This chapter describes how to configure and manage the Geo Redundant High Availability (GRHA) feature. GRHA is a high-availability solution that works across two data centers with a pair of servers connected over a routable network. When the standby AE Services server is activated, AE Services start providing service approximately a minute after the failure detection interval is over. However, all AE Services clients, other than DMCC clients, have to re-establish all monitors or registrations similar to an AE Services server that came up after a reboot.
Important:
Before configuring GRHA, you must create the new Linux users on the secondary server similar to those on the primary server.
Log in to the AE Services Management Console with the customer credentials and reset the user password because AE Services Release 7.1 does not restore the Linux password after migration.
When upgrading from Release 7.1.x or earlier, AE Services does not restore the /etc/shadow file. This results in a log-in issue with the cust and root passwords.
If you face the log-in issue, you must log in to the AE Services virtual machine from the command-line interface. After the AE Services virtual machine deployment, reset the cust and root password to the previous AE Services values, and restore the operation.
Alternately, you can set the cust and root passwords on the previous AE Services version to the values you set during the 7.1.x and 8.x deployment. Backup and restore the /etc/shadow file on the AE Services 7.1.x and 8.x virtual machine.
The encryption setting on the active and standby servers must be the same. Both the servers must be encrypted or none.
Note:
The IP network round trip time between two AE Services servers must be less than 100 milliseconds.
The AE Services Release 7.0 and later supports GRHA for VMware. The AE Services Release 7.0 does not support the use of Machine Preserving High Availability (MPHA) and Fast Reboot High Availability (FRHA) modes.
From Release 10.1.2, AE Services GRHA supports Virtual IP (VIP) configuration on Azure platform. From the AE Services Management Console, ensure to configure Client Connectivity as Any.
To use the GRHA feature, perform the following steps:
Make sure you have the appropriate information for the GRHA feature. Refer Configuration worksheet for Geo Redundant High Availability.
Configure and start GRHA, refer Configuring Geo Redundant High Availability.
Note:
You cannot change the AE Services IP address or hostname after GRHA is enabled. You must disable GRHA to change the hostname or IP address on the AE Services server.
If you perform a backup when GRHA is enabled and then restore that backup file when GRHA is removed, you must remove the GRHA configuration from the OAM to be able to enable HA. Refer Removing Geo Redundant High Availability.
If you configure GRHA with the hostname validation, Avaya recommends that you restart the sohd service to keep the GRHA license working. If not, the GRHA license either returns an error or enters into the error mode.
You cannot change the AE Services Virtual IP addresses after GRHA is enabled. You must disable GRHA to change the Virtual IP addresses on the AE Services server.
You cannot use a Virtual IP address with enterprise-wide licensing. You must configure the primary AE Services IP address on the WebLM server for the enterprise license to work.
If the standby or secondary AE Services server becomes the primary server, you must manually update the AE Services IP address on the AE Services server before the license grace period of 30 days expires.
For more information, refer the Enterprise Licensing topic in the Administering standalone Avaya WebLM guide.
The Virtual IP address and the IP address of both the AE Services servers must be in the same subnet. For two data centers with different subnets, one possible solution is to use an extended subnet between the data centers.
In GRHA, if Virtual IP is used to upgrade AE Services to Release 8.1.3 and later, the Host ID that the embedded WebLM server uses changes. Hence, a new license must be created based on the new Host ID. To obtain a new license, refer the Upgrading Avaya Aura® Application Enablement Services guide. For more information on this issue, refer PSN020518u on the Avaya support site at https://support.avaya.com.
AE Services does not support Virtual IP addresses for GRHA on the following platforms:
Amazon Web Services
Google Cloud Platform
For GRHA configuration, both active and standby servers must be on the same platform and profile. For example, if the active AE Services server uses VMware with profile 1, the standby AE Services server must also use VMware with profile 1.
To improve the performance of the GRHA, use profiles 2 and 3.
