Oracle RDS Multi-AZ Failover: High Availability in AWS

March 31, 2025 ~ admin ~ Leave a comment

Amazon RDS Multi-AZ deployments enhance high availability and reliability for database instances by automatically replicating data to a standby instance in a different Availability Zone (AZ). In the event of a failure, AWS performs an automatic failover to the standby, minimizing downtime and ensuring business continuity. This setup is essential for mission-critical applications that require seamless database availability and disaster recovery.

Lets see how much does it take to perform Oracle RDS database failover? To find out, I created a small Oracle RDS database and tested failover with AWS CLI.

Deploy Oracle on ECS Fargate

March 16, 2025March 16, 2025 ~ admin ~ Leave a comment

If you want auto-scaling and managed containers, AWS ECS has to be used. It has many advantages and some of the main ones are
– Easier Oracle deployment without full VM installations
– More flexibility compared to RDS (can run XE, SE2, or Enterprise)
– Good for cost savings (shutdown when not in use)
– Enables containerized workflows on AWS
– Works well with ECS, Fargate, or Kubernetes for scalability

Lets go through the steps and see how it works.

Disclaimer:
Some steps or configurations described in this post may incur charges when using AWS services. It is your responsibility to review AWS pricing and monitor your usage. After testing, ensure that all resources are properly deleted to avoid unexpected charges. Always use the AWS Free Tier where applicable and test responsibly.

1. Create an ECS Cluster
Go to AWS ECS Console -> Clusters -> Click Create Cluster. I named it ora-cls.
Choose AWS Fargate (serverless).
Click Create.

Cluster creation can be monitored in CloudFormation under Stacks.

2. Create a Task Definition for Oracle
Go to AWS ECS -> Task Definitions -> Click Create New Task Definition. I named it OraXE.
Choose AWS Fargate and unique task definition family name.

Configure the container –
– Container Name: orax213
– Image: XE image in your ECR repository. Check here how to add Docker image to ECR Repository.
– Memory: 3GB
– Port Mapping: 1521 (TCP)

Under Environment variables set the following key – ORACLE_PWD with value ‘oracle’. This is sys password for the Oracle XE database.

The rest can be left as it is. Click Create Task Definition.

3. After creating the task definition, now task can be run from this definition.
Go to ECS Clusters -> Task definitions and select the OraXE. From the menu for Task definition, select Deploy and then just click ‘Run task’.
The ‘Create’ dialog is shown and ora-cls cluster is selected (as there are no other cluster), you can select another cluster if you have more than one.
In ECS, clusters and task definitions are separate entities, but when you run a task (or create a service), you specify the cluster in which the task will run.
Leave all settings as they are – for this exercise no need to make any additional storage or network changes.
Click on Create.

Task status can be seen under Clusters -> <cluster name> -> Tasks
Now, Oracle is running fully managed inside ECS.

You might check the task logs – under Logs tab for the task – to see any unusual/errors by task start

4. Connect to the container
There are different ways to connect to the container – I will use one small EC2 instance in the same VPC running Amazon Linux and Oracle instance client installed on it.
Do not forget to change the security group associated with your Fargate task – add inbound rule allowing 1521 port from the security group of the EC2 instance.
You can directly select Type Oracle-RDS – it is for port 1521 .

Get the container private IP – under Networking settings for the running task.

sqlplus sys/Oracle123@//<Fargate Private IP>:1521/XEPDB1 as sysdba

Happy clouding!

Add Oracle XE Docker Image to ECR Repository

March 11, 2025March 16, 2025 ~ admin ~ 1 Comment

Here’s a short description how to get an Oracle XE Docker image from the Oracle Container Registry (https://container-registry.oracle.com) and add it to ECR Repository.

1. Prerequisites
Docker must be installed and running on your local machine.
AWS CLI must be configured with the necessary permissions to access ECR
Oracle account is needed to access the Oracle Container Registry.

Docker and AWS CLI can be installed on your local machine or if you prefer on small EC2 instance with free tier eligible. Here EC2 instance will be used.
How to install docker on EC2 – check here.

2. Log in to the Oracle Container Registry
From your EC2 login to container-registry.oracle.com

docker login container-registry.oracle.com

3. Pull the Oracle XE Docker Image
docker pull container-registry.oracle.com/database/express:latestt
latest: Pulling from database/express
2318ff572021: Pull complete
c6250726c822: Pull complete
33ac5ea7f7dd: Pull complete
753e0fae7e64: Pull complete
Digest: sha256:dcf137aab02d5644aaf9299aae736e4429f9bfdf860676ff398a1458ab8d23f2
Status: Downloaded newer image for container-registry.oracle.com/database/express:latest
container-registry.oracle.com/database/express:latest

Verify the image was downloaded
docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
container-registry.oracle.com/database/express latest 8da8cedb7fbf 19 months ago 11.4GB

4. Create an ECR Repository in AWS
Navigate to Elastic Container Registry (ECR) and click on Create. Provide a name for the repository(f.i. oracle-xe) and configure settings (or just leave them as they are).

5. Authenticate Docker to Your ECR Registry

To push images to ECR, authenticate Docker with your ECR registry:

— Replace <region> with your AWS region (e.g., us-west-1) and <aws_account_id> with your AWS account ID.
— ‘aws configure’ must have been started before
aws ecr get-login-password –region <region> | docker login –username AWS –password-stdin <aws_account_id>.dkr.ecr.<region>.amazonaws.com
…
Login Succeeded

6. Tag the Oracle XE Image for ECR

–Replace: <aws_account_id> with your AWS account ID, <region> with your AWS region, <repository_name> with the name of your ECR repository, <tag> with the desired tag.

docker tag container-registry.oracle.com/database/express:latest <aws_account_id>.dkr.ecr.<region>.amazonaws.com/<repository_name>:<tag>

7. Push the Oracle XE Image to ECR
docker push <aws_account_id>.dkr.ecr.<region>.amazonaws.com/<repository_name>:<tag>

8. Verify the Image in ECR
From AWS Management Console navigate to Elastic Container Registry (ECR), select your repository and verify that Oracle XE image has been successfully pushed

9. When you finish, EC2 instance can be terminated if no more needed.

10. Pull the Image from ECR
To pull the image from ECR to another machine or service

docker pull <aws_account_id>.dkr.ecr.<region>.amazonaws.com/<repository_name>:<tag>

Happy clouding!

Deploy Oracle on Docker in EC2

March 11, 2025March 16, 2025 ~ admin ~ 1 Comment

Deploying Oracle Database inside a Docker container on AWS has the following advantages –

– Easier Oracle deployment without full VM installations.
– More flexibility compared to RDS (can run XE, SE2, or Enterprise).
– Good for cost savings (shutdown when not in use).
– Enables containerized workflows on AWS.
– Works well with ECS, Fargate, or Kubernetes for scalability.

And of course it is good possibility to play a bit with Oracle on AWS and to refresh your skills with one simple hands-on exercise.

Running Oracle on Docker is simple and gives you full control over your container.

1. Launch an EC2 Instance
This is pretty simple, under EC2 section in AWS Console name your EC2 instance, select Amazon Linux(or what distribution you prefer), instance type (I am going to use t2.medium – not free tier, but need more memory – docker image comes wit SGA 1536M), Key pair, storage 50G gp3 (for non-prod general purpose ssd is fine). Do not forget to select appropriate security group and to allow ssh from anywhere and public IP auto-assign – yes, I know, this is not good idea, but hey, I am not building production environment, just exercising aws 😉

2. Install Docker & Dependencies
There are different ways to connect to your EC2 instance, I just will use EC2 Instance Connect here – connect and run

sudo yum install -y docker
sudo systemctl enable docker
sudo systemctl start docker
sudo usermod -aG docker ec2-user

3. Get the Oracle Docker Image
Log out and log in for group changes to take effect.
Run the following command to get Oracle Database XE Release 21c (21.3.0.0) Docker Image –

docker pull container-registry.oracle.com/database/express:latest
latest: Pulling from database/express
2318ff572021: Pull complete
c6250726c822: Pull complete
33ac5ea7f7dd: Pull complete
753e0fae7e64: Pull complete
Digest: sha256:dcf137aab02d5644aaf9299aae736e4429f9bfdf860676ff398a1458ab8d23f2
Status: Downloaded newer image for container-registry.oracle.com/database/express:latest
container-registry.oracle.com/database/express:latest

Verify it –
docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
container-registry.oracle.com/database/express latest 8da8cedb7fbf 19 months ago 11.4GB

4. Run the Oracle Container

docker run –name orax213 \
-p 1521:1521 -p 5500:5500 \
-e ORACLE_PWD=welcome1 \
-e ORACLE_CHARACTERSET=AL32UTF8 \
-v /home/ec2-user/oradata \
-d container-registry.oracle.com/database/express

5. Verify Oracle is Running

docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
8cbe510f2dd8 container-registry.oracle.com/database/express “/bin/bash -c $ORACL…” About a minute ago Up About a minute (healthy) 0.0.0.0:1521->1521/tcp, :::1521->1521/tcp, 0.0.0.0:5500->5500/tcp, :::5500->5500/tcp orax213

Connect to the database (XEPDB1 is the service name for the first PDB created by default) –
docker exec -it orax213 sqlplus sys/welcome1@//localhost:1521/XEPDB1 as sysdba

SQL*Plus: Release 21.0.0.0.0 – Production on Tue Mar 11 09:41:01 2025
Version 21.3.0.0.0

SQL> show pdbs

CON_ID CON_NAME OPEN MODE RESTRICTED
———- —————————— ———- ———-
3 XEPDB1 READ WRITE NO

If you check for the smon db process –
ps -ef | grep smon
54321 28698 28585 0 09:38 ? 00:00:00 xe_smon_XE

you will notice that the owner of the process is 54321 – this is because Oracle inside the container runs as user ID 54321.

At the end stop and remove the container

docker stop 8cbe510f2dd8
docker rm 8cbe510f2dd8

and terminate the EC2 instance.

Happy clouding!

Running Databases on AWS: Architecture, Performance & Practical Benchmarks

Month: March 2025

Oracle RDS Multi-AZ Failover: High Availability in AWS

Deploy Oracle on ECS Fargate

Add Oracle XE Docker Image to ECR Repository

Deploy Oracle on Docker in EC2