How to find maximum concurrent processes Passenger can create?

I'm running passenger with REE on a Rackspace cloud server. Is there any way to find out what is the maximum concurrent processes开发者_运维技巧 Passenger can create/handle with the provided infrastructure/hardware?

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By default the maximum number of Passenger instances spawned is six. You can adjust this in the configuration. Phusion provide excellent guidelines for setting this value in their documentation:

Nginx - http://www.modrails.com/documentation/Users%20guide%20Nginx.html#PassengerMaxPoolSize

Apache - http://www.modrails.com/documentation/Users%20guide%20Apache.html#_passengermaxpoolsize_lt_integer_gt

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Found a better and easier option. I'm monitoring both my Application and EC2 instance (it should also run on Rackspace) with NewRelic. All I need to do now is find a load testing tool & put the load on my instance. NewRelic shows how many instances Passenger is creating & what is the resource consumption (RAM, CPU..etc) for the same.