@Override
  public String toString() {
    return getClass().getSimpleName() + "(" + memberID
        + (credentials == null ? ")" : "; with credentials)") + " failureDetectionPort:"
        + failureDetectionPort;
  }
A JoinRequestMessage is sent from a prospective member of the cluster to a node
that it believes is the coordinator. Members should retain this message in the
event that they become the coordinator and need to send out a membership view
allowing the prospective member to join. A member that is already filling the role
of coordinator will prepare and install a new membership view allowing the prospect
to join.<br>
A prospective member is not part of the cluster until an InstallViewMessage(INSTALL) has
been sent to the cluster. At that time the membership view will contain its valid
membership address, including it's view ID. This must be registered in the new member's
MemberData. Failure to do so may result in the new member being kicked out of the cluster.
geode-membership/src/main/java/org/apache/geode/distributed/internal/membership/gms/messages/JoinRequestMessage.java