RE: Mixing RAC interconnect with other clusters

From: Mark W. Farnham <>
Date: Sat, 29 Mar 2014 09:15:04 -0400
Message-ID: <015901cf4b50$e6a47c40$b3ed74c0$>

IF the VLAN software quality of service actually works for both latency and throughput and reacts quickly enough when challenged with loads on virtual channels other than the private RAC channel.  

In practice if your in house experts have correctly configured things there is a tendency to disbelieve that they are not actually protecting the required latency and throughput continuously enough to avoid problems.  

As the prices of hardware pieces drop, you need to think long and hard about how few incidents it would take to pay for private physical capacity.  

My experience is that the network group does not have to make a mistake for it to NOT work, and then all variety of hilarity ensues and it becomes difficult to remember that the various teams in infrastructure are trying to help each other out.  


From: [] On Behalf Of Justin Mungal
Sent: Saturday, March 29, 2014 8:08 AM
Subject: Re: Mixing RAC interconnect with other clusters  

Oracle recommends that each RAC Interconnect have a dedicated switch, let alone sharing a single VLAN for multiple RACs (Assuming multiple RAC clusters because you pluralized Interconnect). It can work, but you may run into performance problems and troubleshooting difficulties should the switch backplane(s) you're using as Interconnects become saturated.  


On Sat, Mar 29, 2014 at 4:39 AM, Nadeem M. Khan <> wrote:

I think I already know the answer to this one (No), but thought of taking your opinions.

Suppose a shop wants to use different clusters for different purposes - RAC, RHCS, ServiceGuard, HACMP, Veritas and even VMware vSphere. For interconnects, they plan to have one dedicated private VLAN that will be isolated from public traffic. My question is - can the same private VLAN be used for RAC interconnects as well as other cluster interconnects? They will be having only one cluster of each type.

If the answer is No, I suppose each cluster type will need a separate VLAN? For example -

RAC private VLAN

RHCS private VLAN

HACMP private VLAN and so on.

Thanks in advance!  

-- Received on Sat Mar 29 2014 - 14:15:04 CET

Original text of this message