HTTP-ANALYZE FAQ: LOGFILE ROTATION

Homepage | Product Description | Licensing & Pricing | Registration | Download Area | Documentation | FAQs | Sample Report | Customer Support

1. How can I analyze multiple virtual servers?
   There are basically two ways: Either set up separate analyzer configurations and output directories for complete statistics reports of each virtual server or use the HideURL directive in the configuration file to group together all files of a virtual server in the same statistics report. If you decide to set up separate analyzer configurations for each virtual server and if you use the same logfile for all virtual servers rather than logging into different files, use the DocRoot directive to restrict analysis to the part of the DocumentRoot which corresponds to the virtual server you are going to analyze.
2. The list of user agents and the list of referrer URLs are missing in the statistics report, although the server does indeed write both fields into the logfile.
   Instead of logging an empty field, some servers leave those fields empty if no user-agent or referrer URL was transmitted by the browser. In default mode, http-analyze auto-senses the logfile format by looking for those fields in the first logfile entries it reads. To force http-analyze to recognize the extended logfile format, simply define the appropriate logfile format (DLF or ELF) with the option -F or the LogFormat directive in the configuration file.
3. If I rotate a log file in the middle of the month after having done some monthly runs, and I do another monthly run afterwards, I lose everything in the first half of the current month! This means that I have to be very careful to rotate the logs immediately after 00:00 on the 1st of the month before doing any monthly reports. Doesn't http-analyze keep a history file?
   You can rotate on a daily base if you like, but you have to feed all logfile entries for the current month (from the file just rotated and the current logfile) in chronological order into http-analyze. On Unix systems, it's no problem to easily set up such a scheme using shell scripts. Regarding the history, in full statistics ("monthly") mode http-analyze saves only the totals for a month up to the last day of the previous month, but never the data of the current month. The detailed history for full statistics ("monthly") mode is the logfile itself until it is finally rotated at the 1st of the following month.
4. I rotate the logfiles on a monthly base, at the 1st of a new month shortly after midnight. When http-analyze is then run the first time, the previous month always gets deleted from the stats!
   This most often results from wrong order in calls to http-analyze and the script which rotates the logfile. http-analyze saves full ("monthly") summaries in the history file only up to the last day of the previous (not the current) month. The following steps are required for proper function when rotating a logfile:
   Rotate the logfile as soon as a new month begins, this means at or shortly after 00:00 on the first day of a new month.
   After rotating, run http-analyze with this logfile to create the latest statistics and up-to-date history for the previous month.
   Then run http-analyze with the logfile for the current month or let the regular daily cron job update the statistics later.
5. What happens to the stats when I generate a full report for January 1st of a new year? Will the summary main page get overwritten, with January filled in and the rest empty, or will it retain the last year's statistics?
   It will retain the record of the last twelve month in the summary main page up to the month analyzed the last time. If you rotate (save) the December logfile at January, 1st, 00:00 and then run the analyzer on the December logfile just saved, the full statistics for the previous year will be available separately in addition to the last 12 months summary.
6. It's the first day of a new month and the link to the detailed statistics disappeared suddenly!
   http-analyze needs data for at least one full day to be able to create a full statistics report, so the full statistics report will appear from the second day of a new month on. On the first day of the month, http-analyze can generate a short statistics (option -d) to produce up-to-date results.