Immediate drain for quiesce on a highly available system is the default method for quiescing a node. The following behavior occurs on a Pega Platform server when the quiesce process is enabled.
- When a node is placed in a quiesce mode, all users (new and existing) are passivated immediately and the node can be removed from the load balancer at the same time. Existing active requestors that are locked are passivated at the end of the current interaction.
- Access to the quiescing node is allowed for all users until the node is removed from the
- Active requestors can continue sessions on the quiescing node.
- New sessions can be created on the quiescing node.
- Requestor data is saved after each interaction and the requestor is removed from memory.
- For each new interaction, the saved requestor data is used to activate the session on the node selected by the load balancer.
For a diagram that illustrates the on-premises quiesce flow for highly available systems when using immediate drain, see On-premises immediate drain quiesce flow.
To quiesce a node using immediate drain
Quiescing a node with immediate drain does not require removing the nodes from the load balancer before starting the quiesce process.
- Identify the Pega Platform node or nodes that you want to quiesce.
- Do either of the following:
- In Admin Studio, click .
- In Dev Studio, click .
- Select the check box next to the node or nodes that you want to quiesce.
- Click Quiesce. When the quiesce process is complete, the status
of the node changes to Quiesce Complete in the Runstate or
State column on the landing page.
- To cancel the quiesce process for the selected node or nodes, click Cancel Quiesce.
- The node state might not change to Quiesce Complete until after the node has been removed from the load balancer in the following step.
- To prevent traffic from being directed to the quiesced node or nodes, configure the load balancer to remove the quiecsed node or nodes from the pool.
On-premises immediate drain quiesce flow
The following diagram illustrates the on-premises quiesce flow for highly available systems when using immediate drain.