[Kolab-devel] [issue4553] Should free/busy lists contain outdated free/busy data?

[Gunnar Wrobel]

New submission from Gunnar Wrobel <wrobel at kolabsys.com>:

This issue (or rather a question) is a result of the discussion in
kolab/issue4481 (Automatically trigger a resource when booking in case its
free/busy information is too old).

To summarize again: At some point the following code was added to the free/busy
scripts:
http://kolab.org/cgi-bin/viewcvs-kolab.cgi/server/kolab-resource-handlers/kolab-resource-handlers/freebusy/Attic/freebusycollector.class.php.diff?r1=1.3&r2=1.4&hideattic=0%29.

As detailed in kolab/issue4481 this code section was intended to automatically
clean out old free/busy partial data when fetching the free/busy list of an account.

The code section above did never work as intended (for the actual reason see
msg26430) and still does not in Kolab Server 2.2.4.

So the question I want to raise in this issue is whether we actually need this
section.

There are two variants I'd like to consider:

 1) Does it really make sense to delete outdated partial free/busy lists while
    the complete free/busy data for an account is fetched?

 2) If complete deletion is not necessary then it might still be useful to hide
    the outdated partial free/busy data. If so for what reasons?

I can think of the following reasons at the moment:

 1) Purging old cache data automatically might make sense because of issues 
    kolab/issue614 (Events from deleted/renamed calendar folder
    still show up in free/busy list), kolab/issue800 (Kolab clients must handle
    deletion of calendar folders correctly), kolab/issue3470 (Free/Busy cache 
    not deleted when user gets deleted). This way we don't accumulate too
    much cruft. But other than that I don't see a reason why we would need
    to delete outdated free/busy lists. So I'd rather like to see us fixing
    the issues linked above rather than having this workaround.

 2) Thomas indicated that hiding outdated free/busy data might be important
    for some clients so that it does not look like the free/busy data is 
    actually missing. But I'm tempted to disagree. Because if we only have
    outdated free/busy data there is nothing else that we should show. If the
    client interprets this as "free/busy data missing" (as it is not covering 
    the timespan currently of interest) then this is actually correct. Hiding
    outdated partials and maybe simply indicating the current time span as 
    available seems much more problematic to me.

As a conclusion I currently lean towards removing this purging code completely
and always show outdated data if that is all we have. If a users client displays
this as "free/busy data not available" I think this is the best option as the
user will probably contact the admin about this problem.

----------
assignedto: thomas
keyword: freebusy, server
messages: 26443
nosy: bernhard, cwickert, martin, thomas, wilde, wrobel
priority: feature
status: unread
title: Should free/busy lists contain outdated free/busy data?

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