@Override
  public String getDiagnosis() {
    checkClosed();

    StringBuilder sb = new StringBuilder();

    synchronized (this) {
      for (final Object value : hostMembers.values()) {
        List members = (List) value;
        for (final Object o : members) {
          GemFireVM member = (GemFireVM) o;
          String[] diagnoses = member.getHealthDiagnosis(overallHealth);
          for (final String diagnosis : diagnoses) {
            sb.append(diagnosis).append("\n");
          }
        }
      }
    }

    return sb.toString();
  }
Aggregates the diagnoses from all members of the distributed system.
geode-core/src/main/java/org/apache/geode/admin/internal/GemFireHealthImpl.java