perfSONAR User Q&A and Other Discussion

["Andrew Lake" <>]

Hi,

It could be a number of things. The first thing to check is that your measurement archive is running and responding. As far as I can tell it is since when i go to http://ps-10g-prism.calit2.optiputer.net/esmond/perfsonar/archive/?format=json&time-range=86400 I get a quick response. 

The next thing to check will probably be your DNS configuration. After querying the archive it will do a number of DNS lookups and reverse lookups to display the host names and addresses. If your DNS configuration has a high timeout set and is timing out on one or more of the lookups things could hang. I would suspect it’s something like this as we have seen this type of thing before. You can try doing some lookups on the command-line (e.g. use the ‘host <addres>’ command or similar) of various IPs and hostnames to which you are testing and see if any of them hang. 

Hope that helps,

Andy

On Fri, Jul 17, 2015 at 12:55 PM, Philip Papadopoulos <> wrote:

See the following in /var/log/httpd/error_log

[Fri Jul 17 09:50:25 2015] [error] [client 137.110.119.117] Script timed out before returning headers: graphData.cgi, referer: http://ps-10g-prism.calit2.optiputer.net/serviceTest/psGraph.cgi

Sometimes it works, sometimes it doesn't ... what's the performance bottleneck.

Where should I look to root cause the issue?

--

Philip Papadopoulos, PhD
University of California, San Diego
858-822-3628 (Ofc)
619-331-2990 (Fax)