how_to_debug.md

There is an exception occurring randomly during running full unit tests.

For example: connection obtained from connection pool is closed.

• Step one: in Connection.close() method:

// log the how/where the connection is closed.
public class Connection {
	...
	private Exception lastStackTrace;
	...

	public void close() {
		...
		lastStackTrace = new RuntimeException();
	}

	public boolean isClosed() {
		...
	}

	public void printStackTrace() {
		lastStackTrace.printStackTrace();
	}
...
}

• Step two: in Caller method:

public class SomeClass {
	...
	public void caller() {
		Connection conn = getConnection(); // from pool

		// add below log, so you know where/how the Connection was closed.
		if (conn.isClosed()) {
			conn.printStackTrace();
			Thread.sleep(1000)
			System.exit(1);
		}
	}
	...
}