Central agent

Archipel central agent is an optional module which enables advanced features of Archipel which need central coordination.

For example :

• track the state of your hypervisors
• when an hypervisor gets offline or becomes unavailable, start its VMs somewhere else
• [TODO] high availability support
• [TODO] platform statistics and accounting

It is an autonomous entity which you can start anywhere you want (typically, in your ejabberd server).

Archipel central agent is a new entity which must be considered as beta state for now.

Installation

It is recommended to install central agent on the same server that runs ejabberd. But it could be anywhere else (i.e. one of your hypervisors).

From published package on pypi (will be available when beta7 is out)

As root, run :

easy_install archipel-central-agent

From source :

cd clone_of_archipel_repo/ArchipelAgent
./buildCentralAgent -d

Create the pubsub node for central agent

If not done so already during Archipel Agent installation, login to one hypervisor and type the command :

archipel-centralagentnode --jid=admin@FQDN --password=YOURPASSWORD --create

Finalize the installation by typing :

archipel-central-agent-initinstall -x your_ejabberd_server_FQDN

Configuring your agents

You need to configure your archipel agents to communicate with the central agent.

For this, in your agent, edit /etc/init.d/archipel.conf, and in the modules section, set "centraldb" and "vmparking" to True.

The configuration file for the central agent is in /etc/archipel/archipel-central-agent.conf

You can adjust the following parameters :

Distibuted mode

centralagent parameter can be set to "auto" or "force".

"auto" is the default mode. In this mode, the central agent listens to a pubsub to check that another central agent is not in operation before launching. This way, you can create 2 central agents in order to make it highly available.

If you are sure you only want one central agent, you can switch "centralagent" parameter to "force" so that it will start a bit faster.

Central DB

The central agent stores all the platform information in a sqlite file. The default is to put it in the "vms" folder.