NCP-DB Nutanix Exam Lab Questions

NDB supports PostgreSQL HA software profiles for provisioning PostgreSQL databases with high availability. PostgreSQL HA software profiles consist of three components: etcd, HAProxy, and Patroni.

etcd is a distributed key-value store that provides a reliable way to store configuration data across a cluster of machines. etcd is used by Patroni to store and synchronize the cluster state and configuration.

HAProxy is a load balancer that distributes incoming requests to the PostgreSQL nodes. HAProxy is used to expose a single endpoint for database connections even as the roles of the individual nodes change.

Patroni is a template for PostgreSQL high availability. Patroni is responsible for managing the state of the cluster and handling failover. Patroni uses etcd as the distributed configuration store and relies on HAProxy for load balancing.

Therefore, the software component that manages the state of the cluster and handles failover is Patroni.

References:

• Nutanix Database Automation (NCP-DB) Course Details, Section 2.4: Provisioning PostgreSQL Databases
• Nutanix Database Automation (NCP-DB) Certification Details, Objective 2.4: Provision PostgreSQL Databases
• Nutanix Database Automation (NCP-DB) YouTube Playlist, Video 2.4: Provisioning PostgreSQL Databases
• [Nutanix Database Automation (NCP-DB) User Guide], Section 2.4: Provision PostgreSQL Databases
• [PostgreSQL High Availability: Under the Hood – Nutanix.dev]

Nutanix Era offers Role-Based Access Control capabilities by organically embedding them in the product. It provides the ability to add and remove users from Era, create and assign roles to users, and associate various privileges with a role1. The default roles available within Era for Role-Based Access Control are:

• prism Admin
• Era Super Admin
• Era Database Admin
• Era Infrastructure Admin1 These roles allow for the management of both physical resources like IP addresses and VLANs along with database entities like databases, time-machines, clones, and so on1.

According to the NDB documentation, the NDB patching process for MongoDB Server Cluster follows these steps1:

• NDB identifies the primary member of the MongoDB Server Cluster and patches it first.
• NDB triggers a failover to elect a new primary member from the remaining secondary members.
• NDB patches the former primary member, which becomes a secondary member after the failover.
• NDB patches the remaining secondary members one by one.
• NDB verifies the patching status and the cluster health.

This process ensures that the MongoDB Server Cluster always has a primary member available to handle write operations, while minimizing the downtime and the impact on the cluster performance.

References: Nutanix Support & Insights, section “Patching a MongoDB Server Cluster”

The correct answer is C because a stretched VLAN is a VLAN that spans across multiple Nutanix clusters, which may cause network conflicts or latency issues when starting the database server. Option A is incorrect because a DHCP VLAN is a VLAN that uses dynamic IP address allocation, which does not affect the database server startup. Option B is incorrect because a static VLAN is a VLAN that uses fixed IP address allocation, which also does not affect the database server startup. Option D is incorrect because IPAM is not a type of VLAN, but a feature of NDB that allows managing IP addresses for database servers and databases.

References: The following sources provide more information about the VLAN and IPAM concepts and configuration in NDB:

• Nutanix Database Management & Automation (NDMA) course, Module 2: Deploying and Configuring an NDB Solution, Lesson 2.4: Configuring NDB High Availability
• Nutanix Certified Professional - Database Automation (NCP-DB) v6.5, Knowledge Objectives, Section 2 - Deploy and Configure an NDB Solution
• Nutanix Database Service (NDB) User Guide, Chapter 2: Deploying and Configuring an NDB Solution, Section 2.4: Configuring NDB High Availability
• Nutanix Database Service (NDB) User Guide, Chapter 8: Administering an NDB Environment, Section 8.5: Managing Networks in NDB
• Nutanix Database Service (NDB) User Guide, Chapter 8: Administering an NDB Environment, Section 8.6: Managing IP Addresses in NDB