trusty (1) pmwtf.1.gz

NAME

       pmwtf - compares archives and report significant differences

SYNOPSIS

       pmwtf [-dz] [-p precision] [-q thres] [-S starttime] [-T endtime] [-B starttime] [-E endtime] [-x metric]
       [-X file] [-Z timezone] archive1 [archive2]

DESCRIPTION

       pmwtf compares the average values for every metric in either one or two archives, in a given time window,
       for changes that are likely to be of interest when searching for performance regressions.

       The  archive  log has the base name archive and must have been previously created using pmlogger(1).  The
       pmlogsummary(1) utility is used to obtain the average values used for comparison.

       There are two sorts of invocation of the tool: with either one or two archives.

       In the first case, the only sensible command line requires use of all four time window arguments.   These
       are specified using the same time window format described in PCPIntro(1), and are -S and -T for the start
       and end times of the first time window of interest in the archive, and -B and -E for the  start  and  end
       times of the second time window of interest.

       In  the  second  case,  with two archives, the -B and -E options might be unnecessary.  This might be the
       case, for example, when comparing the same time window of two  consecutive  days  (usually  two  separate
       archives), or a time window on the same day of different weeks.

       In  either  case,  pmwtf  produces a sorted summary of those metrics in the specified window whose values
       have deviated the most from a minimal threshold.  The level of deviation is calculated  by  dividing  the
       average  value  of  each  metric  in both logs, and then calculating whether the ratio falls outside of a
       range considered normal.  This ratio can be adjusted using the -q option, and by default it  is  2  (i.e.
       report  all  metrics with average values that have more than doubled in the two time windows or more than
       halved in the two time windows).

       Should any metrics be present in one window but missing from the other, a diagnostic  will  be  displayed
       listing each missing metric and the archive from which it was missing.

       The  remaining  options  control the specific information to be reported.  Metrics with counter semantics
       are converted to rates before being evaluated.

       -p   Print all floating point numbers with precision digits after the decimal place.

       -x   Compare each metric in each archive in the time windows  specified  to  a  given  egrep(1)  pattern,
            excluding those that match from the report output.

       -X   Allows  a  file  to  be specified which containing egrep(1) patterns which are applied to the metric
            names to optionally exclude some from the report.

       -z   Use the local timezone from the given archives.

       -Z   Changes the timezone in the archive labels to timezone in the format of the environment variable  TZ
            as described in environ(5).

FILES

       $PCP_LOG_DIR/pmlogger/hostname
                 Default directory for PCP archives containing performance metric values collected from the host
                 hostname.

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).

SEE ALSO

       PCPIntro(1), pmlogger(1), pmlogsummary(1), egrep(1), pcp.conf(5) and pcp.env(5).