will store the derivative of the line going from the last to the
current value of the data source. This can be useful for gauges, for
example, to measure the rate of people entering or leaving a
-room. Internally, derive works exaclty like COUNTER but without
+room. Internally, derive works exactly like COUNTER but without
overflow checks. So if your counter does not reset at 32 or 64 bit you
might want to use DERIVE and combine it with a MIN value of 0.
refer only to B<DEF>s and B<CDEF>s previously defined in the same graph command.
=item B<RRA:>I<CF>B<:>I<cf arguments>
-
+
+
The purpose of an B<RRD> is to store data in the round robin archives
(B<RRA>). An archive consists of a number of data values or statistics for
each of the defined data-sources (B<DS>) and is defined with an B<RRA> line.
=back
-=head1 Aberrant Behaviour detection with Holt-Winters forecasting
+=head1 Aberrant Behavior Detection with Holt-Winters Forecasting
by Jake Brutlag E<lt>jakeb@corp.webtv.netE<gt>
=item Mail Messages
-Assume you have a methode to count the number of messages transported by
+Assume you have a method to count the number of messages transported by
your mailserver in a certain amount of time, this give you data like '5
messages in the last 65 seconds'. If you look at the count of 5 like and
B<ABSOLUTE> datatype you can simply update the rrd with the number 5 and the
temperatures supplied for 100 hours (1200 * 300 seconds = 100
hours). The second RRA stores the minimum temperature recorded over
every hour (12 * 300 seconds = 1 hour), for 100 days (2400 hours). The
-third and the fourth RRA's do the same with the for the maximum and
+third and the fourth RRA's do the same for the maximum and
average temperature, respectively.
=head1 EXAMPLE 2
projects / rrdtool.git / blobdiff