Your browser sent a request that this server could not understand

The wrong request, your browser sent a request that the server could not understand. The size of a request header field exceeds the limit of the server. Simply put, this is a server internal error, you can change to a website to access

This sentence is probably saying: Your browser sent a request to the unknown server . This shouldn't be a virus, it feels more like a browser's controls!

Incorrect Requests

Your browser sends a request that the server cannot understand. The size of a request header field exceeds the limit of the server.

Another friend's prompt

During this time, the program is deployed to the apache2 server, which often appears when debugging the program

Your browser sent A request that this server could not understand. Size of a request header field exceeds server limit.

Start with the P3P protocol setting cookie, consult the P3P documentation, no relevant entry. After a tireless search, I finally found out that it was the setting problem of resource usage restrictions in Apache.

Technical Background:

Apache's "Resource Usage Limits" is to restrict users' access to specific resources of the website (such as directories, server hardware, etc.). Related instructions include: LimitRequestBody, LimitRequestFields, LimitRequestFieldSize, LimitRequestLine, RLimitCPU, RLimitMEM, RLimitNPROC, and ThreadStackSize. The LimitRequest* family of directives is used to limit the amount of resources Apache uses in reading client requests. By limiting these values, some Denial of Service (DOS) attacks can be mitigated; the RLimit* family of instructions limits the amount of resources used by processes spawned by Apache subprocesses, which are typically used to control the resources used by CGI scripts and SSI exec commands. The ThreadStackSize directive is used on some platforms to control the stack size.

LimitRequestLine

The LimitRequestLine directive is used to limit the number of bytes of the HTTP request line sent by the receiving client, allowing the server administrator to increase or decrease the allowable size of the client's HTTP request line. Because the request line includes the HTTP method, URI, and protocol version, the LimitRequestLine directive limits the length of the request URI. The server will need this value to be large enough to load all of its resource names, including all the information about the part of the query that might be passed in the GET request.

LimitRequestFieldSize

The LimitRequestFieldSize directive is used to limit the number of bytes in the request header sent by the client, allowing the server administrator to increase or reduce the size of the HTTP request header field. In general, the server needs this value to be large enough to accommodate the header field size of any request from a normal client. The size of a normal header field is very different for different clients, and is generally closely related to the user configuring their browser to support more content protocols.

The LimitRequestLine and LimitRequestFieldSize directives give server administrators greater control over the client's unusual request behavior. This helps to avoid some forms of denial of service attacks. The default value is “8190”.

Solve

Add the following 2 lines of code to the Apache httpd.conf configuration file LimitRequestLine 40940 LimitRequestFieldSize 40940