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
(70-232) |
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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.
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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.
Performance
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.
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Things to Practice |
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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.
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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.
Affinity
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.
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!