I have an idea how to make one OS image that can be used for both the
HTCondor cluster Torque, HTCondor, and Slurm Cluster such that we can have HTCondor jobs
glidein to the Slurm cluster. First we employ /etc/sysconfig/condor. If this file sets CONDOR_CONFIG to a config file that sets START_MASTER = False, then HTCondor will not start. If it sets CONDOR_CONFIG to /etc/condor/condor_config or isn't set at all, then HTCondor will start normally. Next we change the LOCAL_CONFIG_FILE in /etc/condor/condor_config to /var/run/condor/condor_config.#
# CONDOR_CONFIG
#local which can be modified locally on the diskless host. This allows the Slurm pilot job to create this config file with the DAEMON_SHUTDOWN rules.
Now a special pilot job can be submitted to the Slurm cluster that starts an HTCondor startd, by running /usr/sbin/condor_master -f, and therefore makes the node into an HTCondor execution host. This works because the OS is configured as an execution host for HTCondor as well as Slurm (and Torque probably) even though it doesn't start HTCondor on boot. This way when the pilot job starts condor_master which starts condor_startd, the node announces itself as an execution host to the central manager. When there are no more HTCondor jobs to run, the startd will exit then the master will exit, then the Slurm pilot job will do some cleanup and exit, and the will go back to being just a Slurm node.
CONDOR_CONFIG
The condor_startd reads the CONDOR_CONFIG environment variable as its
if it exists, to find its config file instead of the default /etc/condor/condor_config and exits
with an error if there is a problem reading that file.
DAEMON_SHUTDOWN
...
The condor_startd daemon will shutdown gracefully and not be restarted
if the ClassAd STARTD.DAEMON_SHUTDOWN evlauates to True. E.g.
STARTD.DAEMON_SHUTDONW =
...
size(ChildState) ==
...
0 &&
...
size(ChildActivity) ==
...
0 && (
...
MyCurrentTime - EnteredCurrentActivity) > 600'
MASTER.DAEMON_SHUTDOWN = STARTD_StartTime == 0
https://htcondor.readthedocs.io/en/latest/admin-manual/configuration-macros.html#
# sysconfig
#
https://htcondor.readthedocs.io/en/latest/classad-attributes/machine-classad-attributes.html
sysconfig
The condor.service unit in systemd reads /etc/sysconfig/condor but
does not evaluate it. So adding something like the following to
/etc/sysconfig/condor won't work, besides this would cause HTCondor to fail if that file didn't exist and that isn't what I want.
CONDOR_CONFIG=$(cat /var/run/condor/config)
...
EnvironmentFile=-/etc/sysconfig/condor
EnvironmentFile=-/var/run/condor/config
where /var/run/condor/config sets CONDOR_CONFIG=/etc/condor/condor_config
But I can use this to keep HTCondor from starting, just like I do with
Torque and Slurm. I can set CONDOR_CONFIG=/dontstartcondor in
/etc/syconfig/condor in the OS image and override it with a snapshot.
Then stop setting 99-nrao as a snapshot.##
OS image
...
All three schedulers (Torque, slurm, condor) will be configured to
start via systemd. The file pbs_mom, slurm, and condor in
/etc/sysconfig will be set such that all of these schedulers will fail
to start on boot.
/etc/sysconfig/pbs_mom: PBS_ARGS="-h"
/etc/sysconfig/
...
slurmd: SLURMD_OPTIONS="-h"
/etc/sysconfig/condor: CONDOR_CONFIG=/etc/condor/condor_off
Where /etc/condor/condor_off is a copy of /etc/condor/condor_config with LOCAL_CONFIG_DIR commented out and START_MASTER = False added./nosuchfile
If any of these schedulers are wanted to start on boot, the
appropriate /etc/sysconfig file (pbs_mom, slurm, condor) will be
altered via a snapshot.
/etc/sysconfig/pbs_mom: PBS_ARGS=""
/etc/sysconfig/
...
slurmd: SLURMD_OPTIONS="--conf-server testpost-serv-1"
/etc/sysconfig/condor: CONDOR_CONFIG=/etc/condor/condor_config
Change the LOCAL_CONFIG_FILE in HTCondor to a file that will contain
the configurations needed for a Slurm node to run an HTCondor Pilot
job (e.g. STARTD.DAEMON_SHUTDOWN). This file will be created by the
Pilot job.
echo 'LOCAL_CONFIG_FILE = /var/run/condor/condor_config.local' >> /etc/condor/condor_config
The alternative was to make a complete copy of condor_config and all its
sub-config files into an /etc/condor/glidein-slurm.conf and add the
DAEMON_SHUTDOWN ad as well. This seems dangerous to me as now those
two config files can drift.##
Pilot Job
...
The Pilot job submitted to Slurm will do the following. This will start condor because unlike the systemd unit file, calling condor_master manually doesn't check /etc/sysconfig/condor
echo 'CONDOR_CONFIG=/etc/condor/glidein-slurm.conf' > /var/run/condor/config
echo 'STARTD.DAEMON_
...
SHUTDOWN = size(ChildState) ==
...
0 &&
...
size(ChildActivity) ==
...
0 && (
...
MyCurrentTime - EnteredCurrentActivity) > 600' > /var/run/condor/condor_config.local
...
echo 'MASTER.DAEMON_SHUTDOWN = STARTD_StartTime == 0' >> /var/run/condor/condor_config.local
/usr/sbin/condor_master -f
rm -f /var/run/condor/condor_config.local
rm -f /var/run/condor/config
exit
...
Factory
The factory process that watches the clusters and launches Pilot jobs should be pretty simple cron job
PILOT_JOB=/lustre/aoc/admin/tmp/krowe/pilot.sh
idle_condor_jobs=$(condor_q -global -allusers -constraint 'JobStatus == 1' -format "%d\n" 'ServerTime - QDate' | sort -nr | head -1)
#krowe Jul 21 2021: when there are no jobs, condor_q -global returns 'All queues are empty'. Let's reset that.
if [ "${idle_condor_jobs}" = "All queues are empty" ] ; then
idle_condor_jobs=""
fi
# Is there at least one free node in Slurm?
free_slurm_nodes=$(sinfo --states=idle --Format=nodehost --noheader)# launch one pilot job
if [ -n "${idle_condor_jobs}" ] ; then
if [ -n "${free_slurm_nodes}" ] ; then
if [ -f "${PILOT_JOB}" ] ; then
sbatch --quiet ${PILOT_JOB}
fi
fi
fi
...