Module 4: Configuring Caching

Contents Overview 1 Cache Overview 2 Configuring Cache Policy 6 Configuring Cache Settings 17 Configuring Scheduled Content Downloads 20 Lab A: Configuring Caching 22 Review 29 Module 4: Configuring Caching Information in this document is subject to change without notice. The names of companies, products, people, characters, and/or data mentioned herein are fictitious and are in no way intended to represent any real individual, company, product, or event, unless otherwise noted. Complying with all applicable copyright laws is the responsibility of the user. No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without the express written permission of Microsoft Corporation. If, however, your only means of access is electronic, permission to print one copy is hereby granted. 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Instructional Designer: Victoria Fodale (Azwrite LLC) Technical Lead: Joern Wettern (Independent Contractor) Program Manager: Robert Deupree Jr. Product Manager: Greg Bulette Lead Product Manager, Web Infrastructure Training Team: Paul Howard Technical Contributors: Ronald Beekelaar, Adina Hagege, Eran Harel, John Lamb, Lucian Lui, Ron Mondri, Thomas W. Shinder, Bill Stiles (Applied Technology Services), Kent Tegels, Oren Trutner Graphic Artist: Andrea Heuston (Artitudes Layout & Design) Editing Manager: Lynette Skinner Editor: Stephanie Edmundson Copy Editor: Kristin Elko (S&T Consulting) Production Manager: Miracle Davis Production Coordinator: Jenny Boe Production Tools Specialist: Julie Challenger Production Support: Lori Walker ( S&T Consulting) Test Manager: Peter Hendry Courseware Testing: Greg Stemp (S&T OnSite) Creative Director, Media/Sim Services: David Mahlmann CD Build Specialist: Julie Challenger Manufacturing Support: Laura King; Kathy Hershey Operations Coordinator: John Williams Lead Product Manager, Release Management: Bo Galford Group Manager, Business Operations: David Bramble Group Manager, Technical Services: Teresa Canady Group Product Manager, Content Development: Dean Murray General Manager: Robert Stewart Module 4: Configuring Caching iii Instructor Notes This module provides students with the knowledge and skills to configure Microsoft ® Internet Security and Acceleration (ISA) Server 2000 as a caching server. After completing this module, students will be able to:  Describe the cache process that ISA Server uses to process requests from client computers.  Configure the cache policy.  Configure cache settings.  Configure scheduled content downloads. Materials and Preparation This section provides the materials and preparation tasks that you need to teach this module. Required Materials To teach this module, you need the Microsoft PowerPoint ® file 2159A_04.ppt. Preparation Tasks To prepare for this module, you should:  Read all of the materials for this module.  Complete the lab. Make a note of the point in the lab in which you must stop the Web site on the instructor computer.  Study the review questions and prepare alternative answers to discuss.  Anticipate questions that students may ask. Write out the questions and provide the answers.  Read “Internet Acceleration” in ISA Server Help.  Read the Microsoft Knowledge Base Article Q234067 at http://support.microsoft.com/support/kb/articles/Q234/0/67.ASP.  Read RFC 2616, “Hypertext Transfer Protocol -- HTTP/1.1,” under Additional Readings on the Trainer Materials compact disc.  Read Appendix A, “ISA Server Caching Criteria,” on the Trainer Materials compact disc. Presentation: 30 Minutes Lab: 30 Minutes iv Module 4: Configuring Caching Module Strategy Use the following strategy to present this module:  Cache Overview Begin the module by describing the caching functions of ISA Server. Explain that the caching that ISA Server uses is different from any other caching that Microsoft Windows ® 2000 or the hardware on the ISA Server computer may perform. Use the build slides to describe the actions that ISA Server performs when processing requests for new objects and processing requests for cached objects.  Configuring Cache Policy Explain the use of the Time-to-Live (TTL) period for cached objects. Explain that expiration policies set the TTL for only objects that do not contain a specific expiration time. Explain the use of active caching and negative caching. Mention that you can change the error messages that ISA Server returns by editing the Web pages in the ErrorHtmls folder. Refer students to Appendix A for a summary of the criteria that ISA Server uses for caching.  Configuring Cache Settings Describe the procedure that you use to adjust the cache size. Point out the .cdat file in the \urlcache folder. Emphasize that if the cache file becomes corrupted, you cannot modify or delete the \urlcache folder while the Microsoft Web Proxy service is running.  Configuring Scheduled Content Downloads Explain that scheduled content downloads enable you to download content from the Internet directly to the cache according to a predefined schedule. Mention that you can review the ISA Server reports to determine the most frequently accessed Web sites in an organization. Describe the key steps that you perform to configure a scheduled content download. Module 4: Configuring Caching v Customization Information This section identifies the lab setup requirements for a module and the configuration changes that occur on student computers during the labs. This information is provided to assist you in replicating or customizing Microsoft Official Curriculum (MOC) courseware. The lab in this module is also dependent on the classroom configuration that is specified in the Customization Information section at the end of the Classroom Setup Guide for Course 2159A, Deploying and Managing Microsoft Internet Security and Acceleration Server 2000. Lab Setup The following list describes the setup requirements for the lab in this module. Setup Requirement 1 The lab in this module requires that ISA Server be installed on all ISA Server computers. To prepare student computers to meet this requirement, perform one of the following actions:  Complete Module 2, “Installing and Maintaining ISA Server,” in Course 2159A, Deploying and Managing Microsoft Internet Security and Acceleration Server 2000.  Perform a full installation of ISA Server manually. Setup Requirement 2 The lab in this module requires that the ISA Server administration tools be installed on all ISA Server client computers. To prepare student computers to meet this requirement, perform one of the following actions:  Complete Module 2, “Installing and Maintaining ISA Server,” in Course 2159A, Deploying and Managing Microsoft Internet Security and Acceleration Server 2000.  Install the ISA Server administration tools manually. Setup Requirement 3 The lab in this module requires that the Firewall Client software be installed on all ISA Server client computers. To prepare student computers to meet this requirement, perform one of the following actions:  Complete Module 2, “Installing and Maintaining ISA Server,” in Course 2159A, Deploying and Managing Microsoft Internet Security and Acceleration Server 2000.  Install the Firewall Client software manually. Important vi Module 4: Configuring Caching Setup Requirement 4 The lab in this module requires that all of the ISA Server client computers be configured to use the ISA Server computer’s IP address on the private network as their default gateway. To prepare student computers to meet this requirement, perform one of the following actions:  Complete Module 2, “Installing and Maintaining ISA Server,” in Course 2159A, Deploying and Managing Microsoft Internet Security and Acceleration Server 2000.  Configure the default gateway manually. Setup Requirement 5 The lab in this module requires that Microsoft Internet Explorer be configured on all student computers to use the ISA Server computer as a Web Proxy server. To prepare student computers to meet this requirement, perform one of the following actions:  Complete Module 2, “Installing and Maintaining ISA Server,” in Course 2159A, Deploying and Managing Microsoft Internet Security and Acceleration Server 2000.  Configure Internet Explorer manually. Setup Requirement 6 The lab in this module requires that Internet Information Services (IIS) be configured on all ISA Server computers to use Transmission Control Protocol (TCP) port 8008 for the default Web site. To prepare student computers to meet this requirement, perform one of the following actions:  Complete Module 2, “Installing and Maintaining ISA Server,” in Course 2159A, Deploying and Managing Microsoft Internet Security and Acceleration Server 2000.  Configure IIS manually. Setup Requirement 7 The lab in this module requires a protocol rule on the ISA Server computer that allows users to gain access to all sites by using the Hypertext Transfer Protocol (HTTP), Hypertext Transfer Protocol- Secure (HTTP-S), and File Transfer Protocol (FTP) protocols. To prepare student computers to meet this requirement, perform one of the following actions:  Complete Module 3, “Enabling Secure Internet Access,” in Course 2159A, Deploying and Managing Microsoft Internet Security and Acceleration Server 2000.  Create the rule manually. Lab Results Performing the lab in this module introduces the following configuration changes:  The HTTP caching and FTP cache settings are changed.  A scheduled content download job for the Web site www.contoso.msft/lists is created. Module 4: Configuring Caching 1 Overview  Cache Overview  Configuring Cache Policy  Configuring Cache Settings  Configuring Scheduled Content Downloads ***************************** ILLEGAL FOR NON - TRAINER USE ****************************** When you deploy Microsoft ® Internet Security and Acceleration (ISA) Server 2000 in Cache mode or in Integrated mode, ISA Server maintains a centralized cache of Internet objects and fulfills client requests from this cache. When ISA Server retrieves objects from its cache, only local network traffic occurs because the objects are not retrieved from the Internet. By using caching, ISA Server can help an organization reduce the bandwidth consumption of Internet connections. After completing this module, you will be able to:  Describe the cache process that ISA Server uses to process requests from client computers.  Configure the cache policy.  Configure cache settings.  Configure scheduled content downloads. Topic Objective To provide an overview of the module topics and objectives. Lead-in In this module, you will learn about configuring ISA Server as a cache server. 2 Module 4: Configuring Caching    Cache Overview  Caching Functions  Processing Requests for New Objects  Processing Requests for Cached Objects ***************************** ILLEGAL FOR NON - TRAINER USE ****************************** ISA Server uses several caching functions to provide users with fast and efficient access to Web objects. The Microsoft Web Proxy service supports requests from ISA Server clients for access to Web sites and File Transfer Protocol (FTP) sites. When a user requests access to a site on an external network, such as the Internet, the request goes to the ISA Server computer for processing. The process that ISA Server uses to fulfill the request depends on whether the ISA Server computer retrieves the object from the Internet or from its cache. When configuring ISA Server to perform caching of Web objects, configure the Web browsers on the client computers to use the smallest possible amount of disk space for local Web caching. Topic Objective To introduce the caching functions and processes of ISA Server. Lead-in ISA Server uses several caching functions to provide users with fast and efficient access to Web objects. Tip Module 4: Configuring Caching 3 Caching Functions  RAM and Disk Caching  Most of Working Set in RAM  Directory of Cached Objects  Single Cache File  Quick Recovery  Efficient Cache Updates  Active Caching  Cache Pre-Fetching  Automatic Cleanup Cache ***************************** ILLEGAL FOR NON - TRAINER USE ****************************** ISA Server includes the following functions that optimize cache performance:  RAM and disk caching. Allocates random access memory (RAM) for caching popular objects and caches other objects on disk. When caching an object, ISA Server places an object into the RAM cache first and then writes objects to disk. RAM and disk caching help to improve access speed for users to popular Web sites.  Most of working set in RAM. Keeps most of the memory that is used for caching in RAM instead of paging it to disk to ensure faster processing.  Directory of cached objects. Maintains a directory of cached objects in RAM to enable fast access to cached objects.  Single cache file. Maintains a single cache file per disk partition to hold cached objects so that gaining access to objects does not incur additional system resources that would be needed for opening and closing multiple files.  Quick recovery. Quickly rebuilds the directory of cached objects on startup, even after an abnormal termination.  Efficient cache updates. Automatically determines which objects to keep in the RAM cache. This decision is based on the likelihood of a user requesting the same object again, which is determined by how recently and how frequently an object is accessed.  Active caching. Retrieves a more current version of an object automatically from the original Web site before an object becomes outdated. Active caching ensures that the objects that users gain access to most frequently are contained in the cache.  Cache pre-fetching. Allows administrators to define Web sites that ISA Server can cache in advance of the first user gaining access to the site.  Automatic cleanup. Removes objects that have not been accessed recently or frequently when the disk space that is allocated to the cache starts to fill up. Topic Objective To describe the ISA Server caching functions that improve cache performance. Lead-in ISA Server includes several features that optimize cache performance. Delivery Tip Explain that the caching that ISA Server uses is different from any other caching that Windows 2000 or the hardware on the ISA Server computer may perform. 4 Module 4: Configuring Caching Processing Requests for New Objects RAM RAM Disk Disk Cache Directory Objects Objects 1 1 Request http://URL A 4 4 http://URL A http://URL A Cache Directory Backup Cache Entry 1 Allocate Cache Entry 1 2 2 6 6 http://URL A http://URL A Internet Internet 3 3 5 5 Batch Update ***************************** ILLEGAL FOR NON - TRAINER USE ****************************** When a user requests a Hypertext Transfer Protocol (HTTP) or FTP object, the Web Proxy client sends the request to the Web Proxy service that is included with ISA Server. An HTTP object is an object, such as Web pages and images, that a client retrieves from a Web server by using the HTTP protocol. An FTP object is an object, such as a program file, that a client retrieves from an FTP server by using the FTP protocol. When the Web Proxy service receives the request, the following actions occur: 1. The Web Proxy client sends a Web request to the ISA Server computer. 2. The Web Proxy service checks the cache directory to determine whether the ISA Server computer holds a copy of the requested object in its cache. If the object is not in its cache, the Web Proxy service creates an entry for the object in the cache directory and allocates space for the object in the RAM cache. 3. The Web Proxy service retrieves the object from the Internet and then places a copy of the object into the RAM cache. 4. The Web Proxy service returns the object to the Web Proxy client. 5. Periodically, the Web Proxy service copies multiple objects from the RAM cache to the disk cache. These operations are called batch updates because ISA Server copies multiple objects when system usage is lower. 6. Periodically, ISA Server creates a backup copy of its cache directory on the hard disk. This backup copy aides in recovering cache information when restarting the Web Proxy service after an abnormal termination of the service. By default, the Microsoft Firewall service forwards HTTP requests from Firewall clients and SecureNAT clients to the Web Proxy service, which then caches these requests. Forwarding the request results in improved performance for all types of clients. Topic Objective To describe the process that ISA Server uses to process requests for new objects. Lead-in When a user requests an HTTP object or FTP object, the Web Proxy client sends the request to the Web Proxy service that is included with ISA Server. Delivery Tip The slide associated with this topic is an animated slide. Click or press the SPACEBAR to advance the animation. Note [...]... 6 Module 4: Configuring Caching Configuring Cache Policy Topic Objective To identify the topics that are related to configuring cache policy Configuring HTTP Caching Lead-in Configuring Expiration Policies Depending on how you configure the cache policy, ISA Server determines whether to retrieve the Internet content from its cache or from another server Configuring Active Caching Configuring FTP Caching. .. criteria that ISA Server uses for caching, see Appendix A, “ISA Server Caching Criteria,” on the Student Materials compact disc Module 4: Configuring Caching 7 Configuring HTTP Caching Topic Objective To describe the procedure that you use to configure HTTP caching Cache Configuration Properties Select to enable HTTP caching General HTTP FTP Active Caching Advanced Enable HTTP Caching Unless source specifies... dialog box, on the HTTP tab, click Restore Defaults 10 Module 4: Configuring Caching Configuring Active Caching Topic Objective Cache Configuration Properties To describe the procedure that is used for configuring active caching General HTTP Active Caching Advanced Active caching automatically retrieves frequently accessed files Lead-in With active caching enabled, ISA Server analyzes objects that are... Enabling Active Caching To enable active caching: 1 In ISA Management, in the console tree, click Cache Configuration, and then in the details pane, click Configure cache policy 2 In the Cache Configuration Properties dialog box, on the Active Caching tab, select the Enable active caching check box Module 4: Configuring Caching 11 Selecting an Active Caching Policy When you enable active caching, you... protocol Module 4: Configuring Caching Scenario Northwind Traders uses ISA Server to cache Web requests for its users To ensure that users receive the best possible performance when gaining access to the Internet, you will adjust the ISA Server caching settings to use bandwidth more efficiently Estimated time to complete this lab: 30 minutes 23 24 Module 4: Configuring Caching Exercise 1 Configuring. .. box, on the Active Caching tab, click Restore Defaults 12 Module 4: Configuring Caching Configuring FTP Caching Topic Objective Cache Configuration Properties To describe the procedure that you use to configure FTP caching Lead-in You can configure ISA Server to store FTP objects in the cache General HTTP FTP Active Caching Advanced Enable FTP caching Specify a time for FTP objects to remain in the cache... www.contoso.msft Web site again e Close all open windows, and then log off Module 4: Configuring Caching 29 Review Topic Objective To reinforce module objectives by reviewing key points Cache Overview Lead-in Configuring Cache Policy The review questions cover some of the key concepts taught in the module Configuring Cache Settings Configuring Scheduled Content Downloads *****************************ILLEGAL... active caching to occur less frequently a In the Cache Configuration Properties dialog box, on the Active Caching tab, select the Enable active caching check box, click Less frequently, and then click Apply b If the ISA Server Warning dialog box appears, ensure that Save the changes, but don’t restart the service is selected, and then click OK 4 26 Module 4: Configuring Caching Exercise 2 Configuring. .. content download 7 On the Completing the New Scheduled Content Download Job Wizard page, review your choices, and then click Finish 22 Module 4: Configuring Caching Lab A: Configuring Caching Topic Objective To introduce the lab Lead-in In this lab, you will configure caching *****************************ILLEGAL FOR NON-TRAINER USE****************************** Explain the lab objectives Objectives During... Policy 2 In the Cache Configuration Properties dialog box, on the HTTP tab, select the Enable HTTP caching check box 8 Module 4: Configuring Caching Configuring Expiration Policies Topic Objective To describe the procedures that you perform to configure expiration policies Lead-in When you enable HTTP caching, you must select an expiration policy for HTTP objects Cache Configuration Properties General . 6 Module 4: Configuring Caching    Configuring Cache Policy  Configuring HTTP Caching  Configuring Expiration Policies  Configuring Active Caching. Configuring Cache Policy 6 Configuring Cache Settings 17 Configuring Scheduled Content Downloads 20 Lab A: Configuring Caching 22 Review 29 Module 4: Configuring