Re: 9iRAC interconnect protocol

Hm, I'm wondering how does Oracle handle the possible UDP packet loss possibility, because unlike TCP, UDP isn't capable of retransmitting packets, they can be lost. It shouldn't happen with direct LAN connection that much, but the possibility still exists in theory. Is it done with some kind of Oracle timeouts and resending requests when one instance wants to signal another?

Tanel.

"Quarkman" <quarkman_at_myrealbox.com> wrote in message news:6f2ab2f8.0308271650.2a354033_at_posting.google.com...
> ge_2000_2001_at_yahoo.com (gdb_dsr) wrote in message
news:<6299d152.0308261646.295d3344_at_posting.google.com>...
> > Oracle9iRAC 9201/Linux(RH9.0) instance processes and oracm works using
> > UDP protocol over cluster (ethernet) interconnect when I traced it. I
> > want to configure and run on TCP.
> > Wondering if someone knows about it. Thanks in advance.
>
> Why on Earth would you want to use TCP instead of UDP???
>
> TCP/IP was invented as a routable, error-corrected, protocol for
> heteorogenous networks (the name "Internet Protocol" is in there for a
> reason!). There is thus an awful lot of packet overhead to provide the
> necessary routing and error-correcting mechanisms, and the production
> of a TCP packet takes (relatively) a long time. This is an issue of
> high latency, and it will kill a RAC in its tracks, no matter how fast
> you then manage to actually ship the packet over the network cable.
>
> UDP is (as I understand it) a cousin of TCP, but without the routing
> and error-correting stuff. It is a relatively low latency protocol.
> And it is thus ideally suited to use in a RAC.
>
> RACs are not normally based on different machines in different
> countries. My cache fusion transfer of the EMP table block does not
> normally have to be routed via Switzerland. And TCP/IP is thus
> complete networking overkill for a RAC.
>
> Stick with UDP, I think.
> Regards
> HJR
Received on Thu Aug 28 2003 - 01:21:53 CDT