Know Your OSS Logs Part 1 – iTP Web Server Logs

February 6, 2020 by Phil Ly

In this article, I want to share with you some basic information on some important iTP Web Server logs. Since a lot of information is already available in the HP documentation, I thought I would give you a “Cliff Notes ” tour by using “5 W’s + 1 H” approach:

What?

access.log	The access log file records the request history of a server. The information in this file is structured in the common log format (CLF).
httpd.log	The extended log file combines the functions of the access log and the error log files, recording information concerning requests and errors. This format places errors in context with the relevant request
error.log	The error log file records all request and server errors. The information in this file is structured in the common log format (CLF).

Why?

By monitoring these logs, it allow you to gauge the health of the webserver and to detect errors as soon as they occur.

Are Web requests coming in?
Are they completing with code 200 (normal) or errors like 404 or 500?
What pages are being accessed?
Where are the requests coming in from?
Are there any errors?

Where?

The locations of these log files are specified by the ErrorLog directive in the server
configuration file. These are their common locations

access.log	/usr/tandem/webserver/logs/access.log
httpd.log	/usr/tandem/webserver/logs/httpd.log
error.log	/usr/tandem/webserver/logs/error.log

Who?

The Operation team are usually the people that monitor these log files as it allows them to gauge the health of the system. If there are errors, then Development may be contacted to look at them.

access.log	Operation, Administrator
httpd.log	Administrator, Development
error.log	Administrator, Development

How?

If you do it manually, then you should remember cat, tail and vi. For example:

To view the whole log file (equivalent to FUP COPY)
cat access.log
To view the last entries:
tail access.log
You can also view them using the vi editor
vi access.log

The Take-Away

iTP Web Server records its web activities in log files. By monitoring these log files, you can be assured that transactions are flowing normally, or if there is an error condition that needs to be addressed.

Automate!

Instead of having to manually view these files in OSS directly, you can automate by using TIC LogWatch to:

Monitor the files for new entries
Clone a copy of the entries to a Guardian file
Scan the entry content to look for specific information, e.g. any HTTP completion code that is other than “200”
Raise an alert by sending an email to an Administrator or Developer based on the detected condition

Click here to learn more about how LogWatch can help you monitor iTP Web Server logs.

Next Topic: Know your OSS logs – Java Servlet and NS/JSP

Many iTP Web Serve applications are actually built on Java Servlet and Java Server Pages. This environment involves additional log files beyond the ones discussed here. I will discuss the usage of these log files in my next blog.

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Phil Ly is the president and founder of TIC Software, a New York-based company specializing in software and services that integrate NonStop with the latest technologies, including Web Services, .NET and Java.
Prior to founding TIC in 1983, Phil worked for Tandem Computer in technical support and software development.