@Override
    public synchronized void stopConnector(String connName, Callback<Void> callback) {
        try {
            removeConnectorTasks(connName);
            configBackingStore.putTargetState(connName, TargetState.STOPPED);
            callback.onCompletion(null, null);
        } catch (Throwable t) {
            callback.onCompletion(t, null);
        }
    }
Single process, in-memory "herder". Useful for a standalone Kafka Connect process.
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/standalone/StandaloneHerder.java