Pipeline parallelism limited to 2?


I have a multi-agent drone configured with one server and 5 agents co-hosted on the same AWS instance.

I have a drone.yml configuration with 4 distinct pipelines, which I wish to run in parallel.

This seems to be functional, however only two of the pipelines trigger immediately. The other two are “pending” until one or the other first ones complete. When all four pipelines complete, the “roundup” step which depends on all four triggers correctly.

How can I avoid the two “pending” pipelines?

drone v1.1.0


my guess would be a configuration issue, either with the the server and agents or the yaml I would need to see your configuration to advise further. I can confirm there are no known issues with parallelism in drone 1.x. We run the stock Docker image at cloud.drone.io and run dozens of pipelines in parallel (in some cases 50+)


I think I found it. I had DRONE_RUNNER_CAPACITY set to 2.


Question: can each agent run multiple pipelines concurrently?


Yes, agents are configured by default to run 1 pipeline at a time, which can be increased with DRONE_RUNNER_CAPACITY=<integer>. We have some pretty large servers at cloud.drone.io (124 gb ram, 96 cpu) and we use this setting to allow multiple concurrent pipelines per machine.