It is clear that the three JMSs described here exhibit more or less the same basic functionality. They have all matured to a respectable level that they are all currently deployed at complex computing sites and fulfill most of their requirements. It would not be wise in general to recommend a JMS product over another without going through the burdensome selection task that depends heavily on how each product meets the JMS requirements set by compute sites. This article will however recommend a process that may be used as a guideline for site administrators to select the most appropriate JMS for their particular site. The process in question contains the following three main phases:
Produce a list of JMS requirements specific for the site.
The "Feature Classification" section in this article is a good starting point for a JMS requirement list that needs to be first produced by the group in charge of the JMS selection project at a typical compute site. The reader who needs a thorough requirement list is urged to consult the NAS technical document7 which contains a more explanatory and comprehensive list than the one outlined in this article. We can never predict far in the future because computing needs are a moving target at compute sites and a JMS selected today may not be appropriate later, so this requirement needs to be specially taken into account when selecting a JMS.
Match the requirements against the features provided by the candidate JMS.
This stage requires that the functionality of each JMS candidate be scrutinized as to how it is really supported. The level of support of each feature can be translated into a score whose range can be determined by how tricky each feature is supported. The JMS comparison section in this article can be very helpful in this evaluation stage particularly for the candidate JMSs that are particularly covered in this article. The tables used in the comparison section can be modified to use a scoring model which reflects the level of support of each feature by each JMS candidate. This will definitely expedite this phase in order to determine the JMS finalist(s) that would be considered for further consideration.
Evaluate the demo version of the selected JMS candidate(s).
This last stage is very critical because the selected JMS(s) need to be tested in the environment in which it will eventually be deployed. Once the acceptance criteria have been met during the deployment phase, the decision should be easy to make.