---
name: "pmdamemcache"
section: "1"
platform: "linux"
package: "pcp"
version: "7.2.2-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/pmdamemcache"
---

# pmdamemcache(1)

memcached performance metrics domain agent (PMDA)

## NAME

**pmdamemcache** - memcached performance metrics domain agent (PMDA)

## 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**.

## INSTALLATION

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)](/pmcd/1.md) and should never be executed directly. The Install and Remove scripts notify [*pmcd*(1)](/pmcd/1.md) when the agent is installed or removed.

## 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 **pmdamemcache**

## 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)](/pcp.conf/5.md).

## SEE ALSO

[**PCPIntro**(1)](/PCPIntro/1.md) and [**pmcd**(1)](/pmcd/1.md).