You can cluster the SocialAccess appliance. By default, SocialAccess is a single node cluster. You add a node to the cluster by selecting Join Cluster during the initialization process. SocialAccess supports up to a five-node cluster.
The Cluster icon configuration options are global settings for all nodes in the cluster. To manage these configuration options, see the following sections:
SocialAccess provides clustering for different advantages. Most of these advantages are available only if you configure an L4 switch or Round-robin DNS. The L4 switch is the best solution.
Disaster Recovery: Adding additional nodes to the cluster provides disaster recovery for your appliance. If one node goes down or becomes corrupt, you can promote another node to master.
High Availability for Authentications: SocialAccess provides high availability for authentications and the single sign-on service, when using an L4 switch in conjunction with clustering. This solution allows users to authenticate in case of problems with the nodes within the cluster. The L4 switch sends authentication requests to the nodes with which it can communicate.
Load Balancing: You can configure the L4 switch to distribute authentications to nodes so one node does not receive all authentication requests while other nodes sit idle.
Scalability: Configuring an L4 switch with clustering increases the scalability of SocialAccess. Each node in the cluster increases the number of possible simultaneous logins.
SocialAccess supports up to five nodes in a cluster. You add nodes to the cluster through the initialization process, and perform all other initialization tasks on the Admin page.
To add a node to the cluster:
Verify the cluster is healthy.
All nodes must be up and communicating.
All components must be in a green state.
All failed nodes must be removed from the cluster.
For more information about verifying your cluster is healthy, see Section 8.3, Troubleshooting Different States.
Download and deploy a new VM machine for the new node.
For more information, see Section 2.2, Deploying the Appliance.
Select Join Cluster as the first step to initialize the new node, then follow the on-screen prompts.
For more information, see Section 2.4, Initializing the Appliance.
Wait for the login screen for the Admin page to be displayed. A progress bar indicates how much time this takes.
Log in to the Admin page, and wait for all spinner icons to stop processing and all components to be green before performing any other tasks.
The cluster is adding the node and there are a lot of background processes running. This final step could take up to an hour to complete.
The first node installed is the master node of the cluster by default. The master node runs provisioning, reporting, approvals, and mapping policies services. You can promote any node to become the master node.
To promote a node to master:
Take a snapshot of the cluster.
Verify the cluster is healthy.
For more information, see Section 8.3, Troubleshooting Different States.
Click the node to become the master node on the Admin page, then click Promote to master.
An “M” appears on the front of the node icon indicating it is now the master node.
The services move from the old master to the new master. The old master is now just a node in the cluster.
When you switch the master node, the logs start again on the new master and reports start again on the new master. The historical logs are lost. The reporting data is also lost, unless you are using Sentinel Log Manager.
WARNING:If the old master node is down when you promote another node to master, remove the old master from the cluster, then delete it from the VMware server. Otherwise, the appliance sees two master nodes and becomes corrupted.
You can remove a node from the cluster if something is wrong with the node. However, after removing a node, it cannot be added back into the cluster. You must delete this instance of the appliance from your VMware server, then deploy another instance to the VMware server to add a node back into the cluster.
To remove a node from the cluster:
(Conditional) If the node you are removing is the master node, promote another node to be master.
(Conditional) If you are using an L4 switch, delete the node from the L4 switch.
On the Admin page, click the node you want to remove from the cluster.
Click Remove from cluster.
The interface immediately reflects that the node is gone, but it takes some time for the background processes to finish.
Delete the image of the node from the VMware server.
If you want high availability or load balancing, you must configure an L4 switch for the SocialAccess appliance. An L4 switch can be configured in many different ways. Use the following recommendations to configure the L4 switch to work with the appliance.
Heartbeat: Use the following URL to define the heartbeat for the L4 switch:
https://dns_of_appliance/osp/h/heartbeat
or
https://ip_address_of_appliance/osp/h/heartbeat
The L4 switch uses the heartbeat to determine if the node in the cluster is up and working or not. The heartbeat URL returns a text message of Success and a 200 response code.
Persistence: Also known as sticky sessions, allows all subsequent requests from a client to be sent to the same computer. To make this happen, select SSL session ID persistence when configuring the L4 switch.
Persistence increases the performance of the appliance for the end users, by removing the delay that might occur if the client sends a request to a new node instead of using the existing session to the same node.