Like a high-powered microscope, MonitorXIPC from Level 8 Systems opens a window into a tiny world of big events. It lets administrators and developers watch XIPC message queues fill up and empty, and it can reveal the contents of messages in the queues. I tested a beta version of the product to see whether administrators of XIPC-based MOM (message-oriented middleware) should consider adding it to their networking toolkits, and I discovered MonitorXIPC is an excellent MOM diagnostic tool. Its real-time message-queue displays made my MOM test environment much easier to set up and manage.

The tool's usefulness extends far beyond MOM software development. Without a management tool such as MonitorXIPC, administering a MOM-based network is like driving at night without headlights. But MonitorXIPC's useful display of traffic statistics let me pinpoint MOM bottlenecks, and its list of alerts quickly notified me of errors. In the lab, its browser-based interface made remote access a breeze.

MonitorXIPC's lack of security was its single biggest drawback. It was all too easy for any user on the network to access the product's display of queues and messages. To preserve the confidentiality of message queue contents, Level 8 says it will release a separate but complementary platform-neutral MOM security product in the near future.

MonitorXIPC consists of server and client agent components. A client agent pushes XIPC message activity information to the server, which is essentially an HTML engine that's XIPC-aware. The server reformats the XIPC message activity information into Web pages viewable by any frame-capable browser. To keep its displays current, the HTML engine continuously refreshes the browser window with queue instance, link and event status updates. Working together, the client and server components kept up nicely with the message traffic flowing through XIPC's queues. This held true even when I tested MonitorXIPC by forcing XIPC to handle messages at a rate of 10 per second. The server and client components run on XIPC-supported platforms, which include several versions of Unix (AIX, Solaris, SCO and HP-UX), Windows NT 4.0 and Windows95/98.

This tool divulged message queues, instances, queue contents (messages), queue status information, queue utilization, users and alerts, as my test application put messages into or took messages from the XIPC queues that I built with XIPC's MOM product. Level 8 offers a similar product for keeping an eye on IBM's MQSeries called MonitorMQ, which is MonitorXIPC's progenitor. XIPC first developed a monitoring tool for MQSeries and then used what it had learned to develop MonitorXIPC to support its own messaging environment. Level 8 says that it is planning to consolidate these tools into a single observation platform for all popular messaging environments, including Microsoft Corp.'s MSMQ and Level 8's own FalconMQ.

While XIPC is a cross-platform MOM environment as powerful and feature-rich as MQSeries, the MonitorXIPC tool represents a unique capability that both MQSeries and XIPC have lacked in the past, notwithstanding the latter's highly useful interactive debugging windows. Corporate programmers have been known to struggle when building ad hoc, homegrown management tools for MQSeries. IBM supplies just a rudimentary command-line utility with its messaging product. MonitorMQ and now MonitorXIPC eliminate the need to custom-build a MOM debugging and message-watching tool. Best of all, MonitorXIPC sends its real-time MOM data over the network to a browser window. Both Navigator 2.02 or later (on any platform) and Internet Explorer 3.01 or later work well with MonitorXIPC.

MOM Gives You the Lowdown In the lab, I tested XIPC to exchange some simple messages between Windows NT machines. MonitorXIPC saved considerable time during the development of my MOM-based application. It told me exactly where my messages originated, where they were going and whether they were in the correct queue. When I abruptly and deliberately severed the network connection between the machines--one of my favorite tactics when evaluating MOM products--XIPC generated an alert for me to examine with just a single click in the browser window. Additionally, during development, MonitorXIPC displayed alerts that informed me of overflowing queues, halted instances and other conditions in need of attention.

For a complex MOM environment, MonitorXIPC's filters let me drill down to the queue and the specific message within the queue level. In one test, I filtered on queue name, instance and user to find messages sent by a particular application. I used the Messages on Queues window, which showed queue utilization statistics, to start filtering message traffic. That window offered a high-level view of all the XIPC message queues, making it the best place from which to begin filtering.

MonitorXIPC isn't a full-blown management aid for XIPC. It let me monitor queues in a hierarchical fashion, but it didn't let me set up new XIPC queues or reconfigure existing queues and instances. When I deliberately set the size of a queue too small for its message workload, XIPC handled the overflow messages by spooling them to temporary files--a nice MOM feature unique to XIPC. But while MonitorXIPC informed me of the full queue, it said nothing about the temporarily spooled messages.

Barry Nance, a computer analyst and consultant for 28 years, is the author of Introduction to Networking, 4th Edition (Que, 1997) and Client/Server LAN Programming (Que, 1994). Send comments on this article to him at barryn@erols.com.