Exam Reviews

Scaling Out with Application Center

If you survived the Designing Highly Available Web Solutions test, Microsoft load balances the difficulty level with this new exam.

As Chris Wolf explains in his brief report, "Application Center 2000: Super Glue," if you’re hosting and managing distributed applications, then at some point you’ll probably consider the use of Application Center 2000, Microsoft’s Web and server farm solution. Taking on exam 70-232 will truly make you feel as if you’re being tested on all aspects of Windows 2000 base technologies as well as everything that encompasses Application Center. Along with a solid understanding of Win2K basics, you’ll need a full understanding of firewalls, ports, TCP/IP, routing and networking fundamentals. At the same time, you must prove you know all the miniscule details of Application Center, including how to use every aspect of it in a production environment.

Tip: I’d suggest warming up for this exam by taking test 70-226, Designing Highly Available Web Solutions with Microsoft Windows 2000 Server Technologies.

Windows 2000 and SQL Basics
Know Win2K domains and Active Directory from the 40,000-foot view. This means you don’t need to memorize the small details that may be found on one of the AD exams but rather the basics of how it’s all laid out. Understanding the difference between AD replication and Application Center synchronization may save you some grief, and knowledge of file systems is a must. Concentrate on the differences between FAT, FAT32 and NTFS. Spend time reviewing DNS and DNS Round Robin terminology and layout, as well as SQL database placement.

Tip: Make sure you understand DSN (not DNS!), data source names.

TCP/IP, Routing, and Firewalls
Do you know how to subnet? Review all the classes of TCP/IP and how to subnet as well as how to determine what hosts are valid (not network or broadcast) within a subnetted network. For example, could you determine why a certain configuration may or may not work? Review network address translation (NAT) and firewall terminology and fundamentals to understand what benefits or problems their presence adds to your working environment.

Application Center 2000

Reviewer’s Rating
“What saved me was using Application Center, IIS and working with TCP/IP on an almost daily basis. Without a solid background in Microsoft and infrastructure technologies with Application Center specifics, you may feel you’re in over your head.”

Exam Title
Implementing and Maintaining Highly Available Web Solutions with Microsoft Windows 2000 Server Technologies and Microsoft Application Center 2000

Current Status
Active as of November 2001.

Who Should Take It
Professionals using Windows 2000 technologies and Application Center 2000 in a production environment. Elective Credit for MCSE.

What Courses Prepare You? 2087: Implementing Microsoft Windows 2000 Clustering. Three days.
2154: Implementing and Administering Windows 2000 Directory Services. Five days.
1561: Designing a Windows 2000 Directory Services Infrastructure. Three days.
2203: Deploying and Managing Microsoft Application Center Server 2000. Two days.

Application Center may very well be configured on your demilitarized zone (DMZ), a location on the network isolated from the internal network and set up to host servers that are publicly accessible to the Internet DMZ. So study all the components of the DMZ.

Don’t waste time memorizing every port number from www.iana.org, but make sure you have down pat the basic ones like Telnet (23), http (80), and FTP (20 and 21—as well as rolling over after 1023 and snatching available ports per session). More important, gain a thorough understanding of how some of the protocols within the TCP/IP stack function on the port level. Go over the ports you can adjust with Internet Information Server (IIS).

Tip: Practice designing a clustered solution that connects an internal (private) and external (public) network with multiple NICs. Put IP addressing with a subnetted 28-bit subnet mask on both ends and make sure you don’t use addressing with all ones and zeros.

IIS, Web Services and Application Components
You’d better have a deep understanding of IIS before taking this test. If you’ve never worked with IIS, you’ll definitely feel the heat in preparing for the exam. Think about it: A popular use of Application Center will be to tune IIS for load balancing of Web sites and content. That means you’d better know virtual directories and the basics of how a Web Site is laid out with IIS, including directories, default ports and default settings. Go over the permissions of IIS and anonymous access. Make sure you know what accounts are used and what would happen if you had a problem with users who couldn’t view content on your load-balanced site across Application Center.

I can’t stress enough that you really need to know how IIS spreads across Application Center. For instance, can you list what processes IIS uses to keep itself running? Where do you make a change to the site within the Microsoft Management Console? Would you use the master properties or the sites properties? Last, can you configure ISAPI filters and explain why you’re configuring them?

Tip: Set up a Web site on IIS and go through every single configuration parameter available. It’s critical that you know how to configure every detail like IP address bindings, authentication and ISAPI filters.

Installation and Basic Configuration
Once you go beyond the implementation of Win2K technologies, you get to the heart of Application Center. That starts with the topic of installation. There are quite a few things that will stop you from installing this product on a server, including not having Service Pack 1 installed or not having certain hotfixes implemented.

Most things have to be identical (and I mean identical!) on an Application Center installation with multiple servers. For replication reasons, the nodes in thecluster need to have the same drive and directory structure as the cluster controller.

Memorize the prerequisites for installing Application Center. For example, you need a bunch of pre-Service Pack 2 hotfixes that come with the installation media CD. Make sure you can tell if an installation failed because one of the prerequisites was missing. (The installation will end with an error message telling you what you may need to check before running the installation again.)

How do you uninstall Application Center 2000? Can you remove it; if you do, what happens? You may go through the process of uninstalling Application Center, but what happens if it’s still a member of the cluster? Know how to recuperate from this possible incident.

Likewise, understand the ins and outs of cluster controller promotion. One important point to note is that you have the flexibility to promote any cluster member to cluster controller. The whole reason for this is that you have to be able to fix the cluster controller itself in case of a system or hardware failure. This makes for a truly highly available solution. Know how and why to use the ac cluster/clean command.

Become familiar with installing Application Center in load-balanced scenarios with either domain controllers or member servers. Know every single place you can put an IP address to be bound on the cluster itself, IIS or the NIC card of any member. This includes NLB properties, IIS properties and Application Center properties.

Knowing exactly what a cluster controller does and all the little details about it will aid your efforts in working with Application Center. A cluster controller maintains the latest, most accurate content for your cluster members. The controller is responsible for synchronizing its content to the entire cluster. If the content on the controller changes, the changes are synchronized automatically to each cluster member by default. The default time is 60 minutes for a full automatic synchronization. Know how to make synchronization happen faster or where to configure the default time to make it less than an hour. Know how to configure draining in any scenario where you need to “not affect the users” on the network when you have to perform any maintenance on the cluster. When you want the cluster member to no longer accept any new connections and you want to set it “offline” in a graceful manner, you may want to “drain” or gracefully reduce the current connections that are established over a certain amount of time configured as “minutes” in the “set offline” dialog box of the cluster member you’re bringing down.

Tip: Make sure you know every detail about configuring the cluster controller. Practice bringing up other nodes as the cluster controller and taking the original controller out of the equation.

If you set an alarm up, does it pop up in Event Viewer? Is it set up in System Monitor, Performance Monitor or Health Monitor? Where can you go to view what? You need to have a detailed understanding of these three services. Event Viewer is found in the Computer Management MMC, but you can also use the Application Center Event Viewer. It’s critical that you know what you’re looking for and which one you want to view in order to get specific information.

Know how to monitor performance of the entire cluster and tell whether a log file is accurately depicting the errors on a cluster node. It may be that the log file has been replicated from the cluster controller over to that node, and you’re actually looking at the cluster’s controller errors, or lack thereof. Know how to monitor performance on every node in your cluster and combine that information into one chart. In other words, make sure you can distinguish information coming in on the entire cluster vs. that coming from just the cluster controller. Counter display settings incorporated into the Application Center Performance Monitor aren’t synchronized across the cluster, so what you’re looking at on one server node may not be what you’d see on another. Look at them individually or from the cluster controller. Also know what you can configure in the System Monitor for Application Center; you’ll find this in the Administrative Tools folder.

10 Things to Practice

1. Install Windows Application Center 2000 across two or more machines.

2. Install and configure IIS and set up a basic Web site. Configure access to the site. Configure every detail of IIS that you can find.

3. Deploy content from a staging server to a cluster.

4. Install and configure every type of cluster and go through every setting.

5. Configure all affinity settings and make sure you know the differences among all three of them.

6. Configure clusters with Application Center 2000. Take the cluster member offline and online.

7. Practice monitoring every part of Application Center 2000 with System Monitor, Event Viewer and Health Monitor.

8. Set up data groups and alerts.

9. Practice setting another cluster node member to cluster controller and taking the controller out of the cluster.

10. Uninstall Application Center 2000 and use the AC command-line tool.

What Type of Cluster, Buster?
You need to know what cluster type to set up, why and how to use each one. The Web cluster is used to host Web sites and local COM+ applications, staging, monitoring, synchronizing, and component load balancing. The COM+ application cluster hosts COM+ applications that other Windows applications or Web sites would reference. A COM+ routing cluster routes requests to a COM+ application cluster. Make sure you can look at a topology map and know the difference between them all as well as how to configure them.

The definition of affinity is “a natural attraction, liking or feeling of kinship.” In the context of Application Center, the three types of affinity are None, Single and Class C.

None (or no affinity) is implemented if you want multiple requests from the same client to access any member. Use this when you want a cluster setup that doesn’t store session state information on individual members of that cluster. Make sure to review the basics of session state and cookies.

Single affinity is implemented when you have multiple client-based requests from the same client that must access the same member. This type of affinity can be of use in clusters located within an intranet infrastructure where you may only have one address that all clients go to.

Class C affinity is used when multiple requests from the same TCP/IP Class C address range must access the same member This type of affinity is useful for clusters serving content on the public Internet. Memorize these facts and any others you can dig up on TechNet about affinity.

Tip: Make a chart to help memorize all the details of affinity.

Synchronizing: Online vs. Offline
Study the differences between cluster members being online and offline. Practice taking members offline and examine the results of doing such a thing. Know why you would do it and how. Know the fastest way to do things (like synchronization) and how to back out of any problem quickly. You can set synchronization properties to exclude things like files, folders or even file types. Know how to prove things have been synchronized. Practice this technique by synchronizing all data except for .txt files.

Tip: Practice bringing members offline and online. Be aware of what’s happening and check if you get any errors on logs or viewable icons.

Bits, Pieces and Last Tips
Although you don’t need to know brands and their specifics, you should know where third-party load balancers (like Cisco’s Local Director) fit into your design. For example, when you use a third-party load balancer, do the load-balanced servers need to be multihomed? Can they be part of the cluster and managed from the cluster controller?

Also, know when or if you need to make a registry hack for any reason. Practice drawing out n- and three-tier designs and designating where all components for the cluster reside. Practice setting up NLB and figure out what happens with “bad bindings.” How do you manually configure NLB if something doesn’t work?

Finally, learn how to configure data groups and set up alerts and messaging via e-mail. Be prepared to read through scenarios about data groups and analyze how to configure them.

Additional Information

You’ll find the objectives and guidelines for exam 70-232 at www.microsoft.com/traincert/exams/70-232.asp.

Microsoft.com provided all of my preparation materials. You’ll find more than a hundred pages of content on Application Center, including design theory and instructions for configuring the software at www.microsoft.com/technet/treeview/default.asp?

You’ll find the Resource Kit for Application Center here: www.microsoft.com/technet/treeview/

The home page for Application Center 2000 can be found at www.microsoft.com/applicationcenter/default.asp.

You can download Application Center trial software at www.microsoft.com/applicationcenter/evaluation/trial/default.asp.

An interesting article on using Application Center 2000 to build server farms is located at http://msdn.microsoft.com/msdnmag/issues/01/05/appcenter/appcenter.asp.

Background Check
Because of the emphasis on COM and COM+, ASP and other Web-based programming technologies in this exam, you may be asking yourself, “Is this one for developers?” Not to worry. You don’t have to be a programmer to ace this test. It helps, of course; but knowing how to package things up and “roll ’em out” onto the cluster is what you really need to master. Knowing the placement of routing clusters and how to deploy content, especially from a staging server, is important. Don’t let all the terminology shake you. Memorize all the definitions and understand the differences and you’ll be OK.

What I loved about this exam was the extensive background check I received while going through the testing gates. Do you know TCP/IP and network infrastructure fundamentals? This test will make you think about the whole picture while getting into the little details about IIS and Application Center. If you practice with the product and have already tried the other Win2K exams (especially the other Designing Highly Available Web Solutions test), then you’re partway there. Practice with IIS and Application Center to fully prepare. Remember: This exam focuses on setting things up and quizzing you on what works and what doesn’t in Application Center 2000. Challenging for sure, but passable. Good luck!


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