For various reasons the standard logfile analysis reports provided by the ISP do not do the business. logan.pl has been developed to fill the gap. It is designed to give information useful to the webmaster and others developing content for a website, particularly for a CGI driven site.

Logfile analysis is a heavy resource user, therefore the analysis is done in a number of stages. Once the first two stages are complete, displaying results is rapid.

Stage one: Copy

Checks that the most recent logfiles have been copied across, and if not, copies across the oldest.

At present, newly copied logfiles cannot be analysed until they have been manually decompressed. It may be possible to make this step automatic later on.

Stage two: Analyse

Reads each logfile and creates a results file with counts of each relevant activity. This stage is a very heavy resource user and a maximum of 5 logfiles are handled in each pass. In some cases, with very large logfiles, it may be necessary to limit the number handled even further or even, for websites with very heavy traffic, to do this part of the analysis offline. Once complete, the analysis does not normally need to be repeated.

If the option to reanalyse is chosen, it will take several passes to repeat stage two. This option is needed only after enhancements to the analysis routines.

Stage three: Accumulate

Read the results files for the period chosen and accumulate results.

Display logfile dates, total counts, weekly average and, optionally, weekly totals

Interpreting the results

...to follow...