This chapter provides a roadmap to help you solve problems with the Oracle JRockit JVM.
The roadmap to solve problems with the Oracle JRockit JVM consists of the following steps:
Step 1: Eliminate or Identify Common Causes
Often, problems that you encounter while running an application on the JRockit JVM are caused by issues that can be diagnosed and solved with minimal effort. Table 1-1 provides a list of actions that you can take to quickly diagnose and solve basic JVM problems.
Note:
The list is not in any particular order. You can perform each action separately.Table 1-1 Actions to Identify and Eliminate Common Causes for JRockit JVM Problems
| Action | Effect or Significance |
|---|---|
|
Reinstall the JRockit JVM |
This action might correct problems that are caused by installation issues. You can find the relevant installation instructions in Oracle JRockit Installation Guide. |
|
Install the latest patches for the application running on the JRockit JVM |
This action might correct problems that are caused by issues in the application running on the JRockit JVM. |
|
Install the latest release of the JRockit JVM |
This action corrects problems that are fixed in a later release of the JRockit JVM. For information about problems fixed in the release, see the Oracle JRockit Release Notes. |
|
Try to reproduce the problem on the same machine |
A problem that can be reproduced every time a certain sequence of steps are performed could indicate a straightforward programming error. If, however, the problem occurs intermittently (at varying or fixed intervals), thread interaction and timing problems are more likely. |
|
Try to reproduce the problem on another machine |
A problem that occurs on only one machine might be caused by the hardware (number of processors), the operating system, and the application software. For example, the visibility of a race condition in the JVM or a user Java application might be influenced by the speed at which certain operations are performed by the JVM. |
|
Ensure that you are using a supported operating system with the latest patches installed |
This action might correct problems that are caused by an unsupported operating system. |
|
Ensure that third-party JNI code you run is of the latest version |
This action might correct problems that are caused by issues in the third-party JNI code. If the JRockit JVM has crashed, you can find out the libraries ( |
|
Turn off code optimization by using |
Optimization makes code more efficient. Turning off code optimization might help you identify problems related to optimization. |
When you encounter a problem, observe the application behavior carefully and record the symptoms.
Step 3: Identify and Resolve the Problem
Table 1-2 lists symptoms of common JRockit JVM problems, and points you to chapters that contain information to help you diagnose and resolve the problems. Perform the tasks described in the chapters corresponding to the problem you are trying to resolve.
Table 1-2 Symptoms of Common JRockit JVM Problems
| Symptom | For Diagnostics Information, See |
|---|---|
|
The JVM crashes and produces a dump. |
|
|
The JVM takes too long to start. |
|
|
Some transactions take too long to execute even though the overall throughput is acceptable. |
|
|
The overall throughput is too low. |
|
|
After running well for a while, the JVM begins to perform poorly. For example:
|
|
|
The JVM is freezing (without crashing). |
Step 4: Contact Oracle Support
If you are a licensed JRockit JVM user and are unable to resolve the problem on your own, contact Oracle Support.
For more information, see Chapter 9, "Contacting Oracle for Support".