Deadlock errors when saving a task

Symptoms

Occasionally, users report deadlock errors when working with Changepoint. This can be e.g. while saving tasks, but it can occur during other operations as well.

Error/warning messages

Server Error in '/' application.

Transaction (Process ID xxx) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction.

Resolution

It is very frequent that parallel processes update the same data at the same time and SQL Server uses locking to synchronize the parallel processes. Normally this is is transparent to the application. But there can be situations where process 1 needs to wait for process 2 and then process 2 needs to wait for process 1 for another reason. So both are blocked because waiting for each other. This is a deadlock situation and it can only be solved by killing one of the processes (the victim) so at least the other one can continue. The solution is to rerun the 'victimized' transaction.

As long as this happens only very occasionally, this can be ignored and you just need to repeat the aborted operation. Only if it happens all the time or always with certain activities, please inform support to look further into it, because then it might be a design issue.