Using snort version 2.8.6, I am attempting to collect application performance stats such as
- Number of packets not processed due to application overload
- Percentage of time in processing layers (preprocessor, reassembly, pattern matching, etc)
- Number of packets processed
I am currently using perfmonitor preprocessor to dump performance stats, and graphing some of these values through SNMP calls. The documentation on this preprocessor is fairly limited and doesn't do a good job of explaining what the fields actually mean, or what time frame the figures are calculated over.
To get those kinds of performance metrics, what fields should I be looking at and how are those fields measured?