Editing Troubleshooting of HTTP errors

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HTTP status code

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== 400 Bad Request ==

Root cause of 400 Bad Request. HTTP Error 400. The request is badly formed.
* "the server cannot or will not process the request due to something that is perceived to be a client error (for example, malformed request syntax, invalid request message framing, or deceptive request routing)"

Possible solution:
* Modify the request headers

== 403 Forbidden Error ==

See: [[How to fix the 403 forbidden error]]

== 404 File Not Found ==
Solution: Check if the accessed link is correct, see "404 Not Found | Possible solutions for pages not found"

== 405 Method Not Allowed Error ==
Solution: Check if the accessed file or resource supports the HTTP protocol being used. For example, if the resource is restricted to POST requests but you're using GET.

== 414 Request-URI Too Large ==
Solution: Change the request protocol to POST instead of GET

== 415 Unsupported Media Type ==

Solution: "Set the Content-Type or Content-Encoding in the request or direct access to the data." For example: When encountering this error with RESTful API, a possible solution is to add to the HTTP Headers:
<pre>
Content-Type: application/json
</pre>

== 429 Too Many Requests ==
Root Cause:

* Accessing website resources or web service API too frequently

Solutions:

* '''Adjust the delay time''' based on your usage patterns and the service's limits e.g. Increase the delay time between requests (e.g., add a 1-second pause between each request). 
* If accessing a web service API, Please refer to the documentation to understand the API access rate limits, such as:  (1) "Requests Per Minute" (RPM) – the maximum number of API requests you can make per minute, or (2) "Requests Per Day" (RPD) – the maximum number of API requests you can make per day. Check if you can request a higher quota limit from the service provider
* '''Implement exponential backoff retry mechanism''': Detect rate limit errors (HTTP 429) in your application. Increase the delay time with each failed retry (e.g., 2 seconds, 4 seconds, 8 seconds). Continue retrying until the request succeeds or maximum retry count is reached.

== 502 Bad Gateway ==
Cause:
* Error occurs between network devices, users cannot directly handle it.

Solutions:
* Bypass browser cache, refresh the page
* Try reconnecting after a while

== Error 1020: Access Denied ==
* See link for understanding how to resolve Error 1020 Access Denied to get your website back online

<pre>
Content-Type: application/json
</pre>

https://http.cat/200.jpg
From HTTP Cats

Related websites:
* [https://httpstatusdogs.com/ HTTP Status Dogs]

== Other possible root causes ==
* CDN (Content delivery network)

== Related pages ==

* [[Troubleshooting of curl errors]]
* [[Test connectivity for the web service]]

== References ==

<references />

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[[Category: Web server]] [[Category:Programming]] [[Category:Web scraping]]