RRDUPDATE(1) rrdtool RRDUPDATE(1)NAMErrdupdate - Store a new set of values into the RRD
SYNOPSIS
rrdtool {update | updatev} filename [--template|-t ds-name[:ds-
name]...] 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.
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.
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.
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.
EXAMPLE
"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.
AUTHOR
Tobias Oetiker <tobi@oetiker.ch>
1.3.8 2008-03-15 RRDUPDATE(1)
