ClickHouse/tests/integration/test_cluster_copier/task_self_copy.xml

<?xml version="1.0"?>
<clickhouse>
    <tcp_port_secure>9440</tcp_port_secure>
    <remote_servers>
        <source_cluster>
            <shard>
                <internal_replication>false</internal_replication>
                <replica>
                    <host>s0_0_0</host>
                    <port>9000</port>
                    <user>dbuser</user>
                    <password>12345678</password>
                    <secure>0</secure>
                </replica>
            </shard>
        </source_cluster>

        <destination_cluster>
            <shard>
                <internal_replication>false</internal_replication>
                <replica>
                    <host>s0_0_0</host>
                    <port>9000</port>
                    <user>dbuser</user>
                    <password>12345678</password>
                    <secure>0</secure>
                </replica>
            </shard>
        </destination_cluster>
    </remote_servers>

    <max_workers>2</max_workers>

    <settings_pull>
        <readonly>1</readonly>
    </settings_pull>

    <settings_push>
        <readonly>0</readonly>
    </settings_push>

    <settings>
        <connect_timeout>3</connect_timeout>
        <insert_distributed_sync>1</insert_distributed_sync>
    </settings>

    <tables>
        <table1>
            <cluster_pull>source_cluster</cluster_pull>
    	    <database_pull>db1</database_pull>
            <table_pull>source_table</table_pull>

            <cluster_push>destination_cluster</cluster_push>
            <database_push>db2</database_push>
            <table_push>destination_table</table_push>

            <engine>
	            ENGINE = MergeTree PARTITION BY a ORDER BY a SETTINGS index_granularity = 8192
	        </engine>

    	    <sharding_key>rand()</sharding_key>
        </table1>
    </tables>
</clickhouse>