Günay's Coding World

Start Apache and Tomcat Start Apache: $APACHE_HOME / bin / apachectl -k start To stop use: $APACHE_HOME / bin / apachectl -k stop Start Tomcat: $TOMCAT_HOME / bin / startup.sh Stop Tomcat: $TOMCAT_HOME / bin / shutdown.sh

There are pretty much two ways to set up basic clustering, which use two different Apache modules. The architecture for both, is the same. Apache sits in front of the Tomcat nodes and acts as a load balancer. Traffic is passed between Apache and Tomcat(s) using the binary AJP 1.3 protocol. The two modules are mod_jk and mod_proxy . mod_jk stands for “ jakarta ” the original project under which Tomcat was developed. It is the older way of setting this up, but still has some advantages. mod_proxy is a newer and more generic way of setting this up. The rest of this guide will focus on mod_proxy , since it ships “out of the box” with newer versions of Apache. You should be able to follow this guide by downloading Apache and Tomcat default distributions and following the steps. Clustering Background You can cluster at the request or session level. Request level means that each request may go to a different node – this is the ideal since the traffic would be balanced across...

Use the following table to map the versions: Major Minor Java platform version 45 3 1.1 46 0 1.2 47 0 1.3 48 0 1.4 Example: 1.4.x 49 0 1.5 Example: 1.5 50 0 1.6 51 0 1.7 For this example, there are 2 items to map: a) Runtime Java version 1.4.x => major.minor is 48.0 b) Java class file shows "version 49.0", but it should be interpreted as: major.minor 49.0 => Java 1.5 Conclusion: You are trying to run in a system that has Java 1.4 (major.minor 48) a Java class file that was compiled under Java 1.5 (major.minor 49), thus the error message: (Unsupported major.minor version 49.0) In other words, the runtime (major.minor 48) does not support major.minor 49. Check the runtime version of Java. java -version For example, the output might look like this: java version "1.4.2" Java 2 Runtime Environment, Standard Edition (build 1.4.2)