Starting the tool and opening log files in the GUI

You can run the tool from the command line, but using the GUI gives you more flexibility and control over how you view the log data. You can use existing templates to show and plot common groups of data such as memory or performance, or add your own templates. You can modify chart axes, change the colors, or zoom in for more detail. You can use the GCMV preferences to further configure the data display, for example by specifying custom date formats, chart line thickness, or warning thresholds.

Before you begin

The tool is provided as an add-on that you install into another product, such as Eclipse. For more information about system requirements and installation, see the

home page for the tool on developerWorks.

About this task

You can open any type of text file in the IBM® Monitoring and Diagnostic Tools - Garbage Collection and Memory Visualizer (GCMV). If the file contains valid log data, the tool parses it and adds one or more data categories to the Data selector view. For example, if you open a VGC log, GCMV adds a VGC category; if you open a TGC log, GCMV adds a TGC category.

You can also open compressed files, such as *.zip, *.jar, or *.tar files. If the compressed file contains multiple log files, the content from all the log files is presented as a single output. Use this function when you want to view a sequence of log files that was generated by using the -Xverbosegclog:filename,number_of_files,number_of_gc_cycles parameter in a Java™ command. You can also use this function to open large log files in compressed form, without first having to extract them.

Procedure

Start the hosting product.
Start GCMV. The procedure varies depending on the hosting product. Refer to the documentation for the hosting product for instructions. For example, in Eclipse you open the GCMV perspective.
Open a log file by clicking File > Load File.... GCMV displays a dialog box to indicate the progress of the file analysis.

Results

GCMV displays the data from the log file in a tab titled Data set x, where x is a number. The log file name and text content are displayed in a tab within the Data set x window. GCMV also displays, by default, the following windows:

Templates: Configure GCMV to display the data that you want, in the format that you want, then save the configuration in a template for later use. Several templates are already provided by default.
Key: Shows the key for data charts. You can change the colors that are used.
Axes: Control the data type and range for chart axes.
Zoom: Zoom into areas of the chart for a more detailed view of the data.

If the file is not a valid log file, the Data set x window displays the message No data parsed from sources.

What to do next

You can open multiple log files in a single data set; each file is displayed in its own tab within the data set tab.