If you already have a previous version of the LDM installed and working, then you can probably skip these steps.
Edit the pqact configuration-file, etc/pqact.conf, if appropriate
Edit the scour configuration-file, etc/scour.conf, if appropriate
First, find out who your upstream feed site(s) will be. If you don't know and you are qualified to participate in the Unidata IDD, then contact the Unidata Program Center at <idd-connect@unidata.ucar.edu> with the following information:
Ask the administrator of the upstream LDM to add ALLOW entries for your LDM to the upstream LDM's configuration-file, ldmd.conf. For example,
ALLOW UNIDATA your.ldm.host ALLOW NLDN your.ldm.host
Workshop-specific instructions.
This file tells an LDM what to do on startup. Possibilities include executing programs, requesting data, and authorizing connections. The default file that comes with the distribution contains examples. More information on this configuration-file can be found on the ldmd.conf webpage.
Entries that you should or might have in this file -- depending on your exact situation -- are:
REQUEST entries for your primary upstream LDMs. For example
REQUEST UNIDATA ".*" host1.site1.edu PRIMARY
REQUEST NLDN ".*" host2.site2.edu PRIMARY
For a given feedtype and data-product identifier ERE, you may have more than one such PRIMARY request. Read, however, the discussion on tradeoffs in configuring the LDM.
Alternate (i.e., secondary) sources for certain data-feeds, if appropriate. For example
REQUEST UNIDATA ".*" host3.site3.edu ALTERNATE
REQUEST NLDN ".*" host4.site4.edu ALTERNATE
For a given feedtype and data-product identifier ERE, you may have more than one such ALTERNATE request. Read, however, the discussion on the tradeoffs in configuring the LDM.
Because the ALTERNATE keyword is an alias for a maximum HEREIS size of zero, data-products will be delivered more slowly than if the PRIMARY keyword had been used. Consequently, if you have the bandwidth, it might be better to have multiple PRIMARY requests to two distinct upstream LDM-s rather than use ALTERNATE requests.
An EXEC entry for pqact, if appropriate. For example
EXEC "pqact"
Note that you might have more than one such EXEC entry if, for example, you use the pqact configuration-files that come with the GEMPAK or McIDAS packages. For example
# Exec GEMPAK specific pqact(1) processing
EXEC "pqact -f NNEXRAD /usr/local/ldm/etc/GEMPAK/pqact.gempak_nexrad"
EXEC "pqact -f ANY-NNEXRAD /local/ldm/etc/GEMPAK/pqact.gempak_decoders"
An EXEC entry for rtstats if the LDM is a member of the Unidata IDD and is a gateway LDM for your institution. LDM statistics are the best way to monitor IDD performance and to identify problems. It is, therefore, crucial that all gateway LDM-s on the IDD report statistics. Also, data on LDM statistics is vital in preparing reports used to obtain funding to support the LDM system.
IDD statistics are displayed on the IDD rtstats webpages.
An EXEC entry for the pqbinstats utility. A necessary (but not sufficient) condition for enabling this entry is an enabled rtstats entry described above. Files created by the pqbinstats utility are only used to initialize the rtstats program when the LDM system is started. No harm will occur if the pqbinstats program isn't running.
Workshop-specific instructions.
This file tells the pqact utility how to locally process various classes of data-products. Processing actions include filing the data-product, executing a local program, and piping the data-product to the standard input of a local program. If you're not going to process data-products locally, then you don't need to edit this file.
More information on this configuration-file.
Workshop-specific instructions.
This file tells the scour utility what old files should be deleted and when to delete them. This is useful if
More information on this configuration-file.
Workshop-specific instructions.
Edit the crontab file of the LDM-user by, for example, executing the command
crontab -eas the LDM-user. Then
Add an entry to rotate the LDM logfiles by starting a new logfile every day at midnight, changing the names of the old logfiles, and ensuring that the number of logfiles doesn't grow without bound:
0 0 * * * bin/ldmadmin newlogMore information on rotating logfiles.
Add an entry to purge old files if necessary. If you are executing the pqact utility to decode incoming data-products into local files or executing the pqbinstats utility to periodically save LDM statistics, then add an entry like the following to purge outdated files so that your disk doesn't become full:
0 1,4,7,10,13,16,19,22 * * * bin/ldmadmin scourThe above runs the scour program to remove too-old files every three hours. You might choose a different time interval.
Although boot-time start-up procedures vary amongst operating systems, each can be tailored to start the LDM. It is best to start the LDM as late as possible in the boot process to avoid interfering with processes that could hang the system (e.g., the syslog daemon). One possible LDM script is:
export PATH=/bin:/usr/bin:/usr/etc:/usr/ucb
LDMADMIN=/usr/local/ldm/bin/ldmadmin
case "$1" in
start)
if [ -x $LDMADMIN ] ; then
$LDMADMIN queuecheck >/dev/null 2>&1 || {
echo "Corrupt LDM product-queue. Recreating."
/bin/su - ldm -c "$LDMADMIN delqueue"
/bin/su - ldm -c "$LDMADMIN mkqueue"
}
echo 'Starting LDM using "ldmadmin start".'
/bin/su - ldm -c "$LDMADMIN clean"
/bin/su - ldm -c "$LDMADMIN start"
fi
;;
stop)
if [ -x $LDMADMIN ] ; then
/bin/su - ldm -c "$LDMADMIN stop"
fi
;;
esac
Consult the documentation on your operating system or with your system administrator for details on how to incorporate this script (or something similar) into the boot-time start-up procedure of your system.
Workshop-specific instructions.