For a while I wanted to graph the HTTP response time of my server(s). I already had Nagios monitor it but now I wanted a nice Cacti image. Based on the check_http script I created (thanks to guy2006) a Perl wrapper to return the response time part:

# /usr/lib/nagios/plugins/check_http -H foo.bar.com -f follow -t 60
HTTP OK: HTTP/1.1 200 OK - 17235 bytes in 0.135 second response time |time=0.134897s;;;0.000000 size=17235B;;;0

The response time part is used as a “Data Input Method” for Cacti.


Create the file check_http.pl in /usr/share/cacti/site/scripts/.

#!/usr/bin/env perl
$response = `/usr/lib/nagios/plugins/check_http -H $ARGV[0] -f follow -t 60`;
chomp $response;
($load) = ($response =~ /time=(\d+\.\d+|\d+\.|\.\d+|\d+)/);
print "$load\n";

Make sure you have the file check_http (it’s in the nagios-plugins-basic package) and it’s located in /usr/lib/nagios/plugins/.

# apt-file search check_http
kannel-extras: /usr/lib/kannel/checks/check_http.sh
kannel-extras: /usr/lib/kannel/checks/check_httpsmsc_kannel.sh
nagios-plugins-basic: /usr/lib/nagios/plugins/check_http
nagiosgrapher: /usr/share/nagiosgrapher/debian/cfg/ngraph.d/standard/check_http.ncfg
# locate check_http

Test the Perl wrapper, preferably as user cacti:

# perl check_http.pl foo.bar.com

Import the XML Template into Cacti (it’s under Import/Export).

Make sure to change the “Consolidation Function” (of Item # 1) from LAST to Average (it’s under Templates -> Graph Templates). Also make sure to fill in an ip address or hostname. Otherwise your graph will be blank.

Your graph will look something like this:

Cacti - HTTP Response Time

Cacti - HTTP Response Time


12 comments so far

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  1. marco

    “Also make sure to fill in an ip address or hostname”

    Where exactly?

  2. tersmitten

    In the IP Address field under Data Sources -> – HTTP Reponse Time (nrpe) -> Supplemental Data Template Data -> Custom Data

  3. marco

    NRPE is required on the supervised machine?

  4. tersmitten

    No, it just makes HTTP Requests.

    See http://nagiosplugins.org/man/check_http for more information.

  5. marco

    I tested the Perl wrapper. It works but the result contains only an integer.
    perl check_http.pl myHost

    I create a graph ton the corresponding host in Cacti but only got an empty graph.

    Do you have any idea?

  6. marco

    (I filled an hostname)

  7. tersmitten

    I have no idea. I just checked my version.

    # perl check_http.pl http://www.google.nl

    What is the output of the check_http binary?

    # /usr/lib/nagios/plugins/check_http -H http://www.google.nl -f follow -t 60
    HTTP OK: HTTP/1.1 200 OK – 15150 bytes in 0.089 second response time |time=0.088995s;;;0.000000 size=15150B;;;0

  8. marco

    /usr/lib/nagios/plugins/check_http -I -p 5865 -u http://www.google.com HTTP OK: HTTP/1.1 302 Found – 2118 bytes in 2,456 second response time |time=2,456238s;;;0,000000 size=2118B;;;0

    I use a Microsoft ISA proxy whith. The port 5865 is the port of ntlmaps.

  9. tersmitten

    Hey Marco,

    I think I know what the problem is. Your output contains comma decimal separators (non en_US locale?). The perl wrapper probably matches points.

  10. Flo

    I have no graph andI filled an IP

  11. Flo

    and if i execute the script it’s ok

  12. Mischa ter Smitten

    Hey Flo,

    Can you post the output?