PMLOGGER_CHECK(1)

NAME
pmlogger_check - administration of Performance Co-Pilot archive files

SYNOPSIS
$PCP_BINADM_DIR/pmlogger_check [-CNnPpqsTV?] [-c control] [-l logfile]

DESCRIPTION
pmlogger_check and the related pmlogger_daily(1) tools along with associated control files (see pmlogger.control(5)) may be used to create a customized regime of administration and management for historical archives of performance data within the Performance Co-Pilot (see PCPIntro(1)) infrastructure.

pmlogger_check may be run at any time of the day and is intended to check that a desired set of pmlogger(1) processes are running. If not, it (re-)starts any missing logger processes. By default, pmlogger_check also calls pmlogger_daily(1) with a -K option to execute any required archive compression tasks.

OPTIONS

-C  This option causes pmlogger_check to query the system service runlevel information for pmlogger, and use that to determine whether to start processes or not.

-c control, --control=control
    Both pmlogger_check and pmlogger_daily(1) are controlled by PCP logger control file(s) that specifies the pmlogger instances to be managed. The default control file is $PCP_PMLOGGERCONTROL_PATH but an alternate may be specified using the -c option. If the directory $PCP_PMLOGGERCONTROL_PATH.d (or control.d from the -c option) exists, then the contents of any additional control files therein will be appended to the main control file (which must exist).

-l file, --logfile=file
    In order to ensure that mail is not unintentionally sent when these scripts are run from cron(8) or systemd(1) diagnostics are always sent to log files. By default, this file is $PCP_LOG_DIR/pmlogger/pmlogger_check.log but this can be changed using the -l option. If this log file already exists when the script starts, it will be renamed with a .prev suffix (overwriting any log file saved earlier) before diagnostics are generated to the log file. The -l and -t options cannot be used together.

-N, --showme
    This option enables a ``show me'' mode, where the actions are echoed, but not executed, in the style of ``make -n''. Using -N in conjunction with -V maximizes the diagnostic capabilities for debugging.

-n, --noerror
    Force the exit status to be 0 other than for catastrophic errors. Useful when called from a systemd(1) service or timer unit so that the associated unit is not marked as failed in a way that would prevent subsequent execution from systemd(1).

-P, --only-primary
    If this option is specified for pmlogger_check then only the primary logger entry in the control files will be processed. This is the logical opposite of the -p option described above and is intended for use by RC scripts that start only the primary logger, such as the pmlogger.service unit. The -p and -P options are mutually exclusive.

-p, --skip-primary
    If this option is specified for pmlogger_check then any line from the control files for the primary pmlogger will be ignored. This option is intended for environments where some system daemon, like systemd(1), is responsible for controlling (starting, stopping, restarting, etc.) the primary pmlogger.

-q, --quick
    If this option is specified for pmlogger_check then the script will ``quickstart'' avoiding any optional processing like calling pmlogger_daily(1) to perform archive compression tasks.

-s, --stop
    Use of this option provides the reverse pmlogger_check functionality, allowing the set of pmlogger processes to be cleanly shutdown.

-T, --terse
    This option to pmlogger_check produces less verbose output than the default. This is most suitable for a pmlogger ``farm'' where many instances of pmlogger are expected to be running.

-V, --verbose
    The -V option enables verbose tracing. By default pmlogger_check generates no output unless some error or warning condition is encountered. A second -V increases the verbosity. Using -N in conjunction with -V maximizes the diagnostic capabilities for debugging.

-?, --help
    Display usage message and exit.

CONFIGURATION
Refer to pmlogger.control(5) for a description of the control file(s) that are used to control which pmlogger instances and which archives are managed by pmlogger_check and pmlogger_daily(1).

The pmlogctl(1) utility may invoke pmlogger_check using the sudo(1) command to run it under the $PCP_USER ``pcp'' account. If sudo is configured with the non-default requiretty option (see below), pmlogger_check may fail to run due to not having a tty configured. This issue can be resolved by adding a second line (expand $PCP_BINADM_DIR according to your platform) to the /etc/sudoers configuration file as follows:

Defaults requiretty
Defaults!$PCP_BINADM_DIR/pmlogger_check !requiretty

Note that the unprivileged PCP account under which these commands run uses /sbin/nologin as the shell, so the requiretty option is ineffective here and safe to disable in this way.

FILES

$PCP_VAR_DIR/config/pmlogger/config.default
    default pmlogger configuration file location for the local primary logger, typically generated automatically by pmlogconf(1).

$PCP_ARCHIVE_DIR/<hostname>
    default location for archives of performance information collected from the host hostname

$PCP_ARCHIVE_DIR/<hostname>/lock
    transient lock file to guarantee mutual exclusion during pmlogger administration for the host hostname - if present, can be safely removed if neither pmlogger_daily(1) nor pmlogger_check are running

$PCP_ARCHIVE_DIR/<hostname>/Latest
    PCP archive folio created by mkaf(1) for the most recently launched archive containing performance metrics from the host hostname

$PCP_LOG_DIR/NOTICES
    PCP ``notices'' file used by pmie(1) and friends

$PCP_LOG_DIR/pmlogger/pmlogger_check.log
    if the previous execution of pmlogger_check produced any output it is saved here. The normal case is no output in which case the file does not exist.

$PCP_ARCHIVE_DIR/SaveLogs
    if this directory exists, then the log file from the -l argument for pmlogger_check will be saved in this directory with the name of the format <date>-pmlogger_check.log.<pid> This allows the log file to be inspected at a later time, even if several pmlogger_check executions have been launched in the interim. Because the PCP archive management tools run under the $PCP_USER account ``pcp'', $PCP_ARCHIVE_DIR/SaveLogs typically needs to be owned by the user ``pcp''.

$PCP_ARCHIVE_DIR/<hostname>/SaveLogs
    if this directory exists, then the log file from the -l argument of a newly launched pmlogger(1) for hostname will be saved in this directory with the name archive.log where archive is the basename of the associated pmlogger(1) PCP archive files. This allows the log file to be inspected at a later time, even if several pmlogger(1) instances for hostname have been launched in the interim. Because the PCP archive management tools run under the $PCP_USER account ``pcp'', $PCP_ARCHIVE_DIR/<hostname>/SaveLogs typically needs to be owned by the user ``pcp''.

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).

The default behaviour, when pmlogger(1) configuration comes from pmlogconf(1), is to regenerate the configuration file and check for changes whenever pmlogger(1) is started from pmlogger_check. If the PMDA configuration is stable, this is not necessary, and setting $PMLOGGER_CHECK_SKIP_LOGCONF to yes disables the regeneration and checking.

SEE ALSO
mkaf(1), PCPIntro(1), pmie(1), pmlc(1), pmlogconf(1), pmlogctl(1), pmlogger(1), pmlogger_daily(1), pmlogger_daily_report(1), pmlogger_janitor(1), sudo(1), systemd(1), pmlogger.control(5) and cron(8).