WebSphere MQ implements more enhancements and improvements with each new version that is released. While major changes receive a lot of fanfare through topics in the IBM Knowledge Center, there are often many behind-the-scenes updates that aren't as major, but still greatly enhance MQ. Sometimes the code is just tightened up a bit or (for MQ on z/OS) service parameters are implemented to help mitigate undesired behavior. Here, we will take a look at some of these changes, code enforcements, and service parameters that Level 2 cites... [More]

Tags:  chin protocol wmq dns tips channels queue mq zos alias

  WebSphere MQ allows independent and asynchronous applications to communicate with each other across a large number of platforms. MQ software is not optimized for storing a large number of messages on a local queue for an extended period of time. MQ can process millions of messages in a short amount of time as throughput but when they sit on the queues and have to be reloaded from memory, it slows the processing and you would likely see performance issues.   If a large number of messages are left on queue, you may see AMQ7234 messages in the... [More]

Tags:  depth mq performance ibm-blog queue amq7234 websphere wmq

Usually when you are faced with a choice it is an either-or kind of choice. You can choose either one or the other. For example, in WebSphere MQ (WMQ), if you have a channel that is trying to deliver a message and it is unable to deliver the message, you have a choice of how that is handled. In the most simplistic view you can choose whether your channel lives OR whether your channel dies. You do this by deciding whether to define a Dead Letter Queue (DLQ) in your queue manager. Since the earliest days of WebSphere MQ, it has been "best... [More]

Tags:  dlq letter queue terminate mq dead usedlq websphere channel wmq

Often, when a user is having problems with WebSphere MQ one of the first questions asked by the IBM MQ support team is "Are there any FDC files?" The terms FFST and FDC are sometimes used synonymously. These are files written by MQ to record errors and dump information about what occurred at the time MQ encountered the error. FFST stands for First Failure Support Technology, and is technology within WebSphere MQ designed to create detailed reports with information about the current state of a queue manager together with historical... [More]

Tags:  manager fdc queue ffst websphere qmgr mq wmq error ffstsummary

The introduction of the multi-instance(MI) concept into the Websphere MQ and WebSphere Message Broker products helped several clients to make use of this freely available high availability feature in their infrastructure. The earlier cat 2 HA support packs IC91 and MC91 became irrelevant with this new functionality in the products. Thus the multi-instances feature made the existing HA user's job very simple. There have been a number of articles and presentations on how to set up multi-instance queue managers and message brokers. I have included... [More]

Tags:  ha multi-instance availability wmb manager wmq websphere queue faq mi high broker

I remember back when I started a queue manager and I had to start all of the ancillary processes after wards.  So I ended up writing start scripts to start the queue manager,  the listener,  the trigger monitor, the channel initiator, and the command server.  Over time, some of those were started as part of the queue manager start up (command server and channel initiator).  In version 6 you could define the listener(s) as a queue manager object and tell the queue manager when they should run.  In addition you can define a service to start... [More]

Tags:  manager start mq queue websphere stop wmq scripts

Every queue manager should have a dead-letter queue (DLQ). What happens when a message cannot be delivered to the destination queue? Local puts If the message is put to a local queue and the message can't be delivered, then the MQPUT fails.  A reason code is returned to the putting application and the application will need to handle, or manual intervention might be required. Remote puts If a receiving channel cannot put the message to its destination queue, then it is placed on the dead letter queue, if one has been defined. If no dead letter... [More]

Tags:  dead-letter manager persistend speed letter queue non dead npmspeed define mq wmq message dlq mqseries webbsphere

Have you ever taken a good look at Performance Events?  Performance event messages help you to react quickly when your queues have too many, or too few messages.  WebSphere MQ performance events let you know when your queues are reaching thresholds that could affect performance. Queue Depth High Events A Queue Depth High event indicates that the number of messages on the queue is greater than or equal to the queue depth high threshold. Queue Depth Low Events A Queue Depth Low event indicates that the number of messages on the queue is less than... [More]

Tags:  performance mq websphere queue wmq high depth low full events

Now that you have moved to WebSphere MQ V6 or WebSphere MQ V7, you have the option to administer all queue managers from a single location using WebSphere MQ Explorer. What a wonderful idea!  No more logging into each system one by one to determine the status of queue managers, creating or deleting queues, or altering object properties (just to name a few functions which can be carried out). Well, you thought you performed everything needed to connect and administer the remote queue manager objects.  However, you are receiving an AMQ4036... [More]

Tags:  mq administration amq4036 manager remote websphere queue

WebSphere MQ V7.0.1 introduced multi-instance queue managers (qmgrs).  To use this feature,  you will need a shared file system on networked storage.  The storage must be accessed by a network file system protocol that is Posix-compliant and supports lease-based locking. Network File System version 4 (NFS v4) satisfies this requirement.  Note: earlier versions of NFS do NOT satisfy this requirement and must not be used with multi-instance queue managers. For more information about requirements and supported platforms for WebSphere... [More]

Tags:  availability qmgrs mult-instance standby manager queue backup websphere failover mq