# pmdalogger

## 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) 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).
    
           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)
                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) 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) 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) and should never be executed
           directly.  The Install and Remove scripts notify pmcd(1) 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).
    


## 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 end-users.  _debug_ is a comma
           separated list of debugging options; use pmdbg(1) 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).             │
           └────────┴───────────────────────────────────────┘
    


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