Performance monitoring - including SNMP and rstatd data in load test scripts

Occasionally questions come up about how to monitor UNIX servers during load testing. SNMP, rstatd, vmstat - it's all so confusing! Fortunately there are resources to help.

I came across a nice little article recently on this - and there's some interesting references to SNMP techniques:
http://www.myloadtest.com/collecting-performance-stats-with-snmp

To add to the knowledge base, here is a link to an article I wrote a year or so ago on the same subject which may be of interest. Following a proof-of-concept, the conclusion was that a script could be written to extract SNMP counters and record them via user-defined counters for later analysis. The evaluation was done using Compuware's QALoad but should be portable to Mercury LoadRunner.

The link to the article:
http://www.users.globalnet.co.uk/~cater/dave/acutest/TN1.doc

Related references that may be useful:
Open Source project Net-SNMP http://www.net-snmp.org
Linux version of rstatd(1M) http://rstatd.sourceforge.net

Let me know what you think of the article and ideas for the future.