Server Restart Sequence

From AgileApps Support Wiki
Revision as of 03:05, 24 January 2014 by imported>Aeric

When an installation employs memcached or the Messaging Server, it is important to follow this sequence when restarting servers:

# STOP THE MESSAGING SERVER, if one is running:
/etc/init.d/messaging stop
{hornetq-folder}/bin/stop.sh

# STOP ALL APPLICATION SERVERS
# On each server:
{appserver_files}/scripts/longjump stop
ps aux | grep tomcat
   # If you see a Tomcat process running, kill it: 
     kill {tomcat_process_id}
   # Repeat until the system says <tt>"No such process"</tt>

# STOP ALL memcached SERVERS
# On each server:
/bin/memcached -d stop

# START ALL memcached SERVERS
# On each server:
/bin/memcached -d start -p {port} -u {user} -m {MB_of_memory}
   # Typical values:
   #    Port: 11211,  User: root,  MB of memory: 25

# START ALL APPLICATION SERVERS
# On each server:
{appserver_files}/scripts/longjump start 

# START THE MESSAGING SERVER, if you're running one:
{hornetq-folder}/bin/start.sh
/etc/init.d/messaging start
Considerations
  • Stopping application servers ensures that they aren't adding entries to the cache.
  • Stopping memcached makes sure that the cache is flushed.
  • Those two steps can occur in either order. It is the next two for which order is critical:
  • Restarting memcached first makes sure that a clean copy of the cache is available.
  • When the application servers come up, they use the clean cache.