/path/to/jre
Directory that contains the JRE (java.home system property value)
1.7.0
Java version (java.version system property value)
19.0-b09
JVM version (java.vm.version system property value)
Oracle Corporation
Java vendor (java.vendor system property value)
Oracle Corporation
JVM vendor (java.vm.vendor system property value)
Linux
Operating system name (os.name system property value)
i386
Operating system architecture (os.arch system property value)
2.6.29.x86_64
Operating system version (os.version system property value)
-Xmx128m
JVM arguments (space-separated list); empty if there are no JVM arguments; n/a if this information is not available (for example, in Java SE 1.4.2, this information is not available)
/opt/programs
Class path (java.class.path system property value)
user.home=/home/username foo.bar=null
Name=value pairs of any additional system properties specified in the Usage Tracker properties file. Multiple pairs are space-separated; empty if no additional property names are specified (default).
Configuring Usage Tracker
Usage Tracker is disabled by default. Enable it by creating the properties file
Note that the path name is different, depending on whether you are configuring Usage Tracker for a JDK or for a JRE.
For additional flexibility, if you want to use a different properties file, you can specify it with the system property -Dcom.oracle.usagetracker.config.file on the command line. In this case, the properties file
java -Dcom.oracle.usagetracker.config.file=/path/usagetracker.properties MyApplication
Note: To activate Usage Tracker, the usagetracker.properties file that you create must have a valid value for at least one of the following properties: oracle.usagetracker.logToFile, oracle.usagetracker.logToUDP.
Usage Tracker Properties
The following table describes the properties you can specify in the Usage Tracker properties file.
These properties are set only in the Usage Tracker properties file; they are not set at the command line. This is intended so that Usage Tracker has no impact on or interaction with the JRE user or existing applications.
Note: The backslash (\) is an escape character in a properties file. Consequently, when specifying file paths that include directories or drive letters, use a forward slash (/) or an escaped backslash (\\) as a directory separator.
Property Description
com.oracle.usagetracker.logToFile
If this property is specified, the fully qualified path name of the file to which Usage Tracker writes records.
You can specify ${user.home} in the path name. The property will expand to the user's home directory. For example:
com.oracle.usagetracker.logToFile = ${user.home}/.java_usagetracker
com.oracle.usagetracker.logToUDP
If this property is specified, Usage Tracker logs to the specified remote host in a UDP packet. For example:
com.oracle.usagetracker.logToUDP = loggingmachine.domainname:32139Specifying an IP address may be faster in some cases; although, this resolution does not delay the startup of the JVM or the application.
See "Sample: Receiver for UDP Packets" for an example application that can receive UDP packets.
com.oracle.usagetracker.additionalProperties
Use this property to record values of additional Java properties and their values.
The value of this property is a comma-separated list of properties and their values. For example:
com.oracle.usagetracker.additionalProperties = com.company.interestingProperty,com.anotherInterestingPropertyUsage Tracker prints these properties as a space-separated list of properties and their values. For example:
com.company.interestingProperty=value1 com.anotherInterestingProperty=value2
com.oracle.usagetracker.separator
The character or string that separates entries in the log file. The default is the comma (,).
com.oracle.usagetracker.logFileMax
The log file size limit, in bytes. If the file size equals or exceeds the given value when logging is attempted, that attempt will be canceled.
If this property is not set, then there is no log file limit.
com.oracle.usagetracker.verbose
If this property is set to true, error information may be reported to the standard error stream; this is only recommended for diagnostic purposes.
Example Usage Tracker properties File
To create a Usage Tracker properties file, you can use the following example as a template. Lines that begin with the pound sign (#) are comments.
Example Usage Tracker properties File
# UsageTracker template properties file.
# Copy to JRE/lib/management/usagetracker.properties and edit,
# uncommenting required settings, to enable.
# Settings for logging to a UDP socket:
# com.oracle.usagetracker.logToUDP = hostname.domain:32139
# Settings for logging to a file:
# Use forward slashes (/) because backslash is an escape character in a
# properties file.
# com.oracle.usagetracker.logToFile = ${user.home}/.java_usagetracker
# (Optional) Specify a file size limit in bytes:
# com.oracle.usagetracker.logFileMaxSize = 10000000
# If the record should include additional Java properties,
# this can be a comma-separated list:
# com.oracle.usagetracker.additionalProperties =
# Additional options:
# com.oracle.usagetracker.verbose = true
# com.oracle.usagetracker.separator = ,
Sample: Receiver for UDP Packets
The sample UsageTrackerServer.java is a simple application that listens for Usage Tracker data. Follow these steps to run and compile it:
1.Download and save UsageTrackerServer.java to a file named UsageTrackerServer.java.
2.Compile the sample with the following command:
javac UsageTrackerServer.java
3.Run the sample; the following is an example:
java UsageTrackerServer -v -o usagetracker.out :32139
â—¦The -v option is verbose; if you specify this option, the sample displays additional information.
â—¦The -o option enables you to specify the name of a log file; if you do not specify this option, the sample will print messages to standard output.
â—¦In this example, the UDP receiver listens on the localhost address on port 32139. When a JRE (with an enabled and configured Usage Tracker) sends data, the receiver will send the data to the file usagetracker.out. The port number is arbitrary but must be available and must match the one configured in the JRE. If multiple interfaces exist, it may be necessary to specify the port using the form hostname:port or ipaddress:port.
Errors and Exceptions
If Usage Tracker encounters an error or exception during the logging of a record, it does not interrupt the application currently running.
Usage Tracker does not report errors unless the property oracle.usagetracker.verbose is specified in the properties file.
Disk Space
When Usage Tracker incrementally adds records to the log file, it does not check for available disk space or perform administrative tasks such as truncating, deleting, or compressing the log file in order to be minimally intrusive. Although the size of the records is small, it is recommended that you periodically truncate, compress, archive, or delete the log file.
However, you can specify the maximum size of the log file, in bytes, with the oracle.usagetracker.logFileMax property in the properties file.
Limitations
Usage Tracker cannot log Java command line options that are processed by the Java launcher before the JVM is started. For example, Usage Tracker does not record the command line options -client and -server that select the Java HotSpot client and server VM, respectively.
Usage Tracker may not log an application if it terminates immediately because it will not stop a process from exiting.
Frequently Asked Questions
•Does Usage Tracker affect the private JRE within a JDK, or does it only affect the standalone JRE?
If you have a JDK installed in a computer, there is a JRE in the jre subdirectory; this is the private JRE referred to in the question. Yes, Usage Tracker logs the usage of both the private JRE and the standalone JRE, but note that they are configured separately through their own individual lib/management/usagetracker.properties files.
•Can Usage Tracker log the usage of JDK tools?
If Usage Tracker is enabled, it will log the usage of tools that come with the JDK such as jmap and jstack.
•Does Usage Tracker log the usage of JVMs created by native Java applications?
Yes. When a native application creates a JVM with the Java Native Interface (JNI), Usage Tracker logs this invocation with a blank Java command.
•Will an invocation similar to java -jar file.jar be tracked by Usage Tracker?
Yes.
•Does Oracle capture any of the data logged by Usage Tracker?
No. As the administrator of the JRE installation, usage data obtained from Usage Tracker is stored in the file of your choice or sent to the UDP host and port that you specify. There is no facility for this data to leave your own network. (Theoretically, if your firewall permits it, the port your UDP host listens on could be configured as remote, but this is not expected or recommended usage.)
•What does the log record look like for Java Plug-in invocations and applets?
The Java Plug-in creates a JVM within which multiple applets can execute. Therefore, there could be a log record for the new JVM (line breaks were added for clarity):
VM start,Sun Oct 24 21:42:30 BST 2010,
examplehost/192.0.2.1,
oracle.plugin2.main.client.PluginMain write_pipe_name=jpi2_pid4296_pipe2,
read_pipe_name=jpi2_pid4296_pipe1,
C:\Program Files\Java\jre,
1.7.0,
19.0-b09,
Oracle Corporation,
Oracle Corporation,
Windows XP,
x86,
5.1,
-D__jvm_launched=4176676344166
-Xbootclasspath/a:C:\PROGRA~1\Java\jre6\lib\deploy.jar;
C:\PROGRA~1\Java\jre\lib\javaws.jar;
C:\PROGRA~1\Java\jre\lib\plugin.jar
-Dsun.awt.warmup=true,
C:\PROGRA~1\Java\jre\classes,
An additional record is created for each applet started:
plugin2,
Sun Oct 24 21:42:31 BST 2010,
examplehost/192.0.2.1,
http://example.com/myapplications/Bounce/Bounce.html:
height=243 width=243 code=Bounce.class,
C:\Program Files\Java\jre,
1.7.0,
19.0-b09,
Oracle Corporation,
Oracle Corporation,
Windows XP,x86,5.1,
-D__jvm_launched=4176676344166
-Xbootclasspath/a:C:\PROGRA~1\Java\jre6\lib\deploy.jar;
C:\PROGRA~1\Java\jre\lib\javaws.jar;
C:\PROGRA~1\Java\jre\lib\plugin.jar
-Dsun.awt.warmup=true,
C:\PROGRA~1\Java\jre\classes,
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