Re: [nv-l] Problem with dying event windows

[James Shanks <jshanks@us.ibm.com>]

Tracking nvevents is not simple in any
case, and more so in your case.

  As an X-GUI app, it was not designed
to keep a log.  When error messages were intended for the user, they
are put in a pop-up window.  Unexpected  error messages, if any,
are sent to stderr, and would  go to the command window that was active
when the process was started.  Usually, these are grabbed and kept
in the netview_<userid>.log, if that's how you started the NetView
GUI.   If nvevents cores, the core also goes to the active directory
of the active window.   But  nvevents will disappear without
saying anything on receipt of just about  any signal other than SIGCHILD,
so that it goes away whenever the  ovw process or the Control Desk
does .  It's wasn't designed to stay up and keep running when a problem
is encountered.

If your event windows were failing on
the server X-GUI, then we'd be reasonably sure that we'd see any error
message, if any were produced.
  But all bets are off when you
telnet in through an X-emulator, which is one reason why we do not officially
support them.  Another thing we have discovered over the years is
that X emulators are quite sensitive to the level of the X11 library code
used on the server, though they seldom tell you about that.  

So you might try to find out whether
your emulator is expecting you to be using X11/R5 libraries or X11/R6.
 Some of the newer ones don't work well with the R5 libraries on AIX.
 But even if you cannot find out , take a  look into the /usr/OV/bin/netview
script, if that how you are starting the daemons, and locate the "export
LIBPATH" statement near the end.  Before 7.1.4 FixPack2  we
concatenated the X11/R5 libraries ahead of the R6 ones, but discovered
that caused problems with some control desk apps on later levels of AIX,
so now it has been removed.  So if you see "/usr/lpp/X11/lib/R5"
in the concatenation, remove it and just leave everything else.  

You also might have better luck running
nvevents outside the control desk.  You can change that in /usr/OV/app-defaults/Nvevents,
if you like.  Or you might try reducing the number of event windows
you have open at once and see if the problem is load-related.

You see,  I disagree with the diagnosis
that because there's nothing in your emulator logs, then the problem must
be on the server.  I once had an AIX developer tell me that no application
he knew of drove the X server on AIX harder than NetView does, especially
with multiple event windows, because every event is a full-blown X widget,
not just a color change like status is on the map.  So a rapid event
flow is like what happens to the map when you start from nothing but a
really good seed-file.  It populates and re-draws so rapidly that
your eye can hardly follow it.  Ten events per second as a sustained
load can make an event window on the server flicker so fast that you literally
cannot read it all.  Much higher than that, and it will just "white
out" as the X-server cannot draw the updates fast enough.  Now
if that is a huge load for the X-server, imagine what kind of a load that
is for the X-emulator.  Bottom line here, is you have any tuning parameters
you can adjust on your emulator, try doubling them.

Maybe the user's of other X emulators
can tell you about  adjustments they have made to theirs.  They
may not have the same emulator, but they may well have made an adjustment
to solve a similar problem. 


HTH

James Shanks
Level 3 Support  for Tivoli NetView for UNIX and Windows
Tivoli Software / IBM Software Group

Bartlomiej Grenda <Bartlomiej.Grenda@pl.ibm.com>
Sent by: owner-nv-l@lists.us.ibm.com

10/12/2004 08:07 AM

Please respond to
nv-l

To	nv-l@lists.us.ibm.com
cc
Subject	Re: [nv-l] Problem with dying event windows

> This sounds like something X-related. I would be looking at the
> logs on the machines themselves for information from Reflection-X.
> Or see if there is any way to trace or debug Reflection-X. Have you
> recently installed any updates to R-X or the NetView server? Do you
> have the latest patches for R-X?

I've checked R-X logs. Unfortunately, there is nothing interesting there.
It seems that that this is on the server side...
As far as I understand - all Event Viewer windows for single user are
served by single nvevents process, so - if its die then all Event Viewer
windows will dissappear. How can I track nvevent process (log. debug,
trace)?

Regards

Bartlomiej Grenda