Here is the answer to this question, the Host State has the following states,
most likely in this order:
Alert >> Connecting >> Up >> Disconnected
After the Plugin Resource gets called with Configure() and Start(), the Plugin
Agent Manager creates the Host resource associated with the Plugin. The Agent
Manger calls the Plugin Resource with a couple of commands to ensure it is
proper state: ReadyCommand() and MaintainCommand() a response to these
commands brings up and keeps the Plugin in the Up state.
There is an additional Command GetHostStatsCommand() that is sent by Agent
Manager, I don't see any of the Network Plugins respond to this command. I
assume since it Hypervisor focused. If you don't respond to it properly you get
following warnings. It is good practice to fill in the parts of the message
that applies to a generic plugin to get rid of the warnings from log files:
WARN [agent.manager.AgentManagerImpl] (StatsCollector-2:) Unsupported Command:
Unsupported command issued:com.cloud.agent.api.GetHostStatsCommand. Are you
sure you got the right type of server?
WARN [cloud.server.StatsCollector] (StatsCollector-2:) Received invalid host
stats for host: 2
The Agent Manager log error messages don't have the Host name, just the Host
id, so you need to look them up in the database. Probably good practice for the
logs to also print the name, so in the warning above host Id=2 is Infoblox
Controller.
id name
uuid status
1 xenserver1-cloudstack
59f27a99-8133-4890-a845-d45668068742 Up
2 Infoblox Controller - 172.16.197.135
c430126c-97b8-434e-bd8d-db1d96832921 Up
The GetHostStatsCommand() might be a good placeholder to get Network Plugin
stats.
-Soheil
________________________________________
From: Soheil Eizadi [seiz...@infoblox.com]
Sent: Friday, July 05, 2013 6:55 PM
To: dev@cloudstack.apache.org
Subject: Plugin/ Agent/ Host States
I am trying to understand how the Host object state transitions to Up state? I
see it starts in Alert state.
There is not a setter for status and the comment for it in HostVO.java said:
/**
* Note: There is no setter for status because it has to be set in the dao
code.
*/
@Column(name="status", nullable=false)
private Status status = null;
Thanks,
-Soheil
