D Caching with Third-Party Application Web Servers

Web Site Configuration

You configure OracleAS Web Cache to communicate with a third-party application Web servers the same way you do with Oracle HTTP Server, by providing the host name and the listening port number. The default values for the listening ports for the products discussed in this chapter are given in Table D-1.

To configure OracleAS Web Cache to communicate with a third-party application Web server, perform the following tasks:

• "Task 9: Configure Origin Server, Load Balancing, and Failover Settings" to configure application Web server settings

• "Task 10: Configure Web Site Settings" to configure Web site settings

• "Task 6: Configure OracleAS Web Cache with Listening Ports for Browser Requests" to change OracleAS Web Cache port settings

Caching Rules and Expiration Rules

You assign caching rules and expiration rules when using third-party application Web servers in the same way as when using Oracle HTTP Server. You can choose to cache or not to cache content for the following:

• Static objects

• Multiple-version objects for the same URL

• Pages supporting a session cookie or embedded URL parameter

• Pages containing simple personalization

• Dynamic assembly of Edge Side Includes (ESI) fragments

You can also assign an expiration time limit to objects or invalidate objects at any time.

WebLogic SnoopServlet

The SnoopServlet servlet obtains and uses request information, headers, and parameters sent by the browser. Use it to demonstrate how OracleAS Web Cache caches full-page dynamic content with SnoopServlet.

To start, perform the following steps:

1. Ensure that OracleAS Web Cache has been configured to communicate with the WebLogic Application Server, as described in "Web Site Configuration".

2. Start the WebLogic Server, and then access the following URL:

   http://hostname:7001/examplesWebApp/SnoopServlet
   
   

   When you access the URL, notice that your browser displays request information, headers, parameters, and the GIF image "Build On bea."

To cache the content:

1. Create a caching rule for the SnoopServlet output, as described in "Configuring Caching Rules and Rule Association".

   When creating the caching rule for the SnoopServlet output, configure the following in the Edit/Add Caching, Personalization, and Compression Rule dialog box:

   1. In the URL Expression field, enter /examplesWebApp/SnoopServlet.

   2. In the HTTP Method(s) section, click GET.

   3. In the Caching Policy section, click Cache.

   4. Leave all other defaults in the Edit/Add Caching, Personalization, and Compression Rule dialog box as is.

2. Point the browser to the OracleAS Web Cache with following URL:

   http://web_cache_hostname:7777/examplesWebApp/SnoopServlet
   
   

   The output is the same as it was when you accessed SnoopServlet directly from the WebLogic Server. This time, OracleAS Web Cache caches the SnoopServlet output and serves the request to the browser.

   
   

   Note: Port 7777 is the default listening port for OracleAS Web Cache. If you changed the default listening port, use that port number.

   
   

3. View the contents of the cache, as described in "Listing Popular Requests and Cache Contents", to ensure that SnoopServlet is cached.

   From this point on, anytime a browser accesses SnoopServlet, the response will be served from OracleAS Web Cache.

WebLogic SessionServlet

The SessionServlet servlet provides a simple example of an HTTP servlet that uses the HttpSession class to track the number of times that a browser has visited the servlet. Use it to demonstrate how OracleAS Web Cache caches pages with session-encoded URLs.

To start, perform the following steps:

1. Ensure that OracleAS Web Cache has been configured to communicate with the WebLogic Server, as described in "Web Site Configuration".

2. Configure the browser not to accept cookies.

   This is required in order to use session-encoded URLs in this example. Finally, start the WebLogic Server and access the following URL:

   http://hostname:7001/examplesWebApp/SessionServlet
   
   

   Notice that the page displays how many times a browser has visited it. When you click the link labeled "here," notice that the session ID is encoded in the URL. Every time you refresh or reload the page, the counter increases by one.

To cache the content:

1. Create an expiration rule, as described in "Configuring Expiration Policies".

   In the Create Expiration Policy dialog box, perform the following steps:

   1. In the Expire section, specify that the output expire 60 seconds after cache entry.

   2. In the After Expiration section, select Remove immediately.

2. Create a session-caching policy, as described in "Configuring Session or Personalized Attribute Caching Policies".

   When configuring a session-caching policy for SessionServlet, perform the following steps:

   1. In the Edit/Add Session Definition dialog box:

      • In the Session Name field, enter BEASession.

      • In the Cookie Name field, enter JSESSIONID.

        JSESSIONID is the default cookie name used by the WebLogic Server 6.0.

      • In the URL or POST body parameter field, enter jsessionid.

   2. In the Add Session Caching Policy dialog box:

      • From the Please select a session list, select BEASession.

      • Select YES for prompt 1.

      • Select YES for prompt 2.

      • Select NO for prompt 3.

   3. Create a new caching rule for SessionServlet, as described in "Configuring Caching Rules and Rule Association".

      When creating the caching rule for the SessionServlet output, configure the following in the Edit/Add Caching, Personalization, and Compression Rule dialog box:

      • In the URL Expression field, enter /examplesWebApp/SessionServlet.

      • In the HTTP Method(s) section, click GET.

      • In the Caching Policy section, click Cache.

      • From the Expiration Policy list, select Expire: 60 seconds in cache. After: remove immediately.

      • In the Session Caching Policies section, select BEASession, Cache with session, and Cache without session.

      • Leave all other defaults in the Edit/Add Caching, Personalization, and Compression Rule dialog box as is.

3. Point the browser to OracleAS Web Cache with the following URL:

   http://web_cache_hostname:7777/examplesWebApp/SessionServlet
   
   

   The output is the same as it was when you accessed SessionServlet directly from the WebLogic Server. This time OracleAS Web Cache caches the SessionServlet output. When the page is refreshed or reloaded, notice that the counter does not increment by one. This is because OracleAS Web Cache serves the content, and the request never goes to the WebLogic Server.

   
   

   Note: Port 7777 is the default listening port for OracleAS Web Cache. If you changed the default listening port, use that port number.

   
   

4. View the contents of the cache, as described in "Listing Popular Requests and Cache Contents", to ensure that SessionServlet is cached.

   When you reload the page, notice that the cached response appears faster than when you access the WebLogic server directly.

   Because the expiration rule for this URL is set to 60 seconds, OracleAS Web Cache expires the cached content after 60 seconds and reflects the content the next time the user requests the page.

WebSphere Snoop Servlet

The snoop servlet shows getting and using request information, headers, and parameters sent by the browser. Use it to demonstrate how OracleAS Web Cache caches full-page dynamic content.

To start, perform the following steps:

1. Ensure that OracleAS Web Cache has been configured to communicate with the WebSphere Application Server, as described in "Web Site Configuration".

2. Start the WebSphere Application Server, and then access the following URL:

   http://hostname/servlet/snoop
   
   

   Notice that request information, headers, and parameters sent by your browser are displayed.

To cache this content:

1. Create a caching rule for the snoop output, as described in "Configuring Caching Rules and Rule Association".

   When creating the caching rule for the snoop output, configure the following in the Edit/Add Caching, Personalization, and Compression Rule dialog box:

   1. In the URL Expression field, enter /servlet/snoop.

   2. In the HTTP Method(s) section, click GET.

   3. In the Caching Policy section, click Cache.

   4. Leave all other defaults in the Edit/Add Caching, Personalization, and Compression Rule dialog box as is.

2. Point the browser to the OracleAS Web Cache with following URL:

   http://web_cache_hostname:7777/servlet/snoop
   
   

   The output is the same as it was when you accessed snoop directly from the WebSphere Application Server. This time, OracleAS Web Cache caches the snoop output and serves the response to the browser.

   
   

   Note: Port 7777 is the default listening port for OracleAS Web Cache. If you changed the default listening port, use that port number.

   
   

3. View the contents of the cache, as described in "Listing Popular Requests and Cache Contents", to ensure that snoop is cached.

   When you reload the page, you should notice that the cached response appears faster than when you access the WebSphere Application Server directly.

WebSphere SessionSample

The SessionSample servlet is a simple example of an HTTP servlet that tracks the number of times that a browser has visited the servlet using a cookie. Use it to demonstrate how OracleAS Web Cache caches pages with session cookies.

This example is not a pre-deployed WebSphere example like the snoop servlet. You can find this example in Section 4.4.1.1: Session programming model and environment in the WebSphere Application Server online documentation, when you click the SessionSample.java link on that page.

To start, perform the following steps:

1. Compile the SessionSample.java file in the WebSphere environment.

2. Copy the SessionSample.class file to the location where the snoop.class file resides.

   The default location for the snoop.class file is WebSphere's install directory:

   \WebSphere\AppServer\hosts\default_host\default_app\servlets\
   
   

3. Start the WebSphere Application Server, set the browser to accept cookies, and then access the following URL:

   http://hostname/servlet/SessionSample
   
   

   Notice that the page displays the number of times a browser has visited this page. When you reload this page, the counter increments by one.

To cache this content:

1. Create an expiration rule, as described in "Configuring Expiration Policies".

   In the Create Expiration Policy dialog box, perform the following steps:

   1. In the Expire section, specify that the output expire 60 seconds after cache entry.

   2. In the After Expiration section, select Remove immediately.

2. Create a session-caching policy, as described in "Configuring Session or Personalized Attribute Caching Policies".

   When configuring a session-caching policy, perform the following steps:

   1. In the Edit/Add Session Definition dialog box:

      • In the Session Name field, enter IBMSession.

      • In the Cookie Name field, enter sessionid.

        sessionid is the default cookie name used by the WebSphere Application Server, Version 4.0

      • In the URL or Post body parameter field, enter sessionid.

   2. In the Add Session Caching Policy dialog box:

      • From the Please select a session list, select IBMSession.

      • Select YES for prompt 1.

      • Select YES for prompt 2.

      • Select NO for prompt 3.

   3. Create a new caching rule for SessionSample, as described in "Configuring Caching Rules and Rule Association".

      When creating the caching rule for the SessionSample output, configure the following in the Edit/Add Caching, Personalization, and Compression Rule dialog box:

      • In the URL Expression field, enter /servlet/SessionSample.

      • In the HTTP Method(s) section, click GET.

      • In the Caching Policy section, click Cache.

      • From the Expiration Policy list, select Expire: 60 seconds in cache. After: remove immediately.

      • In the Session Caching Policies section, select IBMSession, Cache with session, and Cache without session.

      • Leave all other defaults in the Edit/Add Caching, Personalization, and Compression Rule dialog box as is.

3. Point the browser to OracleAS Web Cache with the following URL:

   http://web_cache_hostname:7777/servlet/SessionSample
   
   

   The output is the same as when you access SessionSample directly from WebSphere Application Server. This time, OracleAS Web Cache caches the SessionSample output. To verify that the content is served by the cache, refresh or reload the page. Notice that the counter remains the same. This is because OracleAS Web Cache serves the content, and the request never goes to WebSphere Application Server.

   
   

   Note: Port 7777 is the default listening port for OracleAS Web Cache. If you changed the default listening port, use that port number.

   
   

4. View the contents of the cache, as described in "Listing Popular Requests and Cache Contents", to ensure that SessionSample is cached.

   When you reload the page, notice that the cached response appears faster than when you access the WebSphere server directly.

   Because the expiration rule for this URL is set to 60 seconds, OracleAS Web Cache expires the cached content after 60 seconds and reflects the content the next time the user requests the page.

Apache Tomcat Snoop JSP

snoop.jsp shows getting and using request information, headers, and parameters sent by the browser. Use it to demonstrate how OracleAS Web Cache caches full-page dynamic content.

To start, perform the following steps:

1. Ensure that OracleAS Web Cache has been configured to communicate with the Apache Tomcat server, as described in "Web Site Configuration".

2. Start the Apache Tomcat server, and then access the following URL:

   http://hostname/examples/jsp/snp/snoop.jsp
   
   

   Notice that request information, headers, and parameters sent by your browser are displayed.

To cache this content:

1. Create a caching rule for the snoop output, as described in "Configuring Caching Rules and Rule Association".

   When creating the caching rule for the snoop output, configure the following in the Edit/Add Caching, Personalization, and Compression Rule dialog box:

   1. In the URL Expression field, enter /examples/jsp/snp/snoop.jsp.

   2. In the HTTP Method(s) section, click GET.

   3. In the Caching Policy section, click Cache.

   4. Leave all other defaults in the Edit/Add Caching, Personalization, and Compression Rule dialog box as is.

2. Point the browser to the OracleAS Web Cache with following URL:

   http://web_cache_hostname:7777/examples/jsp/snp/snoop.jsp
   
   

   The output is the same as it was when you accessed snoop directly from Apache Tomcat. This time, OracleAS Web Cache caches the snoop output and serves the response to the browser.

   
   

   Note: Port 7777 is the default listening port for OracleAS Web Cache. If you changed the default listening port, use that port number.

   
   

3. View the contents of the cache, as described in "Listing Popular Requests and Cache Contents", to ensure that snoop is cached.

   When you reload the page, you should notice that the cached response appears faster than when you access Apache Tomcat directly.

Apache Tomcat Session Servlet

The SessionServlet provides a simple example of an HTTP servlet that uses the HttpSession class to track the number of times that a browser has visited the servlet. Use it to demonstrate how OracleAS Web Cache caches pages with session-encoded URLs.

This servlet may not be included in the Apache Tomcat binary. You can find this example on the Web, or you can use code for the servlet from Example D-1.

/*
 * @(#)SessionServlet.java     1.5 1.5
 * 
 * Copyright (c) 1996-1998 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the confidential and proprietary information of Sun
 * Microsystems, Inc. ("Confidential Information").  You shall not
 * disclose such Confidential Information and shall use it only in
 * accordance with the terms of the license agreement you entered into
 * with Sun.
 * 
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
 * SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES
 * SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
 * THIS SOFTWARE OR ITS DERIVATIVES.
 * 
 * CopyrightVersion 1.0
 */

package sunexamples;

import java.io.*;
import java.util.Enumeration;

import javax.servlet.*;
import javax.servlet.http.*;


/**
 * This is a simple example of an HTTP Servlet that uses the HttpSession
 * class
 *
 * Note that in order to guarantee that session response headers are
 * set correctly, the session must be retrieved before any output is
 * sent to the client.
 */
public class SessionServlet extends HttpServlet { 

    public void doGet (HttpServletRequest req, HttpServletResponse res)
      throws ServletException, IOException
      {
        
       //Get the session object
       HttpSession session = req.getSession(true);
       
       //Get the output stream
       ServletOutputStream out = res.getOutputStream();
       
       res.setContentType("text/html");
       
       out.println("<HEAD><TITLE> SessionServlet Output " +
                "</TITLE></HEAD><BODY>");
       out.println("<h1> SessionServlet Output </h1>");

       //Here's the meat
       Integer ival = (Integer) session.getValue("sessiontest.counter");
       if (ival==null) ival = new Integer(1);
       else ival = new Integer(ival.intValue() + 1);
       session.putValue("sessiontest.counter", ival);

       out.println("You have hit this page <b>" + ival + "</b> times.<p>");

       // encodeURL Encodes the specified URL by including the session ID in it 
       // if cookies are not turned on or not supported by the browser
       out.println("Click <a href=" + res.encodeURL("/session.html") + 
                ">here</a>");
       out.println(" to ensure that session tracking is working even if" +
                " cookies aren't supported.<br>");
       out.println(" Note that by default URL rewriting is not enabled due" +
                " to it's expensive overhead.");
       out.println("<p>");
       
       out.println("<h3>Request and Session Data:</h3>");
       out.println("Session ID in Request: " + req.getRequestedSessionId());
       out.println("<br>Session ID in Request from Cookie: " + 
                         req.isRequestedSessionIdFromCookie());
       out.println("<br>Session ID in Request from URL: " + 
                         req.isRequestedSessionIdFromURL());
       out.println("<br>Valid Session ID: " + 
                         req.isRequestedSessionIdValid());
       out.println("<h3>Session Data:</h3>");
       out.println("New Session: " + session.isNew());
       out.println("<br>Session ID: " + session.getId());
       out.println("<br>Creation Time: " + session.getCreationTime());
       out.println("<br>Last Accessed Time: " + 
                              session.getLastAccessedTime());
       out.println("<br><a href=\"/examples/simple_servlets\">Up</a>");
       out.println("</BODY>");
       out.close();
      }
    
    public String getServletInfo() {
        return "A simple session servlet";
    }
}

To start, perform the following steps:

1. Compile the SessionServlet.java file in the Apache Tomcat environment.

2. Copy the SessionServlet.class to the /examples/servlets/ directory where other servlet examples may reside.

3. Ensure that OracleAS Web Cache has been configured to communicate with the Apache Tomcat, as described in "Web Site Configuration".

4. Configure the browser not to accept cookies.

   This is required in order to use session-encoded URLs in this example.

5. Start Apache Tomcat and access the following URL:

   http://hostname/examples/servlets/SessionServlet
   
   

   Notice that the page displays how many times a browser has visited it. When you click the link labeled "here," notice that the session ID is encoded in the URL. Every time you refresh or reload the page, the counter increases by one.

To cache the content:

1. Create an expiration rule, as described in "Configuring Expiration Policies".

   In the Create Expiration Policy dialog box, perform the following steps:

   1. In the Expire section, specify that the output expire 60 seconds after cache entry.

   2. In the After Expiration section, select Remove immediately.

2. Create a session-caching policy, as described in "Configuring Session or Personalized Attribute Caching Policies".

   When configuring a session-caching policy for the Session servlet, perform the following steps:

   1. In the Edit/Add Session Definition dialog box:

      • In the Session Name field, enter ApacheSession.

      • In the Cookie Name field, enter JSESSION.

      • In the URL or Post body parameter field, enter jsessionid.

   2. In the Add Session Caching Policy dialog box:

      • From the Please select a session list, select ApacheSession.

      • Select YES for prompt 1.

      • Select YES for prompt 2.

      • Select NO for prompt 3.

   3. Create a new caching rule for SessionServlet, as described in "Configuring Caching Rules and Rule Association".

      When creating the caching rule for the Session servlet output, configure the following in the Edit/Add Caching, Personalization, and Compression Rule dialog box:

      • In the URL Expression field, enter /examples/servlets/SessionServlet.

      • In the HTTP Method(s) section, click GET.

      • In the Caching Policy section, click Cache.

      • From the Expiration Policy list, select Expire: 60 seconds in cache. After: remove immediately.

      • In the Session Caching Policies section, select ApacheSession, Cache with session, and Cache without session.

      • Leave all other defaults in the Edit/Add Caching, Personalization, and Compression Rule dialog box as is.

3. Point the browser to OracleAS Web Cache with the following URL:

   http://web_cache_hostname:7777/examples/servlets/SessionServlet
   
   

   The output is the same as it was when you accessed Session servlet directly from Apache Tomcat. This time OracleAS Web Cache caches the Session servlet output. When the page is refreshed or reloaded, notice that the counter does not increment by one. This is because OracleAS Web Cache serves the content, and the request never goes to the Apache Tomcat.

   
   

   Note: Port 7777 is the default listening port for OracleAS Web Cache. If you changed the default listening port, use that port number.

   
   

4. View the contents of the cache, as described in "Listing Popular Requests and Cache Contents" to ensure that Session servlet is cached.

   When you reload the page, notice that the cached response appears faster than when you access the Apache Tomcat server directly.

   Because the expiration rule for this URL is set to 60 seconds, OracleAS Web Cache expires the cached content after 60 seconds and reflects the content the next time the user requests the page.

ServerVariables_Jscript ASP

ServerVariables_JScript.asp demonstrates techniques you can use to access server variable information from an ASP script. Use it to demonstrate how OracleAS Web Cache caches full-page dynamic content.

To start, perform the following steps:

1. Ensure that OracleAS Web Cache has been configured to communicate with IIS, as described "Web Site Configuration".

2. Start IIS, and then access the following URL:

   http://hostname/IISSamples/sdk/asp/interaction/ServerVariables_JScript.asp
   
   

   Notice that request information, headers, and parameters sent by the browser are displayed.

To cache this content:

1. Create a caching rule for the ServerVariables_JScript.asp, as described in "Configuring Caching Rules and Rule Association", using the following information:

   1. In the URL Expression field, enter the following:

      /IISSamples/sdk/asp/interaction/ServerVariables_JScript.asp.
      
      

   2. In the HTTP Method(s) section, click GET.

   3. In the Caching Policy section, click Cache.

   4. Leave all other defaults in the Edit/Add Caching, Personalization, and Compression Rule dialog box as is.

2. Point the browser to the OracleAS Web Cache with following URL:

   http://web_cache_hostname:7777/IISSamples/sdk/asp/interaction/ServerVariables_JScript.asp
   
   

   The output is the same as it was when you accessed ServerVariables_JScript.asp directly from IIS. This time, OracleAS Web Cache caches the ServerVariables_JScript.asp output and serves the request to the browser.

   
   

   Note: Port 7777 is the default listening port for OracleAS Web Cache. If you changed the default listening port, use that port number.

   
   

3. View the contents of the cache, as described in "Listing Popular Requests and Cache Contents", to ensure that ServerVariables_JScript.asp is cached.

   When you reload the page, you should notice that the cached response appears faster than when you access IIS directly.

Cookie_Jscript ASP

Cookie_JScript.asp illustrates how your script can set and read cookies by using the Response.Cookies collection. Use it to demonstrate how OracleAS Web Cache caches pages with session cookies.

To start, perform the following steps:

1. Ensure that OracleAS Web Cache has been configured to communicate with IIS, as described in "Web Site Configuration".

2. Start IIS, verify that your browser is set to accept cookies, and then access the following URL:

   http://hostname/IISSamples/sdk/asp/interaction/Cookie_JScript.asp
   
   

   When you access the URL, notice that the page displays the date and time you last visited this page. When you click "Revisit this page," the date and time is updated.

To cache this content:

1. Create an expiration rule, as described in "Configuring Expiration Policies".

   In the Create Expiration Policy dialog box, perform the following steps:

   1. In the Expire section, specify that the output expire 60 seconds after cache entry.

   2. In the After Expiration section, select Remove immediately.

2. Create a session-caching policy for Cookie_Jscript.asp, as described in "Configuring Session or Personalized Attribute Caching Policies".

   When configuring a session caching policy, perform the following steps:

   1. In the Session Name field, enter MSSession.

   2. In the Cookie Name field, enter CookieJSCript.

   3. In the Add Session Caching Policy dialog box:

      • From the Please select a session list, select MSSession.

      • Select YES for prompt 1.

      • Select YES for prompt 2.

      • Select NO for prompt 3.

   4. Create a new caching rule for Cookie_JScript.asp, as described in "Configuring Caching Rules and Rule Association".

   5. When creating the caching rule for the Cookie_JScript.asp output, configure the following in the Edit/Add Caching, Personalization, and Compression dialog box:

      • In the URL Expression field, enter /IISSamples/sdk/asp/interaction/Cookie_JScript.asp.

      • In the HTTP Method(s) section, click GET.

      • In the Caching Policy section, click Cache.

      • From the Expiration Policy list, select Expire: 60 seconds in cache. After: remove immediately.

      • In the Session Caching Policies section, select MSSession, Cache with session, and Cache without session.

      • Leave all other defaults in the Edit/Add Caching, Personalization, and Compression Rule dialog box as is.

3. Point the browser to OracleAS Web Cache with the following URL:

   http://web_cache_hostname:7777/IISSamples/sdk/asp/interaction/Cookie_JScript.asp
   
   

   The output is the same as it was when you accessed Cookie_JScript.asp directly from IIS. This time, OracleAS Web Cache caches the Cookie_JScript.asp output. To verify that the cache serves the content, click "Revisit this page." Notice that the date and time are not updated. This is because OracleAS Web Cache serves the cached content, and the request never goes to IIS.

   
   

   Note: Port 7777 is the default listening port for OracleAS Web Cache. If you changed the default listening port, use that port number.

   
   

4. View the contents of the cache, as described in "Listing Popular Requests and Cache Contents", to ensure that Cookie_JScript.asp is cached.

   When you reload the page, notice that the cached response appears faster than when you access IIS server directly.

   Because the expiration rule for this URL is set to 60 seconds, OracleAS Web Cache expires the cached content after 60 seconds and reflects the content the next time the user requests the page.