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

+o "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.

+o "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.

+o "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.

+o "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>

1.8.0 2022-03-14 RRDUPDATE(1)