iTP Secure WebServer System Administrator's Guide (iTPWebSvr 6.0+)

Configuring the iTP Secure WebServer
iTP Secure WebServer System Administrator’s Guide—523346-002
7-7
The Secure Transport Configuration File
(httpd.stl.config)
The Secure Transport Configuration File (httpd.stl.config)
Example 7-2 shows how to configure the iTP Secure WebServer for SSL or PCT. This
sample file, httpd.stl.config, is supplied with the iTP Secure WebServer. For
more information about SSL configuration, see Section 4, Configuring for Secure
Transport.
Configuring Global Session Key Caching
Global session key caching is introduced to improve caching performance. The current
architecture has multiple instances of webserver processes running as a Pathway
serverclass. Each instance maintains its own cache of SSL session keys. However,
due to round-robin load balancing of the iTP Secure WebServer environment, SSL
session key cache hits are rare. This enhancement provides increased overall SSL
performance by allowing a cache of SSL session keys to be shared amongst all
instances of the httpd serverclass, thereby maximizing the cache hits and minimizing
the CPU and network resources required for establishing SSL connections to the
NonStop platform.
If global session key caching is desired, the SK_GlobalCache directive (i.e the
GlobalCache variable), must be set to ON to enable the configuration of the server. If
individual httpd server process session key caching is desired, which is the default,
set the variable to OFF, or omit it.
The value of MAXSERVERS must always be set to 1. This is a single process
serverclass. The value of MAXLINKS and LINKDEPTH must both always be set to the
value of the httpd server’s MAXSERVERS value. For example:
Server $root/bin/httpd { Server $root/bin/gcache {
... Maxservers 1
Maxservers 50 ---> Maxlinks 50
... Linkdepth 50
} ...
}
The configuration directives SK_CacheSize and SK_CacheExpiration, which are
set by defining the variables CacheSize and CacheExpiration, are optional. The
default value for SK_CacheSize is 1000, and for SK_CacheExpiration is 86400
(24 hours).
Note. You cannot use httpd.stl.config and httpd.websafe.config in the same
WebServer environment.
Note. If individual httpd server process session key caching is used, each process will create
it's own cache with SK_CacheSize entries. However, if global session key caching is used, that
single process server will create a single cache also with SK_CacheSize entries. Take this into
consideration when determining the value for SK_CacheSize.