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I’ve posted before about setting up WebSphere MQ Explorer as a read-only viewer using setmqaut and MCAUSER ids – a post which has proved quite useful to some readers.
A similar topic which seems to raise questions is using WebSphere MQ Explorer to administer remote queue managers where all server-connection channels are secured using SSL/TLS.
In this post, I will give some background about the issues surrounding using WMQ Explorer with SSL, and outline how it can be used with multiple queue managers.
In MQSeries 5.2 and previous releases, runmqlsr ran each inbound connection as a new thread within itself. If runmqlsr ran out of resources (memory, threads, file descriptors), then it would not accept any new connections. This massively threaded approach worked well on systems with a limited number of channels, but on very busy systems it was necessary to set up multiple listeners and balance connections across them.
The inetd daemon starts a new amqcrsta process for each inbound connection. There is no chance an amqcrsta responsible for only one channel will run out of resources, so even the busiest of queue managers requires only a single port in inetd. However, this massively unthreaded approach means that busy systems may have hundreds of amqcrsta processess, forcing administrators to increase maxuproc. Inetd has no idea when the queue manager is inactive, so it will start amqcrsta processes even when the queue manager is shut down.
We’ve just brought out a new SupportPac that allows access to WebSphere MQ using HTTP: MA0Y: IBM WebSphere MQ Bridge For HTTP.
There is no client involved here – just connect using whatever method you like Ajax, C++, Java, anything that can make a socket connection and send HTTP! This makes it the first zero-footprint client to WMQ.
We’ve defined a bunch of HTTP headers that encapsulate the message headers and the body of the message is sent as the HTTP body.
The support enables three of the standard HTTP verbs:
- GET – browse (get with browse) the currently highest message on the queue.
- DELETE – delete (destructive get) the currently highest message on the queue or topic.
- POST – post (put) a message to the queue or topic.