Deadlock Trace

The deadlock trace contains an entry for every occurrence of a deadlock during a specified time period.

The trace shows when the deadlock occurred and provides details on the resources involved in the deadlock and information about the threads that held the resource or waited to use the resource. If the resource was held by more than one agent and not all of them were actively involved in the deadlock, the holder data cannot be determined and is not printed.

The data specific to the deadlock. For each resource involved in a deadlock there is a block of waiter's data and a block of blocker's data.

A blocker is a thread that prevents the victim getting its lock. The blocker can be a holder of the lock or another waiter (one that came in before the victim) that is incompatible with the holder's lock.

There is no correlation between the number of deadlock events reported by Locking reports and traces and the number of deadlocks reported in Accounting and Statistics reports. Whereas Accounting and Statistics reports count all deadlock occurrences, regardless of how they resolve, Locking reports only those deadlocks that were resolved by DB2®. DB2 can resolve a deadlock either by making a process roll back, thereby releasing the locks it holds on resources, or by requesting a process to terminate.

The format of the deadlock-specific data is shown in The Format of Deadlock-Specific Data.