* we are now creating true RGBA pngs

[rrdtool.git] / doc / rrdupdate.pod

diff --git a/doc/rrdupdate.pod b/doc/rrdupdate.pod
index f150054..2d4ee8c 100644 (file)
--- a/doc/rrdupdate.pod
+++ b/doc/rrdupdate.pod
@@ -1,12 +1,12 @@
 =head1 NAME
 
 =head1 NAME
 

-rrdtool update - Store a new set of values into the rrd
+rrdtool update - Store a new set of values into the RRD

 
 =for html <div align="right"><a href="rrdupdate.pdf">PDF</a> version.</div>
 
 =head1 SYNOPSIS
 
 
 =for html <div align="right"><a href="rrdupdate.pdf">PDF</a> version.</div>
 
 =head1 SYNOPSIS
 

-B<rrdtool> B<update> I<filename> 
+B<rrdtool> {B<update> | B<updatev>} I<filename> 

 S<[B<--template>|B<-t> I<ds-name>[B<:>I<ds-name>]...]> 
 S<B<N>|I<timestamp>B<:>I<value>[B<:>I<value>...]> 
 S<I<at-timestamp>B<@>I<value>[B<:>I<value>...]> 
 S<[B<--template>|B<-t> I<ds-name>[B<:>I<ds-name>]...]> 
 S<B<N>|I<timestamp>B<:>I<value>[B<:>I<value>...]> 
 S<I<at-timestamp>B<@>I<value>[B<:>I<value>...]> 


@@ -20,21 +20,42 @@ which the data is written.
 
 =over 8
 
 
 =over 8
 

+=item B<updatev>
+
+This alternate version of B<update> takes the same arguments and
+performs the same function. The I<v> stands for I<verbose>, which
+describes the output returned. B<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.
+

 =item I<filename>
 
 The name of the B<RRD> you want to update.
 
 =item B<--template>|B<-t> I<ds-name>[B<:>I<ds-name>]...
 
 =item I<filename>
 
 The name of the B<RRD> you want to update.
 
 =item B<--template>|B<-t> I<ds-name>[B<:>I<ds-name>]...
 

-by default, the update function expects the data input in the order,
-the data sources are defined in the RRD. This is not very error
-resistant, as you might be sending the wrong data into a RRD.
+by default, the B<update> function expects the 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 B<DST> is COMPUTE, the third input value
+will be mapped to the fourth data source in the B<RRD>). This is not very
+error resistant, as you might be sending the wrong data into a 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 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
+the template are not available in the RRD file, the update process

 will abort with an error message.
 
 will abort with an error message.
 

+While it appears possible with the template switch to update data sources
+asynchronously, B<RRDtool> implicitly assigns non-COMPUTE data sources missing
+from the template the I<*UNKNOWN*> value. 
+
+Do not specify a value for a COMPUTE B<DST> in the B<update> function. If
+this is done accidentally (and this can only be done using the template switch),
+B<RRDtool> will ignore the value specified for the COMPUTE B<DST>.
+

 =item B<N>|I<timestamp>B<:>I<value>[B<:>I<value>...]
 
 The data used for updating the RRD was acquired at a certain time. This
 =item B<N>|I<timestamp>B<:>I<value>[B<:>I<value>...]
 
 The data used for updating the RRD was acquired at a certain time. This


@@ -49,13 +70,13 @@ important when you are working with data-sources of type B<COUNTER>,
 B<DERIVE> or B<ABSOLUTE>. 
 
 The remaining elements of the argument are DS updates. The order of this list is
 B<DERIVE> or B<ABSOLUTE>. 
 
 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.
+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 
 If there is no data for a certain data-source, the letter 

-B<U> (eg. N:0.1:U:1) can be defined.
+B<U> (e.g., N:0.1:U:1) can be defined.

 
 The format of the value acquired from the data source is dependent of the
 data source type chosen. Normally it will be numeric, but the data acquisition
 
 The format of the value acquired from the data source is dependent of the
 data source type chosen. Normally it will be numeric, but the data acquisition

-modules my impose their very own parsing of this parameter as long as the colon
+modules may impose their very own parsing of this parameter as long as the colon

 (B<:>) remains the data source value separator.
 
 =back
 (B<:>) remains the data source value separator.
 
 =back


@@ -67,7 +88,7 @@ C<rrdtool update demo1.rrd N:3.44:3.15:U:23>
 Update the database file demo1.rrd with 3 known and one I<*UNKNOWN*>
 value. Use the current time as the update time.
 
 Update the database file demo1.rrd with 3 known and one I<*UNKNOWN*>
 value. Use the current time as the update time.
 

-C<rrdtool update demo2.rrd 887457267:U 887457521:22 88745790:2.7>
+C<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 I<*UNKNOWN*> value then with two
 
 Update the database file demo2.rrd which expects data from a single
 data-source, three times. First with an I<*UNKNOWN*> value then with two