On Wed, 2 Dec 2009, Andy Swiffin wrote:

> and definitely *should* happen but there is just the possibility of 
> being shot in the foot.  However I am optimistic that this will go OK, 
> I've not heard any anguished cries from anyone who's already done this 
> (Please tell me that this is not because no-one has actually done this 
> on a live service yet!).  So yes, I am optimistic this will work :-)

If it is any consolation, we changed the algorithm that generates ePTID at 
the tail end of summer (poor early choice of secret, and to deal with:

  http://www.ukfederation.org.uk/content/Documents/EPTIDDefnProblem

amongst other local operational reasons).

We did so at first temporarily out-of-hours, and our clever library staff 
tested a large cross section of sites.  They found that "most" services 
coped OK, in that many of them simply said "ah, a new eptid, let's ask 
some questions to try and associate with a known user" and then did the 
right thing.  A few did lose some preferences I think, or the library had 
to intervene a little bit or provide transitional guidance, but on the 
whole, for the providers we interface with, the change was not too 
painful.  It was a case of necessity anyway, regardless of the potential 
pain, but in the end we were overall pleased with it, and the majority of 
users never noticed (maybe they did not have extensive customisations or 
use such services).

We got grumbles and a snippy conversation from SDSS/EDINA support, because 
a user went directly to them to say things weren't working rather than 
bothering to ask local support (or notice the advertising that we'd put in 
place prior to the change), and they spent time analysing the problem 
before asking us about it.  But you can't cater completely for users 
trying hard to ignore the support structures you put in place for them.  
What I would say, then, is that if you do need to do it, to let them and 
other support parties know in advance that it is going to happen, so they 
can anticipate any issues that get brought to their attention.

Jethro.

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Jethro R Binks
Computing Officer, IT Services, University Of Strathclyde, Glasgow, UK