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This is run twice nightly by the trscrontab on pinger@pinger.slac.stanford.edu to ping the target www.slac.stanford.edu. The first time is to use the enabled landmarks, the second time is to use the disabled landmarks. Reflector.cgi has to run on www-wanmon since that is where the PlanetLab cookie is kept. Since one cannot remotely run a trscronjob on www-wan mon, there is a script (reflector.pl) to execute reflector.cgi twice via twice (with ability=1 and then ability=0) via a wget command. The first time it uses all enabled landmarks (the default or ability=1). The second time it uses the disabled landmarks (or ability=0). Running it regularly ensures the tulip log files are current and therefore the analysis is also current.
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Using the results from the Tulip log analysis script for the last 3 days we can identify the hosts and their success percentages. We opted to disable all the hosts which were having success less than 20%, and to enable the ones with success rate greater than 20%. The tulip-tuning.pl script is in /afs/slac.stanford.edu/package/pinger/tulip and it performs the listed functions. It uses the LWP package to call reflector.cgi?function=log&days=3 to access the Tulip log analysis data for the last 3 days and downloads the analyzed tulip log file by requesting it from the reflector using http://www-wanmon.slac.stanford.edu/cgi-wrap/reflector.cgi?function=analyze&days=days3 and saves it in a file and then parses the output to get: for option ability=1, the faulty (landmarks (i.e. the ones below 20% success rate by default) updating the database to disable such hosts; or option ability=0 the landmarks with a success rate greater than 20% and re-enables them in the database. It (tulip-tuning.pl) is run twice nightly (see the trscrontab) once to disable non working landmarks, once to enable landmarks that are now working again. The runs are before the sites.xml or sites-disabled.xml are created and specify using the tulip log file analyzed for the last 3 days.
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