Integration with RDS

This issue collects all the requirements for RDS support in Spring Cloud AWS 3.0 (based on AWS SDK v2).

The key feature in RDS integration is support for read replicas:

• use RDS read replicas for readOnly connections (transactions started with @Transactional(readOnly=true)

Additionally we need to support:

• https://github.com/awspring/spring-cloud-aws/issues/320
• failover

Both can be achieved with official drivers:

• https://github.com/awslabs/aws-mysql-jdbc
• https://github.com/awslabs/aws-postgresql-jdbc

Regarding read replicas support, in addition to what has been offered in 2.x we must support:

• ability to choose connection pool (in 2.x only Tomcat pool is supported)
• ability to choose JDBC driver
• Add support for passing query parameters to JDBC url #679
• Aurora

To research:

• should we support RDS proxy?
• should we support Aurora Serverless?

[virajkanwade]

For handling clusters -

can we add a flag cloud.aws.employee-db.isCluster=true

And in https://github.com/spring-attic/spring-cloud-aws/blob/e9e7b8cb158013464caa792b3e2de9cf7179678a/spring-cloud-aws-jdbc/src/main/java/org/springframework/cloud/aws/jdbc/rds/AmazonRdsReadReplicaAwareDataSourceFactoryBean.java#L73

Replace getDBInstance with getDBClusterInstance which uses this.amazonRds.describeDBClusters to get the writer instance and getReadReplicaIdentifiers to get read replica identifiers and rest of the code remains the same?

[areddy23]

Hi I am assuming spring-cloud-starter-aws-jdbc is a “io.awspring.cloud” version of “spring-cloud-aws-jdbc” ( 2.x.x version)

I feel this enhancement request should be backed in to 3.x.x if not already.

Steps to recreate:

1. Create a Primary RDS(abc) with Read Replicas in 2 diff regions us-east-1(abc-rr-1) and us-west-2(abc-rr-2). When you configure current “spring-cloud-aws-jdbc” to manage traffic to RR’s it fails the reason is as follows.

In 2.x.x the library is attempting to “createInstance” and calls describe-db-instances which results below: (using cli to replicate the issue)

Class: AmazonRdsReadReplicaAwareDataSourceFactoryBean method: createInstance

1. “aws rds describe-db-instances --db-instance-identifier abc” Primary DB is yielding a list of RR associate with it across regions, please note it is returning DB Identifier for the RR in the same region and arn for the RR in diff region. ============== aws rds describe-db-instances --db-instance-identifier prod-pgsql

From result: “ReadReplicaDBInstanceIdentifiers”: [ “abc-rr1”, “arn:aws:rds:us-west-2:12345678910:db:abc-rr-2” ],

1. For the above list when li to do “describe-db-instances” for each one “arn:aws:rds:us-west-2:868769925241:db:prod-pgsql-pdx-replica” it is resulting in below error which is consistent with what we are receiving from the application. ============== aws rds describe-db-instances --db-instance-identifier arn:aws:rds:us-west-2:868769925241:db:prod-pgsql-pdx-replica

An error occurred (InvalidParameterValue) when calling the DescribeDBInstances operation: The parameter Filter: db-instance-id is not a valid identifier. Identifiers must begin with a letter; must contain only ASCII letters, digits, and hyphens; and must not end with a hyphen or contain two consecutive hyphens.

Class: AmazonRdsDataSourceFactoryBean method: createDataSourceInstance -> getDbInstance

DescribeDBInstancesResult describeDBInstancesResult = this.amazonRds.describeDBInstances((new DescribeDBInstancesRequest()).withDBInstanceIdentifier(identifier)); -> This results in failure as we are doing describe-db-instances with an arn.

Potential solution: getDbInstance method should identify if aws returned an ARN and convert the describe-db-instances to be following aws rds describe-db-instances --db-instance-identifier abc-rr-2 --region us-west-2 instead of calling directly using ARN.

I am unable to open a PR as I am not sure where this module exists.