Re: Beating Oracle - Mailing list pgsql-interfaces

From Jan Wieck
Subject Re: Beating Oracle
Date
Msg-id 200203012024.g21KODS09944@saturn.janwieck.net
Whole thread Raw
In response to Re: Beating Oracle  (Tom Ivar Helbekkmo <tih@kpnQwest.no>)
List pgsql-interfaces
Tom Ivar Helbekkmo wrote:
> Tom Lane <tgl@sss.pgh.pa.us> writes:
>
> > In an RFC-compliant stack, the outage interval required before KEEPALIVE
> > will kill the connection is of the order of hours.  RFC 1122 specifies
> > that the minimum interval before the first probe is even sent is 2 hours
> > (since last activity on connection), and that a single failed probe is
> > not sufficient reason to drop the connection.
>
> Ah, yes, I see that now.  On NetBSD, it's four hours until the first
> keepalive, then eight missed ones at 150 second intervals (totalling
> 20 minutes) are required before the connection is considered dead.
>
> > RFC 2525 does note that excessively short keepalive timeout is a common
> > form of TCP-stack bug.
>
> So, Bruce might still be bothered with something like that, and/or
> (for all he's given us of details) he might actually be talking about
> a situation where Oracle will wait through severely prolonged outages
> where PostgreSQL won't.
   The  question  is  "what  exactly  is  the  network  glitch"?   Firewalls doing NAT frequently cleanup  a  little
too much,   namely  connections  that  just have been idle for some time.   Maybe Oracle has it's private li'l
keepalive ping  to  avoid   that?
 


Jan

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