[AG-TECH] DPPT3 Failure - Conflict description and a fix
Jennifer Teig von Hoffman
jtvh at bu.edu
Thu Oct 18 08:54:06 CDT 2001
Hi Marty,
Thanks for writing this down in such good detail; I'll update the dppt
guide on the AGDP with this information as soon as possible (hopefully
within the next week).
- Jennifer
On Wed, 17 Oct 2001, Marty Hoag wrote:
> For the past few months several of us have had some strange problems
> with DPPT. Our clients would fail for no apparent reason. While the
> last message is something like "nullpointer exception" we noticed that
> up a few lines there is a message like
>
> Caught JSDT exception: name in use
>
> We had this problem on Monday during a virtual conference in genomics
> and bioinformatics we were hub for. Cindy Sievers at LANL mentioned
> a couple times in the moo that her client was failing but then later
> NDSU's failed and hers worked. This pattern was consistent throughout
> the day. We had tried rebooting our display at one point even.
> Kay Gunn was great in calling out slide changes but it wasn't so fun
> for Cindy or Jim Senechal here who had to manually keep up (Jim
> was too far from the screen to read the numbers so we put binoculars
> on our AG Node large event requirements list).
>
> It struck me that this sounded like some sort of resource conflict
> between LANL and NDSU. We looked at the agserv command window and
> noticed the clients are identified by userid and host name. We
> saw that ours was coming in as ag at agdisplay . Cindy had the same
> combination! Bob Olson has verified that this is indeed a problem
> by checking the code.
>
> While I think we had the windows "DNS" stuff set up to use both a
> hostname and domain, we did NOT have that set up in the "Net ID" field
> of windows. We think we have found a quick fix for this to avoid any
> conflict. There could be some strange implications if you are using
> windows networking in some way but we made the change Monday evening
> and ran all day Tuesday with LANL and NDSU coexisting and had no other
> problems.
>
> Here is the "quick fix" we used for W2K (we are at SP2 but I don't
> think that should matter). Please note that I'm not a windows
> expert so my terminology might be wrong but I think I have our
> procedures down). Use at your own risk (at least until independently
> confirmed):
>
> 1) Go do Start / Settings / Control Panel / System
>
> 2) Click on the Network Identification tab. If your "Full computer
> name" already is fully qualified then your machine should be
> uniquely identified (at least for this problem). If not go on...
>
> 3) Click on the Properties button.
>
> 4) The Computer Name is just the first element of the name. To add a
> domain to qualify this click on the More... button.
>
> 5) For primary DNS suffix for this computer enter your domain. E.g.
> if the machine is agdisplay.foo.bar.edu then you'd add foo.bar.edu
> here.
>
> 6) We UNCHECKED the "Change primary DNS suffix when domain membership
> changes" because we didn't understand it and didn't want to do something
> we didn't understand.
>
> 7) We OKed those and I think had to reboot. Then when we connected to
> our agserv we saw our Client ID as ag at agdisplay.ndsu.nodak.edu .
>
> Since more sites are joining the AG and using more standardized
> software and documentation that probably explains why this seems to
> be a more common problem (or maybe Cindy and NDSU are the only ones
> who are "uncreative").
>
> Given work on a future replacement for DPPT (rppt) and the apparent
> ease with fixing this (we probably need more than one site to try the
> fix to confirm that) I'm not sure it is worth spending time rewriting
> DPPT at this point. But that would be for others to decide.
>
> At least LANL and NDSU should be able to both be clients to the same
> dppt server now. ;-) And this is yet another proof of the value of
> collaboration and tools like the moo! I owe Cindy a couple breakfast
> burritos.
>
> Marty
>
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