Chapter 8. Topologies 227
Considerations
For the multi-cell topology, consider the increased costs in hardware, complexity,
configuration, and administration. However, you need to consider these costs in relation to the
gains in performance, throughput, and reliability. You probably have specific requirements you
need to consider in such an architecture.
Setting up this topology
The steps for this topology are the same as for a topology with redundancy of multiple
components as shown in “Setting up the topology” on page 221.
8.3.11 Advanced topology using an administrative agent
Starting with WebSphere Application Server V7, an additional administration component is
available called the
administrative agent. The administrative agent is intended to reduce the
administration costs of large WebSphere deployments. A single server installation is sufficient
for several installation scenarios built according to the requirements. The issue of having
multiple stand-alone application servers in different environments (for example, development,
test, quality assurance, or production) is that they all lack a common administrative interface.
An administrative agent provides a single interface to administer multiple unfederated
application server nodes in such environments. The administrative agent and application
servers must be on the same system. However, you can connect to the system from a
browser or the wsadmin tool on another system.
Remember:
Because this topology is a combination of topologies described previously, the
multi-cell topology also has the considerations of those base topologies.
Restriction: You can register an application server node with the administrative agent or
federate the node with a deployment manager, but you cannot do both.
In addition, a DMZ proxy does not work with the administrative agent when security is
enabled. Keep security enabled, and do not use the administrative agent in a DMZ proxy
environment.
228 WebSphere Application Server V8.5 Concepts, Planning, and Design Guide
Figure 8-13 shows a possible topology that uses an administrative agent to manage all of the
single server installations on System B. Instead of running the Configuration service, the
administrative console application, and so on, in each application server, these services are
running in the administrative agent for all profiles. The administrative agent, therefore,
reduces the administrative tasks for the installation and simplifies the administration, because
all administrative access uses one central point. Therefore, you have one URL for the
administration instead of several.
Figure 8-13 Topology containing an administrative agent
Advantages
The implementation of an administrative agent profile has the following benefits for the
installation:
Reduced administrative footprint
The administrative footprint is reduced when using multiple, single server installations in
the same system.
Central access to administration tools
Access to the administrative tools (the administrative console or wsadmin) is simplified,
because all access is through the administrative console. Only one URL is used instead of
multiple URLs.
Less firewall ports required
If a firewall is between the administrator’s workstation and the servers, fewer ports need to
be opened on the firewall. Instead, you need accessibility only to the administrative agent
to each application server.
Server BServer A
Web
server
Web
server
Web
server
Directory
and
security
services
Existing
applications
and data
Directory
and
security
services
Existing
applications
and data
Outside World DMZ Internal Network
Domain firewall
Protocol firewall
I
N
T
E
R
N
E
T
User
HTTP/HTTPS
Application
server 1
Application
server 2
Application
server n
Administrative agent
Domain firewall
Directory
and
security
services
Existing
applications
and data
Admin
console
Admin
scripts

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