Log4j2 kafka appender failover handling when all of Kafka Brokers are unavailable?

I am sending all my application logs to the Kafka using Log4j2 Kafka appender and it works. But in a situation, when I purposefully bring down the broker, the application gets hung-up and the kafka appender keeps on retrying to establish the connection.

How can I stop writing into Kafka when the broker(s) are down? and resume once it is available?

Following is the appender configuration I have used.

<Kafka name="KafkaServiceStatInfo" topic="testKafkaLogs">
                <PatternLayout pattern="%m"/>
            <Property name="bootstrap.servers">localhost:9092</Property>
            <Property name="acks">0</Property>
        </Kafka>
        <Async name="Async">
            <AppenderRef ref="KafkaServiceStatInfo"/>
        </Async>