Consumer applications need to inspect ClientServersAvailable or be notified when a ClientServerUnavailable occurs

[azuisleet]

On June 30th cm1-ord1.cm.steampowered.com started rejecting PICS requests. Our consumers don't know this is happening because the two mechanisms to handle this aren't exposed.

We need to expose one or both of these so consumers can reconnect to a new CM.

Here's a malfuctioning server:

And here's a functioning server:

[azuisleet]

I have implemented the simple path here: 0c9290f

We will abort the connection and mark the server as failed when we see a ClientServerUnavailable.

As part of that, we will also shuffle the endpoint list so we don't keep hitting the same CM: 90c2847

[xPaw]

I wonder, does this unavailable response come when you send a emsg to an unavailable server? If so, does that mean the emsg and jobid match?

[azuisleet]

ClientServerUnavailable includes the correct emsg and jobid for the request (ClientPICSChangesSince in this example)

[azuisleet]

The shuffle logic has been revised to instead mark all endpoints by host: d8a1f8b