DeviceContextImpl.java class is first starting services before changing mastership on the switch. This could lead to potential race conditions which controllers start sending changes before being master.

I suggest that DeviceContextImpl.java should first ensure it holds the mastership to the switch and if it works start the services.

So, the method

public boolean onContextInstantiateService(final ConnectionContext connectionContext) {

Should call following line after checking connection is not dead.

Futures.addCallback(sendRoleChangeToDevice(OfpRole.BECOMEMASTER), new RpcResultFutureCallback());

For example,

@Override
public boolean onContextInstantiateService(final ConnectionContext connectionContext) {

if (getPrimaryConnectionContext().getConnectionState().equals(ConnectionContext.CONNECTION_STATE.RIP)) {
LOG.warn("Connection on device {} was interrupted, will stop starting master services.", deviceInfo.getLOGValue());
return false;
}

Futures.addCallback(sendRoleChangeToDevice(OfpRole.BECOMEMASTER), new RpcResultFutureCallback());