title: Unable to send message to kafka topic from neo4j stream
body: <p>I'm trying to send messages from neo4j stream to kafka topic.</p>
  <p>this is my docker-compose configuration for neo4j</p>
  <pre><code>version: '3'
  services:
    neo4j:
      image: neo4j:3.5.8-enterprise
      hostname: klinks
      container_name: klinks
      volumes:
        - ./plugins:/plugins
      ports:
      - &quot;7474:7474&quot;
      - &quot;7687:7687&quot;
      environment:
        NEO4J_dbms_logs_query_threshold: 0s
        NEO4J_dbms_logs_query_enabled: &quot;true&quot;
        NEO4J_cypher_lenient__create__relationship: &quot;true&quot;
        NEO4J_apoc_trigger_enabled: &quot;true&quot;
        NEO4J_dbms_security_procedures_unrestricted: &quot;apoc.*,algo.*&quot;
        NEO4J_ACCEPT_LICENSE_AGREEMENT: &quot;yes&quot;
        NEO4J_dbms_logs_debug_level: DEBUG
        NEO4J_dbms_memory_heap_max__size: 2G
        NEO4J_dbms_memory_heap_initial__size: 1G
        NEO4J_dbms_memory_pagecache_size: 1G
        NEO4J_AUTH: neo4j/admin  #la password è admin
        NEO4J_ACCEPT_LICENSE_AGREEMENT: &quot;yes&quot;
        NEO4J_kafka_group_id: p2
        NEO4J_streams_sink_topic_cypher_friends: &quot;
          MERGE (p1:Person { name: event.initiated }) 
          MERGE (p2:Person { name: event.accepted }) 
          CREATE (p1)-[:FRIENDS { when: event.date }]-&gt;(p2)
        &quot;
        NEO4J_streams_sink_enabled: &quot;true&quot;
        NEO4J_streams_procedures_enabled: &quot;true&quot;
        NEO4J_streams_source_enabled: &quot;true&quot;
        NEO4J_kafka_zookeeper_connect: docker.for.win.localhost:2181
        NEO4J_kafka_bootstrap_servers: docker.for.win.localhost:9092
        NEO4J_streams_source_topic_nodes_recommendations: Person{*}
        NEO4J_streams_source_schema_polling_interval: 10000
        NEO4J_kafka_acks: 1
        NEO4J_kafka_num_partitions: 1
        NEO4J_kafka_retries: 2
        NEO4J_kafka_batch_size: 16384
        NEO4J_kafka_buffer_memory: 33554432
        NEO4J_kafka_session_timeout_ms: 15000
        NEO4J_kafka_reindex_batch_size: 1000
        NEO4J_kafka_connection_timeout_ms: 10000
        NEO4J_kafka_replication: 1
        NEO4J_kafka_linger_ms: 1
  </code></pre>
  <p>my final flow should be</p>
  <p>1 [<strong>OK</strong>]. Send a message to  <code>friends</code> topic on <code>kafka</code> with a java producer</p>
  <p>2 [<strong>OK</strong>]. Publish this <code>friends</code> stream to <code>neo4j</code> using the neo4j sink connector applying this rule</p>
  <pre><code>  MERGE (p1:Person { name: event.initiated }) 
          MERGE (p2:Person { name: event.accepted }) 
          CREATE (p1)-[:FRIENDS { when: event.date }]-&gt;(p2)
  </code></pre>
  <p>3 [<strong>Not works</strong>]. Stream back to <code>kafka</code> some data from a <code>neo4j</code> query or listen on some kind of node
  In my configuration (just for testing purpose) i listen on Node of type <code>Person{*}</code></p>
  <pre><code>...
    NEO4J_streams_source_topic_nodes_recommendations: Person{*}
  ...
  </code></pre>
  <p>Step 1 and 2 works as expected, step 3 fail, i see this logs from <code>neo4j</code></p>
  <pre><code>klinks   | 2020-10-02 11:01:17.402+0000 DEBUG Trying to send a transaction event with txId 8 and txEventId 8 to kafka -&gt; recommendations
  klinks   | 2020-10-02 11:02:17.404+0000 DEBUG Sent record in partition null offset null data null key size null
  </code></pre>
  <p>i think i missing something in the configuration of the neo4j stream. Can someone help me to understand.</p>