'\"macro stdmacro
.\"
.\" Copyright (c) 2008 Aconex.  All Rights Reserved.
.\" 
.\" This program is free software; you can redistribute it and/or modify it
.\" under the terms of the GNU General Public License as published by the
.\" Free Software Foundation; either version 2 of the License, or (at your
.\" option) any later version.
.\" 
.\" This program is distributed in the hope that it will be useful, but
.\" WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
.\" or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
.\" for more details.
.\" 
.\"
.TH PMDAMEMCACHE 1 "PCP" "Performance Co-Pilot"
.SH NAME
\f3pmdamemcache\f1 \- memcached performance metrics domain agent (PMDA)
.SH DESCRIPTION
This \s-1PMDA\s0 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.
.SH INSTALLATION
Configure \fBpmdamemcache\fR to extract the values from set of hosts
used in the memcache farm.  These hosts can be listed in the
\&\f(CW$PCP_PMDAS_DIR\fR/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.
.PP
      # cd $PCP_PMDAS_DIR/memcache
.br
      # [ edit memcache.conf ]
.PP
Once this is setup, you can access the names and values for the
memcache performance metrics by doing the following as root:
.PP
      # cd $PCP_PMDAS_DIR/memcache
.br
      # ./Install
.PP
To uninstall, do the following as root:
.PP
      # cd $PCP_PMDAS_DIR/memcache
.br
      # ./Remove
.PP
\fBpmdamemcache\fR is launched by \fIpmcd\fR(1) and should never be executed 
directly. The Install and Remove scripts notify \fIpmcd\fR(1) when the 
agent is installed or removed.
.SH FILES
.IP "\fB$PCP_PMDAS_DIR/memcache/memcache.conf\fR" 4
optional configuration file listing monitored memcache instances
.IP "\fB$PCP_PMDAS_DIR/memcache/Install\fR" 4 
installation script for the \fBpmdamemcache\fR agent 
.IP "\fB$PCP_PMDAS_DIR/memcache/Remove\fR" 4 
undo installation script for the \fBpmdamemcache\fR agent 
.IP "\fB$PCP_LOG_DIR/pmcd/memcache.log\fR" 4 
default log file for error messages from \fBpmdamemcache\fR 
.SH PCP ENVIRONMENT
Environment variables with the prefix \fBPCP_\fR are used to parameterize
the file and directory names used by \fBPCP\fR. On each installation, the
file \fB/etc/pcp.conf\fR contains the local values for these variables. 
The \fB$PCP_CONF\fR variable may be used to specify an alternative 
configuration file, as described in \fIpcp.conf\fR(5).
.SH SEE ALSO
.BR pmcd (1).