How to properly throw runtime exception and restart docker container

Question

I have a Docker container with a Java application that uses a DB to persist some data. My application has a class that extends another one that is not code of mine (specifically SinkTask, a class from Kafka that is used to transfer data from Kafka to another system). When the application starts it opens a connection to the database. Sometimes, the database closes the connection and tasks start to fail. The exceptions thrown by these failures are catched in one part of my code and I can think of different ways to handle them: 1. Simply executing the code from within the application that stops and starts the connection again 2. Restarting the Docker container, creating a new connection in the process

I think the best solution is number 1. However, I wanted to know how could I trigger the second situation. My guess is that I should throw a new Exception in the catch block capable of terminating the application (remember that the SinkTask part of the code is out of my control). Would this be a good solution? Which kind of Exception should I throw in this case?

This is the part of the code where I catch the exception

    private void commitCollections() {
        for (SinkCollection sc : collections.values()) {
            try {
                commitCollection(sc);
            } catch (Exception e) {
                LOG.error("Error flushing collection " + sc.getTableName(), e);
            }
        }
        transactionRecordCount = 0;
        try {
            connection.commit();
        } catch (SQLException e) {
            LOG.error("Commit error", e);
        }
    }

Answer 1

Throwing an Exception and letting it propagate in order to terminate the application is a perfectly nice solution. IMO, using System.exit(exit_code) would be better because it clearly describes what that code is doing.

In addition, docker will display the exit_code in the status of the container (docker ps -a), thus helping differentiate between different error conditions. When an uncaught exception is thrown the exit code is always 1.

Hope that helps.