[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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