Here are the MonaLisa related crontab entries on thpc-1.unl.edu:

10,30,50 * * * * export MYPROXY_SERVER=thpc-1.unl.edu; export MYPROXY_SERVER_DN=/DC=org/DC=doegrids/OU=Services/CN=thpc-1.unl.edu; source /opt/osg/setup.sh; /home/brian/monitoring/mlmetric.py --dest red.unl.edu:58884 -cluster "Auxiliary Services" -node thpc-1.unl.edu -param "Proxy hours left" -value `myproxy-info -l phedex | grep timeleft | tr ':' ' ' | awk '{print $2;}'`
0-59/2 * * * * /home/brian/monitoring/mlmetric.py --dest red.unl.edu:58884 -cluster dCache -node Movers -param Active -value `links -dump http://thpc-1.unl.edu:2288/queueInfo | grep Total | awk '{print $4;}' | tail -n 1`
0-59/3 * * * * /home/brian/monitoring/mlmetric.py --dest red.unl.edu:58884 -cluster dCache -node Movers -param Queued -value `links -dump http://thpc-1.unl.edu:2288/queueInfo | grep Total | awk '{print $8;}' | tail -n 1`
0-59/5 * * * * /home/brian/monitoring/dcache_usage.py --dest red.unl.edu:58884 --dcache thpc-1.unl.edu:2288

The first checks to see how long my myproxy certificate has before it expires.  The second two send Active and Queued mover information from dCache.  The third is a script (documented elsewhere) which sends dCache disk free/used/total information to ML.

Here are some other entries from phedex.unl.edu:

1-59/5 * * * * source /opt/osg/osg-030/setup.sh; /home/phedex/mlmetric.py -dest red.unl.edu:58884 -cluster "Auxiliary Services" -node phedex.unl.edu -param "Phedex proxy" -value `grid-proxy-info -f /etc/grid-security/proxy.cert > /dev/null; echo $?`
1-59/5 * * * * source /opt/osg/osg-030/setup.sh; /home/phedex/mlmetric.py -dest red.unl.edu:58884 -cluster "Auxiliary Services" -node phedex.unl.edu -param "GUMS authentication" -value `globusrun -a -r red.unl.edu > /dev/null; echo $?`
1-59/5 * * * * source /opt/osg/osg-030/setup.sh; /home/phedex/mlmetric.py -dest red.unl.edu:58884 -cluster "dCache" -node "Storage Info" -param "Available Space" -value `srm-storage-element-info -debug=false https://thpc-1.unl.edu:8443/srm/infoProvider1_0.wsdl 2>&1 | grep availableSpace | tr '(' ' ' | awk '{print $3;}'`
1-59/5 * * * * source /opt/osg/osg-030/setup.sh; /home/phedex/mlmetric.py -dest red.unl.edu:58884 -cluster "dCache" -node "Storage Info" -param "Total Space" -value `srm-storage-element-info -debug=false https://thpc-1.unl.edu:8443/srm/infoProvider1_0.wsdl 2>&1 | grep total | tr '(' ' ' | awk '{print $3;}'`
1-59/5 * * * * source /opt/osg/osg-030/setup.sh; /home/phedex/mlmetric.py -dest red.unl.edu:58884 -cluster "dCache" -node "Storage Info" -param "Used Space" -value `srm-storage-element-info -debug=false https://thpc-1.unl.edu:8443/srm/infoProvider1_0.wsdl 2>&1 | grep used | tr '(' ' ' | awk '{print $3;}'`

The first two check the proxy lifetime and GUMS authentication, respectively.  The last three, documented elsewhere, send dCache totals to MonaLisa.