Talend - Out of Memory Error and Java Heap Space Error

The Out of Memory Error and Java Heap Space Error are two of the usual errors which occur in the Talend jobs handling a large volume of data. These errors can be avoided to an extent by following some design guidelines.

(1) Keep in mind that tMap is a heavy component. Minimize its use in your jobs.

• Avoid tMap if you need just simple transformations like trimming the string values, replacing null numbers by zeroes, etc. In its place you can use tJavaRow component.

• If you want to get only a small set of columns from a huge collection avoid using a tMap. For that you can use a lighter component- tFilterColumns

• Similarly, to filter rows you can use tFilterRow instead of a tMap

(2) Use store on disk option whenever necessary.

          This option is available in tMap, tUniqRow, tSortRow, etc.

• tMap

While using store on disk option in tMap the directory to store temporary data will be created automatically. This data will not be deleted or replaced on subsequent run(s) of the job. So it is advised to delete the temporary directory created using tFileDelete component from within the job. You can give that in On Subjob Ok of tPostJob component.

• tUniqRow

In the case of tUniqRow the temporary directory should be created manually before the job run/or can be handled within the job. If the temporary directory is not available, the component tUniqRow will give out FileNotFoundException!

• tSortRow

In the case of tSortRow the temporary directory will be created automatically

(3) The JVM arguments can be modified as and when needed

.

-Xms256M - initial memory size available to JVM is 256 MB

-Xmx1024M - maximum memory size available to JVM is 1024 MB

TALEND Installation Instructions

A)Pre-requisites before Talend Installation :

1)      Talend User needs to be created, in order to access the PROJECTS in REMOTE Repository.

For Local Repository, you can igore this.

2)       Need to have Java  JDK  V1.6 or higher

Oracle JDK Setup Details :

1)      Install Oracle JDK 1.6 or Higher. You will need the JDK, not the JRE to develop jobs using the Talend 6 studio. You can download and install this here:

http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

Talend Installer automatically Checks for JDK version 1.6 or higher version. If no instance of JDK is found, the installer will shutdown.

2)Set up your JAVA_HOME environment Path Variable.

Define your JAVA_HOME evironment variable so that it points to the JDK directory.

For example, if the JDK path is C:\java\JDKx.x.x\bin, then you must set the JAVA_HOME environment variable to point to C:\Java\JDKx.x.x.

It is highly recommended that the full path to the server installation directory is as short as possible and does not contain any space character. If you already have a suitable JDK installed in a path with a space, you simply need to put quotes around the path when setting the values for the environment variable.

If you use Talend Installer, you also have to set the Path system variable.

3)Add the previously defined JAVA_HOME variable to the Path environment variable.

For Example  <PathVariable>%JAVA_HOME%\bin.

Note : You can add the Path variable and  create the JAVA_HOME environment variable in System Variables Section.