In IBM Cloud Pak for Integration (CP4I) v2021.2, ensuring high availability (HA) requires certain components to maintain a quorum. A quorum is a mechanism where a majority of nodes or instances must agree on a state to prevent split-brain scenarios and ensure consistency.

IBM MQ Multi-instance Queue Manager is designed for high availability.

It runs in an active-standby configuration where a shared storage is required, and a quorum ensures that failover occurs correctly.

If the primary queue manager fails, quorum logic ensures that another instance assumes control without data corruption.

API Connect operates in a distributed cluster architecture where multiple components (such as the API Manager, Analytics, and Gateway) work together.

A quorum is required to ensure consistency and avoid conflicts in API configurations across multiple instances.

API Connect uses MongoDB as its backend database, and MongoDB requires a replica set quorum for high availability and failover.

Why "Multi-instance Queue Manager" (A) Requires a Quorum?Why "API Management (API Connect)" (B) Requires a Quorum?

Why Not the Other Options?Option

Reason for Exclusion

C. Application Integration (App Connect)

While App Connect can be deployed in HA mode, it does not require a quorum. It uses Kubernetes scaling and load balancing instead.

D. Event Gateway Service

Event Gateway is stateless and relies on horizontal scaling rather than quorum-based HA.

E. Automation Assets

This component stores automation-related assets but does not require quorum for HA. It typically relies on persistent storage replication.

Thus, Multi-instance Queue Manager (IBM MQ) and API Management (API Connect) require quorum to ensure high availability in Cloud Pak for Integration.

IBM MQ Multi-instance Queue Manager HA

IBM API Connect High Availability and Quorum

CP4I High Availability Architecture

MongoDB Replica Set Quorum in API Connect

IBM Cloud Pak for Integration (CP4I) v2021.2 Administration References: