Sunday, October 5, 2014

Upgrading PeopleTools with Zero Downtime (1/3)

A few months ago, BNB concluded a PeopleTools upgrade with a quite curious approach. Our customer, a leading Spanish financial institution, had PeopleSoft CRM 8.4 installation running under PeopleTools 8.42. Their CRM application was being used to provide support to their 24x7 call centres, and the only reason they had to perform the PeopleTools upgrade was to be able to update their database and WebLogic releases, as the existing ones were already out of support.

Now, the organisation was going under a major structural change, so the customer wanted to perform the PeopleTools upgrade with a minimal disruption of their activities, as it was difficult at that time to obtain the needed sponsorship from higher managerial levels. In other words, they wanted to perform the upgrade as silently as possible. This translated in two particular requirements:
  • Ability to perform the PeopleTools change with zero downtime, in order to avoid any impact on the users.
  • Ability to gradually move users from the old PeopleTools release to the new one, practically limiting the impact of any product issue related to the upgrade. In case anything failed, they wanted to be able to move the users back to the old release.
Having performed quite a few PeopleTools upgrades in the past, I knew that following the standard procedures would not help us in providing a satisfactory answer to the client. So, after some discussions, the customer agreed on trying a non-standard way of upgrade PeopleTools. We agreed to do a prototype, test and if everything went well, then move to Production. If it did not work out, we would need to do it in the standard way. As it finally turned out, the suggested approach worked out.

I cannot say it would work for any other combination of PeopleTools and application versions, nor different customer usage of the application. Anyhow, I thought it may be useful to share it with you, in case any of you can enrich the approach with your feedback. In the next post I will describe the approach and in the third and final one I will describe the issues we faced during the implementation. So... keep tuned ;).


DuncanDavies said...

Sounds really interesting. Looking forward to reading about your approach.

Frans Wilbrink said...

Sounds very interesting indeed.
Did you do it with 2 paralel systems with (near realtime datatransfer)?

Javier Delgado said...

@Duncan, thanks for your feedback. I hope you find the other post also interesting.

@Frank, thanks also. Using DB links is probably not the fanciest approach, but it was quite simple.