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]...] [--daemon|-d 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|-d 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
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 <[email protected]>, Florian Forster <octo at verplant.org>
1.4.8 2013-05-23 RRDUPDATE(1)
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