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).

Performance Co-Pilot                                   PCP                                              PMWTF(1)