REAL APPLICATION CLUSTER : Installation

• Configuring Network Components

 Grid Infrastructure requires a number of network addresses to work correctly: 

#A public network address for each host

# A private network for each host

# A virtual (not yet assigned) IP address per host

# One to three unassigned IP addresses for the Single Client Access Name feature.

# If Grid Plug and Play is used, another non-used virtual address for the Grid Naming Service

• Configuring Hostnames and Name Resolution

Check the file /etc/sysconfig/network -

check the file /etc/resolv.conf -

vi /etc/nsswitch.conf

          #hosts: db files nisplus nis dns

          hosts: files dns

vi /etc/hosts 

127.0.0.1 localhost.localdomain localhost

::1 localhost6.localdomain6 localhost6

# CONFIGURATION RESEAU RAC

# bond0 : Adresses Public

10.178.140.17 frprod01 frprocar01.dc1.fr.myn.dns

10.178.140.18 frprod02 frprocar02.dc1.fr.myn.dns

# bond0 : Adresses Virtuelles

10.178.140.20 frprod01-virt frprod01-virt.myn.dns frprod01-virt.dc1.fr.coface.dns

10.178.140.21 frprod02-virt frprod02-virt.myn.dns frprod02-virt.dc1.fr.coface.dns

# bond1 : Adresses Privees - reseau interconnect

10.178.13.17 frprod01-interco

10.178.13.18 frprod02-interco

# Addresse SCAN : vip 11g

10.178.140.19 frprod-vippub frprod-vippub.myn.dns frprod-vippub.dc1.fr.myn.dns

# FIN CONF RAC

/sbin/ifconfig From the output, identify the interface name (such as eth0) and

IP address for each network adapter you specify as a public network interface

• SCAN

The Single Client Access Name (SCAN) is a new feature in Oracle 11.2. The SCAN name effectively provides a network alias for the cluster.

It replaces individual node names in the connection string and allows clients to connect to the cluster regardless of which nodes it is running on.

The SCAN address is accessed via a SCAN VIP that typically runs on three nodes in the cluster.

If less than three nodes are available, then multiple SCAN VIPs may be running on the same node.

A dedicated SCAN listener process runs on each node that has a SCAN VIP.

The SCAN listener is responsible for load balancing across the cluster, and the connection is forwarded to a local listener process running on one of the nodes currently in the cluster

The benefit is that the client¿s connect information does not need to change if you add or remove nodes in the cluster.

There are 2 options for defining the SCAN:

# Define the SCAN in your corporate DNS (Domain Name Service)

# Use the Grid Naming Service (GNS)

During cluster configuration, several resources are created in the cluster for SCAN.
For each of the 3 IP addresses that the SCAN resolves to, a SCAN VIP resource is created and a SCAN Listener is created
Each pair of resources (SCAN VIP + Listener) will be started on a different server in the cluster, assuming the cluster consists of three or more nodes.

In case, a 2-node-cluster is used (for which 3 IPs are still recommended for simplification reasons),
one server in the cluster will host two sets of SCAN resources under normal operations

• ASM DISKGROUP for ocr/voting
• Type normal ==> 3 disks
• Type high ==> 5 disks