Install guide

Note
The Oracle Cache Fusion links can run over standard UDP Ethernet (GbE links, at least), but can
also run over a proprietary RDMA Infiniband network, and is fully supported by Oracle on RHEL,
starting with RDBMS version 10.2.0.3. T he Oracle GCS protocol functions like many other
conventional cache protocols and must broadcast to all nodes when requesting a cache block.
On a hardware bus, this is called Snooping. With GCS, this tends to generate geometric UDP
broadcast traffic when node count exceeds eight. Most applications become the bottleneck long
before, but GCS snoop traffic eventually limits the scalability of all RAC clusters. The IB/rdma
feature (AKA Reliable Datagram Sockets – RDS/skgxp), mitigates this geometric growth, and
makes larger node counts more practical. This effect is rarely seen in the majority of clusters,
which tends to less than eight nodes.
The heartbeat networks for a cluster should be isolated into a dedicated, private VLAN that also filters
for UDP broadcasting, in the RAC cluster case. All of these service networks should be a private and
physically isolated as is possible. These fabrics should not be considered public, production networks.
Make this clear when requesting network provisioning from NetOPS, or give them a copy of this
document.
Red Hat Enterprise Linux 5 Configuration Example - Oracle HA on Cluster Suite
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