RPC

• RPC - Remote Procedure Call
• RPC is a method of communication btw two programs (even across systems) through function calls
• RPC abstracts the call to the other program in a remote system to a local function call
• The remote program also returns the result to the calling program
• Can be stateful
• RPC usually has only one endpoint, the function being called is added as a part of the message

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RPC vs REST §

RPC is about invoking certain actions and expecting responses,

// client
message UserRequest { 
	int32 user_id = 1; 
} 
 
// server
service UserService { 
	rpc GetUser (UserRequest) returns (UserResponse); 
} 
 
message UserResponse { 
	string username = 1; 
	int32 age = 2; 
}

REST is about asking questions about resources and getting information in return,

GET /users/{userID}