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In this issue, the editor will bring you about Nginx php how to solve 502 Bad Gateway errors. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.

There are many advanced technologies in the Web server, and Nginx php is one of them. Next, let's take a look at the related problem solving in Nginx. I hope you can get something. Configure php fastcgi group in Nginx php to solve the inexplicable 502Bad Gateway error

Generally speaking, Nginx php uses this method:

Location ~\ .php$ {

Proxy_pass http://localhost:9000;

Fastcgi_param SCRIPT_FILENAME / data/_hongdou$fastcgi_

Script_name

Include fastcgi_params

}

This method can only connect to a set of fastcgi enabled by spawn-fcgi, and 502 bad gateway errors often occur when the server load is slightly higher.

At first, it was suspected that the php-cgi process opened too little, but after the increase, there were still frequent errors. Occasionally, it was found that php-cgi would report such an error:

Zend_mm_heap corrupted

It appears that php-cgi has a problem executing some code, so that the thread is aborted.

You may also see fewer php-cgi processes on the server, and it is estimated that the wrong php-cgi process automatically exited.

Php's problems are not always easy to solve, so think about Nginx php. The advantage of Nginx is that it can always reveal some strange practices. In Nginx's proxy, the only way to avoid inexplicable errors is to proxy to a upstream server group, and then configure proxy_next_upstream so that when Nginx encounters a certain error code, it automatically jumps to the next backend. In this way, even if the application server is unstable, it becomes a stable service after the Nginx. Think of Nginx's fastcgi and proxy are the same thing, so proxy can use the experience, transplanted to fastcgi can also run. According to this idea, use spawn-fcgi to open the same set of php processes, but the only difference is the port:

Spawn-fcgi-a 127.0.0.1-p 9000-u nobody-f php-cgi-C 100

Spawn-fcgi-a 127.0.0.1-p 9001-u nobody-f php-cgi-C 100

Then change the configuration of fastcgi to use upstream:

Upstream backend {

Server 127.0.0.1:9000

Server 127.0.0.1:9001

}

Location ~\ .php$ {

Proxy_pass http://backend;

Fastcgi_param SCRIPT_FILENAME / data/_hongdou$fastcgi_

Script_name

Include fastcgi_params

}

Check that the configuration result is correct and run; at the same time, netstat-n | grep 9000 and grep 9001 are recorded on the server to prove that the connection is correct; in the front page, everything is running normally. This configuration is the simplest configuration, since you can connect to upstream, it is obvious that some things of upstream can be used, such as ip_hash, weight, max_fails and so on. I don't know if this configuration can share session on a stand-alone machine, there is no testing, if there is a problem, you can add ip_hash, or configure php to store session in memcached. Then there is the configuration of fastcgi_next_upstream, which is not introduced in Nginx wiki. Check it out. It is mentioned in the CHANGES of Nginx php, and the date of birth is the same as proxy_next_upstream.

In that case, let's match like proxy_next_upstream. Generally speaking, error timeout works according to the default value, because the exception of php with 502 error is the returned 500error, so I set fastcgi_next_upstream as: through this configuration, fastcgi_next_upstream error timeout invalid_header http_500; can basically eliminate any frequent 500error, and the probability of problems will be much less. If the customer response is still fierce, then add a few more groups of fastcgi processes. The above configuration can put an end to the "inexplicable" frequent 502errors caused by php, and at the same time make Nginx with php more powerful than before. If Nginx still returns a 502 error, there must be a server hang or other serious problem this time.

The above is the Nginx php shared by the editor to solve the 502 Bad Gateway error. If you happen to have similar doubts, please refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

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