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Re: [grouper-users] Grouper 1.6.1 UI membership list sorting

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  • From: Tom Barton <>
  • To:
  • Subject: Re: [grouper-users] Grouper 1.6.1 UI membership list sorting
  • Date: Mon, 04 Oct 2010 00:03:18 -0500

I think I agree too, finally. Though we will face new problems when
grouper-resident subject data is not in sync with authoritative subject
data. Perhaps having new problems is progress...


On 10/3/2010 10:41 PM, Chris Hyzer wrote:
> I think we are agreeing... the only difference is whether grouper does the
> caching/aggregation or not. And I think there are more advantages for
> Grouper doing it than for institutions to have to do it. Right?
> Thanks,
> Chris
> -----Original Message-----
> From: Jim Fox
> [mailto:]
> Sent: Sunday, October 03, 2010 11:35 PM
> To: Chris Hyzer
> Cc: Jim Fox; GW Brown, Information Systems and Computing; Peter DiCamillo;
> Subject: Re: [grouper-users] Grouper 1.6.1 UI membership list sorting
> My point is this: There are certain operations in grouper that are
> intolerably slow. This is a common and valid complaint. Most of these
> situations would be solved, or at least mitigated, by a local subject
> source. I think this is a fundamental flaw of grouper. I think it is a
> necessary correction.
> From an external point of view there can be several subject sources. At UW
> we have at least four. However, when cached they can very easily be
> represented as a single source --- at least as a single table, obviating a
> lot of the database unions you speak of. This is our own experience.
> Imagine how much more efficient grouper might be if you could assume a
> local subject source.
> Jim
> On Oct 3, 2010, at 7:48 PM, Chris Hyzer wrote:
>> I think another common use case is finding a subject in a group. i.e. we
>> have a subject picker that wants to do a subject search (in one source)
>> where the subject is an employee. This takes a long time since it has to
>> do the search of 500k subjects, then for the results, see which ones are
>> employees (which is batched, but still takes a while). Since I am a jdbc
>> source guy, I would agree that adding more capabilities into the subject
>> source would be nice (could solve this problem). However, when
>> searching/sorting over multiple sources, it seems more difficult even if
>> the all the sources are jdbc ones... so that is why keeping a sort string
>> in the member table (for all subjects in all sources which are members of
>> groups) seems like a good thing to do. If we kept a sort string in the
>> member table, then we could also keep a lowered search string, then we
>> only need to do that instead of give the JDBC sources extra features over
>> JNDI. And if we do that, we might as well k
eep a name/description so if they become unresolvable, we can still show who
they are (were). Though I don't see keeping other attributes in there (full
replication) :)
>> Thanks,
>> Chris
>> -----Original Message-----
>> From: Jim Fox
>> [mailto:]
>> Sent: Sunday, October 03, 2010 12:20 PM
>> To: GW Brown, Information Systems and Computing
>> Cc: Chris Hyzer; Peter DiCamillo;
>> Subject: Re: [grouper-users] Grouper 1.6.1 UI membership list sorting
>> It is for this reason more than any other that we cache all our subjects
>> in tables in grouper's database. We can use simple database joins to
>> allow the DBMS do all the selecting and sorting, by subject id or name or
>> whatever.
>> It seems obvious enough that caching a subject sort string is not much
>> easier than caching the entire subject record. Possibly version 2.0 could
>> require, or at least optimize for, local caches of subjects.
>> Jim
>> On Oct 3, 2010, at 3:49 AM, GW Brown, Information Systems and Computing
>> wrote:
>>> The problem is that the API is now doing the paging - but it has no means
>>> to sort the data because, as Chris says, we don't store subject
>>> attributes.
>>> API paging was added because even without sorting, processing very large
>>> memberships would bring the UI to a grinding halt. So, unfortunately the
>>> comparator.sort.limit has become redundant.
>>> Going forward I think there are a coupe of options.
>>> 1) The UI checks how many results there will be and if under
>>> comparator.sort.limit sets this as the pagesize for the API.
>>> 2) The API stores a sort String for subjects so it can add an order by
>>> clause to its query. Some mechanism would be needed to refresh sort
>>> Strings.
>>> I can have a look at option 1, but we have talked about option 2 before
>>> so
>>> I'll wait and see what the consensus is. Either way it is likely to be
>>> 2.0
>>> before we resolve it.
>>> Gary
>>> --On 03 October 2010 01:59 -0400 Chris Hyzer
>>> <>
>>> wrote:
>>>> I can reproduce that. The problem is that subject data is stored
>>>> externally to Grouper (in sources), so if there are 50000 subjects in a
>>>> group, that is 50000 subject lookups (assuming none in cache), which
>>>> doesn't scale. Granted if you had 356 with 250 on a page, that should
>>>> sort. :) What use case do you have? Trying to see if someone is in a
>>>> group? Just curious, what is the workaround? Anyways, Im sure Gary will
>>>> weigh in here as well...
>>>> Thanks,
>>>> Chris
>>>> -----Original Message-----
>>>> From:
>>>> [mailto:]
>>>> On Behalf Of Peter DiCamillo
>>>> Sent: Saturday, October 02, 2010 11:14 PM
>>>> To:
>>>> Subject: [grouper-users] Grouper 1.6.1 UI membership list sorting
>>>> I'm having a problem where membership lists I view in the full Grouper
>>>> UI are not sorted as I would expect. When the size of the membership
>>>> list does not exceed the page size the list is sorted. But when more
>>>> than one page is needed, the list on each page is not sorted. The value
>>>> of comparator.sort.limit in is 50000, larger than the
>>>> size of any of our groups, because even if it's slow, we always want
>>>> sorted lists.
>>>> For example, I viewed a list with 2 direct members and 356 indirect
>>>> members. When I viewed the indirect members or all members with a page
>>>> size of 500 the list was sorted. But with a page size of 250 the lists
>>>> on the pages were not sorted.
>>>> I didn't install Grouper 1.3, but we may have had a local fix for this.
>>>> But in any case, it appears that since 1.3 the code that for handling
>>>> pages and sorting has changed
>>>> Peter
>>> ----------------------
>>> GW Brown, Information Systems and Computing

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