Can we provide queue inspection tools?

[CaseyZS]

Is there a reason why it's not possible to view something like the Msg queue size? Being able to see if the queue is getting backed up is valuable information.

[niACS]

Apparently, some large number of developers get themselves in trouble abusing Flush, Queue Status, etc. in queued message handlers, so Stephen opted not to enable those capabilities in the Message Queue.

It may be possible to build some debug tooling into the queue to allow that information to be exposed through the debug API. You'd have to capture the info at every Enqueue and Dequeue, which could get busy.

[CaseyZS]

I can see how operations to manipulate the queue (e.g. flush) could be problematic but it's not as apparent why tools to inspect the queue pose a problem.

Couldn't we just add an API to the Enqueuer.lvclass that could report things like # of messages?

[CaseyZS]

My feeling is that if we're going to provide APIs like "Time-Delayed Send Message" that can potentially add to the queue with reckless abandon, we should at least provide an API to monitor said queue.

[neilfenstein]

I think this would be super helpful, I think it would de-mystify the mechanisms for beginners and help some niche cases in complex systems too.

Inspection is going to be popular.

I think editing less so.

[niACS]

The debug API provides protection proxies that give limited "naughty" access to individual actors. They hold the actor's enqueuer, which is an access point to the queue system. I suppose we could add a tightly scoped method to the enqueuer (only available to the proxy class, for example) that exposes a preview function. We could provide a simple count, or actually preview the messages.

I just want to make sure we don't make it available to production code.