This send policy will prevent any message from being sent more frequently than the permitted "interval". Messages sent more frequently than this will either be delayed to match the interval or discarded.

This is the number of items that will be queued up before additional items will be discarded.

For example, if "interval" were set to 1 second and queue_length to 10 and a burst of 100 items happened within 1 second, only the first 10 would be sent, 1 per second. The other 90 items would be discarded. There's a slight fudge factor here due to times, so you might see a few more actually sent depending on how much delay happens in handling events.

If "discard" is set to false, it is recommended that you set this value to something reasonable.