private void init() throws InitialComponentCatalogException {
        componentName2Id = new HashMap<>();
        componentName2Id.put("N/A", 0);
        componentId2Name = new HashMap<>();
        componentId2Name.put(0, "N/A");
        componentId2ServerId = new HashMap<>();
        componentIDPriorities = new HashMap<>();

        Map<String, String> nameMapping = new HashMap<>();
        try {
            Reader applicationReader = ResourceUtils.read("component-libraries.yml");
            Yaml yaml = new Yaml();
            Map map = yaml.loadAs(applicationReader, Map.class);

            map.forEach((componentName, settingCollection) -> {
                Map settings = (Map) settingCollection;
                if (COMPONENT_SERVER_MAPPING_SECTION.equals(componentName)) {
                    settings.forEach((name, serverName) -> {
                        nameMapping.put((String) name, (String) serverName);
                    });
                } else {
                    Integer componentId = (Integer) settings.get("id");
                    componentName2Id.put((String) componentName, componentId);
                    componentId2Name.put(componentId, (String) componentName);
                    Integer priority = (Integer) settings.get("priority");
                    if (priority == null) {
                        priority = 50;
                    }
                    componentIDPriorities.put(componentId, priority);
                }
            });

            nameMapping.forEach((name, serverName) -> {
                if (!componentName2Id.containsKey(name)) {
                    throw new InitialComponentCatalogException(
                        "Component name [" + name + "] in Component-Server-Mappings doesn't exist in component define. ");
                }
                if (!componentName2Id.containsKey(serverName)) {
                    throw new InitialComponentCatalogException(
                        "Server componentId name [" + serverName + "] in Component-Server-Mappings doesn't exist in component define. ");
                }

                componentId2ServerId.put(componentName2Id.get(name), componentName2Id.get(serverName));
            });
            nameMapping.clear();
        } catch (FileNotFoundException e) {
            log.error("component-libraries.yml not found.", e);
        }

    }
Key is the component ID.
Value is the priority.
oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/config/ComponentLibraryCatalogService.java