Troubleshooting the Gephi installation

While installing Gephi, there are a couple of problems that users encounter quite frequently, most of which are related to memory-specific requirements. Some of these issues are discussed in this recipe, along with the fixes that one can employ to resolve them.

How to do it…

If you encounter any memory- or JVM-related issues, try following these steps to check if the issue can be resolved:

1. If you are using Java 8, try downgrading to Java 7 and check whether the problem is resolved.
2. If you are using the latest version of Gephi, uninstall it and install an older version. If these two fixes do not resolve the problem, then you might need to do operating system-specific fixes, as listed in the following points:
   • For Windows systems, go to the Gephi folder in Program Files in C:\ and then go to the etc folder. Open the gephi.conf file in Notepad. In the default options, change the -J-Xmx512m value to -J-Xmx1024m. This changes the maximum heap size allocated to Java to 1,024 MB. If you are using a 64-bit machine, the gephi.conf file will be located in the Gephi folder in C:\Program Files(x86).
   • For Linux systems, go to the etc folder in the Gephi application directory and open the gephi.conf file. Change the -J-Xmx512m value to -J-Xmx1024m to change the maximum heap size allocated to Java to 1,024 MB.
   • For Mac OS X systems, go to Show Package Contents by right-clicking on the Gephi icon in the Applications folder. Inside the Contents folder, go to the Resources/Gephi/etc folder. Open the gephi.conf file and, in the default options, change the -J-Xmx512m value to -J-Xmx1024m. This changes the maximum heap size allocated to Java to 1,024 MB.

Tip

Unable to save the modified gephi.conf file? Open your text editor in administrator mode, navigate to the folder where the file is located, open the file, and then make the changes. Finally, hit Save to save the changes.

How it works…

Java Virtual Machine (JVM) is an abstract computing machine, otherwise known as a virtual machine. A virtual machine emulates a part of the computing system. JVM executes a Java program compiled into Java bytecode. Since Gephi runs on JVM, its functioning depends on the memory allocated in the system for Java. If very little memory has been allocated to Java, it won't have enough resources to load all the data and, hence, the application won't start. On the other hand, if too much memory has been allocated to Java, then the system won't let Java start and will throw the "JVM Creation failed" message.

See also

• http://docs.oracle.com/cd/E13150_01/jrockit_jvm/jrockit/geninfo/diagnos/garbage_collect.html to understand more about memory management in Java