@Override
    public void putConnectorConfig(final String connName, final Map<String, String> config, final TargetState targetState,
                                   final boolean allowReplace, final Callback<Created<ConnectorInfo>> callback) {
        try {
            validateConnectorConfig(config, (error, configInfos) -> {
                if (error != null) {
                    callback.onCompletion(error, null);
                    return;
                }

                requestExecutorService.submit(
                    () -> putConnectorConfig(connName, config, targetState, allowReplace, callback, configInfos)
                );
            });
        } 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