Adding an api throttling property to limit the number of url calls per second

[cloudfoundry-community]

Adding an api throttling property to limit the number of url calls per second

[poblin-orange]

Many cpi to cloudstack api call are async task result polls.
Which type of apI call do you want to throttle? create_vm and or create_disk?
Maybe u can start by throttling at bosh director level (number of worker thread)

[poblin-orange]

bosh director has already mechanism to limit iaas actions limitations. We usually set a lower value to max_threads parameter.

http://bosh.io/jobs/director?source=github.com/cloudfoundry/bosh&version=234#p=director.max_threads

I guess cloudstack has also some api throttling mechanism.
Given these 2 options, i do not think the cpi is the good place for throttling

[poblin-orange]

hystrix instrumentation has been added. First version limits the concurrent cpi verb to 10 (ie: max 10 concurrent cpi.create_vm, max 10 concurrent cpi.create_disk).
This built in cpi mechanism can protect the iaas in case of bosh max_thread unadapted configuration