Sarwar Kamal's Blog

Prerequisite Blogs: How To Install Apache Tomcat Multiple Tomcat Instances on Single Machine Tomcat Clustering: Loadbalancing with mod_jk and Apache Tomcat Clustering : Session Affinity    Backup Manager Backup manager usually used clustered environment. Its like delta manger. But it will  replicate to exactly one other instance(backup instance). Its act  like one instance is Primary  and another instance as backup. Steps to make Session Replication in Tomcat Clustering I am continue from exactly where I left in last session affinity post . So check that post and make sure jumRoute all are set properly. Steps are Enable Multicast routing Add <Cluster> Entries in conf/server.xml file for all instances. Enable the Web Application as distributable Step1:  Enable Multicast routing In Linux Environment most of the system kernel is capable to process the multicast address. We need to add...

Session affinity/Sticky Session   Session affinity overrides the load-balancing algorithm by directing all requests in a session to a specific tomcat server. So when we setup the session affinity our problem will solved. But how to setup because session values are random value. We need to generate the session value some how identify the which tomcat generate response. Step 1: Tomcat configuration file (conf/server.xml) contain  <Engine> tag have jvmRoute property for this purpose. So edit the config file and update the <Engine > tag like this <Engine name="Catalina" defaultHost="localhost“ jvmRoute=“tomcat1” > Here tomcat1 is worker name of this tomcat. check the workers.properties file in last post .  Change this line to all tomcat instances  conf/server.xml file and change the jvmRoute value according to workers name and restart the tomcat instances. Now all tomcat generate the session-id pattern...

Application servers may have different settings for character encodings. We strongly recommend UTF-8 where possible. By default, Tomcat uses ISO-8859-1 character encoding when decoding URLs received from a browser. This can cause problems when Confluence's encoding is UTF-8, and you are using international characters in the names of attachments or pages. To configure the URL encoding in Tomcat: Step 1 - Configure connector: Edit conf/server.xml and find the line where the Coyote HTTP Connector is defined. It will look something like this, possibly with more parameters: < Connector port = "8080" /> Add a URIEncoding="UTF-8" property to the connector: < Connector port = "8080" protocol = "HTTP/1.1"      connectionTimeout = "20000"      redirectPort = "8443"      URIEncoding = "UTF-8" /> If you are using mod_jk you should appl...

The following JVM parameters are recommended: -Djava.awt.headless=true  -Dfile.encoding=UTF-8  -server  -Xms512m  -Xmx1024m  -XX:NewSize=256m  -XX:MaxNewSize=256m  -XX:PermSize=256m  -XX:MaxPermSize=256m  -XX:+DisableExplicitGC -Djava.awt.headless=true Headless mode is a system configuration in which the display device, keyboard, or mouse is lacking. Sounds unexpected, but actually you can perform different operations in this mode, even with graphic data. -server The JDK includes two flavors of the VM -- a client-side offering, and a VM tuned for server applications. These two solutions share the Java HotSpot runtime environment code base, but use different compilers that are suited to the distinctly unique performance characteristics of clients and servers. These differences include the compilation inlining policy and heap defaults. Although the Server and the Client VMs are similar, the Serv...