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There are two significant type of maintenance issues when we talk about TULIP. The problems we need to address are location change of landmarks and their uptime. The problem with the landmarks being available is discussed in landmarks laundering which is child to TULIP analysis page. The other significant problem is the location update of landmarks. We are getting the location of Planet Lab landmarks using the geoiptool, PingER landmark locations are provided by the site hosts and are manually added to Node Detail database.  We intend to run a nightly cron job to check if there is any host which has changed its position. The script is currently deployed at

 /afs/slac/package/pinger/tulip/maintainPL.pl

We have also discovered problems with geoiptool in some of the hosts. One of the challenging problems were two hosts(planetlab1.pop-mg.rnp.br,planetlab2.pop-rs.rnp.br) in Brazil . We did a ping between the host and got a response of 25~30 ms. Geoip tool showed that the hosts are at the same location which is about the center of brazil. We then inquired further and found the case interesting as the traceroute to both of them was going through different routes i.e. traversing different routers to reach the destination.After confirming the actual latititde and longitude from thier websites we updated the database manually. To cater for the problems like these the hash named errltln(Error in lat/long in geoiptool) contains the host which are not updated in the database with this script. The sample code is given below

#Error in lat/long in geoiptool
 my %errltln = (
 'planet01.hhi.fraunhofer.de' => '1',
 'planet02.hhi.fraunhofer.de' => '1',
 'planet-lab1.ufabc.edu.br' => '1',
 'cs-planetlab3.cs.surrey.sfu.ca' => '1',
 'planetlab1.pop-mg.rnp.br' => '1',
 'planetlab2.pop-rs.rnp.br' => '1',
 'csplanet02.cs-ncl.net' => '1'
 );

How to Find Latitude and Longitude of a Node Manually

Most of the Tulip landmarks are actually the PingER nodes. Almost every PingER node in Node Detail database has very useful information e.g. Node Name, Url, Full Name of the node etc. If you have to find the Geographic coordinates manually then this information proves to be very useful. You have to follow the following steps to find Latitudes and Longitudes using Google Map or the following link: www.satsig.net/maps/lat-long-finder.htm 

  1. Copy Url from Node Detail database, paste it in the Internet Explorer. Go to the site, look for 'Contact us' link or see the bottom of the page to find the street address. Once you have the street address, find its coordinates on Google map or through link (Given above).
  2. Now, suppose you do not have a URL then use Node Name/Full Name from Node Detail database to find some web site for that node. If you find the web site, then do same as explained in Step 1.
  3. If there is no web site listed for that node then Use City information to go to that city. Use Zoom facility to make a rough guess of the coordinates again using google map or link.
  4. If you do not find an entry in Node Detail database for the desired node, then use the Name of the node to find the full name or City of the node using Google help. Once you find any of this information uses a similar process, explained in previous steps, to find coordinates.

Note: If node has an entry in Node Detail database, you can always contact the Contact Person of that node to ask for Latitude and Longitudes.

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