Techlearnings

Advantages of API Gateway ProxySingle point of entry - client doesn’t need to know what is the IP address or microservice they only know the API gateway domain IP. API composition - client can ask for product details in one API end point that can have catalog info, likes, comments, pictures in different services which collate as one response and send it.  Security - Inorder to use each microservice they need to authenticate and authorize that logic can hardwire in gateway or contact a service for Authentication and authorization and decide to call the API or not. Service discovery - If auto scaled up or down we need a way to know the services available hence API gateway will talk to service registry to get those details and route call. If it tracks different version of the services and API’s. Service partition hidden - suppose we can common service for comments and likes we use the same API in client to get the comments and likes together. Later we split it the client doesnt nee...

Problem: Often when writing win32 APIs I need a way to automatically call CloseHandle() for mutex, semaphore, events etc. But the problem writing a code for win32 API is there is not mechanism for automatically calling CloseHandle() function when the scope of the function or class member exits. We have to keep track of return statements and call CloseHandle() in all place we need.  E.g: void SomeOperation() {      WaitforSingleObject(hMutex, INFINITE);       if(do_operation1() != ERROR_SUCCESS)       {         std::cout << "Error operation 1"<<endl;         CloseHandle(hMutex);         return;       }       if(do_operation2() != ERROR_SUCCESS)       {         std::cout << "Error operation 2"<<endl;         CloseHandle(hMutex);         return;   ...