Re: speed of light

From: kerravon <>
Date: Tue, 10 Jun 2008 01:52:31 -0700 (PDT)
Message-ID: <>

On Jun 7, 4:11 pm, kerravon <> wrote:
> Thanks all for the comments.  Several things to follow up now.
> 1. What is DA?  I will try to find out.  The DBA said on multiple
> (written) occasions "replicates to [machine] using DA replication".
> It was also called "line by line replication" by someone else.

Turns out that DA is an in-house product that does replication. Will need to find out why this is sensitive to latency and why it can't be modified to overcome that sensitivity.

> 2. A 400 msec response time shouldn't be caused by the speed of
> light - that should only account for 100 msec and thus can't be the
> main problem.

Was told that this was caused by routers along the way, but actually we get ping times of around 200 msec, so the oft-quoted figure appears to be inaccurate. Still waiting for confirmation of that.

> 3. TCP/IP tuning needs investigating.

Was told that this has already been done, including the setting to 32767.

> 4. Increase frequency of switching redo to decrease problem with
> Dataguard lag time.

Waiting for answers regarding the existing in-house product before pursuing this further.

BFN. Paul. Received on Tue Jun 10 2008 - 03:52:31 CDT

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