QCG-Computing service is an open source service acting as a computing provider exposing on demand access to computing resources and jobs over the HPC Basic Profile compliant Web Services interface. In addition the QCG-Computing offers remote interface for Advance Reservations management.

This document describes installation of the QCG-Computing service. The service should be deployed on the machine (or virtual machine) that:

  • has at least 1GB of memory (recommended value: 2 GB)
  • has 10 GB of free disk space (most of the space will be used by the log files)
  • has any modern CPU (if you plan to use virtual machine you should dedicated to it one or two cores from the host machine)
  • is running under:
    • Scientific Linux 5/6 (in most cases the provided RPMs should work with any operating system based on Redhat Enterpise Linux, e.g. CentOS )
    • Debian 6.X
    • any other modern linux distribution if you are ready to install QCG from source packages


We assume that you have the local resource manager/scheduler already installed. This would be typically a frontend machine (i.e. machine where for example the pbs_server Torque daemon is running). If you want to install the QCG-Computing service on a separate submit host you should read this note.

Since version 2.4 the QCG-Computing services discovers installed application using the  Environment Modules package. For this reason you should install modules on the QCG-Computing host and mount directories that contain all module files used at your cluster and make sure that user qcg-comp can see all modules.

The QosCosGrid services do not require from you to install any QCG component on the worker nodes, however application wrapper scripts need the following software to be available on worker nodes:

  • bash,
  • rsync,
  • zip/unzip,
  • dos2unix,
  • python.

Which are usually available out of the box on most of the HPC systems.

Shared file system

Deployment of the QCG-Computing requires usually two shared file systems in the cluster:

  • "Users' directories" - shared between the QCG host and all worker nodes. Used for storing jobs sandbox directories. It can be either HOME or scratch file system. You can read more about this here.
  • "Applications scripts" - shared between all worker nodes. Used for storing Applications Scripts

Firewall configuration

In order to expose the QosCosGrid services externally you need to open the following incoming ports in the firewall:

  • 19000 (TCP) - QCG-Computing
  • 19001 (TCP) - QCG-Notification
  • 2811 (TCP) - GridFTP server
  • 20000-25000 (TCP) - GridFTP port-range (if you want to use different port-range adjust the GLOBUS_TCP_PORT_RANGE variable in the /etc/xinetd.d/gsiftp file)

You may also want to allow SSH access from white-listed machines (for administration purpose only).

The following outgoing trafic should be allowed in general:

  • NTP, DNS, HTTP, HTTPS services
  • gridftp (TCP ports: 2811 and port-ranges: 20000-25000)

Also the PL-Grid QCG-Accounting publisher plugin (BAT) need access the following port and machine (PL-Grid only):

  • 61616 (TCP)

Preparation of the environment


  • Install database backend (PostgresSQL). On ScientificLinux it can be done with:
    yum install postgresql postgresql-server
  • UnixODBC and the PostgresSQL odbc driver:
    yum install unixODBC postgresql-odbc

CA and host certificates

At first install all need trusted CA certificates ( instruction). Moreover we assume that the X.509 host certificate (signed by your local  Certificate Authority) and key is already installed in the following locations:

  • /etc/grid-security/hostcert.pem
  • /etc/grid-security/hostkey.pem


Most of the grid services and security infrastructures are sensitive to time skews. Thus we recommended to install a Network Time Protocol daemon or use any other solution that provides accurate clock synchronization. Also disable automatic packages update as it may hurt running system.


At first you need to install appropriate  repository or get the newest  source package and use this guide to compile it manually.

Centos 7, Scientific Linux 5/6

yum install qcg-comp qcg-comp-client qcg-comp-logrotate


apt-get install qcg-comp qcg-comp-client qcg-comp-doc

Integration with QCG-Broker

In order to enable this QCG-Computing endpoint to be accessible by the  QCG-Broker service you need to:

  • add a qcg-broker user - the user that the service would be mapped to.
    useradd -r -d /var/log/qcg/  qcg-broker 
  • install grid-ftp server using this  instruction.

Database initializaiton

  • setup QCG-Computing database using provided script:
    Welcome to qcg-comp installation script!
    This script will guide you through process of configuring proper environment
    for running the QCG-Computing service. You have to answer few questions regarding
    parameters of your database. If you are not sure just press Enter and use the
    default values.
    Use local PostgreSQL server? (y/n) [y]: y
    Database [qcg-comp]: 
    User [qcg-comp]: 
    Password [RAND-PASSWD]: MojeTajneHaslo
    Create database? (y/n) [y]: y
    Create user? (y/n) [y]: y
    Checking for system user qcg-comp...OK
    Checking whether PostgreSQL server is installed...OK
    Checking whether PostgreSQL server is running...OK
    Performing installation
    * Creating user qcg-comp...OK
    * Creating database qcg-comp...OK
    * Creating database schema...OK
    * Checking for ODBC data source qcg-comp...
    * Installing ODBC data source...OK
    Remember to add appropriate entry to /var/lib/pgsql/data/pg_hba.conf (as the first rule!) to allow user qcg-comp to
    access database qcg-comp. For instance:
    host    qcg-comp       qcg-comp    md5
    and reload Postgres server.

Add a new rule to the pg_hba.conf as requested:

vim /var/lib/pgsql/data/pg_hba.conf 
/etc/init.d/postgresql reload

Authorization modules

The next subsections describes the three most common modes of authorization.

Manually created grid mapfile

For testing purpose or if your user community is small enough to maintain it manually you can use plain grid mapfile which provides static mapping between user's certificate Distinguish Name and a local account:

#for test purpose only add mapping for your account
echo '"MyCertDN" myaccount' >> /etc/grid-security/grid-mapfile

LDAP generated grid mapfile (PL-Grid only)

In PL-Grid grid-mapfiles are generated automatically, based on information available in local LDAP replicas. You need to install and configure  gridmap-file-generator

At the end add mapping in the grid-mapfile.local for the purpose of QCG-Broker.

"/C=PL/O=GRID/O=PSNC/CN=qcg-broker/" qcg-broker


Since version 3.0 of the service it is possible to authorize and map users based on their VO membership ( instruction).

Getting the DRMAA library

The QCG-Computing service use  DRMAA compilant interface for batch job submission. Thus you need to install library appropriate for your system:

Service configuration

Edit the preinstalled service configuration file (/etc/qcg/qcg-comp/qcg-compd.xml):

<?xml version="1.0" encoding="UTF-8"?>
                <sm:Service xsi:type="qcg-compd" description="QCG-Computing">
                        <sm:Module xsi:type="sm:ecm_gsoap.service">
                                   <sm:Module xsi:type="sm:atc_transport_gsi.service">
                                   <sm:Module xsi:type="sm:atz_mapfile">
                            <sm:Module xsi:type="smc:qcg-comp-service"/>
                        <sm:Module xsi:type="pbs_jsdl_filter"/>
                        <sm:Module xsi:type="atz_ardl_filter"/>
                        <sm:Module xsi:type="sm:general_python" path="/usr/lib64/qcg-comp/modules/python/"/>
                        <!--sm:Module xsi:type="sm:general_python" path="/opt/qcg/lib/qcg-comp/modules/python/"/ this module is Mandatory in  PL-Grid-->
                        <sm:Module xsi:type="sm:general_python" path="/usr/lib64/qcg-comp/modules/python/"/>

                        <sm:Module xsi:type="submission_drmaa" path="/usr/local/lib/"/>
                        <sm:Module xsi:type="reservation_python" path="/usr/lib64/qcg-comp/modules/python/"/>
                        <sm:Module xsi:type="notification_wsn">
                                <sm:Module xsi:type="sm:ecm_gsoap.client">
                                                                <sm:Module xsi:type="sm:atc_transport_http.client"/>
                                                <sm:Module xsi:type="sm:ntf_client"/>
                        <sm:Module xsi:type="application_mapper">
                        <!--UseScratch>true</UseScratch> uncomment this if scratch is the only file system shared between the worker nodes and this machine -->
                                <LongDescription>Cluster description</LongDescription>


In most cases it should be enough to change only following elements:

the hostname of the machine where the service is deployed. You can put here if you want to listen on all interfaces.
Transport/Module/Authentication/Module/X509CertFile and Transport/Module/Authentication/Module/X509KeyFile
If you installed cert and key file in the recommended location you do not need to edit these fields.
the external URL of the QCG-Notification service (You can do it later, i.e. after  installing the QCG-Notification service)
the localhost URL of the QCG-Notification service (You can do it later, i.e. after  installing the QCG-Notification service)
path to the DRMAA library (the
path to the reservation module. Change this if you are using different scheduler than Maui (e.g. use for Moab, for PBS Pro)
the qcg-comp database password
set this to true if you set QCG_SCRATCH_DIR_ROOT in sysconfig so any job will be started from scratch directory (instead of default home directory)
a common name of the cluster (e.g. You can use any name that is unique among all systems (e.g. cluster name + domain name of your institution)
a human readable description of the cluster


path to the reservation module. Change this if you are using different scheduler than Maui (e.g. use for Moab)

PBS Professional

path to the reservation module. Change this to


  • at first replace:
                             <sm:Module xsi:type="pbs_jsdl_filter"/>
  • with:
       			<sm:Module xsi:type="slurm_jsdl_filter"/>
  • also if you want to offer advance reservation interface you need to:
path to the reservation module. Change this to
  • finally make sure that the qcg-comp user exist on the service node and that it can list all nodes:
    scontrol show node -o | wc -l

Configuring QCG-Accounting

Please use  QCG-Accounting agent.

Creating applications' script space

A common case for the QCG-Computing service is that an application is accessed using abstract app name rather than specifying absolute executable path. The application name/version to executbale path mappings are stored in the file /etc/qcg/qcg-comp/application_mapfile:

cat /etc/qcg/qcg-comp/application_mapfile
# ApplicationName ApplicationVersion Executable

bash * /opt/exp_soft/qcg/qcg-app-scripts/app-scripts/bash.qcg

It is also common to provide here wrapper scripts rather than target executables. The wrapper script can handle such aspects of the application lifetime like: environment initialization, copying files from/to scratch storage and application monitoring. It is recommended to create separate directory for those wrapper scripts (e.g. the application partition) for an applications. This directory must be readable by all users and from every worker node (the application partition usually fullfils those requirements). Please read more on Application Scripts. You must provide at least mapping for the 'bash' application.

Starting the service

As root type:

/etc/init.d/qcg-compd start

The service logs can be found in:


Note: In current version, whenever you restart the PosgreSQL server you need also restart the QCG-Computing and QCG-Notification service:

/etc/init.d/qcg-compd restart
/etc/init.d/qcg-ntfd restart

Stopping the service

The service can be stopped using the following command:

/etc/init.d/qcg-compd stop

Verifying the installation

  • Edit the QCG-Computing client configuration file (/etc/qcg/qcg-comp/qcg-comp.xml):
    • set the Host and Port to reflects the changes in the service configuration file (qcg-compd.xml).
      <?xml version="1.0" encoding="UTF-8"?>
                     <sm:Client xsi:type="qcg-comp" description="QCG-Computing client">
                                     <sm:Module xsi:type="sm:ecm_gsoap.client">
                                                     <sm:Module xsi:type="sm:atc_transport_gsi.client"/>
                                             <sm:Module xsi:type="smc:qcg-comp-client"/>
  • Initialize your credentials:
    grid-proxy-init -rfc
    Your identity: /C=PL/O=GRID/O=PSNC/CN=Mariusz Mamonski
    Enter GRID pass phrase for this identity:
    Creating proxy .................................................................. Done
    Your proxy is valid until: Wed Apr  6 05:01:02 2012
  • Query the QCG-Computing service:
    qcg-comp -G | xmllint --format - # the xmllint is used only to present the result in more pleasant way
    <bes-factory:FactoryResourceAttributesDocument xmlns:bes-factory="">
        <bes-factory:CommonName>IT cluster</bes-factory:CommonName>
        <bes-factory:LongDescription>IT department cluster for public   use</bes-factory:LongDescription>
        <bes-factory:ContainedResource xmlns:xsi="" xsi:type="bes-factory:BasicResourceAttributesDocumentType">
                <jsdl:CPUArchitectureName xmlns:jsdl="">x86_32</jsdl:CPUArchitectureName>
        <bes-factory:BESExtension></bes-  factory:BESExtension>
        <smcf:NotificationProviderURL xmlns:smcf="">http://localhost:2211/</smcf:NotificationProviderURL>
  • Submit a sample job:
    qcg-comp -c -J /usr/share/qcg-comp/doc/examples/jsdl/sleep.xml
    Activity Id: ccb6b04a-887b-4027-633f-412375559d73
  • Query it status:
    qcg-comp -s -a ccb6b04a-887b-4027-633f-412375559d73
    status = Executing
    qcg-comp -s -a ccb6b04a-887b-4027-633f-412375559d73
    status = Executing
    qcg-comp -s -a ccb6b04a-887b-4027-633f-412375559d73
    status = Finished
    exit status = 0
  • Submit a job which produces some output:
    $ qcg-comp -c -J /usr/share/qcg-comp/doc/examples/jsdl/date.xml 
    Activity Id: 591effa9-143d-4cae-9dd9-02e40f760448
    $ qcg-comp -s -a 591effa9-143d-4cae-9dd9-02e40f760448
    status = Queued
    $ qcg-comp -s -a 591effa9-143d-4cae-9dd9-02e40f760448
    status = Finished (exit status = 0)
    $ qcg-comp -o -J /usr/share/qcg-comp/doc/examples/jsdl/date.xml
    File /tmp/date.staged.out staged out.
    All files staged out.
    $ cat /tmp/date.staged.out 
    Mon Jul 29 02:23:33 HST 2013

If possible perform a "reboot test", i.e. reboot the machine and check if all services are operational without manual intervention. You can also run extended UMD Verification Procedure.


The historic usage information is stored in two relations of the QCG-Computing database: jobs_acc and reservations_acc. You can always archive old usage data to a file and delete it from the database using the psql client:

psql -h localhost qcg-comp qcg-comp 
Password for user qcg-comp: 
Welcome to psql 8.1.23, the PostgreSQL interactive terminal.
Type:  \copyright for distribution terms
     \h for help with SQL commands
     \? for help with psql commands
     \g or terminate with semicolon to execute query
     \q to quit

qcg-comp=> \o jobs.acc
qcg-comp=> SELECT * FROM jobs_acc where end_time < date '2010-01-10';
qcg-comp=> \o reservations.acc
qcg-comp=> SELECT * FROM reservations_acc where end_time < date '2010-01-10';
qcg-comp=> \o
qcg-comp=> DELETE FROM jobs_acc where end_time < date '2010-01-10';
qcg-comp=> DELETE FROM reservation_acc where end_time < date '2010-01-10';

you should also install logrotate configuration for QCG-Computing:

yum install  qcg-comp-logrotate

Important: On any update/restart of the PostgreSQL database you must restart also the qcg-compd and qcg-ntfd services.

/etc/init.d/qcg-compd restart
/etc/init.d/qcg-ntfd restart

On scheduled downtimes we recommend to disable submission in the service configuration file:



Please remember to register the QCG-Computing and QCG-Notification services in the GOCDB using the QCG.Computing and QCG.Notification services types respectively.