How to solve the 404 problem

How to solve the problem in a big way 404

End of configuration vhost.conf after , Access domain name return 404. Check in turn

• selinux Whether to shut down
• Is the domain name path correct
• hostname And ip Whether it corresponds to

There are no problems in these areas , So what should we do ？

nginx The process model of is master-worker Pattern . from worker Be responsible for specific cgi Request parsing .

[[email protected] public]$>ps aux | grep nginx
root      9977  0.0  0.0  47496  2444 ?        Ss   15:13   0:00 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
sujianh+ 19271  0.0  0.0  49584  2732 ?        S    20:27   0:00 nginx: worker process
sujianh+ 19992  0.0  0.0 112720   964 pts/0    S+   20:44   0:00 grep --color=auto nginx

If you can trace worker process load Which file is good , To verify whether the file exists or not , The question is how to track it ？

linux There is a tool on the strace, System calls initiated by processes can be monitored . in other words , We can see the six basic operations of the operating system . There is a system call stat, Get the meta information of the file .
So we can monitor this .

Because I only opened one worker process . So only strace One worker Process .

[[email protected] network_security]$>strace -p 19271
strace: Process 19271 attached
epoll_wait(11, [{EPOLLIN, {u32=261448992, u64=94395052680480}}], 512, -1) = 1
accept4(7, {sa_family=AF_INET, sin_port=htons(38612), sin_addr=inet_addr("127.0.0.1")}, [16], SOCK_NONBLOCK) = 4
epoll_ctl(11, EPOLL_CTL_ADD, 4, {EPOLLIN|EPOLLRDHUP|EPOLLET, {u32=261449689, u64=94395052681177}}) = 0
epoll_wait(11, [{EPOLLIN, {u32=261449689, u64=94395052681177}}], 512, 60000) = 1
recvfrom(4, "GET / HTTP/1.1\r\nHost: local.lara"..., 1024, 0, NULL, NULL) = 661
stat("/home/sujianhui/PhpstormProjects/blog/public/", {st_mode=S_IFDIR|0775, st_size=95, ...}) = 0
stat("/home/sujianhui/PhpstormProjects/blog/public/", {st_mode=S_IFDIR|0775, st_size=95, ...}) = 0
stat("/home/sujianhui/PhpstormProjects/blog/public/index.php", {st_mode=S_IFREG|0664, st_size=1731, ...}) = 0
epoll_ctl(11, EPOLL_CTL_MOD, 4, {EPOLLIN|EPOLLOUT|EPOLLRDHUP|EPOLLET, {u32=261449689, u64=94395052681177}}) = 0
getsockname(4, {sa_family=AF_INET, sin_port=htons(80), sin_addr=inet_addr("127.0.0.1")}, [16]) = 0
socket(AF_INET, SOCK_STREAM, IPPROTO_IP) = 5
ioctl(5, FIONBIO, [1])                  = 0
epoll_ctl(11, EPOLL_CTL_ADD, 5, {EPOLLIN|EPOLLOUT|EPOLLRDHUP|EPOLLET, {u32=261449457, u64=94395052680945}}) = 0
connect(5, {sa_family=AF_INET, sin_port=htons(9000), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 EINPROGRESS 
epoll_wait(11, [], 512, 60000)          = 0
...
...
close(9)                                = 0
epoll_wait(11, [], 512, 4943)           = 0
close(4)                                = 0
epoll_wait(11, ^Cstrace: Process 19271 detached
 <detached ...>

Extract key information

`stat("/home/sujianhui/PhpstormProjects/blog/public/index.php", {st_mode=S_IFREG|0664, st_size=1731, ...}) = 0`

track stat You can find worker seek /home/sujianhui/PhpstormProjects/blog/public/index.php. This problem is solved .
Empathy , about 403 This solution can also be followed .

5xx series

5xx A series of problems all appear in php over there . Refer to the following nginx Of error Logs are more reliable than blind guessing .