Hi,
I've some questions about scripting creation of the rrdtool database. Since,
my use of the rrdtool is a bit different from most examples which involve
incremental updates to the database of integers, i'm having some trouble
understanding the parameters. currently i'd like to create a database from
the static input file of pc counters which looks like below:
[traces]$ head -n 20 ~/input.log
1:c0103b74
2:c0103b79
3:c0103bf4
4:c0103bf5
5:c0103bf6
...
...
Q1: Tor the time attribute that rrdtool needs--for now-- i've added an
arbitrary value to represent time ticks. The second column is not of a
number format--though the pc which is in hex can easily be coverted to a
number format. This brings me to my first question: Is it possible to plot
time versus a non integer value using rrdtool?
Q2.a: In the below script--which i've written up based on Simon's
pseudocode--are the "rrdtool create" parameters correct? Specifically, since
i'm reading from a file, what should the increment option --step be
(currently it's set to 60, because else i'd get an error saying "ERROR: step
size should b no less than one second"). In the rrdtool create
documentation, i did not see a option for the create command to specify that
the intervals should be right after each other with no wait time in between
(since i'd like to read from a file and stop adding to the database
afterwards).
Q2.b: Also, when specifying the Round Robin Arhive, what is the format for
specifying data source is from a file? I've tried variation of the line
"DS:input:ABSOLUTE:$INPUT_FILE, all without success.
-------------------------------------------------------------------------
#!/bin/sh
rrdtool="/usr/local/rrdtool-1.2.19/bin/rrdtool"
delim=":"
INPUT_FILE=$1
if [ ! -f $INPUT_FILE ]; then
print "File $INPUT_FILE not found"
exit 1
fi
rrdtool create datafile.rrd \
--start N --step 60 \
DS:input:ABSOLUTE:$INPUT_FILE
cat $INPUT_FILE | while read line
do
#timestamp="$(echo ${line} | cut -d: -f1)"
#pc="$(echo ${line} | cut -d: -f2)"
while (read -u 0 -d ":" timestamp value)
do
echo "$timestamp - $pc"
#rrdtool update datafile.rrd $timestamp:$pc
done
done
#rrdtool create graph
-------------------------------------------------------------------------
Thank you for your help,
-Bita.
On 5/16/07, Simon Hobson <[EMAIL PROTECTED]> wrote:
betamaz wrote:
>I'm new to rrdtool and have been reading up on the tutorial posted
>on the main webpage. The examples in the tutorial describe how to
>create a database by taking measurements. For example, using snmp or
>it gives basic examples where the inputs are via the rrdtool create
>command line (for example the speed inputs for test.rrd). Is there a
>way, to read inputs from command line and create a database out of
>that (similar to gnuplot)?
Yes, RRD doesn't care where the data comes from, all it sees are a
series of update with timestamp and a number of values. As long as
the timestamps a) make sense for the data, and b) are always
increasing, then rrd will handle it.
So assuming you have a file containing a series of records, one per
line, of the form time:value then you simply need to write a script
of the form :
create rrd file
while (read timestamp:value pair)
update rrd with timestamp and value
done
create graph
With the exception of drawing a graph which normally takes a few
lines of arguments, the above can be written in about the same number
of statements in most languages (whether that be Bash shell script,
Perl, ...). How much extra checking etc you put in is up to you and
what you know about the source of the data - such as is the file
format likely to be correct (ie it's created by a trustworthy
automated tool) or do you need to do extensive validation on the
input ?
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