Ubuntu Manpage: rrdupdate - Store a new set of values into the RRD

Provided by: rrdtool_1.4.7-2ubuntu5_amd64

NAME

       rrdupdate - Store a new set of values into the RRD

SYNOPSIS

       rrdtool {update | updatev} filename [--template|-t ds-name[:ds-name]...]
       [--daemon address] [--] N|timestamp:value[:value...]  at-timestamp@value[:value...]
       [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.

--daemon address
If given, RRDTool will try to connect to the caching daemon rrdcached at address
and will fail if the connection cannot be established. If the connection is
successfully established the values will be sent to the daemon instead of
accessing the files directly.

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 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.

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 --cache /var/lib/rrd/demo3.rrd N:42"

Update the file "/var/lib/rrd/demo3.rrd" with a single data source, using the current
time. If the caching daemon cannot be reached, do not fall back to direct file access.

• "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>