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NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
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 ** *******************************************************************************
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