public String getLastActiveJobModelVersion() {
    String lastActiveJobModelVersion = zkClient.readData(keyBuilder.getActiveJobModelVersionPath(), true);
    metrics.reads.inc();
    return lastActiveJobModelVersion;
  }
Read the version of the job model that is the most recent agreed version by the quorum.
@return most recent active job model version
samza-core/src/main/java/org/apache/samza/zk/ZkUtils.java