What is HTTP Status Code and Text
HTTP Status Code is a numeric status code (such as "404") in the first line of the HTTP response (the status line) that indicates the health of the web-server or availability of the requested resources.
HTTP Status Text is a textual reason phrase (such as "Not Found") in the first line of the HTTP response (the status line) that describes the numeric status code.
The most common codes
200 - OK
Standard response for successful HTTP requests. The actual response will depend on the request method used. In a GET request, the response will contain an entity corresponding to the requested resource. In a POST request, the response will contain an entity describing or containing the result of the action.
301 - Moved Permanently
This and all future requests should be directed to the given URI.
400 - Bad Request
The server cannot or will not process the request due to an apparent client error (e.g., malformed request syntax, size too large, invalid request message framing, or deceptive request routing).
401 - Unauthorized
Similar to 403 Forbidden, but specifically for use when authentication is required and has failed or has not yet been provided. The response must include a WWW-Authenticate header field containing a challenge applicable to the requested resource. 401 semantically means "unauthenticated", i.e. the user does not have the necessary credentials.
403 - Forbidden
The request was valid, but the server is refusing action. The user might not have the necessary permissions for a resource, or may need an account of some sort.
404 - Not Found
The requested resource could not be found but may be available in the future. Subsequent requests by the client are permissible.
408 - Request Timeout
The server timed out waiting for the request.
500 - Internal Server Error
A generic error message, given when an unexpected condition was encountered and no more specific message is suitable.
502 - Bad Gateway
The server was acting as a gateway or proxy and received an invalid response from the upstream server.
503 - Service Unavailable
The server is currently unavailable (because it is overloaded or down for maintenance). Generally, this is a temporary state.
504 - Gateway Timeout
The server was acting as a gateway or proxy and did not receive a timely response from the upstream server.
So what's the problem?
There is a lot of reasons for the unexpected outage.
Here is just the short list of the possible reasons:
- DNS expiration;
- SSL/TLS expiration;
- server overload due DDoS-attack;
- no space left on HDD/SSD;
- ISP (Internet Service Provider) problems;
- and many more.
What is your approach?
Distributed availability monitoring and real-time notifications.
AppSiteDown checks the availability of your website or service from different places all over the world, gets HTTP Status Code and notifies you if it differs from "200 - OK".
If this notification policy does not suit your requirements or business processes (e.g. "200 - OK" is abnormal for some pages, while "401 - Unauthorized" is actually fine), it can be changed withing our Custom Check offer.