TORQUE is a resource manager providing control over batch jobs and distributed compute nodes. Basically, one can setup a home or small office Linux cluster and queue jobs with this software. A cluster consists of one head node and many compute nodes. The head node runs the torque-server daemon and the compute nodes run the torque-client daemon. The head node also runs a scheduler daemon.

Install the torque^AUR package.

Make sure that /etc/hosts on all of the boxes in the cluster contains the hostnames of every PC in the cluster. Example, cluster consists of 3 PCs, mars, phobos, and deimos.

192.168.0.20 mars
192.168.0.21 phobos
192.168.0.22 deimos

Be sure to open TCP for all machines using TORQUE.

The pbs_server (server) and pbs_mom (client) by default use TCP and UDP ports 15001-15004. pbs_mom (client) also uses UDP ports 1023 and below if privileged ports are configured (the default).

Technically, one does not need to use NFS but doing so simplifies the whole process. An NFS share either on the server or another machine is highly recommended to simplify the process of sharing common build disk space.

Follow these steps on the head node/scheduler.

Edit /var/spool/torque/server_name to name the head node. It is recommended to match the hostname in /etc/hostname for simplicity's sake.

Create and configure the torque server:

# pbs_server -t create
PBS_Server localhost.localdomain: Create mode and server database exists,
do you wish to continue y/(n)?y

Then start trqauthd by running

# trqauthd

A minimal set of options are provided here. Adjust the first line substituting "mars" with the hostname entered in /var/spool/torque/server_name:

qmgr -c "set server acl_hosts = mars"
qmgr -c "set server scheduling=true"
qmgr -c "create queue batch queue_type=execution"
qmgr -c "set queue batch started=true"
qmgr -c "set queue batch enabled=true"
qmgr -c "set queue batch resources_default.nodes=1"
qmgr -c "set queue batch resources_default.walltime=3600"
qmgr -c "set server default_queue=batch"

It may be of interest to keep finished jobs in the queue for a period of time.

qmgr -c "set server keep_completed = 86400"

Here, 86400 sec = 24 h after which point, the job will be auto removed from the queue. One can see the full log of jobs removed from the queue with the -f switch on qstat:

qstat -f

Verify the server configuration with this command:

# qmgr -c 'p s'

Edit /var/spool/torque/server_priv/nodes adding all compute nodes. Again, it is recommended to match the hostname(s) of the machines on the LAN. The syntax is HOSTNAME np=x gpus=y properties

• HOSTNAME=the hostname of the machine
• np=number of processors
• gpus=number of gpus
• properties=comments

Only the hostname is required, all other fields are optional.

Example:

mars np=4
phobos np=2
deimos np=2

Restart the server and the new options are sourced.

Follow these steps on each compute node in the cluster.

Edit /var/spool/torque/mom_priv/config to contain some basic info identifying the server:

$pbsserver mars # note: this is the hostname of the headnode
$logevent 255 # bitmap of which events to log

That should be it. Now restart the server so the settings can take effect.

# killall -s 9 pbs_server
# pbs_server

In order to start the clients run the following on each of the clients, including the server if it is also a client:

# pbs_mom

To check the status of the cluster, issue the following:

$ pbsnodes -a

Each node if up should indicate that it is ready to receive jobs echoing a state of free. If a node is not working, it will report a state of down.

Example output:

 mars
 state = free
 np = 4
 ntype = cluster
 status = rectime=1308479899,varattr=,jobs=0.localhost.localdomain,state=free,netload=1638547057,
gres=,loadave=2.69,ncpus=4,physmem=8195892kb,availmem=7172508kb,totmem=8195892kb,
idletime=24772,nusers=1,nsessions=5,sessions=1333 1349 1353 1388 9095,
uname=Linux mars 2.6.39-ck #1 SMP PREEMPT Sat Jun 18 14:19:01 EDT 2011 x86_64,opsys=linux
 mom_service_port = 15002
 mom_manager_port = 15003
 gpus = 2

phobos
 state = free
 np = 2
 ntype = cluster
 status = rectime=1308479933,varattr=,jobs=,state=free,netload=1085755815,
gres=,loadave=2.84,ncpus=2,physmem=4019704kb,availmem=5753552kb,totmem=6116852kb,
idletime=7324,nusers=2,nsessions=6,sessions=1565 1562 1691 1716 1737 1851,
uname=Linux phobos 2.6.37-ck #1 SMP PREEMPT Sun Apr 3 17:16:35 EDT 2011 x86_64,opsys=linux
 mom_service_port = 15002
 mom_manager_port = 15003
 gpus = 1

deimos
 state = free
 np = 2
 ntype = cluster
 status = rectime=1308479890,varattr=,jobs=2.localhost.localdomain,state=free,netload=527239670,
gres=,loadave=0.52,ncpus=2,physmem=4057808kb,availmem=3955624kb,totmem=4057808kb,
idletime=644,nusers=1,nsessions=1,sessions=865,
uname=Linux deimos 2.6.39-ck #1 SMP PREEMPT Sat Jun 11 12:36:21 EDT 2011 x86_64,opsys=linux
 mom_service_port = 15002
 mom_manager_port = 15003
 gpus = 1

Queuing to the cluster is accomplished via the qsub command.

A trivial test is to simply run sleep:

$ echo "sleep 30" | qsub

Check the status of the queue via the qstat command described below. At this point, the work will have a status of "Q" which means queued. To start it, run the scheduler:

# pbs_sched

One can modify the torque-server systemd daemon to activate pbs_sched at boot.

Another usage of qsub is to name a job and queue a script:

$ qsub -N x264 /home/facade/bin/x264_HQ.sh

Another example can use a wrapper script to make and queue work en mass automatically.

qstat is used to check work status.

$ qstat

Job id Name User Time Use S Queue
------------------------- ---------------- --------------- -------- - -----
13.localhost generic-i686.pbs facade 00:05:06 R batch 
14.localhost atom-i686.pbs facade 00:03:09 R batch 
15.localhost core2-i686.pbs facade 00:01:02 R batch 
16.localhost k7-i686.pbs facade 0 Q batch 
17.localhost k8-i686.pbs facade 0 Q batch 
18.localhost k10-i686.pbs facade 0 Q batch 
19.localhost p4-i686.pbs facade 0 Q batch 
20.localhost pentm-i686.pbs facade 0 Q batch 
21.localhost ...ic-x86_64.pbs facade 0 Q batch 
22.localhost atom-x86_64.pbs facade 0 Q batch 
23.localhost core2-x86_64.pbs facade 0 Q batch 
24.localhost k8-x86_64.pbs facade 0 Q batch 
25.localhost k10-x86_64.pbs facade 0 Q batch 

Append the -n switch to see which nodes are doing which jobs.

$ qstat -n

localhost.localdomain:
405.localhost.lo facade batch i686-generic 3035 1 0 -- 01:00 C 00:12
 mars/3+mars/2+mars/1+mars/0
406.localhost.lo facade batch i686-atom 5768 1 0 -- 01:00 C 00:46
 phobos/1+phobos/0
407.localhost.lo facade batch i686-core2 22941 1 0 -- 01:00 C 00:12
 mars/3+mars/2+mars/1+mars/0
408.localhost.lo facade batch i686-k7 10152 1 0 -- 01:00 C 00:12
 mars/3+mars/2+mars/1+mars/0
409.localhost.lo facade batch i686-k8 29657 1 0 -- 01:00 C 00:12
 mars/3+mars/2+mars/1+mars/0
410.localhost.lo facade batch i686-k10 16838 1 0 -- 01:00 C 00:12
 mars/3+mars/2+mars/1+mars/0
411.localhost.lo facade batch i686-p4 25340 1 0 -- 01:00 C 00:46
 deimos/1+deimos/0
412.localhost.lo facade batch i686-pentm 12544 1 0 -- 01:00 R 00:20
 phobos/1+phobos/0
413.localhost.lo facade batch x86_64-generic 4024 1 0 -- 01:00 C 00:13
 mars/3+mars/2+mars/1+mars/0
414.localhost.lo facade batch x86_64-atom 19330 1 0 -- 01:00 C 00:13
 mars/3+mars/2+mars/1+mars/0
415.localhost.lo facade batch x86_64-core2 2146 1 0 -- 01:00 C 00:13
 mars/3+mars/2+mars/1+mars/0
416.localhost.lo facade batch x86_64-k8 17234 1 0 -- 01:00 R 00:11
 mars/3+mars/2+mars/1+mars/0
417.localhost.lo facade batch x86_64-k10 -- 1 0 -- 01:00 Q -- 
 -- 

• TORQUE short course from University of California, San Francisco - Good guide with templates.
• TORQUE admin manual - Great resource and easy to read.
• Boston College's Torque user guide - Guide not extensive but gives a flavor for how end-users can use a cluster. Probably overkill for home clusters where only one user is submitting work.
• TORQUE mailing lists - The TORQUE community is very knowledgeable and a key asset.
• TORQUE users mailing list archives - Searchable archive of TORQUE-users.