[[PageOutline]] 

= QCG-Notification installation using RPMS =
This document describes basic procedures needed to install QCG-Notification from RPM packages and concentrates on a deployment of the service as a part of the !QosCosGrid middleware. Within !QosCosGrid the QCG-Notification service is widely used for brokering various types of notification messages related to the state of a job (e.g. including predefined status of a job or snippet from the the job's output file). In most cases it is enough that only one instance of the QCG-Notification is deployed per Administrative Domain (i.e.: not necessary one per Cluster). You can install the QCG-Notification service on the same machine where the [[http://www.qoscosgrid.org/trac/qcg-computing|QCG-Computing service]] is installed.

= Installation =
QCG-Notification may be installed using the Yum Package Manager from RPMs. The procedure is as follows:

* if you have not done this yet, install appriopriate for your Linux distribution EPEL, PL-Grid and QCG repositories: [http://apps.man.poznan.pl/trac/qcg/wiki/Software%20repositories instruction];

* install trusted CA certificates: [http://www.qoscosgrid.org/trac/qcg/wiki/CA%20certificates instruction] (this step may be ommited when the GSI authentication is not required);

* install QCG-Notification using YUM Package Manager:
{{{
#!div style="font-size: 90%"
{{{#!sh
yum install qcg-ntf
}}}
}}}

* setup QCG-Notification database using provided script:
{{{
#!div style="font-size: 90%"
{{{#!sh
/usr/share/qcg-ntf/tools/qcg-ntf-install.sh
Welcome to qcg-ntf installation script!

This script will guide you through process of configuring proper environment
for running the QCG-Notification 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-ntf]: 
User [qcg-ntf]: 
Password [qcg-ntf]: MojeTajneHaslo
Create database? (y/n) [y]: y
Create user? (y/n) [y]: y
  
Checking for system user qcg_ntf...OK
Checking whether PostgreSQL server is installed...OK
Checking whether PostgreSQL server is running...OK
  
Performing installation
* Creating user qcg-ntf...OK
* Creating database qcg-ntf...OK
* Creating database schema...OK
* Checking for ODBC data source qcg-ntf...
* Installing ODBC data source...OK

The newly established database settings must be reflected in the Database section of the QCG-Notification configuration file
(by default /etc/qcg/qcg-ntf/qcg-ntfd.xml)
    
Remember to add appropriate entry to /var/lib/pgsql/data/pg_hba.conf (as the first rule!) to allow user qcg-ntf to
access database qcg-ntf. For instance:
  
host    qcg-ntf       qcg-ntf       127.0.0.1/32    md5
  
and reload Postgres server.
}}}
}}}
 

* Add a new rule to the pg_hba.conf as requested and reload Postgres:
{{{
#!div style="font-size: 90%"
{{{#!sh
vim /var/lib/pgsql/data/pg_hba.conf 
/etc/init.d/postgresql reload
}}}
}}}

= Configuration =

== Basic configuration ==
The service should be ready to use "out-of-the-box", however basic configuration may be needed to setup ''Host'' (in most cases it must be an external address, also do not use 0.0.0.0 wildcard address) and ''Port'' on which QCG-Notification should listen as well as parameters of database connection: ''DSN'', ''User'' and ''Password''. It can be done by editing the main QCG-Notification configuration file located in: `/etc/qcg/qcg-ntf/qcg-ntfd.xml`. A part of the configuration file with marked key parameters is presented below:
{{{
#!div style="font-size: 90%"
{{{#!xml
<sm:QCGCore 
   <Configuration>
   ....
              <sm:Module xsi:type="sm:ecm_gsoap.service">
                  <sm:Host>host.example.com</sm:Host>
                  <sm:Port>19001</sm:Port>
                  <sm:UseWsa>true</sm:UseWsa>
              </sm:Module>
   ....
              <smn:Database>
                  <smn:DatabaseEnabled>true</smn:DatabaseEnabled>
                  <smn:DSN>qcg-ntf</smn:DSN>
                  <smn:User>qcg-ntf</smn:User>
                  <smn:Password>qcg-ntf</smn:Password>
                  <smn:CleanAtStart>false</smn:CleanAtStart>
              </smn:Database>
   ....
   </Configuration>
</sm:QCGCore>
}}}
}}}

== Optional Configuration == 
=== GSI Authentication ===
See [[http://www.qoscosgrid.org/trac/qcg-notification/wiki/Configuration#GSIAuthentication|instruction]]

=== Publisher Modules ===
The optional publisher modules, namely XMPP and SMTP, may be configured for QCG-Notification: [[http://www.qoscosgrid.org/trac/qcg-notification/wiki/Configuration#PublisherModules|instruction]]

In case of !QosCosGrid, the presented modules are required when the instance of QCG-Notification cooperates with QCG-Broker. This means that you can skip this section when you are installing QCG-Notification to work with the QCG-Computing component only. 

== Further reading ==
For more information about configuration of the service please take a look at the [[/wiki/technicalGuideAndManual#configuration|QCG-Notification technical guide and manual]]. 

= Running the service =
The QCG-Notification initialization script is automatically added to `init.d` directory and may be run as a standard system service:
{{{
#!div style="font-size: 90%"
{{{#!sh 
/etc/init.d/qcg-ntfd start
}}}
}}}

The service logs can be found in:
{{{
#!div style="font-size: 90%"
{{{#!sh
/var/log/qcg/qcg-ntf/qcg-ntfd.log
}}}
}}}

It could be then stopped with the following command:
{{{
#!div style="font-size: 90%"
{{{#!sh
/etc/init.d/qcg-ntfd stop
}}}
}}}
'''Note:''' `qcg-ntfd` will be started with the `qcg_ntf` user permissions.

= Integration with QCG services and other interested parties =

QCG-Notification simplifyies cooperation of the two key !QosCosGrid services, i.e. QCG-Broker and QCG-Computing, as well as it offers notification capabilities to the external components. The integration of QCG-Notification with these entities is not problematic, however it meet some restrictions:
* QCG-Notification has to be able to initiate connections with QCG-Broker.
* QCG-Computing has to be able to initiate connections with QCG-Notification.
* QCG-Broker has to be able to initiate connections with QCG-Notification.
* If XMPP plugin is used, QCG-Notification should be able to connect to the XMPP server.
* If SMTP plugin is used, QCG-Notification should be able to connect to the SMTP server.
== QCG-Computing ==

After finishing the QCG-Notification configuration you must edit the QCG-Computing service configuration file and update the content of the `<ServiceURL>` elements (in `<Module xsi:type="smc:notification_wsa">` section). For e.g. if in the  `/etc/qcg/qcg-ntf/qcg-ntfd.xml` one can find  `<Host>example.com<Host>` and `<Port>19001<Port>` the `<ServiceURL>` must be set to `http://example.com:19001/`. 

'''Note:''' You must restart the QCG-Computing service after updating the `qcg-compd.xml` configuration file.

== Configuring firewall ==
QCG-Notification requires only one TCP port to be open for incoming connections. By default it should be port 19001.
Note that the QCG-Notification service may publish notifications using various protocols and connect to many notification consumer services deployed on different machines and listening on different ports. Within the PL-Grid, the QCG-Notification sends notifications via HTTP/HTTPS to the QCG-Broker service listening on a predefined port as well as it may use XMPP and SMTP protocols to distribute XMPP and e-mail messages. These all remarks should be reflected in the firewall configuration.

 

Please have a look also at [[https://apps.man.poznan.pl/trac/qcg-computing/wiki/InstallingUsingRPMS#Firewallconfiguration|this section]].

== Verifying ==

After starting the QCG-Notification service and updating the QCG-Computing configuration try to submit a simple job and check the QCG-Computing log file to see if there are now any error messages on sending notifications, e.g.:

{{{
#!div style="font-size: 90%"
{{{#!sh
tail -f /var/log/qcg/qcg-comp/qcg-compd.log
INF Sep 17 16:15:01 24201 0x44b22940 [notification_ws] Sending notify message (topic = ActivityState/TerminalState/Finished, activity_id = 0544b24a-e960-400e-4910-f1a893632610, status = Finished)
}}}
}}}

= Maintenance =

== Log management ==
You may also wish to install logrotate configuration for QCG-Notification:
{{{
#!div style="font-size: 90%"
{{{#!sh
yum install qcg-ntf-logrotate
}}}
}}}

== Nagios probes ==
See: [http://www.qoscosgrid.org/trac/qcg-notification/wiki/NagiosProbes Nagios probes for QCG-Notification]


== Data analysys and management ==
The administrators may need to view or manage data used by QCG-Notification (e.g. verify subscriptions, remove old pullpoints). The easiest way to view the data is to connect to the QCG-Notification database and select values from the particullar relations. This operation is read-only so it may be proceeded also when the QCG-Notification service is running. The more difficult thing is to modify the content of the stored data. When the service is running the operations of this type should be invoked using the provided QCG-Notification client applications. When the service is switched off the persistent data stored by QCG-Notification still can be accessed (if needed also cleaned) using the direct connection to the database. 

{{{
#!div style="font-size: 90%"
{{{#!sh
psql -h localhost qcg-ntf qcg-ntf 
Password for user qcg-ntf: 
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-ntf=>
}}}
}}}

More information about maintenance can be found [http://www.qoscosgrid.org/trac/qcg-notification/wiki/Maintenance here].