07-10-2012 01:23 PM
Upgrading Agent on Infrastructure and satellite servers.
Are you supposed to upgrade the agent on your Infrastructure and satellite servers after a patch? For example going from 9.10 to 9.11?
There has been a lot of discussion about this and we are all trying to verify.
07-10-2012 04:01 PM
I wouldn't say "supposed to", although I can see it possibly being better described as "nice to have".
If an agent upgrade on a core or satellite server were critical to the success of the CORD patch deployment, then I would expect that either a) this process was automated as part of the CORD deployment, or b) the release notes would explicitly call out the activity.
Conversely, upgrading simply for the sake of upgrading tends to create opportunity for failure. This tends to be much moreso the case on a core server than on a satellite, mainly due to users using the Agent Upgrade custom extension. There's no official word that using this custom extension on a core or satellite is officially supported. One of the big risks of an agent upgrade on a core or satellite has to do with node attachments / service levels, ie, they can end up detached. Time-consuming reconstruction of the device record is the path of least resistance at that point.
The other risk (for core servers, as this isn't a risk for satellites) is that an opswgw.args file can get deployed. It may not have an immediate detrimental effect, but as soon as services get restarted, the effects become obvious and significant. If the services restarts don't occur for weeks/ months after the agent upgrade, then it's not immediately obvious what the cause/effect could be.
One other incorrect result that we see from time to time is that a new MID gets created for the core server in question and the value overwritten to /etc/opt/opsware/agent/mid. Once the agent restarts, the server has effectively been dissociated with the original core server device record. So long as the original core server device record still exists (and hasn't been deleted by some well-meaning admin doing cleanup), the recovery is pretty straightforward: just edit /etc/opt/opsware/agent/mid and put the original core server's device record there, then restart the agent. (Make a backup of the interim mid file, just in case there's a need to retrace footsteps.) Make absolutely certain you're restoring the correct device record's MID to the mid file, as specifying one for any other server could have unpredictable results.
I can see wanting to keep all devices' agents up to the exact same version level, but in the case of core and satellite servers, they should be treated as special cases. At the very least, don't use the Agent Upgrade custom extension on cores/satellites, this really should be a manual process, one at a time.
07-11-2012 12:50 PM
This is the response I received from our HP Premier Support Person.
"So far as I know, the core and satellite agents will be upgraded as needed by the installer. In any case, core agents should not be upgraded using the Agent Upgrade Tool, ADT/ODAD, or the Agent Upgrade Custom Extension. This is because even though core agents are used to “manage” the cores, they have a fundamentally different configuration from every other managed server in the mesh. Specifically, the core agents talk directly to the local core’s components, rather than talking to them through the gateway network, and those upgrade tools simply do not understand the special configuration required. There are other problems inherent in deleting/deactivating core agents that will break the core in some unpleasant ways."
07-11-2012 01:06 PM
seems to me engineering could "help prevent" customers from causing issues by creating code that prevents the agent upgrade extension from upgrading core servers.
This article might be the approved method - would probably be beneficial if someone from HP could officially reply in both this forum and the live network forum. Might as well set the record straight as this has caused some discussion.
07-16-2012 08:35 AM
This is the response I received back from my case with HP.
I have discussed this with James Randall and did a main confirmation to answer:
q: Are you supposed to upgrade the agent on your Infrastructure and satellite servers after a patch? For example going from 9.10 to 9.11.
a: No, agent upgrade on core/satellite servers is not suggested or encouraged by Support. Also, CPE has told us previously to tell the customer NOT to do that.
07-19-2012 02:45 PM
The "help prevent" is already present as an Enhancement Request:
The above is titled "RFE: To disable the selection of a Agent upgrade (via CX) for any managerd server with a "Customer: Opsware" role". Please note that I am unable to provide any timelines on when to expect this to be available. Other than clicking on the "E-mail me when this enhancement request is updated or resolved" link, your best bet would be to pursue a conversation with Product Management.
Regarding KM1288049, I'd say it still holds true. I'm the one who authored it.
Please exercise caution and restraint when it comes to upgrading the agents on the cores and satellites. Ask yourself "What is the compelling reason behind wanting to upgrade these?" If the answer is "so they look good on a report", then I would discourage any core/satellite agent upgrades based solely on that.