Tuesday, September 7, 2010

AX 2009 - deadlocks

I recently conducted a system review at a customer site and discovered a message totally new to me beeing logged in on all AOS: "Object Server xx: Dialog issued for client-less session 1: Cannot edit a record in LastValue (SysLastValue). User ID: ,AdminUserSetup. Deadlock where one or more users have simultaneously locked the hole table or part of it."

The database at hand was not configured to use Read Committed Snapshot Isolation (RCSI) as recommended by the AX Performance Team. Enabling RCSI on the database solved the issue.

3 comments:

Turner said...

Do you know if Read Committed Snapshot isolation is allowed for AX 4.0?

Hans-Petter Lund said...

Yes it is (due to support for the optimistic locking scheme).

Hans-Petter Lund said...

And this was on a AX 2009 SP1 solution running 6 AOS instances. One side effect (?) was that the deadlock message was replaced by the dreadful 117 "Language changed..." message (http://ax2009tech.blogspot.com/2010/03/annoying-database-error.html). The issue will not happen in solutions with one AOS instance and it's rather annoying since it bombs the event log...