Software AG Infrasructure 10.7 | Concepts | The Java Service Wrapper
 
The Java Service Wrapper
The Java Service Wrapper is an application developed by Tanuki Software, Ltd. Some Software AG products use the Java Service Wrapper to:
*Start and stop the Java Virtual Machines (JVM) in which they run. You can configure Java startup parameters such as heap size and classpath.
*Record the console output from the JVM in a log file. This log includes stack traces that the JVM produces when a process throws an exception and any thread dumps you generate from the JVM. The wrapper log is particularly useful when a webMethods product runs as a Windows service, because console output is not normally available to you in this mode. The log file is named wrapper.log.
*Monitor the JVM for various fault conditions and take a specified action when a fault occurs. You can do the following:
*Detect a nonoperational (hung) JVM. After the Java Service Wrapper starts the JVM, it pings the JVM periodically to check whether it is operational. If the JVM does not respond to a ping within a specified interval, the Java Service Wrapper assumes that the JVM has stopped functioning and restarts it. Each Software AG product configures this feature differently; some disable it entirely.
*Detect thread deadlocks in the JVM. A thread deadlock occurs when two or more threads try to lock resources in a manner that causes all threads to wait indefinitely. The Java Service Wrapper can monitor the JVM for a deadlock condition and take a specified action (for example, restarting the JVM) when the condition occurs. For most Software AG products, this feature is disabled by default.
*Detect specified messages in the console output. The Java Service Wrapper can monitor the console output and take a specified action when a given string of text appears. This feature is often used to watch for out-of-memory messages.
*Enable you to generate a thread dump when the JVM is running as a service under Windows.
This guide discusses the Java Service Wrapper as it is used by Software AG products that run on the Software AG Common Platform. The documentation for a product might contain additional instructions for using the Java Service Wrapper for that product.
Note:
For information about Software AG products that use the Java Service Wrapper but do not run on the Software AG Common Platform, see the documentation for those products.