Grouper Users - Open Discussion List

["GW Brown, Information Systems and Computing" <>]

Tom,

It isn't 'reasonable' that you get the error, but it is understandable.

MemberFinder.findBySubject(s, SubjectFinder.findById("foo"));

Internally, Grouper checks to see if a record exists. If not it will 
attempt to create one. If two threads do the same check at the same time, 
or within a very short space of time, one will succeed in creating a 
grouper_members record, but the other will fail.

In principle MemberFinder could catch the exception and attempt a new 
lookup, but that would require a code change.

Gary


--On 10 October 2007 08:00 -0500 Tom Zeller 
<>
 wrote:

> Greetings,
>
> Is it reasonable that multiple threads executing :
>
> MemberFinder.findBySubject(s, SubjectFinder.findById("foo"));
>
> may result in :
>
> Exception in thread "Thread-17"
> edu.internet2.middleware.grouper.internal.dao.GrouperDAOException:  Could
> not execute JDBC batch update at
> edu.internet2.middleware.grouper.internal.dao.hibernate.HibernateMemberD
> AO.create(HibernateMemberDAO.java:76)
>          at
> edu.internet2.middleware.grouper.MemberFinder.internal_findOrCreateBySub
> ject(MemberFinder.java:139)
>          at
> edu.internet2.middleware.grouper.MemberFinder.internal_findBySubject
> (MemberFinder.java:123)
>          at  edu.internet2.middleware.grouper.MemberFinder.findBySubject
> (MemberFinder.java:53)
> ...
> Caused by: net.sf.hibernate.exception.ConstraintViolationException:
> Could not execute JDBC batch update
> ...
> Caused by: java.sql.BatchUpdateException: Batch entry 0 insert into
> grouper_members (member_uuid, subject_id, subject_source,  subject_type,
> id) values (5add0097-84b4-4c79-9e41-2588c622bd52, foo,  umrsa, person,
> 0d61f1c2158669ff01158726d47a0013) was aborted.  Call  getNextException to
> see the cause.
> ...
> JDBCExceptionReporter:58 - ERROR: duplicate key violates unique
> constraint "grouper_members_subject_id_key"
> ...
> SessionImpl:2400 - Could not synchronize database state with session
>
> ?
>
> I welcome advice regarding threads and Grouper.
>
> Thank you,
> Tom



----------------------
GW Brown, Information Systems and Computing