MACROMEDIA FIREWORKS 2-USING FIREWORKS, Руководство пользователя

Страница: 15 / 20

Introducing edge servers 15
You can find examples of the configuration files, their tag structures, detailed information
about the tags, including cross references to associated tags, syntax, and examples in
Chapter 3, “Configuration Files” in
Managing Flash Media Server .
Deploying a cluster of edge servers
You can also deploy a group of connected edge servers as a cluster. Each edge server in a cluster
can access the origin server. Clustering lets you distribute across the many edges in the cluster
all connections to applications that are running on the origin server. The origin server always
remains secure behind the edge servers.
For example, Organization A deploys a cluster of edge servers on its internal network. The
edge servers are defined as explicit proxies and dedicated to service specific users. When the
clients or users want to connect to the origin server, the client first connects to one of the edge
servers in the cluster. It is at this point where the connection requests are authorized or
rejected. If the request is valid, the edge server makes the connection to the origin server,
where the application is running. The origin server returns the results to the edge server,
which passes them on to the requesting client. The edge server also stores the results in a
cache, making it available to other servers and clients.
As this organization grows or reallocates its resources, it can add more edge servers to the
cluster or explicitly reassign clients to different edge servers.
Organization B uses a cluster of edge servers to manage the inbound traffic from clients
located outside of the network. This traffic is destined for Flash Media Server applications
running on the origin server. When these users try to connect to the origin server, a load
balancer positioned before the cluster routes the client’s request to one of the edge servers. The
edge server makes the connection to the origin server, where the application is running. The
clients remain unaware of the presence of the edge servers. The origin server returns the results
to the edge server, which in turn passes them to the requesting client. The edge server also
stores the results in a cache, making it available to the other external clients.
In this scenario, connections to applications are distributed across the many edge servers in
the cluster. If one edge server in the cluster cannot access an application, another edge in the
cluster handles the connection. Applications on the origin server are never directly exposed to
connection requests coming through the Internet.
This scenario describes how Organization B uses a reverse proxy to service incoming
connections instead of outgoing connection, as was the case in the Organization A scenario.