This is related to my other question Classes installed as part of a managed package are not found or lead to compile errors in the customer org.

If an ISV app on a customer org is under heavy load (batches running, many users working) and you install a new major release, can this installation silently fail?

By silently I mean, the installation seems to be successful but files cannot compile or cannot be found...

  • I was going to suggest comparing the the ApexClass.BodyCrc for the classes in question, but it and the LengthWithoutComments comes back as -1 in the PartnerApi. You could compare the "Size Without Comments" from the Apex Classes page to see if they are the same. Commented Jun 7, 2013 at 1:51
  • 2
    I've always wondered what happens if you (as a managed package dev) want to update a class that's scheduled in your client's org. Not necessarily running during the upgrade, just scheduled. Unmanaged code gets "Schedulable class has jobs pending or in progress", what about packages?
    – eyescream
    Commented Jun 7, 2013 at 8:35
  • @eyescream: I have no idea how it should be technically possible to replace instantiated classes without a at least small window of inactivity? In the ISV guide I found no real information on when (not) to install or push upgrades. Commented Jun 7, 2013 at 11:37
  • I've done a bit of testing on this, see the results in my answer, along with references to my own experiences. Commented Aug 21, 2013 at 9:37

1 Answer 1


Documentation and a Visualforce State Test I too have not found any documentation on this, which is odd because I do recall knowledge of VF page states getting invalidated when an upgrade occurs. As in when you change the controller in DE org and try to continue to use the page without a full refresh. Again though I can find no reference to this either sadly. That said it ought to be easy to test, here is what I did....

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  • Write a Helloworld Page that accepts input from the user and echos it back to the page. This results in the page having some kind of state.
  • Packaged it (managed) and installed it in another org, ran up the page and used it.
  • While leaving the page open, i uploaded a new version of the package with a different Apex controller (renamed a variable in the controller) and upgraded the package in my test subscriber org.
  • Went back to the tab in my browser still open from the first step and clicked my Say Hello button, i recevied the following message.

An administrator has changed the definition of page or component /apex/packagea__helloworld. Refresh your page and try again Previous version = 3. Current version = 4.

Visualforce Page Conclusion after Upgrade. So it seems this is handled, much like in a developer org.

Apex Code Assumption. I suspect the Apex compiled code cache is version specific, so active requests will continue using the current version of the code until the install is commited. With the exception of the active VF page use case above. What I suspect your other question stumbled apone was an internal cache refresh failure (bug basically), doing the install and reinstall must have flushed it enough the second time. What perhaps could be done as another test is attempt an install during a long running Batch Apex job, one implementing Stateful interface.

Silent Failures, i can only answer based on my experience. It is that I have had failed installs that offer no email or feedback at all. Sometimes trying again works, other times if it is repeating I have raised a case with Salesforce, giving them the org Id of the Subscriber org and they have found unhandled exceptions from the install process in their internal logs. Most of which I've found to be valid errors that I would expect to have been reported (e.g. org config or limits exceeded). I've not had an instance of this for the last 2-3 releases as i recall. Maybe you've found a corner case still not trapped. It maybe be worth a case to have them scan the logs (if it was not that long ago), otherwise attempt to repo it and give them the time reference.

Hopefully this helps shed some light on it and give you some confidence at least for long running tasks your users are performing in Visualforce pages the system handles it.

  • Be sure to gain the full 50 points for this bounty, but don't hesitate to add more and more ideas here ;) Even if this is not the response from a Salesforce employee I expected it definitely worth the points. Commented Aug 21, 2013 at 10:03
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    Thanks Robert, appreciated, you have peaked my curiosity on this, so may well revist regarding long running Batch Apex jobs during upgrades.... ;-) Commented Aug 21, 2013 at 10:23

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