前文Nginx TCP Proxy模块的编译安装描述了如何编译tcp proxy module。现在来实验一下如何用。
首先要创建一个日志目录，因为t该模块的日志默认不在/var/log/nginx目录下
mkdir -p /etc/nginx/logs/在nginx.conf文件中添加下面一节：
tcp {
upstream tcpend {
server localhost:7778;
check interval=3000 rise=2 fall=5 timeout=1000;
}
server {
listen 7777;
proxy_pass tcpend;
}
}
注意，协议是tcp，不能将配置放在http下面。
然后启动本地的某个tcp程序，监听端口7778。用测试程序发起一个7777的连接请求，测试通过。而且不影响http的代理。
但是这个也有副作用，当服务端关闭连接的时候，客户端不可能立刻发觉连接已经被关闭，需要等到：
当Nginx在执行check规则时认为服务端链接关闭，Nginx会关闭与客户端的连接。
此时客户端才能察觉到连接关闭。好在不影响正常连接，所以不是大问题。
对于Nginx内部的工作原理，由于还没有研究过其实现代码，目前只能推测到此。
下面是check命令的解释：
check
syntax: *check interval=milliseconds [fall=count] [rise=count]
[timeout=milliseconds] [type=tcp|ssl_hello|smtp|mysql|pop3|imap]*
default: *none, if parameters omitted, default parameters are
interval=30000 fall=5 rise=2 timeout=1000*
context: *upstream*
description: Add the health check for the upstream servers. At present,
the check method is a simple tcp connect.
The parameters' meanings are:
* *interval*: the check request's interval time.
* *fall*(fall_count): After fall_count check failures, the server is
marked down.
* *rise*(rise_count): After rise_count check success, the server is
marked up.
* *timeout*: the check request's timeout.
* *type*: the check protocol type:
1. *tcp* is a simple tcp socket connect and peek one byte.
2. *ssl_hello* sends a client ssl hello packet and receives the
server ssl hello packet.
3. *http* sends a http request packet, receives and parses the http
response to diagnose if the upstream server is alive.
4. *smtp* sends a smtp request packet, receives and parses the smtp
response to diagnose if the upstream server is alive. The
response begins with '2' should be an OK response.
5. *mysql* connects to the mysql server, receives the greeting
response to diagnose if the upstream server is alive.
6. *pop3* receives and parses the pop3 response to diagnose if the
upstream server is alive. The response begins with '+' should be
an OK response.
7. *imap* connects to the imap server, receives the greeting
response to diagnose if the upstream server is alive.再分享一下我老师大神的人工智能教程吧。零基础！通俗易懂！风趣幽默！还带黄段子！希望你也加入到我们人工智能的队伍中来！https://blog.csdn.net/jiangjunshow