The round-robin database
tool, RRDtool, is a freeware package that is available for download
from Tobias Oetiker.
The RRDtool adapter
reads any round-robin databases that have been created with rrdtool.
The data can be gathered at any interval (step), any metrics can
be gathered, and any consolidation function (CF) can be used. Because
SAS IT Resource Management has its own aggregation process, the data
read from the round-robin databases should be detail data, not consolidated
data. In order to store detail data using rrdtool, set the CF to
any statistic, and then set the number of steps for each consolidation
point to 1. This keeps the data at the detail level, that is, one
record for each time interval.
Note: The RRDtool adapter reads
the data even if it has been consolidated.
The adapter will read
a single round-robin database, or it will read all round-robin databases
in directory. If multiple round-robin databases are read, the data
will be combined into a single staging table.
Because a round-robin
database can store only numeric data, users of rrdtool generally store
identifying character data in the name or path of the round-robin
database. For example, SNMP data is often stored in round-robin databases
and the device and interface information is usually used in the name
of the round-robin database to identify the metrics that are being
gathered. The filename of each round-robin database is saved by the
RRDtool adapter in a field called filename. Therefore, it can be used
to create computed columns with this identifying information. For
example, if you have two round-robin databases:
c:\RRD\ABC.rrd
and
c:\RRD\XYZ.rrd
,
then you can create a computed column with an expression of:
scan(filename,
3, “\.”)
This enables you to
store the name of each RRD (“ABC” and “XYZ”)
in a new column.
Note: You can backload data from
the RRDtool adapter. To do so, use the
rrdtool fetch
--start
option and
rrdtool fetch --end
option
staging parameters to specify the date range of data to be read.