Java VM

The settings on this tab control a variety of parameters that affect the execution of Java in the server. Table 3-2 lists the settings. If you change these settings, you must restart the server before the changes take effect.

To change the JDK version and VM type used in the server, specify them with the command-line arguments described in “Starting the server”.

**Table 3-2: Java VM properties**
Property	Description	Default value
Boot Classpath	Specifies the directories and JAR files in the boot class path search list for the Java virtual machine. Classes loaded from these locations can override the core Java runtime classes. In most cases, the value should match the class path setting. The syntax is the same as for the class path setting.	${BOOTCLASSPATH}, which is replaced by the value of the BOOTCLASSPATH environment variable at runtime.
Boot Library Path	Specifies the directory search path to load native libraries used by Java classes. The syntax is the same as for the platform PATH environment variable setting.	${BOOTLIBRARYPATH}, which is replaced by the value of the BOOTLIBRARYPATH variable at runtime.
Classpath	Specifies the class path for the Java virtual machine, which is the list of directories and JAR files that are searched to load classes. These locations are searched after the boot class path locations and cannot override the core Java runtime classes. The list consists of directories and the full path to JAR files. On Windows platforms, use a semicolon (;) to separate entries. On UNIX platforms, use a colon (:).	${CLASSPATH}, which is replaced by the value of the CLASSPATH variable at runtime.
Display Options at Startup	If this option is selected, the server logs all the Java VM options when starting.	Not selected.
Disable JIT	If this option is selected, the Java just-in-time (JIT) compiler is disabled. The JIT compiler converts Java bytecode to native machine code, which can execute significantly faster.	Not selected.
System Class Loader Tracing	Enables verbose logging in the system class loader. The log output includes the name and source location for each class loaded.	Not selected.
Custom Class Loader Tracing	Enables verbose logging in the custom class loader. In the default configuration, component and Web application classes are loaded by the custom loader to allow refresh of your application code without restarting the server.	Not selected.
Verbose Garbage Collection	Enables logging of Java garbage collector activity.	Not selected.
Verbose JNI	Enables verbose logging of Java Native Interface (JNI) method linking and execution.	Not selected.
System Variables	Read-only list of system variables that are set inside the Java VM.

Table 3-2: Java VM properties

Property

Description

Default value

Boot Classpath

Specifies the directories and JAR files in the boot class path search list for the Java virtual machine. Classes loaded from these locations can override the core Java runtime classes. In most cases, the value should match the class path setting. The syntax is the same as for the class path setting.

${BOOTCLASSPATH}, which is replaced by the value of the BOOTCLASSPATH environment variable at runtime.

Boot Library Path

Specifies the directory search path to load native libraries used by Java classes. The syntax is the same as for the platform PATH environment variable setting.

${BOOTLIBRARYPATH}, which is replaced by the value of the BOOTLIBRARYPATH variable at runtime.

Classpath

Specifies the class path for the Java virtual machine, which is the list of directories and JAR files that are searched to load classes. These locations are searched after the boot class path locations and cannot override the core Java runtime classes. The list consists of directories and the full path to JAR files. On Windows platforms, use a semicolon (;) to separate entries. On UNIX platforms, use a colon (:).

${CLASSPATH}, which is replaced by the value of the CLASSPATH variable at runtime.

Display Options at Startup

If this option is selected, the server logs all the Java VM options when starting.

Not selected.

Disable JIT

If this option is selected, the Java just-in-time (JIT) compiler is disabled. The JIT compiler converts Java bytecode to native machine code, which can execute significantly faster.

Not selected.

System Class Loader Tracing

Enables verbose logging in the system class loader. The log output includes the name and source location for each class loaded.

Not selected.

Custom Class Loader Tracing

Enables verbose logging in the custom class loader. In the default configuration, component and Web application classes are loaded by the custom loader to allow refresh of your application code without restarting the server.

Not selected.

Verbose Garbage Collection

Enables logging of Java garbage collector activity.

Not selected.

Verbose JNI

Enables verbose logging of Java Native Interface (JNI) method linking and execution.

Not selected.

System Variables

Read-only list of system variables that are set inside the Java VM.

Default paths for clusters If you use a cluster, Sybase recommends that you use the default values of class path, boot class path, and boot library path. If you enter paths in these properties, they must be valid on all machines in the cluster.