Spring JPA problems AWS Ec2 & RDS

Question

I tried to deploy my Spring application on an AWS EC2 Ubuntu server, so far so good. My Mysql Database was created with RDS where I am possible to connect with eg SequelPro and also with IntelliJ (When running the server locally but with external database)

When I want to run the Server on the EC2 Ubuntu System I run it with

java -jar

for test purposes only. (I know I have to install it as a service later)

But after a while I get this error when the server starts

> 018-06-20 16:26:37.122 ERROR 12116 --- [           main] com.zaxxer.hikari.pool.HikariPool        : HikariPool-1 - Exception during pool initialization.

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_171]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_171]
.
.
.
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_171]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_171]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_171]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_171]
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425) ~[mysql-connector-java-5.1.46.jar!/:5.1.46]
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:990) ~[mysql-connector-java-5.1.46.jar!/:5.1.46]
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:342) ~[mysql-connector-java-5.1.46.jar!/:5.1.46]
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2188) ~[mysql-connector-java-5.1.46.jar!/:5.1.46]
    at com.mysql.jdbc.ConnectionImpl.connectWithRetries(ConnectionImpl.java:2037) ~[mysql-connector-java-5.1.46.jar!/:5.1.46]
    ... 91 common frames omitted
Caused by: java.net.SocketTimeoutException: connect timed out
    at java.net.PlainSocketImpl.socketConnect(Native Method) ~[

Any ideas whats causing the problem? Ports are open in RDS and EC2...

RDS Security group defined as follows: Inbound:

Outbound:

Answer 1

After several hours trying reinstalling etc. I forgot to change the connection string. I don't know why it still works locally with the wrong connection string but on ec2 it works now