public void toInstanceHierarchyRelation(String upperInstanceName,
                                            String upperServiceName,
                                            Layer upperServiceLayer,
                                            String lowerInstanceName,
                                            String lowerServiceName,
                                            Layer lowerServiceLayer) {
        if (!this.isEnableHierarchy) {
            return;
        }
        Map<String, HierarchyDefinitionService.MatchingRule> lowerLayers = getHierarchyDefinition().get(upperServiceLayer.name());
        if (lowerLayers == null || !lowerLayers.containsKey(lowerServiceLayer.name())) {
            log.error("upperServiceLayer " + upperServiceLayer.name() + " or lowerServiceLayer " + lowerServiceLayer.name()
                          + " is not defined in hierarchy-definition.yml.");
            return;
        }

        buildInstanceHierarchyRelation(upperInstanceName, upperServiceName, upperServiceLayer, lowerInstanceName,
                                           lowerServiceName, lowerServiceLayer);
    }
Build the hierarchy relation between the 2 instances. the `serviceLayer` and `relatedServiceLayer` hierarchy
relations should be defined in `config/hierarchy-definition.yml`.

@param upperInstanceName        the name of the upper instance
@param upperServiceName         the name of the upper service
@param upperServiceLayer        the layer of the upper service
@param lowerInstanceName the name of the lower related instance
@param lowerServiceName  the name of the lower related service
@param lowerServiceLayer the layer of the lower related service
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/hierarchy/HierarchyService.java