解决方法
Phusion Passenger supports two concurrency models:
process: single-threaded,multi-processed I/O concurrency. Each application process only has a single thread and can only handle 1 request at a time. This is the concurrency model that Ruby applications traditionally used. It has excellent compatibility (can work with applications that are not designed to be thread-safe) but is unsuitable workloads in which the application has to wait for a lot of external I/O (e.g. HTTP API calls),and uses more memory because each process has a large memory overhead.
thread: multi-threaded,multi-processed I/O concurrency. Each application process has multiple threads (customizable via PassengerThreadCount). This model provides much better I/O concurrency and uses less memory because threads share memory with each other within the same process. However,using this model may cause compatibility problems if the application is not designed to be thread-safe.
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