Exadata Software - Oracle Exadata Recipes: A Problem-Solution Approach - page 51

SYS @ visx1> show parameter listener

NAME TYPE VALUE
--------------------- ----------- ------------------------------
listener_networks string
local_listener string (DESCRIPTION=(ADDRESS_LIST=(ADDRESS=
(PROTOCOL=TCP)(HOST=172.16.10.12)
(PORT=1521))))
remote_listener string cm01-scan:1521
SYS @ visx1>

How It Works
For those of you who are familiar with Oracle 11gR2 Real Application Cluster, you'll find that the networking
architecture on Exadata is similar to non-Exadata Oracle 11gR2 RAC environments. There are, however, some key
differences that are unique to Exadata. Specifically, database storage is exclusively achieved with Oracle ASM over
the InfiniBand network to the storage cells and the Oracle RAC interconnect traffic utilizes the high-speed InfiniBand
network over Oracle's RDS network protocol.
As mentioned above, assorted Oracle RDBMS and network binaries are linked to use the RDS protocol, and
running skgxpinfo on Exadata demonstrates this.
When attempting to understand how Exadata is allowed to use an InfiniBand-aware (iDB/RDS) disk strings
when creating ASM disk groups, this too is also quite simple. If Oracle can find a valid version of /etc/oracle/cell/
network-config/cellip.ora , you will be able to create ASM disk groups using the ' o/<IP>/<Grid Disk> ' disk string.
In the Solution section of this recipe, you may have noticed that the bonded InfiniBand interface, bondib0 , uses
the 192.168.8.0/22 network with hosts using 192.168.10.1 through 192.168.10.22 (for an Exadata Full Rack).
Oracle uses this 255.255.252.0 subnet to allow multiple Exadata, Exalogic, or other InfiniBand-capable systems to
use the same InfiniBand network. This interconnect InfiniBand traffic is non-routable.
Before closing out this recipe, let's turn our attention to the Oracle SCAN and VIP configuration. On Oracle 11gR2
systems (whether you're on Exadata or not), you typically have three SCAN listeners running on one or more nodes in
your compute grid as well as a database listener listening on the VIP address on each node. As Oracle Exadata comes
in the X2-2 Quarter Rack, X2-2 Half Rack, X2-2 Full Rack, X2-8 Full Rack, X3-2 Eighth Rack, X3-2 Quarter Rack, X3-2
Half Rack, X3-2 Full Rack, and X3-8 Full Rack models, you will find the following:

• X2-2, X3-2 Eighth Rack, and X3-2 Quarter Rack: Three SCAN listeners, two running one node

and one running on the other node (if healthy) and a local listener running on the VIP address

• X2-2 and X3-2 Half Rack: Three SCAN listeners, one running on three of the four compute

nodes, one compute node without a SCAN listener, and a local listener running on the VIP
address

• X2-2 and X3-2 Full Rack: Three SCAN listeners, one running on three of the eight compute

nodes, five compute nodes without a SCAN listener, and a local listener running on the VIP
address

• X2-8 and X3-8 Full Rack: Three SCAN listeners, two running one node and one running on the

other node (if healthy) and a local listener running on the VIP address