Nothing can be as annoying as getting a timeout error when accessing an application or a web page. It can all happen for inexplicable reasons. Basically, timeout errors can occur when the relation between the web server, web application, and the client gets complicated. When you access an application or a web server, an HTTP request is sent to the server, which responds with a status code. All of us have ran into something like this, and it can be a really tough task to find out the root cause of the error.

What Do You Mean By Timeout Errors?

When server takes too long to respond to a request made from another server or a client, it implies a timed-out connection. It occurs when the device that generated the initial request has given up. The main objective of a timeout is to save your time, which you would otherwise waste when waiting to get a response that won’t probably come.

A number of reasons can contribute to timeout errors, and it can be hard to figure out why. Just the error message won’t help us determine the cause.  It could be the web application, the network infrastructure, the requesting client, the web server or just poor Internet connection. Generally, response status in the 5xx category are server error responses and those in 4xx category are client error responses.

What Are The Different Types Of Timeout Errors?

  • 408 Request Timeout

It implies an issue on the client side, where the client didn’t receive a complete request within a specified time by the server. Consequently, the server closes the connection, rather than wait. Take a look at the URL, in case you get this error. You may be requesting something that you are not authorized to access. It ends up routing through a different proxy server, which is used to handle user authentication.

  • 503 Service Unavailable

Temporary overload or scheduled maintenance can limit your access to a particular website or an application. It happens when the server cannot handle the request and ends up throwing the error. In most cases, this error can be resolved quickly.

  • 504 Gateway Timeout

This status code implies that the proxy server or the gateway did not receive a response from another server that it was trying to access. This is basically a network error between servers, such as an issue with the actual server or a silent firewall drop.

  • 502 Bad Gateway

When the proxy server or gateway does not receive a valid response from the backend server, it shows a 502 error. There can be a number of reasons behind it:

  • The origin server has no connectivity
  • A firewall is blocking communication between the origin server and the edge servers
  • Crash due to server overload
  • ISP issues, routing problems, DNS issues and network issues.

When using a load balancer or a reverse proxy server, you need to check that the configuration is done properly. A healthy network connection must exist between the reverse proxy server and backend servers, along with proper specified backends.