# pmdasample

## NAME



           **pmdasample** - sample performance metrics domain agent (PMDA)
    


## SYNOPSIS



           **$PCP_PMDAS_DIR/pmdasample**[**-D** _debug_] [**-d** _domain_] [**-i** _port_] [**-l**
           _logfile_] [**-p**] [**-u** _socket_] [**-U** _username_]
    


## DESCRIPTION



           **pmdasample** is a sample Performance Metrics Domain Agent (PMDA)
           which exports a variety of synthetic performance metrics.
    
           This PMDA was developed as part of the quality assurance testing
           for the PCP product, but has other uses, most notably in the
           development of new PCP clients.
    
           The metrics exported by the sample PMDA cover the full range of
           data types, data semantics, value cardinality, instance domain
           stability and error conditions found in real PMDAs.
    
           A brief description of the **pmdasample** 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.
    
           **-i** Expect PMCD to connect to **pmdasample** on the specified TCP/IP
                port.  _port_ may be a port number or port name.
    
           **-l** Location of the log file.  By default, a log file named
                _sample.log_ is written in the current directory of pmcd(1)
                when **pmdasample** 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.
    
           **-p** Expect PMCD to create a pipe and the connection to **pmdasample**
                is via standard input and standard output.  This is the
                default connection mode.
    
           **-u** Expect PMCD to connect to **pmdasample** on the Unix domain
                socket named _socket_.
    
           **-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.
    
           At most one of the options **-i** , **-p** and **-u** may be specified.
    


## INSTALLATION



           If you want access to the names, help text and values for the
           sample performance metrics, do the following as root:
    
                # cd $PCP_PMDAS_DIR/sample
                # ./Install
    
           Note that the installation script also installs the DSO version of
           the sample PMDA, so there are in fact two PMDAs installed, and two
           sets of performance metrics, namely **sample.*** and **sampledso.***.
    
           If you want to undo the installation (and remove both PMDAs), do
           the following as root:
    
                # cd $PCP_PMDAS_DIR/sample
                # ./Remove
    
           **pmdasample** 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



           **$PCP_PMCDCONF_PATH**
                  command line options used to launch **pmdasample**
           **$PCP_PMDAS_DIR/sample/help**
                  default help text file for the sample metrics
           **$PCP_PMDAS_DIR/sample/Install**
                  installation script for the **pmdasample** agent
           **$PCP_PMDAS_DIR/sample/Remove**
                  undo installation script for the **pmdasample** agent
           **$PCP_LOG_DIR/pmcd/sample.log**
                  default log file for error messages and other information
                  from **pmdasample**
    


## 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 **pmdasample** are as follows:
           ┌────────┬───────────────────────────────────────────────────────┐
           │ **Option** │ **Description** │
           ├────────┼───────────────────────────────────────────────────────┤
           │ **appl0** │ verbose diagnostics for dynamic instance domains and  │
           │        │ metric mapping                                        │
           └────────┴───────────────────────────────────────────────────────┘
    


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