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 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 nonCOMPUTE 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 datasources 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. - 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
- 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 --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.- 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>