php exits with 502 Bad Gateway

[mfouwaaz]

Hello

I have a problem where php exits with a 502 Bad Gateway error every once
in a while.  It appears to be unpredictable.  When it happens I have to
re-start the vm -- restarting nginx doesn't fix it.  The OS is Ubuntu
running on VirtualBox and I am connecting to it over a bridged network
only from the host Vista machine.  This is a portion of the error log
and also the configuration.  Any help will be appreciated.

2012/02/18 18:12:31 [debug] 723#0: accept on 0.0.0.0:443, ready: 0
2012/02/18 18:12:31 [debug] 723#0: *1031 accept: 192.168.1.69 fd:12
2012/02/18 18:12:31 [debug] 723#0: *1031 event timer add: 12:
60000:2472717397
2012/02/18 18:12:31 [debug] 723#0: *1031 epoll add event: fd:12 op:1
ev:80000001
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL_do_handshake: -1
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL_get_error: 2
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL handshake handler: 0
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL_do_handshake: 1
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL: TLSv1, cipher:
"DHE-RSA-AES256-SHA SSLv3 Kx=DH Au=RSA Enc=AES(256) Mac=SHA1"
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL_read: -1
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL_get_error: 2
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL_read: 1
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL_read: 346
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL_read: -1
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL_get_error: 2
2012/02/18 18:12:31 [debug] 723#0: *1031 event timer del: 12:
2472717397
2012/02/18 18:12:31 [debug] 723#0: *1031 epoll add event: fd:12 op:3
ev:80000005
2012/02/18 18:12:31 [debug] 723#0: *1031 socket 13
2012/02/18 18:12:31 [debug] 723#0: *1031 epoll add connection: fd:13
ev:80000005
2012/02/18 18:12:31 [debug] 723#0: *1031 connect to 127.0.0.1:9000,
fd:13 #1032
2012/02/18 18:12:31 [debug] 723#0: *1031 event timer add: 13:
60000:2472717424
2012/02/18 18:12:31 [error] 723#0: *1031 connect() failed (111:
Connection refused) while connecting to upstream, client: 192.168.1.69,
server: 192.168.1.68, request: "GET /pcode/register.php HTTP/1.1",
upstream: "fastcgi://127.0.0.1:9000", host: "192.168.1.68"
2012/02/18 18:12:31 [debug] 723#0: *1031 event timer del: 13:
2472717424
2012/02/18 18:12:31 [debug] 723#0: *1031 write new buf t:1 f:0 099429A4,
pos 099429A4, size: 157 file: 0, size: 0
2012/02/18 18:12:31 [debug] 723#0: *1031 write old buf t:1 f:0 099429A4,
pos 099429A4, size: 157 file: 0, size: 0
2012/02/18 18:12:31 [debug] 723#0: *1031 write new buf t:0 f:0 00000000,
pos 080E7600, size: 120 file: 0, size: 0
2012/02/18 18:12:31 [debug] 723#0: *1031 write new buf t:0 f:0 00000000,
pos 080E6460, size: 53 file: 0, size: 0
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL buf copy: 157
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL buf copy: 120
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL buf copy: 53
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL to write: 330
2012/02/18 18:12:31 [debug] 723#0: *1031 SSL_write: 330
2012/02/18 18:12:31 [debug] 723#0: *1031 event timer add: 12:
75000:2472732425


... and nginx.conf

user root;
worker_processes 4;

events {

}


http {
  index index.php;
  include   /etc/nginx/mime.types;
  default_type application/octet-stream;
  
  server {
    listen 80;
    
    location ~* /pcode/(register|loginout).php {
      rewrite ^ https://$host$uri permanent;
    }
    
    include /etc/nginx/server_params;
 
 }
  
  server {
    listen 443 ssl;
    ssl on;
    ssl_certificate /usr/local/nginx/conf/server.crt;
    ssl_certificate_key /usr/local/nginx/conf/server.key;

    include /etc/nginx/server_params;
  }
}

...the include file server_params being called:

   server_name 192.168.1.68;
    root /usr/share/nginx/www;
    
    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log debug_event;    
    
    location / {
      try_files  $uri $uri/ /index.php;
    }
  
    location ~ \.php$ {
      include /etc/nginx/fastcgi_params;
      try_files $uri =404;
      fastcgi_pass 127.0.0.1:9000;   
      fastcgi_param HTTPS on;
    }
    
    location @rewrites{
      rewrite ^ /index.php last;
    }
    
  
    #catch static file requests
    location ~* \.(?:ico|css|js|gif|jpe?g|png)$ {
      expires max;
      add_header Pragma public;
      add_header Cache-Control "public, must-revalidate,
proxy-revalidate";
    }
    
    #prevent hidden file requests --starting with a period
    
    location ~ /\. {
      access_log off; log_not_found off; deny all;
    }

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,222625,222625#msg-222625