[SunRay-Users] EXTERNAL:Re: EXTERNAL: Sun Desktop AccessClient (SDAC / soft client) poor performance

Devin Nate Devin.Nate at cloudwerxdata.com
Tue Mar 2 02:25:21 EET 2010


Thanks Bob for the followup.

I've been up and down over mtu ... that was my guess at first too. I can confirm by packet capture that SDAC is using a mtu no larger than the slider in the client is set to for udp packets. Tcp packets appear to be using pmtud and getting an fine mtu also.

I'm spinning up a host in our data center to test... but so far, no good solutions have come out of this.

I suspect I'm going to need to get Oracle/Sun to open a case.. this is frustrating enough that I'd like to get folks with access to the source code involved. Where every other app works...?

I may get a Solaris SRS running here as well for comparative testing.

Anyhow, if anyone has any more ideas, let me know.

Thanks,
Devin




-----Original Message-----
From: sunray-users-bounces at filibeto.org [mailto:sunray-users-bounces at filibeto.org] On Behalf Of Bob Doolittle
Sent: Monday, March 01, 2010 3:43 PM
To: SunRay-Users mailing list
Subject: Re: [SunRay-Users] EXTERNAL:Re: EXTERNAL: Sun Desktop AccessClient (SDAC / soft client) poor performance

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: sunray-users-bounces at filibeto.org
> [mailto:sunray-users-bounces at filibeto.org] 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: sunray-users-bounces at filibeto.org
> [mailto:sunray-users-bounces at filibeto.org] 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: sunray-users-bounces at filibeto.org
> [mailto:sunray-users-bounces at filibeto.org] On Behalf Of Devin Nate
> Sent: Monday, March 01, 2010 2:06 PM
> To: lars.tunkrans at bredband.net; 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: sunray-users-bounces at filibeto.org
> [mailto:sunray-users-bounces at filibeto.org] 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
> _______________________________________________
> SunRay-Users mailing list
> SunRay-Users at filibeto.org
> http://www.filibeto.org/mailman/listinfo/sunray-users
> _______________________________________________
> SunRay-Users mailing list
> SunRay-Users at filibeto.org
> http://www.filibeto.org/mailman/listinfo/sunray-users
> _______________________________________________
> SunRay-Users mailing list
> SunRay-Users at filibeto.org
> http://www.filibeto.org/mailman/listinfo/sunray-users
> _______________________________________________
> SunRay-Users mailing list
> SunRay-Users at filibeto.org
> http://www.filibeto.org/mailman/listinfo/sunray-users
> _______________________________________________
> SunRay-Users mailing list
> SunRay-Users at filibeto.org
> http://www.filibeto.org/mailman/listinfo/sunray-users
>   

_______________________________________________
SunRay-Users mailing list
SunRay-Users at filibeto.org
http://www.filibeto.org/mailman/listinfo/sunray-users


More information about the SunRay-Users mailing list