We are using sortvals on both member and memberUid. We have been seeing duplicate member/memberUid attributes on some objects that have been modified (as well as a lack of sorting on those attributes). It seemed that there was a correlation between modifies to objects that experienced deadlocks and the objects that had duplicate member/memberUid attributes on them. We put the seqmod overlay in place - and this reduced the number of occurrences of the issue but did not eliminate them. Upon further investigation, I discovered that it was possible to bypass the sorting behavior if the object was not created with an instance of the attribute with sorting enabled as a part of it. It would seem that attr_merge() (in attr.c) should have something like this: if ( *a == NULL ) { *a = attr_alloc( desc ); if (desc->ad_type->sat_flags & SLAP_AT_SORTED_VAL) { (*a)->a_flags |= SLAP_ATTR_SORTED_VALS; } } else { Further pursuing the issue, I started to focus on the index deletion code that was changed as a part of ITS#5183. Specifically, the portion of code within bdb_modify_internal() (in back-bdb/modify.c) that is commented: /* Move deleted values to end of array */ This code modifies save_attrs, which is actually apparently a pointer to memory that resides within the cache. If a deadlock occurs, these changes are not reverted, thereby corrupting the entry in the cache. I replaced this code with the pre-ITS#5183 code and I am no longer able to 'break' the object and insert duplicate member/memberUids. I also found it surprising that the call to bdb_idl_cache_del() in bdb_idl_delete_key() in back-bdb/idl.c occurred prior to any calls to the database? I can answer any questions about the specifics of the environment in which where we are seeing this - it is a somewhat difficult problem to reproduce outside of our production environment. I'm not terribly familiar with the code - I'm looking to see if I have collected enough data here to open an ITS to have this fixed. (or if I'm just way off base) Thanks, Andy -- Andrew W. Elble aweits(a)discipline.rit.edu Infrastructure Engineer, Communications Technical Lead Rochester Institute of Technology PGP: BFAD 8461 4CCF DC95 DA2C B0EB 965B 082E 863E C912 CONFIDENTIALITY NOTE: The information transmitted, including attachments, is intended only for the person(s) or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and destroy any copies of this information.