this is the xml code for the hz_proxy_server.xml and someone please write the alternate code for this one for the hazelcast 5.2.1
<hazelcast-client xsi:schemaLocation=""
xmlns=""
xmlns:xsi="">
<group>
<name>HZuser</name>
<password>passwd</password>
</group>
<network>
<cluster-members>
<address>199.23.32.23:1212</address>
</cluster-members>
<aws enabled="false"/>
<connection-timeout>50000</connection-timeout>
<connection-attempt-period>9000</connection-attempt-period>
<connection-attempt-limit>4</connection-attempt-limit>
</network>
<properties>
<property name="hz.loging.type">log4j</property>
<property name="hz.cli.heartbeat.interval">2345</property>
<property name="hz.cli.heartbeat.timeout">5654</property>
<property name="hz.cli.invocation.timeout.seconds">35</property>
</properties>
</hazelcast-client>
First please see related document for migrations, you can probably find answers for all your possible questions in there: https://docs.hazelcast.com/imdg/4.2/migration-guides
And your new xml should be like this: