HTTP proxy plugin configuration in weblogic and Failover Demo in Cluster

I have explained in my previous post in more detail about the cluster configuration and deployment of sample application. This post is the continuation to access the deployed application.

In order to access the application deployed in the Cluster environment, we should access via HTTP web servers. We can configure apache HTTP servers  or any other client proxy to access the deployed application.

Simple flow diagram to understand the requests managed by Load Balancer

 In this sample am going use the HTTP proxy  plugin , for that I have created the simple webapplication in JDeveloper and configured the HttpClusterServlet and managed servlets details in web.xml and weblogic.xml. Download web app here.

web.xml (sample and hihglighted important configs)

<?xml version = '1.0' encoding = 'windows-1252'?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"

         version="2.5" xmlns="http://java.sun.com/xml/ns/j2ee">

<servlet>

  <servlet-name>HttpClusterServlet</servlet-name>

    <servlet-class>

      weblogic.servlet.proxy.HttpClusterServlet

    </servlet-class>

  <init-param>

    <param-name>WebLogicCluster</param-name>

    <param-value>localhost:7881|localhost:7882</param-value>

  </init-param>

  <init-param>

    <param-name>KeyStore</param-name>

    <param-value>/mykeystore</param-value>

  </init-param>

  <init-param>

    <param-name>KeyStoreType</param-name>

    <param-value>jks</param-value>

  </init-param>

  <init-param>

    <param-name>PrivateKeyAlias</param-name>

    <param-value>passalias</param-value>

  </init-param>

  <init-param>

    <param-name>KeyStorePasswordProperties</param-name>

    <param-value>mykeystore.properties</param-value>

  </init-param>

</servlet>

<servlet-mapping>

  <servlet-name>HttpClusterServlet</servlet-name>

  <url-pattern>/</url-pattern>

</servlet-mapping>

<servlet-mapping>

  <servlet-name>HttpClusterServlet</servlet-name>

  <url-pattern>*.jsp</url-pattern>

</servlet-mapping>  

<servlet-mapping>

  <servlet-name>HttpClusterServlet</servlet-name>

  <url-pattern>*.jspx</url-pattern>

</servlet-mapping> 

<servlet-mapping>

  <servlet-name>HttpClusterServlet</servlet-name>

  <url-pattern>*.htm</url-pattern>

</servlet-mapping>

<servlet-mapping>

  <servlet-name>HttpClusterServlet</servlet-name>

  <url-pattern>*.html</url-pattern>

</servlet-mapping>

</web-app>

weblogic.xml

<!DOCTYPE weblogic-web-app PUBLIC "-//BEA Systems, Inc.//DTD Web Application 9.1//EN" "http://www.bea.com/servers/wls810/dtd/weblogic

810-web-jar.dtd">

  <weblogic-web-app>

    <context-root>/ </context-root>

  </weblogic-web-app>

 When ManagedServer1 is in not running or down, the request will go to the other servers which is active and running with the requested state without any loss of data. The Managerserver mapping will be taken care by the algorithm you chose when you are creating the Cluster. In my case its round-robin.

Failover flow diagram- ManagedServer 1 is in Shutdown state

Now deploy the web application HTTPProxy plugin into weblogic Admin server (not on cluster).

After deployment, you can access the deployed adf application via admin port. Given below my local sample url for reference

http://localhost:8891/ClusterTestContext/faces/clustertest.jspx

Failover demonstration (Demo app download here)

Look at the below screen, Its Running on Adf_Server-1. Server Name is shown in simple outPutText with weblogic.Name property

JSFUtils.setExpressionValue("#{pageFlowScope.serverName}", System.getProperty("weblogic.Name"));

 <af:panelLabelAndMessage label="Running on :: " id="plam4"

                               inlineStyle="color:Blue; font-size:medium;">

        <af:outputText value="#{pageFlowScope.serverName}" id="ot4"/>

    </af:panelLabelAndMessage>

Note: Fields also binded with Richcomponent and values with scopes

<af:inputText label="Name" id="it1" value="#{pageFlowScope.name}"

                        binding="#{pageFlowScope.clustertestbean.nameRichTxt}"/>

 <af:inputText label="Department" id="it2" value="#{pageFlowScope.department}"/>

<af:inputText label="Location" id="it3" value="#{backingBeanScope.location}"/>

Now stopping my managed server Adf_Server-1 and click Next button

Adf_Server-1 is in SHUTDOWN state, and Keeping the same page same session clicking Next button,

Now it’s showing the server name as Adf_Server-2 which is in running state. Also all the values in the form from Main page carried to Details page as well.

Here we can understand that when the one server is down i.e., when failover happens cluster automatically manages state and keeps the application stable without any service interruption.Your application will be Highly available always.

Downloads

Sample adf application

Http proxy plugin web app

Leave your comments below if any issues. Thanks