I have recently had builds queued for 2.5 hours or more, because they require SQL Server or Oracle, and there are no agents available. The Bamboo instance won't spin up an elastic agent that provides these requirements because it's already at its elastic agent limit. Idle elastic agents hang around for up to an hour, which means it can take a long time to get a suitable elastic agent spun up. In some cases, there have not been any agents that can build the job at all, in others there has been one agent but it's busy building other builds.

These builds often have 5 stages that take 1.5 hours each, so with one agent, the build can take over 7 hours. If you have 2 builds which require that same agent, obviously you wait a very long time.

It would be great if we could do some analysis of which builds need more agents, possibly to try to normalise the time-to-completion, eg if a build has only one agent but multiple stages and is going to take over one hour to complete, terminate some idle agents and spin up some more of the one that build requires.