PanDA server

This is the setup guide of the PanDA server.

Note

This is a complete guide. It is recommended to have a look at Quick Admin Tutorial beforehand.

Software requirements

The PanDA server requires:

CentOS 7 or similar Linux distribution
httpd ≥ 2.4
httpd-devel
python ≥ 3.6
pip
gridsite

Dependent python packages are automatically installed by pip.

Installation

It is a good practice to do installation in virtual environment.

python3 -m venv <install dir>
. <install dir>/bin/activate
pip install -U pip setuptools

Then

pip install panda-server[<database type>]

which will install panda-server, panda-common, and dependent python packages. The <database type> is oracle, postgres, or mysql depending on your database backend.

If the latest panda-server in the git master repository is required,

pip install git+https://github.com/PanDAWMS/panda-server.git

Configuration

There are two python, one httpd, and one system configuration files under ${VIRTUAL_ENV}/etc/panda.

panda_common.cfg

This configuration file sets various parameters for logging.

cd ${VIRTUAL_ENV}/etc/panda
mv panda_common.cfg.rpmnew panda_common.cfg

The following parameters need to be modified if any.

panda-common parameters
Name	Description	Default
loghost	The hostname of PanDA monitor	panda.cern.ch
logdir	The directory name where common log files are placed	/var/log/panda
log_level	Logging level	DEBUG

panda_server.cfg

This configuration file sets various parameters of the PanDA server.

cd ${VIRTUAL_ENV}/etc/panda
mv panda_server.cfg.rpmnew panda_server.cfg

The following parameters need to be modified if any.

panda-server parameters
Name	Description	Default
logdir	The directory name where server’s log files are placed	/var/log/panda
dbhost	The database hostname
dbuser	The database username
dbpasswd	The database password
nDBConForFastCGIWSGI	The number of database connections in each Web application	1
backend	Set mysql to use MySQL database	oracle
pserveralias	The common name of the http server	pandaserver.cern.ch
adder_plugins	Adder plugins
setupper_plugins	Setupper plugins
token_authType	Set to oidc to enable OIDC-based auth	x509
auth_config	The directory name for OIDC-based auth configuration files
auth_policies	The policy file of OIDC-based auth

Parameters of PanDA Daemon are descrribed in PanDA Daemon.

panda_server-httpd.conf

This configuration file set varous parameters of httpd.

cd ${VIRTUAL_ENV}/etc/panda
mv panda_server-httpd-FastCGI.conf.rpmnew panda_server-httpd.conf

The following parameters need to be modified. See Apache doc for detailed explanation of each directive.

httpd parameters
Name	Description
User	The userid under which httpd runs
Group	The group under which httpd runs
LoadModule wsgi_module	The file path of the mod_wsgi module
ServerName	The httpd server name
Alias /auth/	The directory name for OIDC-based auth configuration files. Must be consistent with panda_server.cfg
WSGIDaemonProcess	Config of WSGI daemons. Change `processes` and `home` if any

Also you need to get/generate host certificate and key files and place them at /etc/grid-security/hostcert.pem and /etc/grid-security/hostkey.pem, respectively.

The following httpd parameters can be configured dynamically by setting corresponding environment variables when the service gets started. The default values of those variables are defined in ${VIRTUAL_ENV}/etc/panda/panda_server.sysconfig.

httpd parameters dynamically configurable
Name	Environment variable	Default value
PANDA_SERVER_CONF_SERVERNAME	The common name of httpd service	pandaserver.cern.ch
PANDA_SERVER_CONF_MIN_WORKERS	The minimum number of httpd workers	25
PANDA_SERVER_CONF_MAX_WORKERS	The maximum number of httpd workers	512
PANDA_SERVER_CONF_NUM_WSGI	The number of WSGI deamons	12

panda_server.sysconfig

cd ${VIRTUAL_ENV}/etc/panda
mv panda_server.sysconfig.rpmnew panda_server.sysconfig

httpd parameters
Name	Description
HOME	The non-NFS home directory to run the service
X509_USER_PROXY	Proxy file path

System Setup

Then you need to register the PanDA server as a system service, make some directories, and setup log rotation if any.

# register the PanDA server in the system
mkdir -p /etc/panda
ln -s ${VIRTUAL_ENV}/etc/panda/*.cfg /etc/panda/
mv ${VIRTUAL_ENV}/etc/idds/idds.cfg.client.template ${VIRTUAL_ENV}/etc/idds/idds.cfg
ln -fs ${VIRTUAL_ENV}/etc/panda/panda_server.sysconfig /etc/sysconfig/panda_server
ln -fs ${VIRTUAL_ENV}/etc/rc.d/init.d/panda_server /etc/rc.d/init.d/httpd-pandasrv
/sbin/chkconfig --add httpd-pandasrv
/sbin/chkconfig httpd-pandasrv on

# make dirs
mkdir -p <logdir in panda_common.cfg>/wsgisocks
chown -R <userid in httpd.conf>:<group in httpd.conf> <logdir in panda_common.cfg>

# setup log rotation if necessary
ln -fs ${VIRTUAL_ENV}/etc/panda/panda_server.logrotate /etc/logrotate.d/panda_server

Service Control

# start
/sbin/service httpd-pandasrv start

# stop
/sbin/service httpd-pandasrv stop

There should be log files in the logdir. If httpd doesn’t get started there could be clues in panda_server_error_log.

Test

curl http://localhost:25080/server/panda/isAlive

It will show the following message if successful.

alive=yes

If not, see log files under logdir, especially panda_server_access_log, panda_server_error_log, panda-Entry.log, panda-DBProxyPool.log, and panda-DBProxy.log would help.

Deployment with Helm

It is possible to deploy PanDA server instances on Kubernetes cluster using Helm.

wget https://github.com/PanDAWMS/helm-k8s/raw/master/panda-server/panda-server-helm.tgz
tar xvfz panda-server-helm.tgz
cd panda-server-helm

First, copy your host certificate and key files in the current directory.

cp /somewhere/hostcert.pem .
cp /somewhere/hostkey.pem .

Next, edit panda_server_configmap.json where each json entry corresponds to the attribute in panda_server.cfg. For example,

{
    "server": {
        ...
        "dbuser": "FIXME",

in panda_server_configmap.json corresponds to

[server]
...
dbuser = FIXME

in panda_server.cfg.

Finally, you can install the PanDA server.

helm install mysrv ./

The service doesn’t get started automatically. To start it, set autoStart to true in values.yaml before installing the PanDA server.

autoStart: true

Or

helm install mysrv ./ --set autoStart=true