Installation guide

CHAPTER 4 Installing and Configuring a Web Server Redirector Plug-In
Installation Guide 41
When a request arrives from a client, the Web server redirector sends it to an
EAServer application server. The redirector selects the server based on a
round-robin scheme where each new request from a client is directed to the
next available application server that can service the request. If the application
server is not responding to a request from a client (for example, temporarily
down for administrative reasons), the redirector marks the application server
unavailable for a fixed period of time and sends the request to the next
application server that can service the request.
If a request arrives from a client and an application server has been unavailable
for more than the retry value, the redirector sends the request to this
unavailable server. If the server responds, it is marked as “available.”
The default retry value is 300 seconds (five minutes). You can change the
default by adding this directive to the redirector configuration file, where
seconds is the number of seconds the application server is unavailable:
Connector.RetryAfter <seconds>
If the redirector has connected successfully to an application server, and while
awaiting the response, the network connection is broken between the redirector
and EAServer, the redirector does not attempt to restore the connection. The
client must retry the request.
See “Editing the redirector configuration file” on page 46 (iPlanet) or 52
(Apache) for more information.
Binding to a specific application server
If you are using the Apache redirector plug-in, you can bind the redirector to a
specific server. If a redirector is bound to a server and the server fails to respond
to a request, the redirector returns immediately. By default, a request fails over
to another server when the initial server does not respond. If you are running
Web applications that are not marked as distributable, you must bind the
redirector to a specific server. If a bound server fails to respond to a request, the
redirector returns the error status to the client. To bind the redirector to a server,
add this line to the redirector configuration file; serverName is the name of the
server:
Connector.BindToServer /serverName
See “Editing the redirector configuration file” on page 46 (iPlanet), or 52
(Apache) for more information.