Patching HA Agents of an Application
Gurus,
So far we've been delivering a HA Agent package for our application. There was no need for us to modify the RTR file (ORCL.scocs) that comes with the package, until now. Recently we revamped the way we implemented our agents, this resulted in us modifying our RTR file ORCL.scocs
So far we've been fixing bugs and delivering patches for our HA Agents. The customer used to apply this patch, and every things perfectly fine. But with the changed RTR file, in our next release; how do we deal with this ?.
Question 1) Does the customer has to reregister this RTR file ?.
Questions 2 ) If there are any changes to the RTR file, do we need to modify any field in the RTR file ? say version ? etc...
Question 3 ) Are there any alternatives for the Customer, to not unregister and re-register the current RTR file ?
How do most customers implement in such a scenario ?
_Thanks in Advance
D
# 1
Hi Durga,
Check out the procedure for "How to Migrate Existing Resources to a New Version of the Resource Type" at http://docs.sun.com/app/docs/doc/819-2974/6n57pdjtl?a=view
That is the procedure the customers of the RT would use to migrate to the new version of
RT. Note that whether that can be done without a downtime depends upon exactly how
the developer (that is you!) provides for compatibility (more on that below). Typically, you would want the resources to be in "Unmonitored" state (that is, the fault monitor is not
running) before upgrade. A downtime is typically not required, unless the upgrade is somehow not backward compatible.
So much for how to USE rt upgrade. For developers, check out the procedure for
"Modifying a Resource Type" at http://docs.sun.com/app/docs/doc/819-0581/6n30f91s3?a=view
Here are the key things to keep in mind.
1) Make sure your new code (the method implementations for the new version) can work with resources of old types. One way i have seen that to go wrong is if the new version of the RT introduces a new property and the new method implmentation FAILs if it does not find that new property. The right way to deal with that is to look for error code SCHA_ERR_PROP from scha_resource_get() calls and if you get that error, take the course of action which your implementation did in earlier implementation instead of erroring out.
2) Make sure there is a #$upgrade_from directive in your new RTR file. You would want it to be WHEN_UNMONITORED. Read the documentation for details.
Take a close read of the documentation, you would find that it is pretty thourough. But
ABOVE ALL, "Please do test!!". :-)
Post here if you have any specific questions even after reading the documentation, or run into any specific issues. Or even if you succeed at first try and don't actually have any questions, just want to report your success.
Best of Luck!
-ashu
