Workshop-Specific Instructions

The following comprises workshop-specific instructions and details for the 2003 LDM Training Workshop.


Create the LDM user-account

Because this step requires superuser privileges, the LDM user-account has been created for you on your workshop computer. Execute the following command to verify:

grep '^ldm' /etc/passwd

For reference, see LDM Basics: LDM user.


Create directories for data-files and LDM logfiles

Because user's home-directories aren't backed-up on the workshop computers, there is no need to perform this step. Skip it.


Edit file /etc/services

Because this step requires superuser privileges, it has already been done. Execute the following command to verify:

grep 388 /etc/services

Edit file /etc/rpc

Because this step requires superuser privileges, it has already been done. Execute the following command to verify:

grep 388 /etc/rpc

Edit file /etc/syslog.conf

Because this step requires superuser privileges, it has already been done. Execute the following command to verify:

grep local0 /etc/syslog.conf
The "local0.none" entry ensures that no LDM log-messages are written to the system logfile. The "local0.*" entry ensures that LDM messages are logged to the LDM logfile.

Become the LDM user in the user's home-directory

You should already be the LDM user in that user's home-directory.


Edit the LDM user's profile-file

Add the following lines to the file $HOME/.bash_profile:

export LDMHOME=$HOME
export MANPATH=$HOME/man:/usr/share/man
Note that the PATH environment variable is already set.

Create directories for data-files and log-files

Execute the following command:

mkdir data logs

Build and Install the Distribution

$ cd $VERSIONDIR/src
$ make distclean
...
$ ./configure &>configure.log
$ less configure.log
$ make &>make.log
$ less make.log
$ make install &>install.log
$ less install.log
$ sudo make install_setuids
...
$ make clean
...

Vet the ldmadmin script

The only variables that need to be modified are pq_size and pq_slots.

Because we are going to receive only the IDS|DDPLUS and NNEXRAD data-feeds, the product-queue creation-parameters should be the following:

size       = (1 h) * (16 MB/h + 170 MB/h)= 186 MB
maxNumProd = (1 h) * (16000/h + 18000/h) = 34000
(See, for example, Thelma's data-volume summary webpage.) Therefore, modify the file to ensure the following:
$pq_size = "186M";
$pq_slots = "34000";

Request authorization at the upstream LDM

Add the following entry to the file $HOME/etc/ldmd.conf to allow all workshop LDM-s to obtain data from any workshop LDM:

ALLOW	ANY	work1?[0-9]\.unidata\.ucar\.edu

For reference, see LDM Basics: ldmd.conf.


Edit the LDM configuration-file, etc/ldmd.conf

Un-comment-out the "EXEC pqact" entry to enable local processing of received data-products.

Add the following entries to the LDM configuration file, ldmd.conf, to request the IDS|DDPLUS and NNEXRAD data-feeds:

REQUEST	IDS|DDPLUS	.*	worknn.unidata.ucar.edu	PRIMARY
REQUEST	NNEXRAD		.*	worknn.unidata.ucar.edu	PRIMARY
where "worknn" is the name of the workshop computer that will be upstream of yours (which will be decided during the class).

For reference, see LDM Basics: ldmd.conf.


Edit the pqact configuration-file, etc/pqact.conf

Because we will only process data-products of the IDS|DDPLUS data-feed, have the following entry be the only active one in the configuration-file:

IDS|DDPLUS
	^(..)(..).. .... (..)(..)
	FILE
	data/IDS_DDPLUS/\1/\2/(\3:yyyy)(\3:mm)(\3:dd)T\4.txt
Remember to start the continuation-lines with a tab character.

For reference, see LDM Basics: pqact.conf.


Edit the scour configuration-file, etc/scour.conf

The workshop won't last long enough to require any files to be scoured. If it did, however, then an entry like the following would be appropriate:

data/IDS_DDPLUS 1
This would remove all files in the data directory hierarchy that are older than one day.

For reference, see LDM Basics: scour.conf.


Edit the LDM-user's crontab(1) file

The workshop won't last long enough to require any files to be scoured, so the only relevant crontab(1) entry is the one to rotate the LDM logfiles.

Return to the previous webpage and create the "newlog" entry using the crontab(1) utility.


Ensure that the LDM is started at boot-time

We're not concerned about restarting the LDM at boot-time for this workshop. So we'll skip this step.