To connect to a MySQL DB system from an OCI Cloud Shell session when the VCN is not configured with VCN peering, VPN access, or FastConnect, the following must be true:

A.You must attach the Cloud Shell session to a VCN subnet that can connect to the MySQL DB system: The Cloud Shell must be in the same network or have a route to the network containing the MySQL DB system. C.The MySQL DB system subnet must be in theCloud Shell tenancy home region: Cloud Shell sessions operate within the OCI home region, so the target MySQL DB system must be accessible from within the same region.

Before deleting a DB system in Oracle Cloud Infrastructure (OCI), you mustdisable delete protection if it is enabled(Answer C). Delete protection is a feature that prevents accidental deletion of DB systems. If enabled, it must be turned off before the DB system can be deleted.

Steps:

Navigate to the DB system in the OCI Console.

Check if delete protection is enabled.

If enabled, disable it by updating the DB system settings.

Proceed with deleting the DB system.

References:

OCI Console Documentation on DB System Management

MySQL Database Service Documentation

To prepare data for a new DB system with data import in OCI, you shouldexport the data into an Object Storage bucket with a MySQL Shell dump utility(Answer B). This method allows you to store the data in a scalable and durable object storage service before importing it into the new DB system.

Steps:

Use MySQL Shell dump utility to export the data.

Save the export files to an Object Storage bucket in OCI.

Import the data from the Object Storage bucket into the new DB system.

References:

MySQL Shell Documentation

OCI Object Storage Documentation

A.Reduce query latency: By distributing read queries across multiple replicas, the load on the primary instance is reduced, which can decrease query latency. D.Scale read queries: Read replicas allow scaling of read operations by providing additional instances to handle read queries, improving overall performance and throughput.

To migrate an on-premises MySQL database to a MySQL DB system on OCI with the least amount of application downtime,use inbound replication to synchronize the MySQL database transactions to the DB system(Answer C).

Inbound Replication: This method involves setting up replication from your on-premises MySQL database to the MySQL DB system in OCI. This ensures that all changes and transactions are continuously replicated, keeping the DB system up to date with minimal downtime.

Steps to Implement:

Set up the MySQL DB system in OCI.

Configure the on-premises MySQL database as the master and the OCI DB system as the slave.

Start the replication process to keep the DB system synchronized with the on-premises database.

When ready, switch the application to the DB system with minimal downtime as the data is already synchronized.

References:

MySQL Replication Documentation

OCI MySQL Database Service Replication

To enable high availability for a stand-alone DB system, the following conditions are required:

The DB system must be active(Answer D): The DB system needs to be in an active state to enable high availability features.

The DB system automatic backup must be enabled(Answer E): Automatic backups must be enabled to ensure data protection and facilitate failover operations.

Steps:

Ensure the DB system is running and operational.

Enable automatic backups through the OCI Console or API.

References:

MySQL High Availability Documentation

Automatic Backups Documentation

When exporting data to Object Storage withMySQL Shell util.dumpInstance,you must specifyociParManifest: true(Answer B). This option creates a pre-authenticated request (PAR) manifest file, which allows for secure access and upload to Object Storage without requiring direct credentials.

References:

MySQL Shell Documentation

OCI Object Storage Documentation

Creating a new DB system with data import provides the benefit of faster import with minimal logging. This process is optimized to import large datasets efficiently and quickly, reducing the amount of logging overhead and ensuring a rapid setup of the new DB system.

When creating a custom configuration for the MySQL DB system in OCI Console, you can set the following:

A.Shape: This defines the compute resources (CPU, memory) allocated to the DB system. B.VCN (Virtual Cloud Network): This defines the network in which your DB system will be placed. E.Compartment: This is an OCI resource management feature that allows you to organize and isolate your cloud resources.

To deploy a high-availability MySQL DB system in a region with multiple availability domains, the following types of subnets provide maximum redundancy:

A private regional subnet(Answer B): This type of subnet spans all availability domains in the region, ensuring high availability and fault tolerance.

A public regional subnet(Answer C): Similar to the private regional subnet, a public regional subnet spans all availability domains, providing maximum redundancy and accessibility.

References:

OCI Networking Documentation

MySQL High Availability Documentation

When creating a new DB system with data import, the following conditions apply:

The data must be stored in an Object Storage bucket in the same OCI region as the new DB system(Answer C): This ensures that the data is readily accessible and can be efficiently imported into the new DB system.

A valid pre-authenticated request must be provided to access the data(Answer D): This allows secure access to the data stored in the Object Storage bucket without needing to handle credentials directly.

References:

OCI Object Storage Documentation

Pre-Authenticated Requests Documentation

When automatic backup retention of a DB system is disabled,deleting the DB system(Answer C) will delete all automatic backups of the DB system.

Automatic Backups: These are backups created automatically by the OCI service to ensure data protection.

Backup Deletion: If automatic backups are disabled and you delete the DB system, all associated automatic backups are also deleted. This operation is irreversible, and you should ensure that necessary backups are taken before deleting the DB system.

References:

OCI MySQL Database Service Backup and Restore

When high availability is enabled for a stand-alone DB system,the DB system has three instances running in different availability or fault domains(Answer D).

High Availability Configuration: This setup involves creating multiple instances of the DB system across different availability or fault domains to ensure redundancy and minimize the risk of downtime due to hardware or network failures.

Instances: Typically, there are three instances—one primary and two replicas—ensuring that the system can failover seamlessly if one instance goes down.

References:

OCI MySQL High Availability

To enable client applications to connect to a MySQL DB system that uses default port numbers and is attached to a subnet, you need tocreate an ingress rule that allows stateful connections on port 3306 and 33060(Answer C).

Ingress Rule: An ingress rule specifies the types of inbound connections that are allowed to a resource within a subnet.

Stateful Connections: Stateful connections keep track of the state of network connections passing through them, allowing return traffic to pass automatically.

Steps:

Navigate to the Virtual Cloud Network (VCN) in the OCI Console.

Open the subnet to which the MySQL DB system is attached.

Add an ingress rule to the subnet's security list to allow traffic on port 3306 (MySQL) and 33060 (MySQL X Protocol).

Ensure the rule is stateful to maintain the connection state.

References:

OCI Networking Documentation

MySQL X Protocol Documentation

To change the configuration of an active stand-alone DB system that is configured as the target of a channel, and the channel is currently active, you must:

D.Stop the channel, edit the DB system, change the configuration, and start the channel: This sequence ensures that no data inconsistency or replication issues occur while the configuration changes are being applied.

When creating a Bastion service to connect to a MySQL DB system, the following are true:

The Bastion CIDR block allowlist must include the IP address of all valid client machines(Answer C): This ensures that only the IP addresses specified in the allowlist can access the Bastion service, enhancing security by restricting access to known clients.

The Bastion subnet must have an ingress rule to allow stateful connections on the MySQL DB system port number(Answer E): This allows the Bastion service to communicate with the MySQL DB system by permitting traffic through the necessary ports.

References:

OCI Bastion Service Documentation

Setting Up Bastion with MySQL DB System