OCI On-Prem to Cloud Database Migration | DMS - Online Migration | Part 1

Introduction

In this article, I will explain step by step how to migrate a 19C PDB to Oracle cloud infrastructure Autonomous Database(ADB).

For the convenience of these labs the following resource prerequisites have been created in advance:

• A Vault and a Key
• A Virtual Cloud Network (VCN)
• An Object Storage Bucket
• An Oracle Database 19c PDB instance (source)
• An Oracle Autonomous Database (ADB) instance (target)

You will create the Database Connections for the source and target databases.

You will also create an online Migration that you will later Validate and finally you will Run the actual migration in article part 2.

With DMS we make it quick and easy for you to migrate databases from on-premises, Oracle or third-party cloud into Oracle databases on OCI.

Note: Here I used another Oracle Cloud environment where I configured SourceCDB & SourcePDB that will act as an on-prem environment as I had some limitations to arrange real on-prem env. In the next article, I will show that one also.

OCI Database Migration

DMS provides high performance, fully managed approach to migrating databases from on-premises, Oracle, or third-party cloud into OCI-hosted databases. Migrations can be in either one of the following modes:

• Offline: The Migration makes a point-in-time copy of the source to the target database. Any changes to the source database during migration are not copied, requiring any applications to stay offline for the duration of the migration.
• Online: The Migration makes a point-in-time copy and replicates all subsequent changes from the source to the target database. This allows applications to stay online during the migration and then be switched over from source to target database.

In the current release of DMS we support Oracle databases located on-premises, in third-party clouds, or on OCI as the source. The supported targets are in OCI, below is a table of supported configurations;

The DMS service runs as a managed cloud service separated from the user's tenancy and resources. The service operates as a multitenant service in a DMS Service Tenancy and communicates with the user's resources using Private Endpoints (PEs). PEs are managed by DMS and are transparent to the user.

• DMS Control Plane: Used by DMS end user to manage Migration and Registered Database objects. The control plane is exposed through the DMS Console UI as well as the REST API.
• DMS Data Plane: Managed by DMS Control Plane and transparent to the user. The GGS Data Plane manages ongoing migration jobs and communicates with the user's databases and GoldenGate instance using PEs. The DMS data plane does not store any customer data, as data flows through GoldenGate and Data Pump directly within the user's tenancy.
• Migration: A Migration contains metadata for migrating one database. It contains information about source, target, and migration methods and is the central object for users to run migrations. After creating a migration, a user can validate the correctness of the environment and then run the migration to perform the copy of database data and schema metadata from source to target.
• Migration Job: A Migration Job displays the state or a given Migration execution, either for validation or migration purposes. A job consists of a number of sequential phases, users can opt to wait after a given phase for user input to resume with the following phase.
• Database Connection: A Database Connection represents information about a source or target database, such as connection details and authentication credentials. DMS uses the OCI Vault to store credentials. A Database Connection is reusable across multiple Migrations.

Step 1: Create Database Connections

Database connection resources enable networking and connectivity for the source and target databases. You will also create and Online Migration leveraging the integrated GoldenGate feature available in DMS.

Task 1: Create Database Connection for Source CDB

For this task you need the following info from previous steps:

• Source DB Public IP
• Database Administrator Password

1. In the OCI Console Menu, go to Migration & Disaster Recovery > Database Migration > Database Connections

2. Select your assigned compartment. In OCI go to the Compartment field and set you desired compartment:

3. Press Create connection

4. On the page General information, fill in the following entries, otherwise leave defaults:

• Name: SourceCDB
• Type: Oracle Database
• Vault: DMSVault
• Encryption Key: DMSKey

5. Press Next

6. On the page Connection details, fill in the following entries, otherwise leave defaults:

• Database details, select Enter database information
• Database connection string : CDB Connection String value
• Initial load database username: system
• Initial load database password: Select Admin Password
• Select Use different credentials for replication
• Replication database username: c##ggadmin
• Replication database password: Select Admin Password

Note: Everywhere I mentioned Admin Password that actually means a common password I used for database system user, CDB c##ggadmin user, and goldengate ggadmin user and ADB admin user.

Please uncheck the checkbox Create private endpoint to access this database.

7. Press Create

8. Wait for connection to get created and press Test connection to confirm that your Database Connection details are correct

If the test is not successful, correct your connection details and try again

Task 2: Create Database Connection for Source PDB

For this task you need the following info from previous steps:

• Source DB Public IP
• Source DB PDB Service Name
• Database Administrator Password

1. In the OCI Console Menu, go to Migration & Disaster Recovery > Database Migration > Database Connections

2. Press Create connection

3. On the page General information, fill in the following entries, otherwise leave defaults:

• Name: SourcePDB
• Type: Oracle Database
• Vault: DMSVault
• Encryption Key: DMSKey

4. Press Next

5. On the page Connection details, fill in the following entries, otherwise leave defaults:

• Database details, select Enter database information
• Database connection string: PDB Connection String
• Initial load database username: system
• Initial load database password: Select Admin Password
• Select Use different credentials for replication
• Replication database username: ggadmin
• Replication database password: Select Admin Password

Please uncheck the checkbox Create private endpoint to access this database.

6. Press Create

7. Wait for connection to get created and press Test connection to confirm that your Database Connection details are correct

Task 3: Create Database Connection for Target ADB

For this task you need the following info from previous steps:

• Administrator Password

1. In the OCI Console Menu, go to Migration & Disaster Recovery > Database Migration > Database Connections

2. Press Create connection

3. On the page General information, fill in the following entries, otherwise leave defaults:

• Name: TargetADB
• Type: Oracle Autonomous Database
• Vault: DMSVault
• Encryption Key: DMSKey

4. Press Next

5. On the page Connection details, fill in the following entries, otherwise leave defaults:

• Database: TargetADB#####
• Initial load database username: admin
• Initial load database password: Select Admin Password
• Select Use different credentials for replication
• Replication database username: ggadmin
• Replication database password: Select Admin Password

Please uncheck the checkbox Create private endpoint to access this database needs to stay unchecked.

6. Press Create

Please wait for all Database Connection resources to display as Active before proceeding to the next task.

7. Press Test connection to confirm that your Database Connection details are correct

8. Database Connections Details as below

Part 2 coming soon!!! Stay tuned...

Mentions:

Oracle Cloud Computing Oracle Cloud Amazon Web Services (AWS) Microsoft Azure Google Cloud @ OCI Database Migration Services @Oracle CDB @Oracle PDB @AutonomousDB