Difference between revisions of "Gyrex/Administrator Guide/Cloud"

Revision as of 15:53, 2 February 2011

Cloud

The Gyrex cloud functionality is implemented based on ZooKeeper. When running in development mode, an embedded ZooKeeper server is started automatically so you don't have to configure anything at all. For production environments we highly recommend running a standalone ZooKeeper ensemble. Please have a look at the ZooKeeper Administrator's Guide for details on how to setup your own ensemble.

Node Management

An essential part of a cloud is node membership. Node membership in Gyrex is implemented by explicit approval of nodes. Each node has a unique identifier. Upon first start a new one is generated. It's also possible to manually set node ids. However, you need to ensure that node ids are unique. No two nodes with the same identifier are allows to join the cloud.

After a new node joins a cloud it will be registered with a pending state. In this state the node is not allowed to participate in any cloud activity other than node registration. An administrator need to explicitly approve the node first. Once the node has been approved it will become online.

Tags may be assigned to nodes. They will play an important role when distributing functionality and responsibilities within your cloud.

Console Commands

Two commands are available in the Equinox OSGi console for managing and analyzing the cloud. They both come with a small syntax help

osgi> help
[...]
---Cloud Commands---
	cloud <cmd> [args]
		approve nodeId
		ls pending|approved
		retire nodeId
---ZooKeeper Commands---
	zk <cmd> [args]
		create [-s] [-e] path [data]
		get path
		ls [-r] path
		rm [-r] path
		set path data
		stat path
		sync path
[...]
osgi>

List pending (unapproved) nodes:

osgi> cloud ls pending
[nodeId] (hostname)
...
osgi>

Approve a node:

osgi> cloud approve <nodeId>