JVM log settings

Use this page to view and modify the settings for the Java virtual machine (JVM) System.out and System.err logs.

To view this administrative console page, click Troubleshooting > Logs and Trace >server > JVM Logs.

 

Configuration tab

File Name Name of one of the log file described on this page.

The first file name field specifies the name of the System.out log. The second file name field specifies the name of the System.err file.

Press the View button on the Runtime tab to view the contents of a selected log file.

The file name specified for the System.out log or the System.err log must have one of the following values...

filename The name of a file in the file system. It is recommended that you use a fully qualified file name. If the file name is not fully qualified, it is considered to be relative to the current working directory for the server. Each stream must be configured with a dedicated file. For example, you cannot redirect both System.out and System.err to the same physical file.

If the directory containing the file already exists, the user ID under which the server is running requires read/write access to the directory. If the directory does not exist, it will be created with the proper permissions. The user id under which the server is running must have authority to create the directory.

console This is a special file name used to redirect the stream to the corresponding process stream. If this value is specified for System.out, the file is redirected to stdout. If this value is specified for System.err, the file is redirected to stderr.

none Discards all data written to the stream. Specifying none is equivalent to redirecting the stream to dev/null on a UNIX system.

File formatting Specifies the format to use in saving the System.out file.

Log file rotation

Use this set of configuration attributes to configure the System.out or System.err log file to be self-managing.

A self-managing log file writes messages to a file until reaching either the time or size criterion. At the specified time or when the file reaches the specified size, logging temporarily suspends while the log file rolls over, which involves closing and renaming the saved file. The new saved file name is based on the original name of the file plus a timestamp qualifier that indicates when the renaming occurs. Once the renaming completes, a new, empty log file with the original name reopens and logging resumes. All messages remain after the log file rollover, although a single message can split across the saved and the current file.

You can only configure a log to be self-managing if the corresponding stream is redirected to a file.

File Size Click this attribute for the log file to manage itself based on its file size. Automatic roll over occurs when the file reaches the specified size you specify in the maximum size field.

Maximum Size Specify the maximum size of the file in megabytes. When the file reaches this size, it rolls over.

This attribute is only valid if you click File size.

Time Click this attribute for the log file to manage itself based on the time of day. At the time specified in the start time field, the file rolls over.

Start Time Specify the hour of the day, from 1 to 24, when the periodic rollover algorithm starts for the first time after an Application Server restart. The algorithm loads at Application Server startup. Once started at the (start time field) hour, the rollover algorithm rolls the file every (repeat time field) hours. This rollover pattern continues without adjustment until the Application Server stops.

Repeat Time Specify the number of hours, from 1 to 24, when a periodic rollover occurs.

Repeat time Specifies the number of hours after which the log file rolls over. Valid values range from 1 to 24.

Configure a log file to roll over by time, by size, or by time and size. Click File Size and Time to roll the file at the first matching criterion. For example, if the repeat time field is 5 hours and the maximum file size is 2 MB, the file rolls every 5 hours, unless it reaches 2 MB before the interval elapses. After the size rollover, the file continues to roll at each interval.

Maximum Number of Historical Log Files

Specifies the number of historical (rolled) files to keep. The stream writes to the current file until it rolls. At rollover, the current file closes and is saved as a new name consisting of the current name plus the rollover timestamp. The stream then reopens a new file with the original name to continue writing. The number of historical files grows from zero to the value of the maximum number of historical files field. The next rollover deletes the oldest historical file.

Installed Application Output

Specifies whether System.out or System.err print statements issued from application code are logged and formatted.

Show application print statements Click this field to show messages that applications write to the stream using print and println stream methods. WebSphere Application Server system messages always appear.

Format print statements Click this field to format application print statement like WebSphere Application Server system messages.

Runtime tab

File Name Name of one of the log file described on this page.

The first file name field specifies the name of the System.out log. The second file name field specifies the name of the System.err file.

Press the View button on the Runtime tab to view the contents of a selected log file.

The file name specified for the System.out log or the System.err log must have one of the following values...

filename The name of a file in the file system. It is recommended that you use a fully qualified file name. If the file name is not fully qualified, it is considered to be relative to the current working directory for the server. Each stream must be configured with a dedicated file. For example, you cannot redirect both System.out and System.err to the same physical file.

If the directory containing the file already exists, the user ID under which the server is running requires read/write access to the directory. If the directory does not exist, it will be created with the proper permissions. The user id under which the server is running must have authority to create the directory.

console This is a special file name used to redirect the stream to the corresponding process stream. If this value is specified for System.out, the file is redirected to stdout. If this value is specified for System.err, the file is redirected to stderr.

none Discards all data written to the stream. Specifying none is equivalent to redirecting the stream to dev/null on a UNIX system.