Application deployed on Amazon ECS (using Fargate) is facing issues connecting with Serverless Aurora DB.
I can successfully connect to this serverless DB using the bastion host, EC2 instance in the same VPC with public IP and SSH Tunnel.
DB connection works successfully for provisioned EngineMode but for serverless it throws the following error:
2020-11-23 10:31:09.378 ERROR [main] com.zaxxer.hikari.pool.HikariPool request-id: ; user-id: - jdbc:mysql:aurora://db-cluster-endpoint.us-west-2.rds.amazonaws.com:3306/test_service - Exception during pool initialization.
java.sql.SQLNonTransientConnectionException: Communications link failure with primary. No active connection found for master.
at org.mariadb.jdbc.internal.failover.AbstractMastersListener.throwFailoverMessage(AbstractMastersListener.java:559)
at org.mariadb.jdbc.internal.failover.impl.MastersSlavesListener.checkInitialConnection(MastersSlavesListener.java:350)
...
at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:473)
at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:554)
at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115)
DB Cluster Configuration: I've disabled the auto-pause feature and configured cluster such that 2 instances would be up all the time. I can see CPU utilization and capacity unit 2 in RDS (AWS Console).
Type: AWS::RDS::DBCluster
Properties:
BackupRetentionPeriod: !Ref DbBackupRetentionPeriod
DBClusterParameterGroupName: !Ref DbClusterParameterGroup
DBSubnetGroupName: !Ref DbSubnetGroup
Engine: aurora-mysql
EngineMode: serverless
ScalingConfiguration:
AutoPause: false
MinCapacity: 2
MaxCapacity: 32
Datasource configuration:
<bean name="dataSource" class="com.zaxxer.hikari.HikariDataSource">
<property name="jdbcUrl"
value="#{'jdbc:mysql:aurora') + '//${database.host}:${database.port:3306}/${database.name}'}"/>
<property name="username" value="${database.username}"/>
<property name="password" value="${database.password}"/>
<property name="driverClassName" value="org.mariadb.jdbc.Driver"/>
SOLVED:
The problem was with the access restriction for the user that a client was using to establish a DB connection.