Frequent 500 Errors

[Neo]

Hi,

I am running ProcessWire 3.0.62 on a 512 MB VPS with CentOS 7.3.1611 x64.

The site operates stable for a couple of days and then suddenly shuts down with an internel server error - 500.

I first thought this might be a caching issue and I disabled mod_pagespeed, but the problem persists.

 

I noticed the following errors in the ProcessWire log that match this timeframe:

Error: Exception: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away (in /var/www/html/wire/core/WireDatabasePDO.php line 454)

Error: Exception: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away (in /var/www/html/wire/core/PagesLoader.php line 1110)

Error: Exception: SQLSTATE[HY000] [2002] Connection refused (in /var/www/html/wire/core/ProcessWire.php line 377)

 

Having a look at /var/log/httpd/error_log shows the following entries:

[Mon Apr 30 03:36:02.299543 2018] [auth_digest:notice] [pid 835] AH01757: generating secret for digest authentication ...
[Mon Apr 30 03:36:02.300730 2018] [lbmethod_heartbeat:notice] [pid 835] AH02282: No slotmem from mod_heartmonitor
[Mon Apr 30 03:36:02.496198 2018] [mpm_prefork:notice] [pid 835] AH00163: Apache/2.4.6 (CentOS) OpenSSL/1.0.2k-fips PHP/7.1.16 configured -- resuming normal operations
[Mon Apr 30 03:36:02.496220 2018] [core:notice] [pid 835] AH00094: Command line: '/usr/sbin/httpd -D FOREGROUND'
[Mon Apr 30 08:58:41.709509 2018] [mpm_prefork:notice] [pid 835] AH00170: caught SIGWINCH, shutting down gracefully
[Mon Apr 30 11:59:04.905878 2018] [suexec:notice] [pid 832] AH01232: suEXEC mechanism enabled (wrapper: /usr/sbin/suexec)
AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using ::1. Set the 'ServerName' directive globally to suppress this message
[Mon Apr 30 11:59:05.452221 2018] [auth_digest:notice] [pid 832] AH01757: generating secret for digest authentication ...
[Mon Apr 30 11:59:05.456054 2018] [lbmethod_heartbeat:notice] [pid 832] AH02282: No slotmem from mod_heartmonitor
[Mon Apr 30 11:59:05.922452 2018] [mpm_prefork:notice] [pid 832] AH00163: Apache/2.4.6 (CentOS) OpenSSL/1.0.2k-fips PHP/7.1.16 configured -- resuming normal operations
[Mon Apr 30 11:59:05.922522 2018] [core:notice] [pid 832] AH00094: Command line: '/usr/sbin/httpd -D FOREGROUND'

There is nothing in the log that would immediately catch my attention regarding this 500 error.

If I reboot the server the site operates normally again.

 

Would appreciate your assistance to find the problem.

Thanks

[pwired]

You are not giving us much info here so the first 3 things I can think of are these:

server time out ?
mysql max_allowed_packet too low ?
try to downgrade the php version ?

 

 

[dragan]

mySQL server has gone away - well, seems like your DB has some hickups.

5 hours ago, Neo said:

AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using ::1. Set the 'ServerName' directive globally to suppress this message

This sounds like the server setup is not kosher.

Have you done any upgrades lately? (Apache, PHP, mySQL... config)

[Neo]

To provide further details regarding the server configuration:

httpd -v
Server version: Apache/2.4.6 (CentOS)
Server built:   Oct 19 2017 20:39:16

----------

php -v
PHP 7.1.16 (cli) (built: Mar 28 2018 13:19:29) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2018 Zend Technologies
    with Zend OPcache v7.1.16, Copyright (c) 1999-2018, by Zend Technologies

----------

mysql -V
mysql  Ver 15.1 Distrib 5.5.56-MariaDB, for Linux (x86_64) using readline 5.1

 

I could post the complete php.ini if required, but will share some key values for the moment:

output_buffering = 4096
max_input_time = 60
memory_limit = 128M
post_max_size = 8M
upload_max_filesize = 2M
max_file_uploads = 20
default_socket_timeout = 60

 

Http and database are running:

sudo netstat -plunt | grep httpd
tcp6       0      0 :::80                   :::*                    LISTEN      832/httpd           
tcp6       0      0 :::443                  :::*                    LISTEN      832/httpd 

sudo netstat -plunt | grep mysql
tcp        0      0 0.0.0.0:3306            0.0.0.0:*               LISTEN      1085/mysqld 

 

Last updates have been installed in March, but this is an issue that happened before.

 

 

[Gary Austin]

Does your mysql error log show anything at the time the error occurs?