API Gateway should scale (enhancement)

[alexellis]

The gateway could be a bottleneck in very high workloads. It should be able to scale.

Current Behavior

Prometheus scraping would break

Possible Solution

Add to prometheus.yml config:

  - job_name: "gateway"
    scrape_interval: 5s
    dns_sd_configs:
      - names: ['tasks.gateway']
        port: 8080
        type: A
        refresh_interval: 5s

[rcarmo]

I'm looking at deploying this on a Swarm cluster with dynamically scaled VMs. I was thinking of deploying the admin UI on the master node (on a separate port) and having the gateway be a Swarm replicated service.

Being able to split the admin UI from the gateway (on separate ports) would also help with #32, since it would make it easier to put something like an OAuth-enabled reverse proxy in front to authenticate humans.

[alexellis]

Would be good to find out more of your use cases. What are the benefits of splitting UI/gateway over keeping them together and just scaling?

[alexellis]

The gateway can now scale and Prometheus will respond to this too - docker service scale func_gateway=2. I'm still interested in the idea of scaling via CPU workload.