@Override
  public GemFireHealth.Health getHealth() {
    checkClosed();
    return overallHealth;
  }
Returns the overall health of GemFire. Note that this method does not contact any of the member
VMs. Instead, it relies on the members to alert it of changes in its health via a
{@link HealthListener}.
geode-core/src/main/java/org/apache/geode/admin/internal/GemFireHealthImpl.java