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 updateing an rrd file with data earlier than the latest update already
               applied, rrdtool will issue an error message an 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@oetiker.ch>, Florian Forster <octo at verplant.org>