By default, derby.stream.error.logSeverityLevel is set to 40000. If derby.stream.error.logSeverityLevel is set to display transaction-level errors (that is, if it is set to a value less than 40000), deadlock errors are logged to the derby.log file. If it is set to a value of 40000 or higher, deadlock errors are not logged to the derby.log file.
The derby.locks.monitor property ensures that deadlock errors are logged regardless of the value of derby.stream.error.logSeverityLevel. When derby.locks.monitor is set to true, all locks that are involved in deadlocks are written to derby.log along with a unique number that identifies the lock.
To see a thread's stack trace when a lock is requested, set derby.locks.deadlockTrace to true. This property is ignored if derby.locks.monitor is set to false.
For information about how to set properties, and information about the specific properties that are mentioned in this topic, see
Here is an example of an error message when