new aggregated WLM threshold for LOCKLIST at workload/service class level

We have MAXLOCK db-cfg parameter which can be used to avoid a single connection (UOW) to consume the LOCKLIST space.

But this parameter some times it not enough. I have seen LOCK escalation cases happening (which locked system tables, causing huge LOCK CHAIN contention for hours) in the database, because there was too much concurrent applications running together, but none of them breached the MAXLOCK limit individually, but all of them consumed like 10 to 15% of the lock-list individually, exhausting the resource, and preventing it to be used by other "good" regular workload .

We need to have the ability to control the locklist in a more aggregated fashion, either at WORKLOAD , and/or at SERVICE CLASS level.

The final purpose is to manage the locks are resource to be used in a more intelligent way, avoiding specific workload (together) to consume all of it, and preventing other "good" users to use them as well.

Same way we do have options to control concurrent usage of TEMPSPACE (AGGSQLTEMPSPACE) by any given workload/service class, we should also have the same capability to control this important shared resource, which is the LOCKLIST utilization.

This way we could prevent "bad workloads" to consume this important resource, either by QUEUEING them, or CANCELING their activity.

It's important to note as well, that as part of this new threshold violation, the database engine should not ESCALATE the locks, as our purpose is to avoid ESCALATIONS , which will result in other problems like lock contention and lock chains scenarios. If this threshold is breached (collectively), it means we are in a heavy-workload scenario, so escalating LOCKS will just make things worst.

So, from threshold ACTIONs point of view, we either QUEUE the activity to be retried later on, when the lock-list get reduced (by the same workload) , or either we CANCEL the activity retuning an error to the application.

This new aggregated lock utilization threshold could be defined as a percentage (%) of the entire lock-list , same way the MAXLOCK parameter!

Regards