Weather Decision Technologies uses the Unidata Local Data Manager, the industry standard for transporting meteorological data. This system offers transmission correction and queuing capabilities, as well as a distributed networking topology - allowing for fault tolerance should one site fail. For specific information on the Unidata LDM, see the documentation available from Unidata.
Customers and partners can contact our customer support representatives for additional information on utilizing this system for ingest and reception of radar, satellite and model forecast data from our datacenter.
If LDM does not start
If there are still problems, go through the Source Code Installation steps. Be sure to check that the path is properly setup – putting this path into the '.cshrc' file (or proper shell initiation file) is recommended. Make sure the permissions on the 'data' directory and 'ldm.pq' file are correct.
Still not starting? Go through the Activating the LDM Installation. Make sure your 'runtime' link is set correctly.
If the Log file is empty
- Make sure that 'rpc.ldmd' and 'hupsyslog' are both SETUID to root.
- Make sure the ~ldm/logs directory has proper permissions.
- Check the Pre-Installation Steps to make sure all the proper files were modified.
If LDM runs, but no data is seen
Try to 'ldmping' the WDT servers (ldm.wdtinc.com); if successful (responding) then the WDT servers is configured properly. If 'ldmping' times out, then your machine did not see the WDT servers at all. Make sure you can ping out of your machine. There could be a networking or firewall issue.
Look at your configuration in the ldmd.conf file. You must have a 'request' to the WDT servers. Examples are found in the New Users Guide in step #4. Make sure you have 'tabs' not 'spaces' between each entry on the request line.
If this does not work, please contact WDT support to get this fixed.
If LDM is running and data coming in, but no data is being written to disk
Examine your pqact.conf file. Examples are found in the New Users Guide in step #4. Make sure your directory is correct. Make sure there are 'tabs' not 'spaces' between all entries in your configuration line as well as before the FILE and/or PIPE.
Still not seeing written data? Examine your log files for any data write-errors. The permissions on the destination directory could be wrong.
Data has stopped
If you still see some feeds, run 'ldmadmin watch' to see the data come in. If the feeds appear to be up, but you are not receiving the data please contact WDT support via the Support tab on the left hand side of the page.
If all of the data has stopped, try to 'ldmping' the WDT servers. If you can see it, stop LDM, delete and remake your queue, and start LDM. If 'ldmping' is unsuccessful, try to 'ping' the WDT servers. There could be networking issues to deal with.
Has anything changed in your configuration? If your configuration has changed, check your configuration for syntax errors; if found, modify and restart LDM. Has your system changed IP addresses? If so, you will need to send this new information to WDT support via the Support tab on the left hand side of the page.