This PMDA extracts performance data from memcached, a distributed memory caching daemon commonly used to improve web serving performance. A farm of memcached processes over multiple servers can be utilised by a single web application, increasing the total available object cache size, and decreasing the database load associated with smaller cache sizes. This system is described in detail at http://www.danga.com/memcached.
Configure pmdamemcache to extract the values from set of hosts used in the memcache farm. These hosts can be listed in the
$PCP_PMDAS_DIR/memcache/memcache.conf file, in the format (i.e. Perl array) described at the top of pmdamemcache.pl. A custom refresh rate can also be configured using this mechanism.
# cd $PCP_PMDAS_DIR/memcache # [ edit memcache.conf ]
Once this is setup, you can access the names and values for the memcache performance metrics by doing the following as root:
# cd $PCP_PMDAS_DIR/memcache # ./Install
If you want to undo the installation, do the following as root:
# cd $PCP_PMDAS_DIR/memcache # ./Remove
pmdamemcache is launched by pmcd(1) and should never be executed directly. The Install and Remove scripts notify pmcd(1) when the agent is installed or removed.
optional configuration file listing monitored memcache instances
installation script for the pmdamemcache agent
undo installation script for the pmdamemcache agent
default log file for error messages from pmdamemcache
Environment variables with the prefix PCP_ are used to parameterize the file and directory names used by PCP. On each installation, the file /etc/pcp.conf contains the local values for these variables. The $PCP_CONF variable may be used to specify an alternative configuration file, as described in pcp.conf(5).
PCPIntro(1) and pmcd(1).