Chapter 4

Troubleshooting

This chapter lists problems that may occur with McIDAS-XCD. Under each symptom or error message, possible solutions are given. The problems discussed here are listed below.

• -XCD is not receiving real-time data - users report no real-time data, or the ingestor status display is red
• -XCD is not creating McIDAS Grid files
• -XCD is not writing GRIB files
• -XCD is not writing to the real-time GRIB MySQL database
• -XCD data is garbled or missing

-XCD is not receiving real-time data - users report no real-time data, or the ingestor status display is red

• Verify with your LDM Administrator that the LDM is ingesting data. Verify that startxcd.k is running under the user ldm. If it is not, see Starting and Stopping McIDAS-XCD for information on starting -XCD. If you are filing GRIB information into a real-time MySQL database, verify with your MySQL Administrator that mysql is running. Contact your System Administrator to add all three of these to your machine's start-up process.
• The file system may be full. You can use the McIDAS-XCD commands DELWXT, QRTMDG, and xcdscour to delete older text, point, grid, and grib files and to clean the real-time GRIB database. Do not delete any files for the current day.
• If the file system is not full, check the LDM configuration file pqact.conf to make sure it is calling ingebin.k and ingetext.k via the script xcd_run. If this is OK, check the LDM configuration file ldmd.conf to see that it is making the proper requests.
• Check the ~ldm/logs/XCD_START.log file for any useful information that may help to resolve the problem.

-XCD is not creating McIDAS Grid files

The DMGRID GRIB decoder can't file grids if it can't find RTMODELS.CFG, which contains information about real-time grid file locations.

The file RTMODELS.CFG should reside in ~mcidas/workdata when McIDAS-XCD is installed correctly. Either the decoder can't reach the file or it is missing. If it's missing, recreate the file or copy a new version of the default file from ~mcidas/workdataversion/data/RTMODELS.CFG (where version is the version number, e.g., 2015).

-XCD is not writing GRIB files

Look for the *.gr* and *.bu* directory entries and verify that these directories exist on your workstation.  If these directories do not exist, create them. Once this is done, -XCD will automatically start writing GRIB1 and GRIB2 files to this directory, which in turn will allow for data to be written to the database. Then users should be able to access the GRIB data.

-XCD is not writing to the real-time GRIB MySQL database

• If MySQL is installed properly and the mcrtgrib database was created, the most recent record filed in the database will be listed. The modtime is the last line of the record. If the GRIB file information is being filed correctly, this should be today's date and a very recent time.
• If no record is returned, or if the modtime is not recent, this means that the mcrtgrib database exists, but no data is being written to it. Verify with your -X and -XCD Administrator that both packages were compiled with the -mysql flag.
• If an error message containing "Can't connect to local MySQL server" is displayed, this means that MySQL is installed on your machine, but that it was not started. Contact your MySQL Administrator to restart MySQL.
• If an error message from gribadmin containing "mysql: not found" is displayed, this means that the gribadmin command can not find the mysql executable. Confirm that mysql is in the PATH of the user mcidas.
• If an error message from gribadmin containing "Access denied for user ''@'localhost' to database 'mcrtgrib'" is displayed, this means that MySQL is running, but the mcrtgrib database was never created. See Configuring the GRIB Decoders for more information on creating the mcrtgrib database.

-XCD data is garbled or missing

When more than one ingestor is trying to read the same circuit, text data may be missing or text output garbled. If you are decoding grids, grids may be missing.

Only one ingetext.k process should be running for each text circuit, and only one ingebin.k process should be running for each binary circuit (e.g., one ingebin.k process running for GRIB data while another is running for NEXRAD data). Check the number of ingetext.k and ingebin.k processes and -XCD data monitors running. At a Unix shell prompt, as user ldm,

If there are multiple processes running for one of the circuits or one of the data monitors, stop and restart -XCD and the LDM. Some data may be lost while the processes are stopped.

1. Stop -XCD and kill any remaining data monitors (DM*) and ingest (inge*) processes, if necessary. At a Unix shell prompt, as user ldm,

Type: ldmadmin stop

Type: ps -ef | grep DM
Type: kill -9 process_id (if necessary)

Type: ps -ef | grep inge
Type: kill -9 process_id (if necessary)


2. Restart the LDM and -XCD by running the two commands below, in order.

Type: ldmadmin start

If this process doesn't work, check for an obstruction in the receiving antenna.