Throughout our documentation we refer to 'catch-all' Waiting Rooms. This is simply shorthand for a room that matches all urls on a given domain. It's the default setting for new Waiting Rooms but you can set a room to catch-all status by editing the room, and setting URL match to 'all of <your domain>'.
Catch-all Waiting Rooms are intended to monitor all incoming traffic and be the last line of resort in the case of traffic to your domain exceeding your Ingress Rate. They can be an important safety-net. However, they are also something of a special case, and have some different characteristics to waiting rooms that are more selective on the URLs they match. It may be important to understand these differences if you are need to schedule multiple overlapping Waiting Rooms.
Let's say you have a big concert selling now. You have a low-level of background traffic, regular users checking their account, and a big wave of dedicated fans, waiting for tickets for a specific show. You want the background traffic to be checked by your catch-all Waiting Room, but not to get stuck behind traffic in the show-specific Waiting Room. But what happens when your dedicated fans get promoted from the concert Waiting Room? If they all go to check their account, you'll simply create a second surge in the catch-all Waiting Room, a second queue and a lot of angry fans.
To avoid this scenario, catch-all rooms have a special property. When a user is promoted in any specific waiting room on your domain, CrowdHandler automatically, and simultaneously gives them promoted status in any catch-all rooms on the same domain. The same is not true for other Waiting Rooms. There's no way we'll allow users to get through a queue for an unpopular act, and achieve promoted status for the much more popular act that everyone else is queueing for.
Can I have more than one catch-all on a domain? And why would I do that?
You can, but incoming users will only get attached to one, the one with the most recent activation date. Why might you want to do that? Maybe you have a regular catch-all Waiting Room set up how you like it, but you're about to start some planned-maintenance on your website. Rather than changing the message on your existing catch-all, you could pre-schedule a catch-all Waiting Room to co-incide with your maintenance window, with appropriate messaging etc and an ingress rate of 0. At the appointed time, new users will move into the new maintenance window catch-all. When maintenance is finished, you can simply delete the new room, and the original catch-all will resume intercepting users based on your typical and tested settings.