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<DIV dir=ltr align=left><SPAN class=499450719-30112007><FONT face=Arial
color=#0000ff size=2>You know what -- it almost looks like you are getting a
timestamp where another data value is suspected. It could be that the
client is not sending data reliably, and the field positions are off by
one?</FONT></SPAN></DIV><BR>
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<FONT face=Tahoma size=2><B>From:</B> Gary Baluha [mailto:gumby3203@gmail.com]
<BR><B>Sent:</B> Friday, November 30, 2007 12:31 PM<BR><B>To:</B>
hobbit@hswn.dk<BR><B>Subject:</B> Re: [hobbit] strange graph behavior - random
machines & graphs<BR></FONT><BR></DIV>
<DIV></DIV>On Nov 30, 2007 1:15 PM, Hubbard, Greg L <<A
href="mailto:greg.hubbard@eds.com">greg.hubbard@eds.com</A>> wrote:<BR>
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<DIV dir=ltr align=left><SPAN><FONT face=Arial color=#0000ff size=2>It
sounds like you are zeroing in on the problem. Based on your other
post (and this) it seems that the data is getting logged okay in the RRD,
and that data is being faithfully reproduced by the graphs. The
problem is that the data itself has unexpected values. So whatever is
providing that data to the RRD is either faulty, or is in turn being misled
by something else further upstream.</FONT></SPAN></DIV></DIV></BLOCKQUOTE>
<DIV><BR>Yeah, I'm fairly confident now that it is the initial data being fed
into the rrd file that is faulty. I'm still not sure what the initial
"entry point" of this bad data is, though, nor why it is happening. I
have a feeling that once I determine where the entry point is, that will lead
me to the "why". <BR> </DIV>
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<DIV dir=ltr align=left><SPAN><FONT face=Arial color=#0000ff size=2>I don't
remember where you said that this data was coming from. I know there
can be a problem with "rollovers" when a signed integer is used as a
counter and it grows to the point where the sign bit flips. This can
cause a big jump in a reading if the software cannot handle the switch from
2,147,483,647 (hex 7FFFFFF) to the next value (hex 80000000) which flips the
sign bit for a signed 32 bit integer. This has been a problem in the
SNMP world for YEARS.</FONT></SPAN></DIV></DIV></BLOCKQUOTE>
<DIV><BR>Hrm, that has been something vaguely on my mind. But I haven't
really thought of that as _the_ reason why, since I don't know why there would
be some sort of data rollover. We're talking about load average and disk
space usage graphs that are showing invalid data. I'm also curious why
it would have started all of a sudden, on two separate machines. But it
does seem more and more like something like an integer rollover, or similar
situation. <BR></DIV></DIV><BR></BLOCKQUOTE></BODY></HTML>