Grouper Developers Forum

[Shilen Patel <>]

Tom Barton wrote:
> > > I can't think of a downside to pre-fetching group attributes.
>
> Beyond the space they take up, compared to a list of UUIDs. So this is 
> a clear space/time trade-off. Could you arrange to observe jvm memory 
> usage with a search that nets an even larger number of groups, try to 
> get a sense of how much of a trade-off?

The space can definitely add up as the number of groups returned 
increases.  I performed a query for all of our approximately 100,000 
course groups.  The attributes are stored in HashMaps and each HashMap 
has the 4 default key-value pairs for the names and extensions of the 
group.  We don't have any additional attributes for these course 
groups.  Anyways, the 100,000 HashMaps take up about 22MB of space.


Since Michael brought up the comparison with LDAP, I just had a 
thought.  When you perform an LDAP search you can provide a list of 
attributes you want returned.  Has there been a consideration of doing 
something similar with Group searches?  Just a thought....


I also find it interesting that when I do the search that gives 100,000 
results, it takes 107 seconds when I use the default TTL and memory 
values in the ehcache.xml file used by hibernate.  However, if I set the 
TTL and memory values to something that would not be reached, the query 
takes 76 seconds.  31 seconds are spent just flushing the cache. 


Thanks,

-- Shilen