Beefy Boxes and Bandwidth Generously Provided by pair Networks
We don't bite newbies here... much

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
OK, I found out that there is not a way to create a COMPUTE resource out of the box in RRDTool::OO, but it is possible to workaround this lack of functionality by using the dry run mode. Here is how.

First, you need to create an RRDTool::OO object in dry run mode. Then you prepare all the "standard" data sources in the usual way, and call create. It won't actually execute the call, but now you can retrieve a reference to the function that it would have called, along with a reference to the function arguments. You can now fiddle with the arguments and call the function when you are ready.

This is how I did it:

# Creation of a COMPUTE data source is not contemplated in the # documentation, nor it is in the code. That's why we use an # object in dry-run mode: we'll get a reference to the function # and arguments that were about to be called, and add our # resource. Finally, we run the call. # Pretty bad it didn't have the function already... my $dsdef = q{DS:aggregate:COMPUTE:}. join(",",@dsources).",ADDNAN"x$#dsources ; $rrdbuilder->create(@rrd_parms) ; # Get references to the RRD function and arguments # Push the COMPUTE data source in it # Run the create command, see what happens my ($subref,$args) = $rrdbuilder->get_exec_env(); push @$args,$dsdef ; eval { $subref->(@$args) ; } ;


In theory, there is no difference between theory and practice. In practice, there is.

In reply to How to create a COMPUTE data source in RRDTool::OO by bronto
in thread RRDTool::OO not able to create a COMPUTE data source? by bronto

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?

What's my password?
Create A New User
Domain Nodelet?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others studying the Monastery: (1)
As of 2023-09-23 11:15 GMT
Find Nodes?
    Voting Booth?

    No recent polls found