configuration issue or an internal problem with an MQ component. In this case, the MQ Telemetry channel has been asked to process a message which has an unexpected format. The channel is able to process this message, so the error is not unrecoverable, and there is no internal MQ issue or configuration issue, which means that an FDC is not required here. --------------------------------------------------------------- The fix is targeted for delivery in the following PTFs: Version Maintenance Level v8.0 8.0.0.7 v9.0 LTS 9.0.0.2 The latest available maintenance can be obtained from 'WebSphere MQ Recommended Fixes' http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037 If the maintenance level is not yet available information on its planned availability can be found in 'WebSphere MQ Planned Maintenance Release Dates' http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309 ---------------------------------------------------------------
Temporary fix
Comments
APAR Information
APAR number
IT19521
Reported component name
WMQ BASE MULTIP
Reported component ID
5724H7251
Reported release
800
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2017-03-09
Closed date
2017-03-27
Last modified date
2017-03-27
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
WMQ BASE MULTIP
Fixed component ID
5724H7251
Applicable component levels
R800 PSY
UP
[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSYHRD","label":"IBM MQ"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"8.0.0.0","Edition":"","Line of Business":{"code":"LOB45","label":"Automation"}}]
Document Information
Modified date:
27 March 2017