The logfile analyzer can be used to review the low-level web server (HTTP) logs, to gain a better understanding of how a user accessed Mallard, from what machine and at what times. This information is most useful when correlated with the Mallard logs and grade details.
A note about rotation. The logfile analyzer will search more efficiently if the HTTP logs are rotated periodically. For most servers, rotation on a weekly (or daily, for heavily-loaded servers) basis should yield the fastest search times. Note, however, that the logfile analyzer will only search for logfiles matching 'access*' in the HTTP log directory, and that only unarchived / uncompressed logs will be searched.
Selecting what program(s) to view
If you are interested in only certain activity, such as when users have
taken a particular quiz, you may select the corresponding programs (webquiz
and webgrade) and optionally specify the quiz ID in the search string.
The search string is case-insensitive and must appear exactly as typed in
the log file in order to be considered a 'hit.'
Selecting what user(s) to view
You may restrict your search to one or more users.
Specify start and end dates
Enter dates of the format mm/dd/yy hh:mm:ss am/pm to restrict
your search to entries logged between the start and end dates. You may
specify a start date earlier than the earliest log, if you wish, or an
end date later than the last log entry (even into the future!).
Limiting maximum 'hits'
You may limit the total amount of information returned by your search,
by specify a maximum number of 'hits.' A hit is a single log file
entry, corresponding to the execution of a single Mallard program. If a
student grades a quiz ten times, ten hits for webgrade will be
logged. If you wish to not limit the number of hits returned, you may
enter '0' into the maximum hits field. Be advised, however, that putting
no limit on the maximum hits may cause the analyzer to run out of memory,
run for a very long time, or take a long time to transfer the data to
your web browser.
Retrieving the data
You may select the 'View Histogram Analysis' button to see a timeline and
sorted session activity for the selected users. Alternatively, the 'View
Raw Data' button will list the matching hits as they occur in the logfiles,
without the timeline and without session sorting.
Below the histogram is a listing of each active user and Mallard sessions corresponding to the session bars in the histogram. Clicking on a session listing will pop up the detailed display of every hit for that session.