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

# pmdalogger(1)

log file performance metrics domain agent (PMDA)

## NAME

**pmdalogger** - log file performance metrics domain agent (PMDA)

## SYNOPSIS

**$PCP\_PMDAS\_DIR/logger/pmdalogger** \[**-D** *debug*\] \[**-d** *domain*\] \[**-l** *logfile*\] \[**-m** *memory*\] \[**-s** *interval*\] \[**-U** *username*\] \[*configfile*\]

## DESCRIPTION

**pmdalogger** is a configurable log file monitoring Performance Metrics Domain Agent (PMDA). It can be seen as analogous to the **-f** option to [**tail**(1)](/tail/1.md) and converts each new log line into a performance event. It was the first PMDA to make extensive use of event metrics, which can be consumed by client tools like [**pmevent**(1)](/pmevent/1.md).

The **logger** PMDA exports both event-style metrics reflecting timestamped event records for text logged to a file (or set of files or output from a process), as well as the more orthodox sample-style metrics such as event counts and throughput size values.

The PMDA is configured via a *configfile* which contains one line for each source of events (file or process). This file is setup by the Install script described in the later section on \`\`INSTALLATION'' of the PMDA.

A brief description of the **pmdalogger** command line options follows:

- **-d**

  It is absolutely crucial that the performance metrics *domain* number specified here is unique and consistent. That is, *domain* should be different for every PMDA on the one host, and the same *domain* number should be used for the same PMDA on all hosts.

- **-l**

  Location of the log file.  By default, a log file named *logger.log* is written in the current directory of [**pmcd**(1)](/pmcd/1.md) when **pmdalogger** is started, i.e. **$PCP\_LOG\_DIR/pmcd**. If the log file cannot be created or is not writable, output is written to the standard error instead.

- **-m**

  Limit the physical memory used by the PMDA to buffer event records to *maxsize* bytes. As log events arrive at the PMDA, they must be buffered until individual client tools request the next batch since their previous batch of events. The default maximum is 2 megabytes.

- **-s**

  Sets the polling interval for detecting newly arrived log lines. Mirrors the same option from the [**tail**(1)](/tail/1.md) command.

- **-U**

  User account under which to run the agent. The default is the unprivileged "pcp" account in current versions of PCP, but in older versions the superuser account ("root") was used by default.

## INSTALLATION

If you want access to the names, help text and values for the logger performance metrics, do the following as root:

```
# cd $PCP_PMDAS_DIR/logger
# ./Install
```

This is an interactive installation process which prompts for each log file path to be monitored (or command to be run), a metric instance name to identify it, and whether access should be restricted (refer to the **-x** option to [**pmevent**(1)](/pmevent/1.md) for further details).

If you want to undo the installation, do the following as root:

```
# cd $PCP_PMDAS_DIR/logger
# ./Remove
```

**pmdalogger** 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\_PMCDCONF\_PATH**

  command line options used to launch **pmdalogger**

- **$PCP\_PMDAS\_DIR/logger/logger.conf**

  default configuration file for the logger metrics

- **$PCP\_PMDAS\_DIR/logger/help**

  default help text file for the logger metrics

- **$PCP\_PMDAS\_DIR/logger/Install**

  installation script for the **pmdalogger** agent

- **$PCP\_PMDAS\_DIR/logger/Remove**

  undo installation script for the **pmdalogger** agent

- **$PCP\_LOG\_DIR/pmcd/logger.log**

  default log file for error messages and other information from **pmdalogger**

## 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).

## DEBUGGING OPTIONS

The **-D** or **--debug** option enables the output of additional diagnostics on *stderr* to help triage problems, although the information is sometimes cryptic and primarily intended to provide guidance for developers rather than for end-users. *debug* is a comma separated list of debugging options; use [**pmdbg**(1)](/pmdbg/1.md) with the **-l** option to obtain a list of the available debugging options and their meaning.

Debugging options specific to **pmdalogger** are as follows:

| | |
| --- | --- |
| Option | Description |
| appl0 | *configfile* processing and PMNS setup |
| appl1 | loading event data from the log files |
| appl2 | interaction with [**pmcd**(1)](/pmcd/1.md). |

## SEE ALSO

[**PCPIntro**(1)](/PCPIntro/1.md), [**pmevent**(1)](/pmevent/1.md), [**pmcd**(1)](/pmcd/1.md), [**tail**(1)](/tail/1.md), [**pcp.conf**(5)](/pcp.conf/5.md) and [**pcp.env**(5)](/pcp.env/5.md).