iTP Secure WebServer System Administrator's Guide (iTPWebSvr 5.1+)

Planning the iTP Secure WebServer PATHMON
Environment
iTP Secure WebServer System Administrator’s Guide—522659-001
3-3
Configuring the PATHMON Environment
Because the httpd servers are now picking the new connections by themselves, removing
an httpd server may disrupt the pending new connections (those connection requests
have been forwarded to the httpd server and has not yet picked up by the httpd server).
Unfortunately, the PATHWAY is unaware of these pending connections and may remove
a dynamic server when it has no more links with the Link Manager.
A further delay has been instrumented in the httpd server to complete all of its
outstanding pending connections before it does the exit. However, timing window may
still exist. Therefore, the new Deletedelay server directive is introduced to allow user to
specify a longer delay before a dynamic server is removed.
Deletedelay is documented in Server
on page A-59.
A survey of the request load and a better planning are essentially to achieve a better
performance and non-disrupt Web server environment. Listed below are some of the
configuration guidelines recommended:
•
Specify at least the same number of static httpd servers as those CPUs intended to
run httpd servers. For example, if the httpd SERVERCLASS is configured to run on
CPU 0 to 5 (total of 6 CPUs), the Numstatic value should be at least 6. In fact, tests
have shown 3 httpd servers per CPU will achieve the best performance.
•
A higher value should be used for TANDEM_RECEIVE_DEPTH. The maximum
value support is 255. Depending on the speed of the CPU, higher value will
potentially reuse more sockets created for accepting new connections and save more
CPU cycles. Specifies a value lower than 50 may not be adequate.
•
Time your operation’s peak hours and off-peak hours, and specify an adequate value
for the Deletedelay. In other words, the dynamic servers will only be created in the
peak hours, specify a Deletedelay that will allow them to be removed only in the
off-peak hours. For example, if the peak operation hours are 11AM to 6PM,
specifying 7 hours of Deletedelay will allow the dynamic servers to be removed
after 6PM. But, if you have multiple peak hours, it may require more detailed
planning. The best way to avoid these types of problems is to make all of the httpd
servers static servers.
Configuring the PATHMON Environment
The configuration of the iTP Secure WebServer PATHMON environment is specified in
the httpd.config file. You specify the configuration file when you start the iTP Secure
WebServer process.
The httpd.config file consists of keyword-value pairs. The sample configuration file
httpd.config.sample is included in the /usr/tandem/webserver/conf directory. That file
contains all keywords along with their default values and ranges.
The configuration file can contain spaces, tabs, blank lines, and lines that start with a
pound sign (#), which identifies the line as a comment. The keywords are case-sensitive
and must be spelled exactly as defined or they will not be recognized. A keyword must
be followed by a valid value.
Refer to Section 7, Configuring the iTP Secure WebServer
, for an example of the
httpd.config file. The example includes commands for configuring several processes that