@Override
  @SuppressWarnings("ReferenceEquality")
  public boolean equals(Object obj) {
    if (obj == this) {
      return true;
    }
    if (!(obj instanceof ConnectionId)) {
      return false;
    }
    ConnectionId id = (ConnectionId) obj;
    return address.equals(id.address)
      && ((ticket != null && ticket.equals(id.ticket)) || (ticket == id.ticket))
      && Objects.equals(this.serviceName, id.serviceName);
  }
This class holds the address and the user ticket, etc. The client connections to servers are
uniquely identified by &lt;remoteAddress, ticket, serviceName&gt;
hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/ConnectionId.java