NAME

SYNOPSIS

DESCRIPTION

One application of the tune function is to relax the validation rules on an RRD. This allows you to fill a new RRD with data available in larger intervals than what you would normally want to permit. Be very careful with tune operations for COMPUTE data sources. Setting the min, max, and heartbeat for a COMPUTE data source without changing the data source type to a non-COMPUTE DST WILL corrupt the data source header in the RRD.

A second application of the tune function is to set or alter parameters used by the specialized function RRAs for aberrant behavior detection.

Still another application is to add or remove data sources (DS) or add / remove or alter some aspects of round-robin archives (RRA). These operations are not really done in-place, but rather generate a new RRD file internally and move it over the original file. Data is kept intact during these operations. For even more in-depth modifications you may review the --source and --template options of the create function which allow you to combine multiple RRD files into a new one and which is even more clever in what data it is able to keep or "regenerate".

filename

The name of the RRD you want to tune.

--heartbeat|-h ds-name:heartbeat

modify the heartbeat of a data source. By setting this to a high value the RRD will accept things like one value per day.

--minimum|-i ds-name:min

alter the minimum value acceptable as input from the data source. Setting min to 'U' will disable this limit.

--maximum|-a ds-name:max

alter the maximum value acceptable as input from the data source. Setting max to 'U' will disable this limit.

--data-source-type|-d ds-name:DST

alter the type DST of a data source.

--data-source-rename|-r old-name:new-name

rename a data source.

--deltapos|-p scale-value

Alter the deviation scaling factor for the upper bound of the confidence band used internally to calculate violations for the FAILURES RRA. The default value is 2. Note that this parameter is not related to graphing confidence bounds which must be specified as a CDEF argument to generate a graph with confidence bounds. The graph scale factor need not to agree with the value used internally by the FAILURES RRA.

--deltaneg|-n scale-value

Alter the deviation scaling factor for the lower bound of the confidence band used internally to calculate violations for the FAILURES RRA. The default value is 2. As with --deltapos, this argument is unrelated to the scale factor chosen when graphing confidence bounds.

--failure-threshold|-f failure-threshold

Alter the number of confidence bound violations that constitute a failure for purposes of the FAILURES RRA. This must be an integer less than or equal to the window length of the FAILURES RRA. This restriction is not verified by the tune option, so one can reset failure-threshold and window-length simultaneously. Setting this option will reset the count of violations to 0.

--window-length|-w window-length

Alter the number of time points in the temporal window for determining failures. This must be an integer greater than or equal to the window length of the FAILURES RRA and less than or equal to 28. Setting this option will reset the count of violations to 0.

--alpha|-x adaption-parameter

Alter the intercept adaptation parameter for the Holt-Winters forecasting algorithm. This parameter must be between 0 and 1.

--beta|-y adaption-parameter

Alter the slope adaptation parameter for the Holt-Winters forecasting algorithm. This parameter must be between 0 and 1.

--gamma|-z adaption-parameter

Alter the seasonal coefficient adaptation parameter for the SEASONAL RRA. This parameter must be between 0 and 1.

--gamma-deviation|-v adaption-parameter

Alter the seasonal deviation adaptation parameter for the DEVSEASONAL RRA. This parameter must be between 0 and 1.

--smoothing-window|-s fraction-of-season

Alter the size of the smoothing window for the SEASONAL RRA. This must be between 0 and 1.

--smoothing-window-deviation|-S fraction-of-season

Alter the size of the smoothing window for the DEVSEASONAL RRA. This must be between 0 and 1.

--aberrant-reset|-b ds-name

This option causes the aberrant behavior detection algorithm to reset for the specified data source; that is, forget all it is has learnt so far. Specifically, for the HWPREDICT or MHWPREDICT RRA, it sets the intercept and slope coefficients to unknown. For the SEASONAL RRA, it sets all seasonal coefficients to unknown. For the DEVSEASONAL RRA, it sets all seasonal deviation coefficients to unknown. For the FAILURES RRA, it erases the violation history. Note that reset does not erase past predictions (the values of the HWPREDICT or MHWPREDICT RRA), predicted deviations (the values of the DEVPREDICT RRA), or failure history (the values of the FAILURES RRA). This option will function even if not all the listed RRAs are present.

Due to the implementation of this option, there is an indirect impact on other data sources in the RRD. A smoothing algorithm is applied to SEASONAL and DEVSEASONAL values on a periodic basis. During bootstrap initialization this smoothing is deferred. For efficiency, the implementation of smoothing is not data source specific. This means that utilizing reset for one data source will delay running the smoothing algorithm for all data sources in the file. This is unlikely to have serious consequences, unless the data being collected for the non-reset data sources is unusually volatile during the reinitialization period of the reset data source.

Use of this tuning option is advised when the behavior of the data source time series changes in a drastic and permanent manner.

--step|-t newstep

Changes the step size of the RRD to newstep.

TODO: add proper documentation

--daemon|-D address

NOTE: Because the -d (small letter 'd') option was already taken, this function (unlike most other) uses the capital letter 'D' for the one-letter option to name the cache daemon.

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 data for the filename will be flushed before performing the copy/modify operation. Afterwards the filename will be forgotten by the cache daemon, so that the next access using the caching daemon will read the proper structure.

This sequence of operations is designed to achieve a consistent overall result with respect to RRD internal file consistency when using one of the DS or RRA changing operations (that is: the resulting file should always be a valid RRD file, regardless of concurrent updates through the caching daemon). Regarding data consistency such guarantees are not made: Without external synchronization concurrent updates may be lost.

For a list of accepted formats, see the -l option in the rrdcached manual.

DEL:ds-name

Every data source named with a DEL specification will be removed. The resulting RRD will miss both the definition and the data for that data source. Multiple DEL specifications are permitted.

DS:ds-spec

For every such data source definition (for the exact syntax see the create command), a new data source will be added to the RRD. Multiple DS specifications are permitted.

DELRRA:index

Removes the RRA with index index. The index is zero-based, that is the very first RRA has index 0.

RRA:rra-spec

For every such archive definition (for the exact syntax see the create command), a new RRA will be added to the output RRD. Multiple RRA specifications are permitted.

RRA#index:[+-=]<number>

Adds/removes or sets the given number of rows for the RRA with index <index>. The index is zero-based, that is the very first RRA has index 0.

EXAMPLE 1

Set the minimum required heartbeat for data sources 'in', 'out' and 'through' to 100'000 seconds which is a little over one day in data.rrd. This would allow to feed old data from MRTG-2.0 right into RRDtool without generating *UNKNOWN* entries.

EXAMPLE 2

If the FAILURES RRA is implicitly created, the default window-length is 9 and the default failure-threshold is 7. This command now defines a failure as 3 or more violations in a temporal window of 5 time points.

EXAMPLE 3

Delete the data source named a and extend the very first archive by 10 rows. This will in fact replace the input RRD with a new RRD keeping all existing data. For most practical use cases this is identical to a real in-place modification.

AUTHORS