Re: The problem is that SQL*Net is too chatty, because FTP runs fine.

  • From: "David Taft" <oradbt054@xxxxxxxxx>
  • To: "Mark W. Farnham" <mwf@xxxxxxxx>
  • Date: Thu, 31 Jan 2008 16:59:52 -0500


It is a materialized view complete refresh.  The source is always the same
(US-EC).  The ultimate target is in a new data center (US-SE).  This refresh
was duplicated to US-SW as a sanity check comparison.  Your last statement
about the queue situation is interesting.  When we graphed our throughput
testing on the refresh, it does start out faster and then steps down over
time.  We are in the process of rerunning all tests.  One piece of info I
was given before needs to be corrected.  When asked in a meeting (I didn't
attend), the network group did say they could give us traceroute statistics,
but they said it wouldn't show anything because our connection is set up as
a tunnel.  I am guessing that means that even if there are router hops along
the way, we can't see them from inside the tunnel?  Also, I agree with
everything you said in the second paragraph.  I got pulled into this
situation after it had already progressed to the point it is at now.  I am
hoping we can find a resolution rather than digressing to trying to prove
somebody else's stuff is the problem.


On Jan 31, 2008 4:16 PM, Mark W. Farnham <mwf@xxxxxxxx> wrote:

> Is there some reason that you think the amount of data across the network
> will be the same for the US-SW to US-EC refresh as for the US-SE to US-EC
> refresh? I guess I am getting at precisely what do you mean when you write
> "That same refresh...?" Are duplicate threads of changes being made at
> and US-SE so when the refresh is made data is identical? Are they both
> complete refreshes?
> And of course it is entirely possible in a queue situation to have a large
> chunk transmitter like FTP work okay while a small chunk, chatty
> tranmitter
> like a materialized view refresh gets differentially slower and slower.
> Think of an up escalator feeding a slide. One person per step, no matter
> how
> big (or small). Even though the occupation of the slide is low and the
> large
> persons move many pounds down the slide relatively quickly and the itsy
> bitsy children get just as many turns on the up escalator, the little kids
> move pounds down the slide very slowly.

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