Error 502 What do you mean by bad gateway?

　　First, 502 bad gateway meaning

502 Bad Gateway English translates into 502 types of errors or invalid gateways, where 502 refers to the error type code.

　　Second, produce 502 bad Gateway error reason

There are many reasons for the 502 bad Gateway, in essence, we connect the server to the server to send a request failed, it is possible that the server is currently too many links, causing the server can not give the normal response, resulting in such an error, but also may be the server connection is incorrect, It is also possible that the server is really dead and inaccessible, of course this does not mean that the server has been shut down (no response gateway/proxy), or that the upstream server and gateway/agent disagree with the protocol exchange data. Most of them appear in one or two machines that have been incorrectly or incompletely programmed.

This refers to a server (not necessarily a Web server) as a gateway or proxy to meet customer requirements (such as a Web browser or our Checkupdown robot) to access the requested URL. This server received an invalid response from an upstream server to fulfill its requirements.

Three, 502 HTTP cycles of errors

Any client (such as a Web browser or our Checkupdown robot) communicates with your Web server through the following loops:

Get the IP address of the IP name of your website (your site URL's leader ' http://'). This finds (converts the intellectual property name, IP address) provided by the Domain name server (DNSS).

Open an IP socket to connect to the IP address.

Write an HTTP data stream through the socket.

Received a response from your Web server for an HTTP data stream. This data flow contains the value of the status code by the HTTP protocol. Resolves the status code and other useful information for this data flow.

This error occurs in the last step when the client above receives an HTTP status code, which admits to 502 '.

Fixed 502 Error

Generally this problem is due to poor IP communication between the backend computers that may be included on the Web server where you try to access the Web. In analyzing this problem, you should clear the browser cache completely.

If you surf the web, look at this problem for all the sites you try to access and then select

1 Your ISP has a major equipment failure/overload or

2 There is a problem with the internal Internet connection such as your firewall does not function properly.

In the first case, only your ISP can help you. In the second case, what you need to solve is to stop you from getting into the Internet.

If you receive this question only some of the sites you are trying to access are likely to be a problem, that is, one of these sites whose devices fail/overload. Contact the people at these locations.

　Fixed 502 Error-Checkupdown

Use of proxy and cache additions on the network. We checkupdown robots will always try to ' drill through ' the real computer host, actually your site, but we don't have full control, our HTTP request actually ends up. If only one link of the computer processing our HTTP request is broken, then an error such as 502 can easily occur.