Skip to main content

Intermittent 500 errors opening webmail when Calendar and Contacts Server (CCS) is installed

JC Newton
  • Updated

Symptoms

Attempting to access webmail occasionally gives a 500 error when Calendar and Contacts Server (CCS) is installed, and errors similar to the following can be found in /opt/cpanel-ccs/data/Logs/error.log.

2020-09-04T17:47:20+0100 [caldav-47]  pg8000.core.ProgrammingError: (u'FATAL', u'53300', u'sorry, too many clients already', u'proc.c', u'336', u'InitProcess', u'', u'')

 

Description

The issue will occur when cpanel-ccs attempts to run more postgres processes than the maximum number of configured Postgres connections.

Please note that there will be a number of idle connections based on the number of cores the system has, which means systems with 64+ cores will reach the default process limit without any active connections.

 

Workaround

  1. Access the server's command line as the 'root' user via SSH or "Terminal" in WHM.
  2. Run the following command to find the number of postgres processes the cpanel-ccs user is running. 
    [root@server ~]cPs# pgrep -u cpanel-ccs|grep postgres|wc -l
    71
    [root@server ~]cPs#
  3. Find the current max_connections value. 
    [root@server ~]cPs# grep max_connections /opt/cpanel-ccs/conf/caldavd-dev.plist
     <string>-c max_connections=64</string>
    [root@server ~]cPs#
  4. Open /opt/cpanel-ccs/conf/caldavd.tmpl in your preferred text editor.
  5. Locate the max_connections entry under the Postgres key. 
    <!-- Support for Postgres -->
    <key>Postgres</key>
    <dict>
       <key>Options</key>
       <array>
          <string>-c deadlock_timeout=[% PGLOCKTIMEOUT %]s</string>
          <string>-c max_connections=[% PGMAXCONNECTIONS %]</string>
  6. Replace [% PGMAXCONNECTIONS %] with a value greater than the number found using the pgrep command.
  7. Save the changes and exit the text editor.
  8. Rebuild the CCS configuration. 
    /opt/cpanel-ccs/bin/rebuildccsconfig
  9. Verify the caldavd-dev.plist file shows the updated max_connections value. 
    grep max_connections /opt/cpanel-ccs/conf/caldavd-dev.plist
  10. Restart the CCS service. 
    /usr/local/cpanel/scripts/restartsrv_cpanel_ccs

 

Additional resources

Calendar and Contacts Server

Related articles