Re: [HTCondor-users] trouble get started

[Michael V Pelletier <Michael.V.Pelletier@xxxxxxxxxxxx>]

From: Lee Gramling <leegramling@xxxxxxxxx>
Date: 02/18/2016 08:58 AM
 
> Yes, I used trusty and all installed and is running well now.
> I was originally hoping to use the deb install
so my IT guy could install 
> them on each machine, which I think is a more manageable solution.

> Now I just have to learn how to write the condor_config
files for each machine. :)

One nice thing about the HTCondor configuration mechanisms
is that you often don't need to write a separate config file for each system.

My current 8.4.4 systems have the unmodified /etc/condor/condor_config
file - the only thing I do on the local machine is add an identical /etc/condor/condor_config.local
file which sets CONFIG_DIR to /home/condor/config/config.d and LOCAL_CONFIG
to /home/condor/config/host.d/condor_config.$(HOSTNAME)

In the host.d directory, I have two files, one for
the central manager role and the other for the exec node role:

In cm_role.conf:
        CENTRAL_MANAGER_ROLE
= True

and in ded_exec.conf:
        DEDICATED_EXEC_ROLE
= True

Then the condor_config.hostname file is merely a symlink
to the appropriate role file.

Next, I have all the customizations in the /home/condor/config/config.d
directory. The "001roles" file in there sets the DAEMON_LIST
based on the role value:

if CENTRAL_MANAGER_ROLE:
    DAEMON_LIST = MANAGER, NEGOTIATOR, COLLECTOR,
SCHEDD
else:
    DAEMON_LIST = MANAGER, STARTD

For a pool where I have opportunistic machines, I'd
have a desktop_role.config file, and set the daemon list to include the
KBDD in the 001roles config file, as well as modifying its start _expression_
in a different config file pertaining to opportunistic machine configuration
details.

With this approach every single machine uses the exact
same configuration files with the sole exception of that one-line role-definition
file which sets the value used in the configuration's "if" statements
elsewhere.

If I want to tinker with one machine, I can drain
it and put whatever expressions I want in the /etc/condor/condor_config.local
file at the end, or create a new role file and change the symlink for just
that host in the /home/condor/config/host.d directory.

The caveat is that NFS has to be up and running for
the machine to be able to reach the config files before HTCondor starts
up, but if you make sure that it starts in runlevel 3 you should be fine
there.

Kudos to the CHTC team - the new config design that
enables this approach is a very big improvement over the requirements of
7.8 where I started.

        -Michael Pelletier
_