{"id":875,"date":"2021-04-08T15:09:54","date_gmt":"2021-04-08T14:09:54","guid":{"rendered":"https:\/\/marketaylor.synology.me\/?p=875"},"modified":"2021-05-04T20:50:16","modified_gmt":"2021-05-04T19:50:16","slug":"ibm-mq-spring-boot-queue-manager-connections-logging","status":"publish","type":"post","link":"https:\/\/marketaylor.synology.me\/?p=875","title":{"rendered":"What did Spring do to my queue manager"},"content":{"rendered":"\n

If you’ve done any work with the Spring frameworks for Java programs, then you will know that one of the good things about Spring is that it hides a lot of the underlying operations from you. But equally, one of the bad things about Spring is that it hides a lot of the underlying operations from you. I noticed that I was getting several questions about what was happening under the covers from people using the MQ Spring Boot starter<\/a>. This post shows how you can see what Spring is doing to a queue manager. <\/p>\n\n\n\n\n\n\n\n

The MQ Spring Boot starter has two primary concerns. I wrote a general introduction to the MQ starter in this post<\/a>. But briefly, it first gives a single artifact that can be used in your programs without needing to know any further about dependencies.<\/p>\n\n\n\n

It also enables simple configuration of the ConnectionFactory objects used by a JMS program, with sensible default values and non-default values or overrides provided by external configuration files. Just about everything else in the JMS API can be handled by the Spring core classes and methods. But in this starter, we need to get involved in the connection process which is so specific to the MQ provider – what are the configuration parameters, what are some of the default session options and so on.<\/p>\n\n\n\n

Connection Types<\/h3>\n\n\n\n

It’s understanding a bit more about that connection management that I thought I’d write today. Spring has a number of APIs and mechanisms to configure how connections are made. In the simplest case, you use the JMSTemplate<\/a> class. But that can be very inefficient if you use it frequently without additional options. The JavaDoc for that class even says: <\/p>\n\n\n\n

“NOTE: The ConnectionFactory<\/code> used with this template should return pooled Connections (or a single shared Connection) as well as pooled Sessions and MessageProducers. Otherwise, performance of ad-hoc JMS operations is going to suffer.<\/strong>“<\/p><\/blockquote>\n\n\n\n

But outside of a JEE environment, the MQ JMS classes do not directly provide cached connections. The MQ documentation<\/a> suggests that you make use of framework provided mechanisms:<\/p>\n\n\n\n

With Java\u2122 SE (or with another framework such as Spring) the programming models are extremely flexible. Therefore a single pooling strategy does not suit all. You should consider if there is a framework in place that could do any form of pooling, for example, Spring.<\/p><\/blockquote>\n\n\n\n

Which is fine, because there are frameworks that can be utilised with the MQ Boot starter. In fact, there are two commonly-used approaches. Historically, people used an external connection pooling library<\/a>. At one time, that was the only real option. But Spring has since added its own caching layer, with a CachingConnectionFactory<\/a> class. There are different views<\/a> on which is to be preferred, and “which is best” may depend on the underlying JMS provider and how the connections are going to be used. In the MQ Boot starter, we don’t take a prescriptive approach and allow either to be configured.<\/p>\n\n\n\n

Though that leads to the question when testing and debugging applications of which type of connection was actually used. Did I correctly configure the JMS pool property? Am I getting too many real MQ connections being made? <\/p>\n\n\n\n

The most recent version (2.4.4) of the MQ Spring Boot package tries to help, by providing some trace information using Spring’s logging mechanisms.<\/p>\n\n\n\n

Using Spring logging<\/h3>\n\n\n\n

Spring provides integration with various Java logging frameworks. For the most part we don’t really need to care in this post about how all of that works or where the output goes to. But there are generally two things you need to configure:<\/p>\n\n\n\n