Learn how to fix the 408 Request Timeout in HAproxy. Our HAProxy Support team is here to help you with your questions and concerns.

408 Request Timeout in HAproxy | How to Fix

The 408 error usually occurs when a client-side request times out. According to our experts, it may occur due to several reasons like network connection problems, client firewalls, or browser extensions.

Interestingly, the 408 error is often referenced in different forms as seen here:

• 408 Request Time-out
• The Request Has Timed Out
• Request Timeout
• 408: Request Timeout
• Error Code 408
• HTTP Error 408 – Request Timeout
• HTTP Status 408

Different Causes Behind 408 Errors

According to our experts, a common cause of 408 errors is a feature called “TCP pre-connect.” It allows web browsers to start a TCP connection with a server before actually sending any data. This helps speed up browsing by saving time on establishing connections.

However, if the pre-connection is not used, the server or proxy will close the connection. Hence, if the browser then tries to use the connection, it will receive a 408 error.

Another common cause of 408 errors is network connection problems. A problem with the network connection between the client and the server, will cause the request to time out.

Furthermore, 408 errors can also be caused by client firewalls or security settings. If the firewall or security settings are blocking requests from the client, the request may time out.

How to Prevent the 408 Request Timeout Error Message

If the 408 error is a client-side issue, we can work on the proxy side to prevent the error message from being sent to the client.

This includes changing the timeout settings in the proxy configuration. This tells the proxy to close connections that have not been used after a certain period of time.

Alternatively, we can use the errorfile directive in the proxy configuration. This tells the proxy to send a blank response when a 408 error occurs. This prevents the client from seeing the error message.

Our experts recommend the following workaround to prevent the 408 error message from being sent to the client in HAProxy:

errorfile 408 /dev/null

This tells HAProxy to send a blank response when a 408 error occurs.

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Conclusion

In summary, our Support Techs demonstrated how to fix the 408 Request Timeout in HAProxy.