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Re: 20020906 UCLA latencies
- Subject: Re: 20020906 UCLA latencies
- Date: Tue, 10 Sep 2002 16:18:53 -0600 (MDT)
HI James,
I see we have tried the IP spoof to split the feeds, now we go one step
further.
Go into etc/hosts and create aliases for aeolus.ucsd.edu to
aeolus1.ucsd.edu
aeolus2.ucsd.edu
aeolus3.ucsd.edu
Then, try splitting your DDPLUS|IDS feed (which is really one feedtype)
into:
request DDPLUS|IDS "^[^S]" aeolus.ucsd.edu
request DDPLUS|IDS "^S[AR]" aeolus1.ucsd.edu
request DDPLUS|IDS "^S[^AR]" aeolus2.ucsd.edu
or 1,2,3 and use aeolus.ucsd.edu for another feed. We have found this to
be successful.
Also, are you not requesting any NNEXRAD prods?
Do you want them?
I hope this works, let me know what you find out, and we will be watching
the stats!
Cheers,
-Jeff
____________________________ _____________________
Jeff Weber address@hidden
Unidata Support PH:303-497-8676
COMET Case Study Library FX:303-497-8690
University Corp for Atmospheric Research 3300 Mitchell Ln
http://www.unidata.ucar.edu/staff/jweber Boulder,Co 80307-3000
________________________________________ ______________________
On Mon, 9 Sep 2002, James Murakami wrote:
> Hi Jeff.
>
> Yes, we've been suffering from high latencies much of the summer. For a while
> I
> thought it was TYPHOON's aging disks. So, I started up ldm on a separate,
> newer
> workstation (PERIDOT). Things worked fine on it though I never could get the
> logs to be posted. Sometime in August, things returned to "normal" on
> TYPHOON.
> However, a few days before Labor Day, latency problems returned (plagued
> PERIDOT
> as well).
>
> I tried all sorts of combinations, even to the point of ingesting only MCIDAS
> data. Strangely, latencies last week were still horrible with that little
> data
> transmission. Shortly before you emailed me, transmissions seemed faster on
> both
> workstations. I increased the data load on both (MCIDAS/DDPLUS/FSL on TYPHOON
> and UNIDATA/FSL on PERIDOT). It was less than hour latencies on TYPHOON but
> sometimes over an hour on PERIDOT. Latencies were worse during the day than
> at
> night (about 7:30- 8AM, local time, onward into early evening). This has been
> the case each day that I've monitored the activty (using ldmadmin watch).
>
> I heard from my systems admin that UCLA is using packetshaper but only to
> monitor the Internet flow into campus (not restricting data flow). Whenever I
> do
> traceroute, there seems to be nothing greatly slow. This is what I got this
> morning (other days have been better even when latencies exceeded an hour):
>
> 1528Z 9 Sep 2002
>
> traceroute to aeolus.ucsd.edu (132.239.114.58), 30 hops max, 40 byte packets
> 1 psnet-ms77.atmos.ucla.edu (128.97.77.231) 1 ms 1 ms 1 ms
> 2 164.67.160.1 (164.67.160.1) 2 ms 2 ms 6 ms
> 3 mathsci--mathsci.backbone.ucla.net (169.232.9.1) 2 ms 2 ms 1 ms
> 4 mathsci--core.backbone.ucla.net (169.232.6.61) 2 ms 1 ms 1 ms
> 5 core--border.backbone.ucla.net (169.232.6.11) 2 ms 2 ms 1 ms
> 6 border--calren.backbone.ucla.net (169.232.35.11) 1 ms 2 ms 2 ms
> 7 ISI--UCLA.POS.calren2.net (198.32.248.29) 3 ms 2 ms 2 ms
> 8 USC--ISI.POS.calren2.net (198.32.248.25) 3 ms 3 ms 3 ms
> 9 UCSD--USC.POS.calren2.net (198.32.248.34) 6 ms 6 ms 6 ms
> 10 198.32.248.186 (198.32.248.186) 7 ms 7 ms 6 ms
> 11 sio-rsm--ucsd-gw.ucsd.edu (132.239.255.145) 9 ms 7 ms 7 ms
> 12 aeolus.ucsd.edu (132.239.114.58) 65 ms 57 ms 86 ms
>
> traceroute to sunny89.atmos.washington.edu (128.95.89.38), 30 hops max, 40
> byte
> packets
> 1 psnet-ms77.atmos.ucla.edu (128.97.77.231) 1 ms 1 ms 1 ms
> 2 164.67.160.1 (164.67.160.1) 2 ms 2 ms 1 ms
> 3 mathsci--mathsci.backbone.ucla.net (169.232.9.1) 2 ms 1 ms 2 ms
> 4 mathsci--core.backbone.ucla.net (169.232.6.61) 1 ms 1 ms 1 ms
> 5 core--border.backbone.ucla.net (169.232.6.11) 2 ms 2 ms 1 ms
> 6 border--calren.backbone.ucla.net (169.232.35.11) 2 ms 2 ms 1 ms
> 7 ISI--UCLA.POS.calren2.net (198.32.248.29) 2 ms 2 ms 2 ms
> 8 USC--ISI.POS.calren2.net (198.32.248.25) 3 ms 3 ms 3 ms
> 9 Abilene--USC.ATM.calren2.net (198.32.248.86) 3 ms 3 ms 3 ms
> 10 scrm-losa.abilene.ucaid.edu (198.32.8.17) 14 ms 10 ms 10 ms
> 11 sttl-snva.abilene.ucaid.edu (198.32.8.9) 28 ms 28 ms 28 ms
> 12 hnsp1-wes-so-5-0-0-0.pnw-gigapop.net (198.48.91.77) 29 ms 28 ms 29 ms
> 13 uwbr1-GE3-0.cac.washington.edu (198.107.151.51) 28 ms 28 ms 28 ms
> 14 dustbuster-V23.cac.washington.edu (140.142.153.2) 29 ms 29 ms 29 ms
> 15 sunny.atmos.washington.edu (128.95.89.38) 29 ms 29 ms 29 ms
>
>
> Wouldn't the traceroute show significant slowing if packetshaper were
> limiting
> the rate of flow? I'm also wondering if the "logjam" is occurring somewhere
> between the UCLA campus and San Diego (when we're on aeolus.ucsd.edu). It's
> strange that the latency occurs routinely by mid-morning (local time) and
> pretty
> much ends in the dead of night.
>
> Anyway, any suggestions are welcome. I've attached a copy of my ldmd.conf
> file.
> You'll see various commented out data type requests. That's my attempts at
> getting data without huge latencies. Currently, I see latencies of about
> 30-40
> minutes on TYPHOON and PERIDOT.
>
> James
>
>
> >
> > Hello James,
> >
> > We are using some new diagnostics for network and LDM/IDD performance, and
> > we noticed you are still experiencing some large latencies.
> >
> > We have come up with some ideas that may decrease latencies and improve
> > performance.
> >
> > Could you please send me your ldmd.conf file so we can take a look at your
> > requests. Your network connectivity seems to be great, so there is no
> > reason to be experiencing these latencies. We have found some alternative
> > methods for requesting data (using aliases in etc/hosts) that has shown to
> > improve performance. I look forward to working on this with you.
> >
> > Thank you,
> >
> > -Jeff
> > ____________________________ _____________________
> > Jeff Weber address@hidden
> > Unidata Support PH:303-497-8676
> > COMET Case Study Library FX:303-497-8690
> > University Corp for Atmospheric Research 3300 Mitchell Ln
> > http://www.unidata.ucar.edu/staff/jweber Boulder,Co 80307-3000
> > ________________________________________ ______________________
> >
>
> --------------------------------------
> James Murakami
> Staff Meteorologist/Student Affairs
> Department of Atmospheric Sciences
> University of California, Los Angeles
> 405 Hilgard Ave.
> Los Angeles, CA 90095-1565
>
>
> e-mail: address@hidden
> telephone: 310-825-2418
> Fax: 310-206-5219
> ---------------------------------------
>