pmdamemcache - memcached performance metrics domain agent (PMDA)
Contents
Description
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.
Files
$PCP_PMDAS_DIR/memcache/memcache.conf
optional configuration file listing monitored memcache instances
$PCP_PMDAS_DIR/memcache/Install
installation script for the pmdamemcache agent
$PCP_PMDAS_DIR/memcache/Remove
undo installation script for the pmdamemcache agent
$PCP_LOG_DIR/pmcd/memcache.log
default log file for error messages from pmdamemcacheInstallation
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.
Name
pmdamemcache - memcached performance metrics domain agent (PMDA)
Pcp Environment
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).
See Also
PCPIntro(1) and pmcd(1). Performance Co-Pilot PCP PMDAMEMCACHE(1)
