Improve services performance

**Feature request**
It would be great to have monitoring for handlers.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_monitoring` with default `false`.

Start by locating the service and handler entry points, configuration handling, and any existing monitoring or logging facilities. Determine how handler activity should be exposed and what production behavior is expected when enable_monitoring defaults to false; done means the option is available and handler monitoring works when enabled.

Written by the indexing model from the issue text.