Fastcgi CGI shallow understanding

About CGI Relevant definitions and introductions

        CGI（COMMON GATEWAT INTERFACE） The full name is universal gateway interface WEB The server and PHP An interface for applications to talk   The program needs to run on the network server .CGI It can be written in any language , As long as the language has standard input 、 Output and environment variables . Such as perl、tcl、php etc. .

        CGI For each HTTP request Metropolis fork A new process to handle （ Parse configuration file , Initialize execution environment , Processing requests ） Then, the result of this process is passed through WEB The server forwards it to the user , just fork The new process will also exit if the user requests dynamic resources again the next time , that web The server again fork A new process , This cycle goes back and forth .

About FAST CGI Related definitions and introductions of

        FASTCGI As the name suggests, it is CGI Updated version of  

        FASTCGI We will first fork One master New process , Parse configuration file , Initialize the executor , And then it goes on fork Multiple work process （ And nginx More similar ）, When HTTP When the request comes in ,master The process passes it to a work process , Then you can immediately accept the next request , This avoids repeated initialization operations , Efficiency naturally increases , When work When the request is not enough ,master The process will also be pre started several times according to the configuration work Process waiting , When work When there are too many requests master The process will kill several work request , This not only improves performance , It also saves a lot of system resources . This is it. FASTCGI And CGI The difference between