Reviews : JProbe Suite 5.0.1 :

JProbe Profiler

The profiler is, in my opinion a cool tool, and the one you will probably be using the most. Using the profiler, you can locate bottlenecks in your applications, the obvious first step in any performance analysis. JProbe will give you a visual layout of your application (see Figure 1) and will highlight problematic method calls. Additionally, you can zoom in on your application by applying a flexible set of filters. After setup, the profiler itself performs rather well. Once the initial report is generated, you can select from nine different metrics to display. This allows developers a more granular and controlled approach to determine the exact heuristics by which they want to measure their application.

Another nice feature in the Profiler is the automated triggers. These triggers allow you to collect performance information without having to be tied to the JProbe console.

Figure 1.
The JProbe Profiler shows a graph of method calls.

JProbe Memory Debugger

Many problems in applications are due to memory issues. These can be a matter of garbage collection, memory leaks that crash applications and just generally inefficient use of memory space. The JProbe Memory Debugger allows developers to observe and record how an application is using memory as it runs. This, as with the Profiler, was surprisingly fast considering the overhead that is surely involved. A graph records memory usage (not unlike the Performance Monitor in Windows) at regular intervals that are user selectectable. Additionally, the Memory Leak Doctor will allow developers to take a more granular look at what is going on inside the application and help to identify the key causes.

Additionally, a line-by-line output can be viewed and saved It is worthy to note that this is true of all the JProbe applications.

Figure 2.
The JProbe Memory Debugger finds a leak.

JProbe Threadalyzer

Multi-threaded applications are the grail and the demise of many developers; they allow applications to perform multiple tasks simultaneously, but can also cause serious problems in application stability. As a server-side developer, I find often that threading issues can quickly compound and can greatly effect the scalability of applications. Enter the threadalyzer which shows threading performance of applications.

The Threadalyzer browser has three sections:

• The visualizer shows the different threads and their state (locked, running, waiting, etc.)
• The message panel outputs logging information: warnings, messages, etc.
• The results panel shows problems (if there are any) and specifically what is causing them.

Using this basic information makes it fairly intuitive to find threading issues in an application.

Figure 3.
The JProbe Threadalyzer gets deadlocked.

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