Simultaneous Lag

We have a Windows 2003 file server on which we store all of our drawings. We map drives to this server in two ways: as a standard share and via DFS.

We are using primarily AutoCAD 2002 network clients (transitioning to 2005 which exhibits similar behavior).

The problem we are seeing is that users throughout the building occasionally experience hesitations in AutoCAD. They all experience it at the same time. The lag last 5-20 seconds and then clears up. Most people describe the phenomenom as crosshairs freezing. It happens several times a day during their normal workflow. My IT guys have checked the NICs against the switches to ensure that the throughput speeds match. We've added a RAID controller to the server itself. We haven't found the bottleneck yet.

I have one network folder in the users search path for office customization. I've tried removing this path and it doesn't make any difference. I've tried running everything local and the problem goes away. Obviously I must be able to access, and edit drawings on the server.

Most of our workstations have a Windows 2000 OS, though some are XP. We are running McAfee anti-virus. We are running Outlook 2003. Sometimes CAD users will tab over to other applications, like Explorer, and notice the lag there as well, which makes me as a CAD Manager point to the network. But non-CAD users don't seem to have this hesitation, freeze up problem (at least I've heard no complaints.)

I've seen other posts that seem very much like this, but have not seen anyone who's found a successful resolution.

 

My experience was the same effect, and it took 2 years to track down the
offending device. Check *everything* connected to your network, including
the switches/routers/hubs/jetdirect cards/etc to make sure that the connect
speeds are the same. I had a Cisco 1720 router connecting at 100MB
half-duplex that caused the exact crosshair freezing symptoms you describe.

Literally the moment I changed that router to force a 100MB FullDuplex
connection, the cursor hangs vanished.

Also you may want to see if disabling spanning-tree protocol on the switches
has any effect - some network wiring schemes may make this impossible, but
it's worth looking into...

Mark Evinger

We map drives to this server in two ways: as a standard share and via DFS.

which exhibits similar behavior).

occasionally experience hesitations in AutoCAD. They all experience it at
the same time. The lag last 5-20 seconds and then clears up. Most people
describe the phenomenom as crosshairs freezing. It happens several times a
day during their normal workflow. My IT guys have checked the NICs against
the switches to ensure that the throughput speeds match. We've added a RAID
controller to the server itself. We haven't found the bottleneck yet.

customization. I've tried removing this path and it doesn't make any
difference. I've tried running everything local and the problem goes away.
Obviously I must be able to access, and edit drawings on the server.

are running McAfee anti-virus. We are running Outlook 2003. Sometimes CAD
users will tab over to other applications, like Explorer, and notice the lag
there as well, which makes me as a CAD Manager point to the network. But
non-CAD users don't seem to have this hesitation, freeze up problem (at
least I've heard no complaints.)

anyone who's found a successful resolution.

 

DFS is not supported. Might be the cause here. We don't use DFS for this
very reason even though I've not found any problems in the tests I've done
with DFS.

http://usa.autodesk.com/adsk/servlet/ps/item?siteID=123112&id=2863238&linkID=2475323
http://usa.autodesk.com/adsk/servlet/ps/item?siteID=123112&id=2874506&linkID=2475323

--
Best Regards, Jimmy Bergmark
CAD and Database Developer Manager at www.pharmadule-emtunga.com
Take a look at
JTB FlexReport (FLEXlm report tool) - www.jtbworld.com/jtbflexreport
SmartPurger (Purges automatically) - www.jtbworld.com/?/smartpurger.htm
or download some freeware at www.jtbworld.com
More on AutoCAD 2005;
www.jtbworld.com/autocad2005.htm

 

Mark,

Thank you for your reply. In your 2-year quest to track down your hesistation issue did you ever have occasion to work with Autodesk towards a solution? That is, do they have some history of this behavior?

I've been down the connect speeds path, and have found that it makes a profound difference if set incorrectly. More profound in fact than the mere annoying hesistations that we are experiencing. We've tried forcing speed settings but have found that auto-negotiation almost always connects at 100msp anyway and causes less problems than a forced mismatch.

In your experience did you have users experiencing the lag, freeze, hesistations, whatever we want to call it, all at the same time? And would it just as suddenly clear up all at once?

I'll pass along the "spanning-tree" protocol suggestion to my IT switch guy.

 

Jimmy,

Thanks for the info. I was not aware that Autodesk had any compunctions regarding DFS. We've been using it since the beginning of the year and have had little or no trouble with it. We have found that it performs significantly better under the XP OS as compared to the W2K OS.

Ward

 

Nope, Adesk never really fessed up to any issues - other than to say that
with Novell Client32 installed things can get funky. I ran all the tweaks
at http://www.ithowto.com/novell/clientspeed.htm site to resolve my Netware
issues. The cursor hangs were the last of the problems, and once we could
verify that all devices were connected at the right speed/duplex settings
all was good.

All the client computers autonegotiate the speeds (all Compaq Evo units) and
will get the settings right. It was our Cisco routers that were not
correctly autonegotiating and had to be forced to the correct setups.

When the lags did hit, they went switch by switch in our setup - you could
hear people banging their mice around on the desks throughout the office.
It's like the work version of The Wave, it would start just outside my door
and travel counterclockwise until all the switches had been stepped through.
It worked from the bottom of the switch stack back up to the top - always
started at random times, but was consistent in that it moved 6-5-4-3-2-1
through the stack. Didn't seem to matter where in the stack the Cisco
routers were plugged in.

Mark Evinger

hesistation issue did you ever have occasion to work with Autodesk towards a
solution? That is, do they have some history of this behavior?

profound difference if set incorrectly. More profound in fact than the mere
annoying hesistations that we are experiencing. We've tried forcing speed
settings but have found that auto-negotiation almost always connects at
100msp anyway and causes less problems than a forced mismatch.

hesistations, whatever we want to call it, all at the same time? And would
it just as suddenly clear up all at once?

guy.