Understanding HTTP Status Codes in Microservice Environments: A Guide to 200, 201, 400, 401, 404, and 500.
Tags: beginners, programming
Published: 2023-03-25 01:47:52

HTTP status codes play a crucial role in communicating the success or failure of an API request in a microservice environment. In this article, we will explore the differences between the main HTTP status codes, including examples of how they are used in microservices.

### HTTP Status 200
HTTP status 200 is the most commonly used status code and indicates that the server has successfully processed the request and returned the requested data. This code is used to indicate that the API call was successful and that the response contains the requested data. HTTP status 200 is typically used for GET requests, where the client is requesting data from the server.

For example, if a client makes a GET request to retrieve a list of products from a server, the server should return an HTTP status code of 200 along with the requested list of products.

### HTTP Status 201
HTTP status 201 indicates that the server has successfully processed the request and created a new resource. This code is used to indicate that a new resource has been created as a result of the API call. HTTP status 201 is typically used for POST requests, where the client is creating a new resource on the server.

For example, if a client makes a POST request to create a new user on a server, the server should return an HTTP status code of 201 along with the details of the newly created user.

### HTTP Status 400
HTTP status 400 indicates that the server cannot process the request due to a client-side error. This code is used to indicate that the client's request contains invalid data or incorrect parameters, preventing the server from processing the request.

For example, if a client makes a GET request for a non-existent resource or provides an incorrect value for a parameter, the server should return an HTTP status code of 400.

### HTTP Status 401
HTTP status 401 indicates that the client is not authorized to access the requested resource. This code is used to indicate that the client needs to provide valid authentication credentials to access the resource.

For example, if a client attempts to access a resource that requires authentication without providing the correct credentials, the server should return an HTTP status code of 401.

### HTTP Status 404
HTTP status 404 indicates that the server cannot find the requested resource. This code is used to indicate that the client has requested a resource that does not exist on the server.

For example, if a client makes a GET request for a non-existent endpoint or a resource that has been deleted, the server should return an HTTP status code of 404.

### HTTP Status 500
HTTP status 500 indicates that an internal server error has occurred. This code is used to indicate that the server encountered an unexpected error that prevented it from processing the client's request.

For example, if the server encounters an unexpected error while processing a client's request, it should return an HTTP status code of 500.

### Conclusion
HTTP status codes provide crucial information about the outcome of API requests in a microservice environment. By using the appropriate HTTP status codes, clients can understand whether their requests were successful, and if not, what went wrong. Understanding the differences between HTTP status codes and using them correctly can help ensure the smooth functioning of microservices and enable effective communication between servers and clients.