Most of them are outdated, but provide historical design context.
They are not user documentation and should not be treated as such.
Documentation is available here.
Detailed Host PM Multiple Agents
Host Power Management Multiple Agent Support
Current implementation assumes that a Host that its Power Management is configured has only one fencing agent from a certain type (i.e. rsa, ilo, apc etc.) This document describes what should be done in order to support dual-power Hosts in which each power switch may have its own agent or two agents connected to the same power switch. Agents may be from same or different type We will treat current Power Management agent as Primary Agent and the added one as Secondary Agent.
Feature owner: Eli Mesika (emesika)
GUI Component owner: Eli Mesika (emesika)
REST Component owner: Eli Mesika (emesika)
Engine Component owner: Eli Mesika (emesika)
QA Owner: Yaniv Kaul (ykaul)
- Target Release: 3.2
- Status: Design
- Last updated date: Nov 15 2012
There may be two main configurations for Primary/Secondary Agents: 1) Concurrent, when Host is fenced both agents are used concurrently, for Stop command we need both to succeed and for Start command if one succeeded the Host is considered to be UP. 2) Sequential, when Host is fenced either for Stop or Start commands, Primary Agent is used, if it fails (after all configured retries) then the Secondary Agent is used.
Adding the following columns to vds_static:
pm_secondary_ip pm_secondary_options pm_secondary_port pm_secondary_password pm_secondary_user pm_secondary_type pm_secondary_concurrent
vds (adding all pm_secondary* fields)
vds_with_tags (adding all pm_secondary* fields) dwh_host_configuration_history_view (adding only pm_secondary_ip) dwh_host_configuration_full_check_view (adding only pm_secondary_ip)
InsertVdsStatic UpdateVdsStatic InsertVds
Adding handling of
pm_secondary* fields to
Adding test data for
Change default configuration
FenceStartStatusDelayBetweenRetriesInSec to 10 and
FenceStartStatusRetries to 18, this will insure we are responding faster to Hosts while it change status.
pm_secondary* fields to
pm_secondary* fields to
FenceVdsBaseCommand::executeCommand() to handle all scenarios described in Flow
The REST API will be enhanced to include the multiple Agents definitions as follows Keep in mind that we should preserve the former syntax for backward compatibility and deprecate it in future For any case in which we found old flat PM definitions and other definitions inside the agents block, the setting in the agent block will take presence.
<power_management type="rsa"> <enabled>true</enabled> <address>ip or fqdn</address> <username>user</username> <password>password</password> <options><option value="" name="port"/><option value="false" name="secure"/></options> <agents> <agent type="rsa"> <address>ip or fqdn</address> <username>user</username> order="primary" <password>password</password> <options><option value="" name="port"/><option value="false" name="secure"/></options> <concurrent>false</concurrent> <order>1</order> </agent> <agent type="ipmi"> <address>ip or fqdn</address> <username>user</username> order="primary" <password>password</password> <options><option value="" name="port"/><option value="false" name="secure"/></options> <concurrent>false</concurrent> <order>2</order> </agent> ... </agents> </power_management>
concurrent flag will be handled in the Host level Add custom mapping for these new power-management fields in HostMapper.java, for both REST–>Backend and Backend–>REST directions)
No Secondary Agent If no Power Management is defined , the Stop/Start scenarios works without a change. For example, the Restart scenario is:
Send a Stop command Wait for status 'off'  Send a Start command Wait for status 'on' 
If a secondary agent is defined Sequential: Send a Stop command to Primary agent
Wait for status 'off'  If Stop failed Send a Stop command to Secondary agent and wait for status 'off' Send a Start command to Primary agent Wait for status 'on'  If Start failed Send a Start command to Secondary agent and wait for status 'on'
Send a Stop command to Primary and Secondary agents Wait for status 'off' on both Primary and Secondary agents Send a Start command to Primary and Secondary agents Wait for status 'on' on either Primary or Secondary agent
 Controlled by FenceStopStatusDelayBetweenRetriesInSec,FenceStopStatusRetries configuration values  Controlled by FenceStartStatusDelayBetweenRetriesInSec,FenceStartStatusRetries configuration values
A new drop-down box will be added to the Power Management screen that enables selection of Primary/Secondary agents in order to insert agent details and test the agent. The Concurrent check box controls if the secondary agent works in the concurrent or sequential mode
Add the new
pm_secondary* columns in the upgrade script.
Dependencies / Related Features and Projects
Affected oVirt projects
Host Power Management Proxy Preferences
Documentation / External references
For 3.2 we will handle only Primary/Secondary agents We may add 3rd agent support in future to handle other scenarios