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This article mainly introduces the php+nginx service 500,502 error how to do, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor with you to understand.

Overview

When there is a 500 or 502 error in online service access, you need to deal with it urgently and troubleshoot the problem. what should you do? You can locate the problem by analyzing some error logs or tracking the php-fpm process.

Nginx error_log

The error_log of nginx is defined in the configuration file of nginx

Server {listen 80; server_name localhost; root / var/www; access_log / Users/jiao/logs/default.access.log; error_log / Users/jiao/logs/default.error.log; location / {index index.html index.htm index.php; autoindex on;} location = / info {allow 127.0.0.1; deny all; rewrite (. *) / .info.php;} location ~\ .php$ {root / var/www; fastcgi_pass 127.0.0.1V9000 Fastcgi_index index.php; fastcgi_param SCRIPT_FILENAME / var/www$fastcgi_script_name; include / usr/local/etc/nginx/fastcgi_params;}}

View error_log

➜tail / Users/jiao/logs/default.error.log

11:08:18 on 2019-07-17 [error] 77416: * 76 kevent () reported about an closed connection (54: Connection reset by peer) while reading response header from upstream, client: 127.0.0.1, server: localhost, request: "GET / HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "localhost"

Connection reset by peer is found and the connection is reset. At this time, you can check php-fpm 's error_log for further analysis of the problem.

Php-fpm error_log

The error_log of php-fpm is defined in the configuration in the php-fpm.conf file

; Error log file; If it's set to "syslog", log is sent to syslogd instead of being written; in a local file.; Note: the default prefix is / usr/local/var; Default Value: log/php-fpm.logerror_log = log/php-fpm.log

The content in error_log is like this.

➜tail / usr/local/var/log/php-fpm.log [17-Jul-2019 10:49:54] NOTICE: [pool www] child 81948 started [17-Jul-2019 11:08:18] WARNING: [pool www] child 77537, script'/ var/www/index.php' (request: "GET / index.php") execution timed out (3.801267 sec) Terminating [17-Jul-2019 11:08:18] WARNING: [pool www] child 77537 exited on signal 15 (SIGTERM) after 1503.113967 seconds from start [17-Jul-2019 11:08:18] NOTICE: [pool www] child 94339 started

You can see that the request / var/www/index.php file timed out

Dtruss

Dtruss is a dynamic tracking command that can track processes according to PID,name

Using dtruss,linux in mac environment can use strace,pstack

➜dtruss USAGE: dtruss [- acdefholLs] [- t syscall] {- p PID |-n name | command |-W name}-p PID # examine this PID-n name # examine this process name-t syscall # examine this syscall only-W name # wait for a process matching this name-a # print all details-c # print syscall counts-d # print relative times (us)-e # print elapsed times (us)-f # follow children-l # force printing pid/lwpid-o # print on cpu times-s # print stack backtraces-L # don't print pid/lwpid-b bufsize # dynamic variable bufsize

Eg

Dtruss df-h # run and examine "df-h" dtruss-p 1871 # examine PID 1871 dtruss-n tar # examine all processes called "tar" dtruss-f test.sh # run test.sh and follow children

Tracking php-fpm:sudo dtruss-a-n php-fpm

When you visit the web page, you can see the tracking content.

21416/0x3479b6: 1559 63 3 getrusage (0x0, 0x7FFEE1EC0760, 0x0) = 0 021416/0x3479b6: 1561 40 getrusage (0xFFFFFFFFFFFFFFFF, 0x7FFEE1EC0760, 0x0) = 0 021416/0x3479b6: 1627 77 17 poll (0x7FFEE1EC08C0, 0x1) 0x1388) = 1 0dtrace: error on enabled probe ID 2174 (ID: syscall::read:return): invalid kernel access in action # 13 at DIF offset 68dtrace: error on enabled probe ID 2174 (ID: syscall::read:return): invalid kernel access in action # 13 at DIF offset 68dtrace: error on enabled probe ID 2174 (ID: syscall::read:return): invalid kernel access in action # 13 at DIF offset 68dtrace: error on enabled probe ID 2174 (ID: syscall::read:return): invalid kernel access in action # 13 at DIF offset 68dtrace: error on enabled probe ID 2174 (ID: syscall::read:return): invalid kernel access in action # 13 at DIF offset 6821416/0x3479b6: 1872 29 24 lstat64 ("/ var/www/index.php\ 0" 0x7FFEE1ECFF38, 0x0) = 0 021416/0x3479b6: 1884 9 6 lstat64 ("/ var/www\ 0", 0x7FFEE1ECFDF8, 0x0) = 0 021416/0x3479b6: 1889 63 lstat64 ("/ var\ 0", 0x7FFEE1ECFCB8, 0x0) = 0 021416/0x3479b6: 1899 128 readlink ("/ var\ 0", 0x7FFEE1ED0090, 0x400) = 11 021416/0x3479b6: 1905 64 lstat64 ("/ private/var\ 0", 0x7FFEE1ECFB78, 0x0) = 0 021416/0x3479b6: 1917 63 lstat64 ("/ private\ 0", 0x7FFEE1ECFA38) 0x0) = 0 021416/0x3479b6: 2178 18 14 stat64 ("/ var/www/.user.ini\ 0", 0x7FFEE1ED0240, 0x0) =-1 Err#221416/0x3479b6: 2217 51 setitimer (0x2, 0x7FFEE1ED07E0, 0x0) = 0 021416/0x3479b6: 2225 40 sigaction (0x1B, 0x7FFEE1ED0788, 0x7FFEE1ED07B0) = 0 021416/0x3479b6: 2237 51 sigprocmask (0x2, 0x7FFEE1ED0804, 0x0) = 0x0 021416/0x3479b6: 3643 48 40 open_nocancel (".\ 0", 0x0) 0x1) = 5 021416/0x3479b6: 3648 7 3 fstat64 (0x5, 0x7FFEE1ED0110, 0x0) = 0 021416/0x3479b6: 3653 7 2 fcntl_nocancel (0x5, 0x32, 0x10F252158) = 0 021416/0x3479b6: 3661 127 close_nocancel (0x5) = 0 021416/0x3479b6: 3670 10 7 stat64 ("/ usr/local/var\ 0", 0x7FFEE1ED0080, 0x0) = 0 021416/0x3479b6: 3681 11 8 chdir ("/ var/www\ 0", 0x0, 0x0) = 0 021416/0x3479b6: 3698 40 setitimer (0x2, 0x7FFEE1ED02D0) 0x0) = 0 021416/0x3479b6: 3710 63 fcntl (0x3, 0x8, 0x10F3FD858) = 0 021416/0x3479b6: 3733 9 6 stat64 ("/ private/var/www/index.php\ 0", 0x7FFEE1ECFF10, 0x0) = 0 074904/0x332630: 723125 1073381 19 kevent (0x9, 0x0, 0x0) = 0 074902/0x332629: 770666 1073387 17 kevent (0x8, 0x0, 0x0) = 0 074904/0x332630: 723165 1061954 20 kevent (0x9, 0x0, 0x0) = 0 074902/0x332629: 770709 1061954 20 kevent (0x8, 0x0) 0x0) = 0 074904/0x332630: 723201 1074786 16 kevent (0x9, 0x0, 0x0) = 0 074902/0x332629: 770747 1074783 16 kevent (0x8, 0x0, 0x0) = 0 074904/0x332630: 723229 1069141 13 kevent (0x9, 0x0, 0x0) = 0 074902/0x332629: 770777 1069145 11 kevent (0x8, 0x0, 0x0) = 0 021416/0x3479b6: 3942 3902233 7 _ semwait_signal (0x703, 0x0, 0x1) =-1 Err#474902/0x332629: 770814 103 25 kill 15) = 0 0dtrace: error on enabled probe ID 2172 (ID 2172: syscall::write:return): invalid kernel access in action # 13 at DIF offset 68dtrace: error on enabled probe ID 2172 (ID 161: syscall::write:return): invalid kernel access in action # 13 at DIF offset 6874902/0x332629: 771325 72 sigreturn (0x7FFEE1ECFC40, 0x1E, 0xC1A4B78E0404663A) = 0 Err#-274902/0x332629: 771336 7 3 kevent (0x8, 0x0) 0x0) = 1 0dtrace: error on enabled probe ID 2174 (ID: syscall::read:return): invalid kernel access in action # 13 at DIF offset 6874902/0x332629: 771352 11 7 wait4 (0xFFFFFFFFFFFFFFFF, 0x7FFEE1ED0748, 0x3) = 21416 0dtrace: error on enabled probe ID 2172 (ID: syscall::write:return): invalid kernel access in action # 13 at DIF offset 6874902/0x332629: 773511 1957 1899 fork () = 28060 028060/0x3754c5: 125: 0: 0 fork () = 0 028060/0x3754c5: 128 9 2 bsdthread_register (0x7FFF6774C418, 0x7FFF6774C408) 0x2000) =-1 Err#22dtrace: error on enabled probe ID 2172 (ID 2172: syscall::write:return): invalid kernel access in action # 13 at DIF offset 6874902/0x332629: 773737 41 wait4 (0xFFFFFFFFFFFFFFFF, 0x7FFEE1ED0748, 0x3) = 0 074902/0x332629: 773742 63 read (0x5, "\ 0", 0x1) =-1 Err#3528060/0x3754c5: 32040 getpid (0x0, 0x0, 0x0) = 28060 028060/0x3754c5: 328 72 _ mac_syscall (0x7FFF67758A17, 0x4) 0x7FFEE1ED0208) =-1 Err#4528060/0x3754c5: 332 52 csops (0x6D9C, 0xB, 0x7FFEE1ED0248) =-1 Err#2228060/0x3754c5: 755 14 11 dup2 (0x1, 0x2, 0x0) = 2 028060/0x3754c5: 797 89 22 close (0x4) = 0 028060/0x3754c5: 806 11 6 dup2 (0x7, 0x0, 0x0) = 0 028060/0x3754c5: 817 40 geteuid (0x0, 0x0) 0x0) = 501 028060/0x3754c5: 820 30 close (0x5) = 0 028060/0x3754c5: 821 30 close (0x6) = 0 028060/0x3754c5: 824 5 1 sigaction (0xF, 0x7FFEE1ED0688, 0x0) = 0 028060/0x3754c5: 825 30 sigaction (0x2, 0x7FFEE1ED0688, 0x0) = 0 028060/0x3754c5: 827 30 sigaction (0x1E, 0x7FFEE1ED0688, 0x0) = 0 028060/0x3754c5: 828 30 sigaction (0x1F, 0x7FFEE1ED0688, 0x0) = 0 028060/0x3754c5: 829 30 sigaction (0x14, 0x7FFEE1ED0688) 0x0) = 0 028060/0x3754c5: 830 30 sigaction (0x3, 0x7FFEE1ED0688, 0x0) = 0 028060/0x3754c5: 1043 30 close (0x7) = 0 0

You can see the functions executed at the bottom of the system, such as lstat64 getting the file content information, kill (21416, 15) kill the php-fpm process, and fork () the new php-fpm process.

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