Configuring High Availability - Adaptive Applications - BlueCat Gateway - 24.1

Global Server Selector Administration Guide

Product name
BlueCat Gateway

To configure high availability for GSS services, you can deploy multiple instances of the GSS application in each health-check region. By default, all GSS instances will perform health-checks and scheduled ACL updates. To simplify operation and troubleshooting, configure GSS instances in the same health-check region as a cluster, so that only one instance will perform health-check server functions and scheduled ACL updates at any time.

When you configure a group of GSS instances as a cluster, all instances can receive API calls but only one instance will perform regular health-checks of application servers and scheduled ACL updates. Having only one Active instance prevents possible conflicts caused by both GSS instances trying to update the same data at the same time.

To add a node to a High Availability cluster, each node must be configured with the published IP address and UDP port number where it can be reached by other cluster nodes. This is typically an IP address on the host server and not the private IP address assigned to a docker container. To configure the cluster, you need the list of IP address and port for all cluster nodes.

To configure high availability:
  1. In the left navigation, click DNSTrafficSteering > High Availability.
  2. Under Local IP Address, enter the published IP address and UDP port configured for heartbeat traffic when the docker container was deployed.
    • If you deployed GSS on a DNS/DHCP Server, the IP address is the IP address of the DNS/DHCP Server and the UDP port of the container is 4789.
    • The Local IP address must be configured for each node in the cluster. This can also be provided in the LOCAL_ADDRESS environment variable when starting the docker container. For more information, refer to Installing the GSS Adaptive Application.
  3. Under Address, add the IP address and port for all nodes in the cluster. Click the + symbol to add the nodes to the cluster.
    • List the IP addresses with the highest-priority nodes first. Higher-priority nodes will change to Active state faster than lower-priority nodes. The highest-priority node that is available should become Active when there is no other active node available.
    • You can drag the nodes to reorder the priority of the nodes.
  4. Click Save.

When configuring high availability, the list of cluster nodes is stored in SRV records in the status zone for the configured health-check region: cluster.<region>.status.gss.bluecat

Remove cluster nodes from the cluster before changing the GSS region configuration for the node.

After configuring or updating the list of cluster nodes and configuring a local IP address on all nodes, restart the other GSS cluster nodes to load the new high availability configuration.