Category: Kev’s Blog

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Installing Oracle Instant Client and Tools in an AWS EC2

I’m using the AWS Amazon Linux 2 AMI on my EC2. To download the Oracle Instant Client get the download urls for the instant client and instant client tools from: https://www.oracle.com/database/technologies/instant-client/linux-x86-64-downloads.html

Download using curl and install with rpm:

curl instant-client-url-from-page-above --output instant-client.rpm
rpm -i instant-client.rpm
curl instant-client-tools-from-page-above --output instant-client-tools.rpm
rpm -i instant-client-tools.rpm

To connect using sql-plus:

sqlplus 'admin@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=your-instance-endpoint.rds.amazonaws.com)(PORT=1521))(CONNECT_DATA=(SID=your-db-name)))'

Enter password when prompted.

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AWS Lambda access to AWS RDS databases

For a Lambda to access an AWS RDS database instance, it needs to be in the same VPC as the RDS instance. However, if you haven’t created and assigned a role with persmissions for the Lambda to access the VPC, you’ll see this error when creating your Lambda:

To fix this per steps in the tutorial here, create a role with permission ‘AWSLambdaVPCAccessExecutionRole’.

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Connecting to an AWS RDS Oracle instance from an EC2 in same VPC

I’ve created an RDS Oracle instance and I want to connect to it from an EC2 instance. I created both in the same VPC.

By default, even though they’re in the same VPC, the EC2 will not be able to connect to the Oracle instance because you still need to configure the Security Group to allow inbound traffic.

Let’s summarize the setup like this – both are in VPC1:

EC2 : Security Group SG-111

RDS Oracle instance: Security Group SG-222

Edit SG-222 for the Oracle instance, and add an inbound rule. Instead of adding a CIDR block range, start typing SG-111… and it will list matching SGs with that id – click to select the id for Security Group associated to the EC2. You’ve now allowed inbound traffic to your RDS Oracle instance from the EC2.

Done!

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Creating AWS RDS Oracle instances for personal dev projects

AWS (as in any cloud provider) for spinning something up ondemand for a quick test. Need an Oracle database? Couple of clicks and you’re done.

With the RDS options on AWS be careful of the EC2 type if you’re trying to keep costs down. For example if you leave the DB Instance Size at ‘Standard’, you only get db.m4 and db.m5 instances which are definitely not your cheapest options:

If you select ‘Burstable’, the smallest instance size you can select is a db.t3.small:

According to the Simple Monthly Calculator, at 100% 24/7 usage for a month the cost is around $57/month:

If you’re usage for development is going to be low, and/or if you can stop the instance when you’re not using it (and only pay for storage), for example at 10% usage for a month you can get the cost down to around $8:

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