<p>I´m trying to run hazelcast on Kubernetes, i have 2 pods with hazelcast last version image
:hazelcast/hazelcast running, each pod detect each other so all okay.</p>
<p>When I run the pod with my spring boot aplication that have:</p>
<pre><code>&lt;hazelcast.ver&gt;3.9-EA&lt;/hazelcast.ver&gt;
</code></pre>
<p>Also I use</p>
<pre><code> &lt;groupId&gt;com.hazelcast&lt;/groupId&gt;
              &lt;artifactId&gt;hazelcast-client&lt;/artifactId&gt;
              &lt;version&gt;3.9-EA&lt;/version&gt;
</code></pre>
<p>I get on hazelcast pod this error:</p>
<pre><code>java.lang.IllegalStateException: Unknown protocol: CB2
    at `com.hazelcast.internal.server.tcp.UnifiedProtocolDecoder.onRead(UnifiedProtocolDecoder.java:132) ~[hazelcast-5.2.1.jar:5.2.1]`
</code></pre>
<p>Any idea ?</p>

flteam
<p>Hazelcast clients of version 3.x are not compatible with Hazelcast 4.x or 5.x servers. Since the Hazelcast version you use for your servers is 5.2.1 (latest, as of now) 3.9 clients cannot work with them. You need to use 4.x or 5.x clients in your Spring Boot application, preferably the same version with your server.</p>
