Build stays in the queue with the "The maximum number of concurrent builds on JetBrains-hosted agents is reached" message

Symptoms

1. The queued build, which can be run on JetBrains-hosted build agents, is not getting started.
2. The build page shows the following message: The maximum number of concurrent builds on JetBrains-hosted agents is reached

The documentation on TeamCity Cloud Subscription and Licensing does not mention any limit on the number of concurrently running JetBrains-hosted agents. It looks like only self-hosted agents should be limited this way.

Cause

While the JetBrains-hosted build agents don't have a concurrent build limit imposed by subscription or licensing, there's a technical limitation.

Resolution

By default, the limit on the number of concurrently running JetBrains-hosted agents is 50 per agent type. Meaning that the TeamCity Cloud instance may have 50 concurrently running Linux Small agents and 50 concurrently running Linux Medium agents and 50 concurrently running Windows Small agents and so on. The only exception is macOS build agents, which have a limit of 2.

This limit is not imposed by the subscription, and these defaults should be enough for most TeamCity Cloud users.

However, if your instance frequently hits this limit and you want to increase it, it is possible to adjust it. Please submit a support request through our Help Center to do so.

Additional information

Types of build agents available in TeamCity Cloud