Veritas InfoScale™ 8.0 Solutions in Cloud Environments

Failover across AWS subnets using overlay IP - Linux

InfoScale clusters let you fail over IPs - and thereby, the application configured for HA - between different subnets in the same AZ or in different AZs.

AWS does not allow the private IP of one subnet to be failed over to a different subnet. To overcome this limitation, provides an overlay IP, which is defined at the VPC level, so that it can be used across subnets.

The following graphic depicts a sample failover configuration across subnets within the same AZ using an overlay IP:

The following snippet is a service group configuration from a sample VCS configuration file (main.cf):

group appnetworkSG (
 	SystemList = { ip-172-34-20-109 = 0, ip-172-34-30-231 = 1 }
	 AutoStartList = { ip-172-34-20-109, ip-172-34-30-231 }
	 )

 	AWSIP AwsIp_Res (
	  	OverlayIP = "172.35.1.3/32"
  		Device = eth0
  		AWSBinDir = "/usr/local/bin"
		  )

 	IP Ip_Res (
	  	Device = eth0
  		Address = "172.35.1.3"
		  NetMask = "255.255.255.255"
  		)

 	NIC Nic_Res (
	  	Device = eth0
  		)

AwsIp_Res requires Ip_Res
Ip_Res requires Nic_Res

The following graphic depicts a sample failover configuration across subnets in different AZs using an overlay IP:

The following snippet is a service group configuration from a sample VCS configuration file (main.cf):

group appnetworkSG (
 	SystemList = { ip-172-34-20-109 = 0, ip-172-34-30-231 = 1 }
	 AutoStartList = { ip-172-34-20-109, ip-172-34-30-231 }
 	)

	 AWSIP AwsIp_Res (
		  OverlayIP = "172.35.1.3/32"
  		Device = eth0
  		AWSBinDir = "/usr/local/bin"
  		)

 	IP Ip_Res (
	  	Device = eth0
  		Address = "172.35.1.3"
  		NetMask = "255.255.255.255"
  		)

 	NIC Nic_Res (
  		Device = eth0
		  )

AwsIp_Res requires Ip_Res
Ip_Res requires Nic_Res