Provided by: pcp_3.8.12ubuntu1_amd64 bug

NAME

       pmlogrewrite - rewrite Performance Co-Pilot archives

SYNOPSIS

       $PCP_BINADM_DIR/pmlogrewrite [-Cdiqsvw ] [-c config] inlog [outlog]

DESCRIPTION

       pmlogrewrite  reads  a  Performance  Co-Pilot  (PCP)  archive  log identified by inlog and
       creates a PCP archive log in outlog.  Under normal usage, the -c option will  be  used  to
       nominate  a  configuration  file  or files that contains specifications (see the REWRITING
       RULES SYNTAX section below) that describe how the data and metadata from inlog  should  be
       transformed to produce outlog.

       The  typical  uses  for  pmlogrewrite would be to accommodate the evolution of Performance
       Metric Domain Agents (PMDAs) where the names, metadata and semantics of metrics and  their
       associated instance domains may change over time, e.g. promoting the type of a metric from
       a 32-bit to a 64-bit integer, or renaming a group  of  metrics.   Refer  to  the  EXAMPLES
       section for some additional use cases.

       pmlogrewrite  is  most useful where PMDA changes, or errors in the production environment,
       result in archives that cannot be combined with pmlogextract(1).   By  pre-processing  the
       archives  with  pmlogrewrite  the  resulting  archives  may  be  able  to  be  merged with
       pmlogextract(1).

       The input inlog must be a PCP archive log created by pmlogger(1), or possibly one  of  the
       tools that read and create PCP archives, e.g.  pmlogextract(1) and pmlogreduce(1).

       If no -c option is specified, then the default behavior simply creates outlog as a copy of
       inlog.  This is a little more complicated than cat(1), as each PCP archive is made  up  of
       several physical files.

       While  pmlogrewrite  may  be  used to repair some data consistency issues in PCP archives,
       there is also a class  of  repair  tasks  that  cannot  be  handled  by  pmlogrewrite  and
       pmloglabel(1) may be a useful tool in these cases.

COMMAND LINE OPTIONS

       The command line options for pmlogrewrite are as follows:

       -C     Parse  the rewriting rules and quit.  outlog is not created.  When -C is specified,
              this also sets -v and -w so that all warnings and verbose messages are displayed as
              config is parsed.

       -c config
              If  config  is  a file or symbolic link, read and parse rewriting rules from there.
              If config is a directory, then all of the files or symbolic links in that directory
              (excluding  those  beginning  with  a  period  ``.'')  will  be used to provide the
              rewriting rules.  Multiple -c options are allowed.

       -d     Desperate mode.  Normally if a fatal error  occurs,  all  trace  of  the  partially
              written  PCP  archive outlog is removed.  With the -d option, the partially created
              outlog archive log is not removed.

       -i     Rather than creating outlog, inlog is rewritten in place  when  the  -i  option  is
              used.   A  new  archive  is  created using temporary file names and then renamed to
              inlog in such a way that if  any  errors  (not  warnings)  are  encountered,  inlog
              remains unaltered.

       -q     Quick  mode,  where  if there are no rewriting actions to be performed (none of the
              global data, instance  domains  or  metrics  from  inlog  will  be  changed),  then
              pmlogrewrite  will  exit  (with status 0, so success) immediately after parsing the
              configuration file(s) and outlog is not created.

       -s     When the ``units'' of a metric are changed, if the dimension  in  terms  of  space,
              time and count is unaltered, then the scaling factor is being changed, e.g. BYTE to
              KBYTE, or MSEC-1 to USEC-1, or the  composite  MBYTE.SEC-1  to  KBYTE.USEC-1.   The
              motivation  may be (a) that the original metadata was wrong but the values in inlog
              are correct, or (b) the metadata is changing so the values need to change as  well.
              The default pmlogrewrite behaviour matches case (a).  If case (b) applies, then use
              the -s option and the values of all the metrics with a scale factor change in  each
              result  will  be  rescaled.   For  finer  control over value rescaling refer to the
              RESCALE option for the UNITS clause of the metric rewriting rule described below.

       -v     Increase verbosity of diagnostic output.

       -w     Emit warnings.  Normally pmlogrewrite remains silent for any warning  that  is  not
              fatal  and  it  is expected that for a particular archive, some (or indeed, all) of
              the rewriting specifications may not apply.  For example, changes to a PMDA may  be
              captured  in  a set of rewriting rules, but a single archive may not contain all of
              the modified metrics nor all of the modified  instance  domains  and/or  instances.
              Because  these  cases are expected, they do not prevent pmlogrewrite executing, and
              rules that do not apply to inlog are silently ignored by default.  Similarly,  some
              rewriting rules may involve no change because the metadata in inlog already matches
              the intent of the rewriting rule to correct data from a previous version of a PMDA.
              The -w flag forces warnings to be emitted for all of these cases.

       The argument outlog is required in all cases, except when -i is specified.

REWRITING RULES SYNTAX

       A configuration file contains zero or more rewriting rules as defined below.

       Keywords  and  special  punctuation  characters are shown below in bolditalic font and are
       case-insensitive, so METRIC, metric and Metric are all equivalent in rewriting rules.

       The character ``#'' introduces a comment  and  the  remainder  of  the  line  is  ignored.
       Otherwise  the  input is relatively free format with optional white space (spaces, tabs or
       newlines) between lexical items in the rules.

       A global rewriting rule has the form:

       GLOBAL { globalspec ...  }

       where globalspec is zero or more of the following clauses:

           HOSTNAME -> hostname

               Modifies the label records in the outlog PCP archive, so  that  the  metrics  will
               appear to have been collected from the host hostname.

           TIME -> delta

               Both  metric  values  and  the  instance  domain  metadata  in a PCP archive carry
               timestamps.  This clause forces all the timestamps to be adjusted by delta,  where
               delta  is  an  optional  sign  ``+'' (the default) or ``-'', an optional number of
               hours followed by a colon ``:'', an optional number of minutes followed by a colon
               ``:'',  a  number  of  seconds, an optional fraction of seconds following a period
               ``.''.  The simplest example would be ``30'' to  increase  the  timestamps  by  30
               seconds.  A more complex example would be ``-23:59:59.999'' to move the timestamps
               backwards by one millisecond less than one day.

           TZ -> "timezone"

               Modifies the label records in the outlog PCP archive, so  that  the  metrics  will
               appear  to  have  been  collected  from  a host with a local timezone of timezone.
               timezone must be enclosed in quotes, and should  conform  to  the  valid  timezone
               syntax rules for the local platform.

       An indom rewriting rule modifies an instance domain and has the form:

       INDOM domain.serial { indomspec ...  }

       where  domain  and  serial  identify  one  or  more existing instance domains from inlog -
       typically domain would be an integer in the range 1 to 510 and serial would be an  integer
       in the range 0 to 4194304.

       As  a special case serial could be an asterisk ``*'' which means the rule applies to every
       instance domain with a domain number of domain.

       If a designated instance domain is not in inlog the rule has no effect.

       The indomspec is zero or more of the following clauses:

           INAME "oldname" -> "newname"

               The instance identified by the  external  instance  name  oldname  is  renamed  to
               newname.  Both oldname and newname must be enclosed in quotes.

               As  a  special  case, the new name may be the keyword DELETE (with no quotes), and
               then the instance oldname will be expunged from outlog which removes it  from  the
               instance  domain  metadata  and  removes  all  values of this instance for all the
               associated metrics.

               If the instance names contain any embedded spaces then special care  needs  to  be
               taken in respect of the PCP instance naming rule that treats the leading non-space
               part of the instance name as the unique portion of the name for  the  purposes  of
               matching   and   ensuring   uniqueness   within   an  instance  domain,  refer  to
               pmdaInstance(3) for a discussion of this issue.

               As an illustration, consider the hypothetical instance domain for a  metric  which
               contains 2 instances with the following names:
                   red
                   eek urk

               Then some possible INAME clauses might be:

               "eek" -> "yellow like a flower"
                         Acceptable, oldname "eek" matches the "eek urk" instance.

               "red" -> "eek"
                         Error, newname "eek" matches the existing "eek urk" instance.

               "eek urk" -> "red of another hue"
                         Error, newname "red of another hue" matches the existing "red" instance.

           INDOM -> newdomain.newserial

               Modifies the metadata for the instance domain and every metric associated with the
               instance domain.  As a special case, newserial could be an  asterisk  ``*''  which
               means  use serial from the indom rewriting rule, although this is most useful when
               serial is also an asterisk.  So for example:
                   indom 29.* { indom -> 109.* }
               will move all instance domains from domain 29 to domain 109.

           INDOM -> DUPLICATE newdomain.newserial

               A special case of the previous  INDOM  clause  where  the  instance  domain  is  a
               duplicate copy of the domain.serial instance domain from the indom rewriting rule,
               and then any mapping rules are applied to the copied newdomain.newserial  instance
               domain.  This is useful when a PMDA is split and the same instance domain needs to
               be replicated for domain domain and domain  newdomain.   So  for  example  if  the
               metrics  foo.one  and  foo.two  are  both  defined over instance domain 12.34, and
               foo.two is moved to another PMDA using domain 27,  then  the  following  rewriting
               rules could be used:
                   indom 12.34 { indom -> duplicate 27.34 }
                   metric foo.two { indom -> 27.34 pmid -> 27.*.*  }

           INST oldid -> newid

               The instance identified by the internal instance identifier oldid is renumbered to
               newid.  Both oldid and newid are integers in the range 0 to 231-1.

               As a special case, newid may be the keyword DELETE and  then  the  instance  oldid
               will  be  expunged  from outlog which removes it from the instance domain metadata
               and removes all values of this instance for all the associated metrics.

       A metric rewriting rule has the form:

       METRIC metricid { metricspec ...  }

       where metricid identifies one or more existing metrics from inlog using  either  a  metric
       name,  or the internal encoding for a metric's PMID as domain.cluster.item.  In the latter
       case, typically domain would be an integer in the range 1 to  510,  cluster  would  be  an
       integer in the range 0 to 4095, and item would be an integer in the range 0 to 1023.

       As  special  cases  item  could be an asterisk ``*'' which means the rule applies to every
       metric with a domain number of domain and a cluster number of cluster, or cluster could be
       an  asterisk  which  means the rule applies to every metric with a domain number of domain
       and an item number of item, or both cluster and item could be asterisks, and rule  applies
       to every metric with a domain number of domain.

       If a designated metric is not in inlog the rule has no effect.

       The metricspec is zero or more of the following clauses:

           DELETE

               The  metric is completely removed from outlog, both the metadata and all values in
               results are expunged.

           INDOM -> newdomain.newserial [ pick ]

               Modifies the metadata to change the instance domain  for  this  metric.   The  new
               instance domain must exist in outlog.

               The  optional  pick  clause  may  be used to select one input value, or compute an
               aggregate value from the instances in an  input  result,  or  assign  an  internal
               instance identifier to a single output value.  If no pick clause is specified, the
               default behaviour is to copy all input values from each input result to an  output
               result,  however  if  the  input instance domain is singular (indom PM_INDOM_NULL)
               then the one output value must be assigned an internal instance identifier,  which
               is 0 by default, unless over-ridden by a INST or INAME clause as defined below.

               The choices for pick are as follows:

               OUTPUT FIRST
                           choose the value of the first instance from each input result

               OUTPUT LAST choose the value of the last instance from each input result

               OUTPUT INST instid
                           choose  the  value  of  the instance with internal instance identifier
                           instid from each result; the sequence of rewriting rules  ensures  the
                           OUTPUT  processing happens before instance identifier renumbering from
                           any associated indom rule, so instid should be  one  of  the  internal
                           instance identifiers that appears in inlog

               OUTPUT INAME "name"
                           choose  the  value of the instance with name for its external instance
                           name from each result; the sequence of  rewriting  rules  ensures  the
                           OUTPUT processing happens before instance renaming from any associated
                           indom rule, so name should be one of the external instance names  that
                           appears in inlog

               OUTPUT MIN  choose  the smallest value in each result (metric type must be numeric
                           and output instance will be 0 for a non-singular instance domain)

               OUTPUT MAX  choose the largest value in each result (metric type must  be  numeric
                           and output instance will be 0 for a non-singular instance domain)

               OUTPUT SUM  choose  the  sum  of  all  values  in each result (metric type must be
                           numeric and output instance will be  0  for  a  non-singular  instance
                           domain)

               OUTPUT AVG  choose  the  average of all values in each result (metric type must be
                           numeric and output instance will be  0  for  a  non-singular  instance
                           domain)

               If the input instance domain is singular (indom PM_INDOM_NULL) then independent of
               any pick specifications, there is at most one value in each input  result  and  so
               FIRST,  LAST,  MIN,  MAX,  SUM  and AVG are all equivalent and the output instance
               identifier will be 0.

               In general it is an error to specify a rewriting action for the same  metadata  or
               result  values  more  than  once,  e.g.  more  than  one INDOM clause for the same
               instance domain.  The one exception is the possible interaction between the  INDOM
               clauses  in  the  indom  and  metric  rules.  For example the metric sample.bin is
               defined over the instance domain 29.2 in inlog and  the  following  is  acceptable
               (albeit redundant):
                   indom 29.* { indom -> 109.* }
                   metric sample.bin { indom -> 109.2 }
               However  the following is an error, because the instance domain for sample.bin has
               two conflicting definitions:
                   indom 29.* { indom -> 109.* }
                   metric sample.bin { indom -> 123.2 }

           INDOM -> NULL[ pick ]

               The metric (which must have been previously defined over an  instance  domain)  is
               being  modified  to  be  a  singular  metric.  This involves a metadata change and
               collapsing all results for this metric so that multiple values become one value.

               The optional pick part of the clause defines how the one  value  for  each  result
               should  be  calculated  and  follows  the same rules as described for the non-NULL
               INDOM case above.

               In the absence of pick, the default is OUTPUT FIRST.

           NAME -> newname

               Renames the metric in the PCP archive's metadata  that  supports  the  Performance
               Metrics  Name  Space  (PMNS).   newname  should not match any existing name in the
               archive's PMNS and must follow the syntactic  rules  for  valid  metric  names  as
               outlined in pmns(5).

           PMID -> newdomain.newcluster.newitem

               Modifies  the  metadata  and  results  to  renumber the metric's PMID.  As special
               cases, newcluster could be an asterisk ``*'' which  means  use  cluster  from  the
               metric  rewriting  rule and/or item could be an asterisk which means use item from
               the metric rewriting rule.  This is most useful when cluster and/or item  is  also
               an asterisk.  So for example:
                   metric 30.*.* { pmid -> 123.*.* }
               will move all metrics from domain 30 to domain 123.

           SEM -> newsem

               Change  the semantics of the metric.  newsem should be the XXX part of the name of
               one of the PM_SEM_XXX macros defined in  <pcp/pmapi.h>  or  pmLookupDesc(3),  e.g.
               COUNTER for PM_TYPE_COUNTER.

               No  data  value  rewriting  is  performed  as  a  result of the SEM clause, so the
               usefulness is limited to  cases  where  a  version  of  the  associated  PMDA  was
               exporting  incorrect  semantics  for  the  metric.   pmlogreduce(1) may provide an
               alternative in cases where re-computation of result values is desired.

           TYPE -> newtype

               Change the type of the metric  which  alters  the  metadata  and  may  change  the
               encoding  of values in results.  newtype should be the XXX part of the name of one
               of the PM_TYPE_XXX macros defined in <pcp/pmapi.h> or pmLookupDesc(3), e.g.  FLOAT
               for PM_TYPE_FLOAT.

               Type  conversion  is only supported for cases where the old and new metric type is
               numeric, so PM_TYPE_STRING, PM_TYPE_AGGREGATE and PM_TYPE_EVENT are  not  allowed.
               Even  for  the  numeric  cases, some conversions may produce run-time errors, e.g.
               integer overflow, or attempting to rewrite a negative value into an unsigned type.

           UNITS -> newunits [ RESCALE ]

               newunits is six values separated by commas.   The  first  3  values  describe  the
               dimension  of  the metric along the dimensions of space, time and count; these are
               integer values, usually 0, 1 or -1.  The remaining 3 values describe the scale  of
               the  metric's  values  in  the  dimensions  of space, time and count.  Space scale
               values should be 0 (if the space dimension is 0), else the XXX part of the name of
               one  of the PM_SPACE_XXX macros, e.g.  KBYTE for PM_TYPE_KBYTE.  Time scale values
               should be 0 (if the time dimension is 0), else the XXX part of the name of one  of
               the PM_TIME_XXX macros, e.g.  SEC for PM_TIME_SEC.  Count scale values should be 0
               (if the time dimension is 0), else ONE for PM_COUNT_ONE.

               The PM_SPACE_XXX, PM_TIME_XXX and PM_COUNT_XXX macros are defined in <pcp/pmapi.h>
               or pmLookupDesc(3).

               When  the  scale  is changed (but the dimension is unaltered) the optional keyword
               RESCALE may be used to chose value rescaling as per the -s  command  line  option,
               but applied to just this metric.

           When changing the domain number for a metric or instance domain, the new domain number
           will usually match an existing PMDA's domain number.  If this is not  the  case,  then
           the new domain number should not be randomly chosen; consult $PCP_VAR_DIR/pmns/stdpmid
           for domain numbers that are already assigned to PMDAs.

EXAMPLES

       To promote the values of the per-disk IOPS metrics to 64-bit to allow aggregation  over  a
       long  time  period for capacity planning, or because the PMDA has changed to export 64-bit
       counters and we want to convert old archives  so  they  can  be  processed  alongside  new
       archives.
           metric disk.dev.read { type -> U64 }
           metric disk.dev.write { type -> U64 }
           metric disk.dev.total { type -> U64 }

       The instances associated with the load average metric kernel.all.load could be renamed and
       renumbered by the rules below.
           # for the Linux PMDA, the kernel.all.load metric is defined
           # over instance domain 60.2
           indom 60.2 {
               inst 1 -> 60 iname "1 minute" -> "60 second"
               inst 5 -> 300 iname "5 minute" -> "300 second"
               inst 15 -> 900 iname "15 minute" -> "900 second"
           }

       If we decide to split the ``proc'' metrics out  of  the  Linux  PMDA,  this  will  involve
       changing  the  domain  number  for  the  PMID of these metrics and the associated instance
       domains.  The rules below would rewrite an old archive to match the changes after the PMDA
       split.
           # all Linux proc metrics are in 7 clusters
           metric 60.8.* { pmid -> 123.*.* }
           metric 60.9.* { pmid -> 123.*.* }
           metric 60.13.* { pmid -> 123.*.* }
           metric 60.24.* { pmid -> 123.*.* }
           metric 60.31.* { pmid -> 123.*.* }
           metric 60.32.* { pmid -> 123.*.* }
           metric 60.51.* { pmid -> 123.*.* }
           # only one instance domain for Linux proc metrics
           indom 60.9 { indom -> 123.0 }

FILES

       For each of the inlog and outlog archive logs, several physical files are used.
       archive.meta
                 metadata (metric descriptions, instance domains, etc.) for the archive log
       archive.0 initial volume of metrics values (subsequent volumes have suffixes 1, 2, ...).
       archive.index
                 temporal  index to support rapid random access to the other files in the archive
                 log.

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),  pmdaInstance(3),  pmdumplog(1), pmlogger(1), pmlogextract(1), pmloglabel(1),
       pmlogreduce(1), pmLookupDesc(3), pmns(5), pcp.conf(5) and pcp.env(5).

DIAGNOSTICS

       All error conditions detected by pmlogrewrite are reported  on  stderr  with  textual  (if
       sometimes terse) explanation.

       Should  the  input  archive  log  be  corrupted  (this can happen if the pmlogger instance
       writing the log suddenly dies), then pmlogrewrite will detect and report the  position  of
       the  corruption in the file, and any subsequent information from that archive log will not
       be processed.

       If any error is detected, pmlogrewrite will exit with a non-zero status.