MTU settings sound more plausible than uttsc to me.
uttsc should not affect latency as measured by utcapture - that's purely
a metric measured between the X server and the client.
-Bob
Nishimura, Scott L (IT Solutions) wrote:
Devin,
I'll have to defer to more knowledgeable members of this list. The
performance you describe, however, is suspiciously similar to what we
experienced a few years back before we had tuned our MTU settings [we
ultimately settled on 1470]: when going through a PowerPoint stack,
we'd get 5-second delays in screen redraw.
The only other time I've seen something like this was when I was using
PCSC [PC Smart Card] 1.0 and when I got a normal workload on the SRS,
pcscd started taking up 6% of the CPU and users would see many 5-second
delays during their session.
Scott
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Devin Nate
Sent: Monday, March 01, 2010 2:27 PM
To: SunRay-Users mailing list
Subject: Re: [SunRay-Users] EXTERNAL:Re: EXTERNAL: Sun Desktop
AccessClient (SDAC / soft client) poor performance
Ahh, now that's something we haven't done yet... packet capture of the
uttsc data. So far we've done a packet capture of the dtu<-->srss and
compared with sdac<-->srss, and we couldn't see any difference there.
I'll report observations asap.
That said, would a difference in uttsc traffic to the terminal servers
cause utcapture to indicate a higher latency?
Thanks,
Devin
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Nishimura, Scott
L (IT Solutions)
Sent: Monday, March 01, 2010 3:16 PM
To: SunRay-Users mailing list
Subject: Re: [SunRay-Users] EXTERNAL:Re: EXTERNAL: Sun Desktop Access
Client (SDAC / soft client) poor performance
Devin,
How about if you run a truss or pstack or similar troubleshooting tool
on uttsc and compare the results between the actual DTU and SDAC?
Does your sniffer test show excessive retransmissions?
Also, what MTU size is being used? Too large [> 1470?] could lead to
fragmentation; too small [< 500] could lead to "laggy" performance
[we've run into that before on a physical DTU before].
Scott
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Devin Nate
Sent: Monday, March 01, 2010 2:06 PM
To: [email protected]; SunRay-Usersmailing list
Subject: EXTERNAL:Re: [SunRay-Users] EXTERNAL: Sun Desktop Access Client
(SDAC / soft client) poor performance
Hi Lars;
I completely agree... the problem is, the DTU and SDAC clients are on
identical networks... in fact, I've taken the cable out of a perfect DTU
and put it into a PC. I was thinking perhaps QoS or something tagging
the udp packages.
The PCs have Intel nic's. I'm tracking down totally different
architectures. Our core is all Cisco networking gear. We're looking to
setup a host on the same LAN directly connected to the core, that said
we had some hosts in the datacenter getting latency of 500.000, gig
connected but on a different subnet.
All that aside, the Sun DTU's work perfect on the same network. We're
going through everything with a fine tooth comb, but I'm not optimistic.
More thoughts?
Thanks,
Devin
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Lars Tunkrans
Sent: Monday, March 01, 2010 2:36 PM
To: SunRay-Users mailing list
Subject: Re: [SunRay-Users] EXTERNAL: Sun Desktop Access Client (SDAC /
soft client) poor performance
2010-03-01 20:31, Devin Nate skrev:
I'm really appreciating the ideas, please keep them coming?
Thanks,
Devin
Hi,
When I experience laggy screen updates on a DTU ist is usually
becase there is
a problem with the network .
As the list can testify:
One returning problem is Low end flaky L2 switches with a
gigabit input from the CORE switch
and 100Mbit link out to the DTU. These L2 switches drops UDP packets
and forces the DTU
to ask for them again . Hence the Laggy screen updates.
Now heres a long shot.....
if you are using mainly the same brand pc , do they all have the
same LAN Card / CHipset ?
There are many kinds of problems with Chinese wierdo combines of
PHY / MAC chipsets.
They come up with new combinations every week just to be able to
produce the motherboard 5 cents
cheaper.
Should you try an Intel Pro1000 GT Desktop adaptor ? I think
so.
http://www.intel.com/products/desktop/adapters/pro1000gt/pro1000gt-overv
iew.htm
This is probably the the most stable ethernet card today, since
3COM stopped making
ethernet cards.
Did you try to attach the PC directly to core switch yet ?
//Lars
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