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Re: CONDUIT latencies (fwd)
- Subject: Re: CONDUIT latencies (fwd)
- Date: Fri, 16 Jul 1999 10:11:55 -0600
I answered Dave's question and provided him with several things to try.
The feed from flip has been consistent if you look at:
http://www.unidata.ucar.edu/staff/chiz/ncep_idd/gifs/latency.gif
The big spike each night between 0 and .5 of the day is caused by the
MRF and the big spike between .5 and the next day is cause by the AVN.
This behavior has been there since the beginning.
The biggest contributor to the latency is the T-1 connection from NCEP
to GSFC. Little things to contribute: the AVN now contains more data...out
through 84 hours.
Chiz
On Fri, 16 Jul 1999, Linda Miller wrote:
> Hi Chiz,
>
> Can we talk about Dave's note this a.m.? I've been noticing on your charts
> that the data just doesn't seem to be consistent. Is this due to NCEP's
> computers being up and down or lack of Internet and T1 capacity or
> something else?
>
> Thanks,
> Linda
>
> ---------- Forwarded Message ----------
> Date: Fri, Jul 16, 1999 12:49 PM +0000
> From: "David J. Knight" <address@hidden>
> To: address@hidden, address@hidden
> Subject: CONDUIT latencies
>
> Hi,
> We've being receiving the CONDUIT/NMC2 data feed
> at UAlbany for some time now. Unfortunately it has not proven
> to be particularly reliable. Specifically, there are
> many hours of the day when latencies get to 3600 sec
> and we start losing data. Right now the nmc2 feed is
> of little value to us, so we have to continue to
> ftp the files from the oso server.
>
> I wonder if other NMC2 sites are seeing *very*
> inconsistant receipt of data? If not, then it is
> probably a local problem, so you don't need to read
> further unless you are willing to serve us the feed ;)
>
> We currently obtain the feed from flood.atmos.uiuc.edu
> Here are entries from last 24 hours of stat files:
>
> 1999071512.stats:19990715125444 NMC2 tgsv7a
> 8430 121583537 1658.38 3660@5442 19990715135542
> 1999071513.stats:19990715134129 NMC2 tgsv7a
> 11 1225 3053.57 3640@2725 19990715143959
> 1999071514.stats:19990715145703 NMC2 tgsv7a
> 4303 105105886 3256.68 3661@3443 19990715155125
> 1999071515.stats:19990715155934 NMC2 tgsv7a
> 1483 32642622 3224.65 3660@1245 19990715162745
> 1999071516.stats:19990715165234 NMC2 tgsv7a
> 85 9179 2657.02 3560@4717 19990715174638
> 1999071518.stats:19990715184725 NMC2 tgsv7a
> 15 1675 163.28 516@0710 19990715184845
> 1999071519.stats:19990715195817 NMC2 tgsv7a
> 4484 109037162 1405.73 3656@5814 19990715205910
> 1999071520.stats:19990715203610 NMC2 tgsv7a
> 3645 60369581 3017.24 3660@0115 19990715213615
> 1999071521.stats:19990715215229 NMC2 tgsv7a
> 21 2345 465.78 1006@5221 19990715220907
> 1999071522.stats:19990715224341 NMC2 tgsv7a
> 12 1340 406.33 923@4327 19990715225849
> 1999071523.stats:19990715234338 NMC2 tgsv7a
> 12 1340 340.78 876@4326 19990715235802
> 1999071600.stats:19990716003757 NMC2 tgsv7a
> 3 335 134.08 271@3757 19990716004227
> 1999071601.stats:19990716015253 NMC2 tgsv7a
> 33 3685 1091.47 2428@5233 19990716023301
> 1999071602.stats:19990716025911 NMC2 tgsv7a
> 2453 59397579 2824.92 3660@2035 19990716040007
> 1999071603.stats:19990716035113 NMC2 tgsv7a
> 800 18925585 3577.05 3660@0206 19990716045200
> 1999071604.stats:19990716045539 NMC2 tgsv7a
> 8 892 3210.54 3545@5539 19990716055445
> 1999071605.stats:19990716054700 NMC2 tgsv7a
> 12 1340 1517.95 2727@4651 19990716063217
> 1999071606.stats:19990716064901 NMC2 tgsv7a
> 3080 74064891 2620.21 3660@2430 19990716074938
> 1999071607.stats:19990716075937 NMC2 tgsv7a
> 1932 120454025 3094.27 3661@5311 19990716090037
> 1999071608.stats:19990716083903 NMC2 tgsv7a
> 2320 46350502 3575.35 3661@0515 19990716093802
> 1999071609.stats:19990716095420 NMC2 tgsv7a
> 19 2120 1531.36 3359@5420 19990716105019
> 1999071610.stats:19990716104532 NMC2 tgsv7a
> 11 1228 2111.46 3260@4532 19990716113952
> 1999071611.stats:19990716114554 NMC2 tgsv7a
> 9 1003 1538.50 2273@4554 19990716122347
>
> Looking at
> http://www.unidata.ucar.edu/staff/chiz/ncep_idd/gifs/latency_NMC.gif it
> appears this is the worse possible place to obtain the feed from!
>
>
> I wonder if would be possible to get the feed from some other site.
> Perhaps PSU. traceroutes look good to there (at least right now).
>
> traceroute ihlseng.ugems.psu.edu
> traceroute to ihlseng.ugems.psu.edu (128.118.41.50), 30 hops max, 40 byte
> packets 1 be102 (169.226.4.1) 2 ms 1 ms 1 ms
> 2 169.226.13.1 (169.226.13.1) 1 ms 1 ms 1 ms
> 3 at-gw3-alb-1-0-T3.appliedtheory.net (169.130.23.5) 2 ms 9 ms 2 ms
> 4 at-gw2-alb-0-0.appliedtheory.net (169.130.20.2) 3 ms 3 ms 3 ms
> 5 at-gw2-syr-1-1-0-T3.appliedtheory.net (169.130.1.22) 6 ms 4 ms 4 ms
> 6 at-bb1-pen-5-0-0-T3.appliedtheory.net (169.130.1.121) 17 ms 18 ms
> 18 ms 7 sl-bb11-pen-4-2.sprintlink.net (144.232.5.113) 18 ms 17 ms 17
> ms 8 sl-bb12-pen-10-0.sprintlink.net (144.232.5.158) 17 ms 16 ms 16 ms
> 9 sl-bb10-rly-10-1.sprintlink.net (144.232.8.153) 17 ms 16 ms 17 ms
> 10 144.232.0.62 (144.232.0.62) 18 ms 18 ms 17 ms
> 11 sl-pittssup-1-0-0-T3.sprintlink.net (144.232.184.10) 28 ms 30 ms 26
> ms 12 penn-state.psc.net (192.88.115.90) 30 ms 30 ms 30 ms
> 13 Willard1-Fddi5-0.gw.psu.edu (128.118.100.4) 29 ms 31 ms 30 ms
> 14 172.28.20.2 (172.28.20.2) 32 ms 31 ms 30 ms
> 15 ihlseng.ugems.psu.edu (128.118.41.50) 30 ms * 31 ms
>
> Actually traceroutes to flood.atmos.uiuc.edu don't look too bad either
> ..
> 15 flood.atmos.uiuc.edu (128.174.80.47) 44 ms 58 ms 48 ms
>
> But they get the data later than most sites, and by the time
> it gets to us much of it gets dropped
>
> Thanks for your consideration
> David
>
> David Knight
> Department of Earth and Atmospheric Sciences Tel: (518)-442-4204
> SUNYA ES-228 Fax: (518)-442-4494
> Albany, NY 12222 Email:
> address@hidden
>
>
>
> ---------- End Forwarded Message ----------
>
>
>
> Linda Miller
> External Liaison, Unidata
> University Corporation for Atmospheric Research
> P.O. Box 3000
> Boulder, CO 80307-3000
> 303 497-8646 fax: 303-497-8690
> URL: http:/www.unidata.ucar.edu/staff/lmiller/un.act.html
>
>