first datasocket write slow on localhost with XP SP2

[Balze]

Hi there,

i've got the following problem:

I use datasocket to share information between 2 labview applikations.
This applications run fine using win2k.
Now i transfered these applications to Win XP SP2.
(I found, that there is a problem with the local host adress space in win XP and installed update kb884020 from MS homepage.)

If i try to write an item for the first time, it takes several seconds to write it. (dstp://localhost/set_plc or dstp://127.0.0.1/set_plc) (several seconds for EACH item)
If i change the adress to the local IP, everything works immediately (dstp://192.168.101.73/set_plc for example)

Does someone have a similar problem? Did someone find a solution for that?

Details:
Windows XP professional SP 2 (+ kb884020)
Dell PowerEdge 1800 Dual Xeon 3.6, 2Gb RAM
no firewall installed, XP firewall disabled
No DNS server entered (there was a DNS server entered before)

Labview 7.1
Datasocket 4.3.0

Every hint is appreciated, thanks in advance

Rainer

[Jochen]

It looks like something is wrong with your DNS settings in your TCP/IP configuration so it takes very long to resolve the computer name. Please contact your PC administrator to check these settings.
As a workaround you could use the IP address as you have mentioned in your posting already. If your IP address is dynamically assigned by an DHCP server you could use the ipconfig command in combination with the system exec.vi to find out the IP address of your system in your LabVIEW vi.

Best regards,

Jochen Klier
National Instruments Germany

[Balze]

Jochen,

thanks for your suggestions.

I allready thought about the DNS settings.
But as i mentioned, there are no entries for a DNS Server.
The IP Adress is fixed, no DHCP Server is used.

If the DNA settings are responsible for this behavior, shouldn't the adress be resolved after the first successful access of one DataSocket Item and the following accesses must be fast?

Best regards,

Rainer

P.S.: Due to the fact that i'm responsible for the PC the software is running on, there's no administrator i could ask (except myself). 😞

[Balze]

In addition:

Whhen i use the ping command with localhost (or 127.0.0.1), the PC responses imediately. This shouldn't work if it's a problem with the DNS settings. Or am i wrong here?

Regards,

Rainer

[Jochen]

I have done some tests here and I couldn't reproduce the behavior but the environment is not comparable as we use DNS. On the other hand I wasn't able to find any other hints than potential problems with DNS or non-existent host names or IP-addresses. By the way: What happens if you use 127.0.0.1 instead of localhost. Do you see the same problem? Is there a technical reason why you can't use the IP-address?

Jochen

[Balze]

Hi Jochen,

There's no difference between the use of localhost or 127.0.0.1 !
It's still the same behavior.

No, there's no technical reason. I use the local IP-adress now. This works without any problems.

As mentioned, this software is transfered from a Win2k PC to a WinXP PC and doesn't work the same.
I had to tweak some vis, but now it works.

I'm still curious, what is different on the XP PC, so that it doesn't work anymore.

Thank you for your support.

Regards,

Rainer

P.S.: I'm able to reproduce this behavior. 🙂