Hello Waldenio,
Very good post. A couple of thoughts:
Dear Peter,
I read all the e-mails from this thread and checked the statistics of your
machines, including the latencies.
ldmingest01.nwc.ou.edu [6.8.1]
<http://www.unidata.ucar.edu/cgi-bin/rtstats/siteindex?ldmingest01.nwc.ou.edu>
ldmingest02.nwc.ou.edu [6.8.1]
<http://www.unidata.ucar.edu/cgi-bin/rtstats/siteindex?ldmingest02.nwc.ou.edu>
BTW, the rtstats pages have been having serious trouble over the last few
weeks, and have been completely unreliable for me. UNIDATA is aware of
the issue.
1) check the network connection to idd.unidata.ucar.edu, your feeder.
Traceroute is ok, but I prefer to use the "mtr":
mtr idd.unidata.ucar.edu
I have mtr on my system, and I had no idea what that program was for.
This is a small but excellent tool, Waldenio, thank you for the heads up!
2) Your LDM machines are getting a lot of data. Someone in your path could
have set a kind of "packet shaping", "QoS" or anything else to reduce the
priority of who is getting too much data (you). For the others the network
will be nice and faster, and only your LDMs will suffer.
If this is the case, there are tricks to cheat these things, like to replace
one request line for several ones. This worked fine to improve the massive
LDM feeds to South America.
I had completely forgotten about packet shaping. That will do it. I had to
get an exeption from my University several years ago when they began doing
it.
By:
REQUEST NEXRAD2 ".*" idd.unidata.ucar.edu
REQUEST CONDUIT ".*" idd.unidata.ucar.edu
REQUEST FNMOC ".*" idd.unidata.ucar.edu
REQUEST NGRID ".*" idd.unidata.ucar.edu
REQUEST NEXRAD3 ".*" idd.unidata.ucar.edu
REQUEST HDS ".*" idd.unidata.ucar.edu
and so on...
However, Peter has said that everything has been working great until
recently, and, as far as I know, there haven't been any dramatic traffic
increases. If this were the case, he'd notice a gradual decrease in
performance, rather than one so abrupt where he loses everything.
And, if his time were off, he'd get nothing...if his connection were slow,
he'd know it...but I agree, Peter, a mtr run should reveal something.
If not, the symptoms are pretty consistent with packet shaping.
Peter, put this in your ldmd.conf and see if this gets you anything:
REQUEST NEXRAD3 ".*" noaaport.admin.niu.edu
I have opened up all of the .nwc.ou.edu domain to you with an "ANY",
but this server has the direct NOAAPort feed straight off the Novra S75
receiver box, and nothing more. Load average on that machine is
pretty much nil. See what you get and let me know.
*******************************************************************************
Gilbert Sebenste ********
(My opinions only!) ******
Staff Meteorologist, Northern Illinois University ****
E-mail: sebenste@xxxxxxxxxxxxxxxxxxxxx ***
web: http://weather.admin.niu.edu **
*******************************************************************************
