title: Number of connections to Kafka boot strap server
body: <p>I have two topics with 10 partition on each and I am using below code to listen to messages. Here how many connections will establish ? is it 20?
  Does each connection will be at partition level or namespace (bootstarap server) level ?</p>
  <pre><code>@Bean
      public KafkaListenerContainerFactory&lt;ConcurrentMessageListenerContainer&lt;Object, Object&gt;&gt; kafkaListenerContainerFactory() {
          final ConcurrentKafkaListenerContainerFactory&lt;Object, Object&gt; factory = new ConcurrentKafkaListenerContainerFactory&lt;&gt;();
          factory.setConsumerFactory(consumerFactory());
  </code></pre>
  <hr />
  <pre><code> @KafkaListener(topics = &quot;#{'${spring.kafka.topics}'.split(',')}&quot;,
              concurrency = &quot;20&quot;,
              clientIdPrefix = &quot;client123&quot;,
              groupId = &quot;group123&quot;)
      public void listen(final ConsumerRecord&lt;Object, Object&gt; inputEvent) throws Exception {
          handleMessage(inputEvent);
      }
  </code></pre>