man > rrdupdate(1)

RRDUPDATE(1)                                   rrdtool                                  RRDUPDATE(1)

NAME
       rrdupdate - Store a new set of values into the RRD

SYNOPSIS
       rrdtool {update | updatev} filename [--template|-t ds-name[:ds-name]...]
       [--skip-past-updates|-s] [--daemon|-d address] [--] N:value[:value]...
       timestamp:value[:value]...  at-timestamp@value[:value]...

DESCRIPTION
       The update function feeds new data values into an RRD. The data is time aligned
       (interpolated) according to the properties of the RRD to which the data is written.

       updatev This  alternate  version  of  update  takes  the same arguments and performs the same
               function. The v stands for verbose, which  describes  the  output  returned.  updatev
               returns  a  list  of any and all consolidated data points (CDPs) written to disk as a
               result of the invocation of update. The values are indexed by timestamp (time_t), RRA
               (consolidation function and PDPs  per  CDP),  and  data  source  (name).   Note  that
               depending  on  the arguments of the current and previous call to update, the list may
               have no entries or a large number of entries.

               Since updatev requires direct disk access, the --daemon option cannot  be  used  with
               this command.

       filename
               The name of the RRD you want to update.

       --template|-t ds-name[:ds-name]...
               By  default, the update function expects its data input in the order the data sources
               are defined in the RRD, excluding any COMPUTE data sources (i.e. if  the  third  data
               source DST is COMPUTE, the third input value will be mapped to the fourth data source
               in  the RRD and so on). This is not very error resistant, as you might be sending the
               wrong data into an RRD.

               The template switch allows you to specify which data sources you are going to  update
               and  in  which order. If the data sources specified in the template are not available
               in the RRD file, the update process will abort with an error message.

               While  it  appears  possible  with  the  template  switch  to  update  data   sources
               asynchronously,  RRDtool implicitly assigns non-COMPUTE data sources missing from the
               template the *UNKNOWN* value.

               Do not specify a value for a COMPUTE DST in the update  function.  If  this  is  done
               accidentally  (and  this  can  only  be done using the template switch), RRDtool will
               ignore the value specified for the COMPUTE DST.

               The caching daemon rrdcached cannot be used together with templates yet.

       --skip-past-updates|-s
               When updating an rrd file with data earlier than the latest update  already  applied,
               rrdtool  will  issue  an  error  message  and abort. This option instructs rrdtool to
               silently skip such data. It can be useful when re-playing old data into an  rrd  file
               and you are not sure how many updates have already been applied.

       --daemon|-d address
               If  given, RRDtool will try to connect to the caching daemon rrdcached at address. If
               the connection is successfully established the values will  be  sent  to  the  daemon
               instead  of  accessing the files directly. If the connection cannot be established it
               will fall back to direct file-access.  While this  is  convenient,  it  can  silently
               create problems so please read the warning in the examples.

               For a list of accepted formats, see the -l option in the rrdcached manual.

       {N | timestamp}:value[:value]...
               The  data  used  for  updating  the RRD was acquired at a certain time. This time can
               either be defined in seconds since 1970-01-01 or by using the letter  'N',  in  which
               case  the  update  time  is  set  to  be  the  current time. Negative time values are
               subtracted from the current time. An AT_STYLE TIME SPECIFICATION  (see  the  rrdfetch
               documentation)  may also be used by delimiting the end of the time specification with
               the '@' character instead of a ':'.  Getting  the  timing  right  to  the  second  is
               especially  important when you are working with data-sources of type COUNTER, DERIVE,
               DCOUNTER, DDERIVE or ABSOLUTE.

               When using negative time values, options and data have to be separated by two  dashes
               (--), else the time value would be parsed as an option.  See below for an example.

               The  remaining elements of the argument are DS updates. The order of this list is the
               same as the order the data sources were defined in the RRA. If there is no data for a
               certain data-source, the letter U (e.g., N:0.1:U:1) can be specified.

               The format of the value acquired from the data source is dependent on the data source
               type chosen. Normally it will be numeric, but the data acquisition modules may impose
               their very own parsing of this parameter as long as the colon (:)  remains  the  data
               source value separator.

ENVIRONMENT VARIABLES
       The following environment variables may be used to change the behavior of "rrdtool update":

       RRDCACHED_ADDRESS
           If  this  environment  variable  is  set  it  will have the same effect as specifying the
           "--daemon" option on the command line. If both are present,  the  command  line  argument
           takes precedence.

       RRDCACHED_STRIPPATH
           If  this  environment  variable is set it will strip the leading string from the filename
           prior to sending the filename to rrdcached.  This is mostly intended to  allow  rrdcached
           to work with xymon and cacti tools without having to modify those tools.

EXAMPLES
       •   "rrdtool update demo1.rrd N:3.44:3.15:U:23"

           Update  the database file demo1.rrd with 3 known and one *UNKNOWN* value. Use the current
           time as the update time.

       •   "rrdtool update demo2.rrd 887457267:U 887457521:22 887457903:2.7"

           Update the database file demo2.rrd which expects data from a  single  data-source,  three
           times.  First with an *UNKNOWN* value then with two regular readings. The update interval
           seems to be around 300 seconds.

       •   "rrdtool update demo3.rrd -- -5:21 N:42"

           Update the database file demo3.rrd two times, using five seconds  in  the  past  and  the
           current time as the update times.

       •   "rrdtool update --daemon unix:/tmp/rrdd.sock demo4.rrd N:23"

           Use the UNIX domain socket "/tmp/rrdd.sock" to contact the caching daemon. If the caching
           daemon is not available, update the file "demo4.rrd" directly.  WARNING: Since a relative
           path is specified, the following disturbing effect may occur: If the daemon is available,
           the  file  relative  to the working directory of the daemon is used. If the daemon is not
           available, the file relative to the current working directory of the invoking process  is
           used.   This  may  update  two  different  files depending on whether the daemon could be
           reached or not. Don't do relative paths, kids!

AUTHORS
       Tobias Oetiker <tobi AT oetiker.ch>, Florian Forster <octo at verplant.org>

1.7.2                                        2024-03-31                                 RRDUPDATE(1)