Re: [conduit] Large CONDUIT latencies to UW-Madison idd.aos.wisc.edu starting the last day or two.

  • To: Pete Pokrandt <poker@xxxxxxxxxxxx>
  • Subject: Re: [conduit] Large CONDUIT latencies to UW-Madison idd.aos.wisc.edu starting the last day or two.
  • From: Arthur A Person <aap1@xxxxxxx>
  • Date: Fri, 19 Feb 2016 13:57:10 -0500 (EST)
Pete, 

We've been struggling with latencies for months to the point where I've been 
feeding gfs 0p25 from NCEP and the rest from Unidata... that is, up untl Feb 
10th. The afternoon of the 10th, our latencies to NCEP dropped to what I 
consider "normal", an average maximum latency of about 30 seconds. Our 
networking folks and NCEP have been trying to identify what this problem was, 
but as far as I know, no problem has been identified or action taken. So, it 
appears it's all buried in the mysteries of the internet. I've switched data 
collection back to NCEP at this point, but I'm on the edge of my seat waiting 
to see if it reverts back to the old behavior... 

Art 

> From: "Pete Pokrandt" <poker@xxxxxxxxxxxx>
> To: "Carissa Klemmer - NOAA Federal" <carissa.l.klemmer@xxxxxxxx>, "Arthur A
> Person" <aap1@xxxxxxx>, "_NCEP.List.pmb-dataflow"
> <ncep.list.pmb-dataflow@xxxxxxxx>
> Cc: "support-conduit@xxxxxxxxxxxxxxxx" <conduit@xxxxxxxxxxxxxxxx>, "Michael
> Schmidt" <mschmidt@xxxxxxxx>, "Bentley, Alicia M" <ambentley@xxxxxxxxxx>, 
> "Daes
> Support" <daessupport@xxxxxxxxxx>
> Sent: Friday, February 19, 2016 12:20:20 PM
> Subject: Large CONDUIT latencies to UW-Madison idd.aos.wisc.edu starting the
> last day or two.

> All,

> Not sure if this is on my end or somewhere upstream, but the last several runs
> my CONDUIT latencies have been getting huge to the point where we are losing
> data.

> I did stop my ldm the other day to add in an alternate feed for Gilbert at
> allisonhous.com, not sure if that pushed me over a bandwidth limit, or by
> reconnecting we got hooked up to a different remote ldm, or taking a different
> path, that shot the latencies up.

> Seems to be really only CONDUIT, none of our other feeds show this kind of
> latency.

> Still looking into things locally, but wanted make people aware. I just 
> rebooted
> idd.aos.wisc.edu, will see if that helps at all.

> Here's an ldmping and traceroute from idd.aos.wisc.edu to 
> conduit.ncep.noaa.gov.

> [ldm@idd ~]$ ldmping conduit.ncep.noaa.gov
> Feb 19 17:16:08 INFO: State Elapsed Port Remote_Host rpc_stat
> Feb 19 17:16:08 INFO: Resolving conduit.ncep.noaa.gov to 140.90.101.42 took
> 0.00486 seconds
> Feb 19 17:16:08 INFO: RESPONDING 0.115499 388 conduit.ncep.noaa.gov

> traceroute to conduit.ncep.noaa.gov (140.90.101.42), 30 hops max, 60 byte
> packets
> 1 r-cssc-b280c-1-core-vlan-510-primary.net.wisc.edu (144.92.130.3) 0.760 ms
> 0.954 ms 0.991 ms
> 2 internet2-ord-600w-100G.net.wisc.edu (144.92.254.229) 18.119 ms 18.123 ms
> 18.107 ms
> 3 et-10-0-0.107.rtr.clev.net.internet2.edu (198.71.45.9) 27.836 ms 27.852 ms
> 27.838 ms
> 4 et-11-3-0-1276.clpk-core.maxgigapop.net (206.196.177.4) 37.363 ms 37.363 ms
> 37.345 ms
> 5 noaa-i2.demarc.maxgigapop.net (206.196.177.118) 38.051 ms 38.254 ms 38.401 
> ms
> 6 140.90.111.36 (140.90.111.36) 118.042 ms 118.412 ms 118.529 ms
> 7 140.90.76.69 (140.90.76.69) 41.764 ms 40.343 ms 40.500 ms
> 8 * * *
> 9 * * *
> 10 * * *

> Similarly to ncepldm

> [ldm@idd ~]$ ldmping ncepldm4.woc.noaa.gov
> Feb 19 17:18:40 INFO: State Elapsed Port Remote_Host rpc_stat
> Feb 19 17:18:40 INFO: Resolving ncepldm4.woc.noaa.gov to 140.172.17.205 took
> 0.001599 seconds
> Feb 19 17:18:40 INFO: RESPONDING 0.088901 388 ncepldm4.woc.noaa.gov
> ^C

> [ldm@idd ~]$ traceroute ncepldm4.woc.noaa.gov
> traceroute to ncepldm4.woc.noaa.gov (140.172.17.205), 30 hops max, 60 byte
> packets
> 1 r-cssc-b280c-1-core-vlan-510-primary.net.wisc.edu (144.92.130.3) 0.730 ms
> 0.831 ms 0.876 ms
> 2 internet2-ord-600w-100G.net.wisc.edu (144.92.254.229) 18.092 ms 18.092 ms
> 18.080 ms
> 3 ae0.3454.core-l3.frgp.net (192.43.217.223) 40.196 ms 40.226 ms 40.256 ms
> 4 noaa-i2.frgp.net (128.117.243.11) 40.970 ms 41.012 ms 40.996 ms
> 5 2001-mlx8-eth-1-2.boulder.noaa.gov (140.172.2.18) 42.780 ms 42.778 ms 42.764
> ms
> 6 mdf-rtr-6.boulder.noaa.gov (140.172.6.251) 40.869 ms 40.922 ms 40.946 ms
> 7 * * *
> 8 * * *

> Pete

> --
> Pete Pokrandt - Systems Programmer
> UW-Madison Dept of Atmospheric and Oceanic Sciences
> 608-262-3086 - poker@xxxxxxxxxxxx

-- 
Arthur A. Person 
Research Assistant, System Administrator 
Penn State Department of Meteorology 
email: aap1@xxxxxxx, phone: 814-863-1563