elasticSearch6源码分析(2)模块化管理

elasticsearch里面的组件基本都是用Guice的Injector进行注入与获取实例方式进行模块化管理。

在node的构造方法中

/**
     * Constructs a node
     *
     * @param environment                the environment for this node
     * @param classpathPlugins           the plugins to be loaded from the classpath
     * @param forbidPrivateIndexSettings whether or not private index settings are forbidden when creating an index; this is used in the
     *                                   test framework for tests that rely on being able to set private settings
     */
    protected Node(
            final Environment environment, Collection<Class<? extends Plugin>> classpathPlugins, boolean forbidPrivateIndexSettings) {
        logger = LogManager.getLogger(Node.class);
        final List<Closeable> resourcesToClose = new ArrayList<>(); // register everything we need to release in the case of an error
        boolean success = false;
        try {
            originalSettings = environment.settings();
            Settings tmpSettings = Settings.builder().put(environment.settings())
                .put(Client.CLIENT_TYPE_SETTING_S.getKey(), CLIENT_TYPE).build();

            nodeEnvironment = new NodeEnvironment(tmpSettings, environment);
            resourcesToClose.add(nodeEnvironment);
            logger.info("node name [{}], node ID [{}]",
                    NODE_NAME_SETTING.get(tmpSettings), nodeEnvironment.nodeId());

            final JvmInfo jvmInfo = JvmInfo.jvmInfo();
            logger.info(
                "version[{}], pid[{}], build[{}/{}/{}/{}], OS[{}/{}/{}], JVM[{}/{}/{}/{}]",
                Version.displayVersion(Version.CURRENT, Build.CURRENT.isSnapshot()),
                jvmInfo.pid(),
                Build.CURRENT.flavor().displayName(),
                Build.CURRENT.type().displayName(),
                Build.CURRENT.shortHash(),
                Build.CURRENT.date(),
                Constants.OS_NAME,
                Constants.OS_VERSION,
                Constants.OS_ARCH,
                Constants.JVM_VENDOR,
                Constants.JVM_NAME,
                Constants.JAVA_VERSION,
                Constants.JVM_VERSION);
            logger.info("JVM arguments {}", Arrays.toString(jvmInfo.getInputArguments()));
            warnIfPreRelease(Version.CURRENT, Build.CURRENT.isSnapshot(), logger);

            if (logger.isDebugEnabled()) {
                logger.debug("using config [{}], data [{}], logs [{}], plugins [{}]",
                    environment.configFile(), Arrays.toString(environment.dataFiles()), environment.logsFile(), environment.pluginsFile());
            }

            this.pluginsService = new PluginsService(tmpSettings, environment.configFile(), environment.modulesFile(), environment.pluginsFile(), classpathPlugins);
            this.settings = pluginsService.updatedSettings();
            localNodeFactory = new LocalNodeFactory(settings, nodeEnvironment.nodeId());

            // create the environment based on the finalized (processed) view of the settings
            // this is just to makes sure that people get the same settings, no matter where they ask them from
            this.environment = new Environment(this.settings, environment.configFile());
            Environment.assertEquivalent(environment, this.environment);

            final List<ExecutorBuilder<?>> executorBuilders = pluginsService.getExecutorBuilders(settings);

            final ThreadPool threadPool = new ThreadPool(settings, executorBuilders.toArray(new ExecutorBuilder[0]));
            resourcesToClose.add(() -> ThreadPool.terminate(threadPool, 10, TimeUnit.SECONDS));
            // adds the context to the DeprecationLogger so that it does not need to be injected everywhere
            DeprecationLogger.setThreadContext(threadPool.getThreadContext());
            resourcesToClose.add(() -> DeprecationLogger.removeThreadContext(threadPool.getThreadContext()));

            final List<Setting<?>> additionalSettings = new ArrayList<>(pluginsService.getPluginSettings());
            final List<String> additionalSettingsFilter = new ArrayList<>(pluginsService.getPluginSettingsFilter());
            for (final ExecutorBuilder<?> builder : threadPool.builders()) {
                additionalSettings.addAll(builder.getRegisteredSettings());
            }
            client = new NodeClient(settings, threadPool);
            final ResourceWatcherService resourceWatcherService = new ResourceWatcherService(settings, threadPool);
            final ScriptModule scriptModule = new ScriptModule(settings, pluginsService.filterPlugins(ScriptPlugin.class));
            AnalysisModule analysisModule = new AnalysisModule(this.environment, pluginsService.filterPlugins(AnalysisPlugin.class));
            // this is as early as we can validate settings at this point. we already pass them to ScriptModule as well as ThreadPool
            // so we might be late here already

            final Set<SettingUpgrader<?>> settingsUpgraders = pluginsService.filterPlugins(Plugin.class)
                    .stream()
                    .map(Plugin::getSettingUpgraders)
                    .flatMap(List::stream)
                    .collect(Collectors.toSet());

            final SettingsModule settingsModule =
                    new SettingsModule(this.settings, additionalSettings, additionalSettingsFilter, settingsUpgraders);
            scriptModule.registerClusterSettingsListeners(settingsModule.getClusterSettings());
            resourcesToClose.add(resourceWatcherService);
            final NetworkService networkService = new NetworkService(
                getCustomNameResolvers(pluginsService.filterPlugins(DiscoveryPlugin.class)));

            List<ClusterPlugin> clusterPlugins = pluginsService.filterPlugins(ClusterPlugin.class);
            final ClusterService clusterService = new ClusterService(settings, settingsModule.getClusterSettings(), threadPool);
            clusterService.addStateApplier(scriptModule.getScriptService());
            resourcesToClose.add(clusterService);
            final IngestService ingestService = new IngestService(clusterService, threadPool, this.environment,
                scriptModule.getScriptService(), analysisModule.getAnalysisRegistry(), pluginsService.filterPlugins(IngestPlugin.class));
            final DiskThresholdMonitor listener = new DiskThresholdMonitor(settings, clusterService::state,
                clusterService.getClusterSettings(), client);
            final ClusterInfoService clusterInfoService = newClusterInfoService(settings, clusterService, threadPool, client,
                listener::onNewInfo);
            final UsageService usageService = new UsageService(settings);

            ModulesBuilder modules = new ModulesBuilder();
            // plugin modules must be added here, before others or we can get crazy injection errors...
            for (Module pluginModule : pluginsService.createGuiceModules()) {
                modules.add(pluginModule);
            }
            final MonitorService monitorService = new MonitorService(settings, nodeEnvironment, threadPool, clusterInfoService);
            ClusterModule clusterModule = new ClusterModule(settings, clusterService, clusterPlugins, clusterInfoService);
            modules.add(clusterModule);
            IndicesModule indicesModule = new IndicesModule(pluginsService.filterPlugins(MapperPlugin.class));
            modules.add(indicesModule);

            SearchModule searchModule = new SearchModule(settings, false, pluginsService.filterPlugins(SearchPlugin.class));
            CircuitBreakerService circuitBreakerService = createCircuitBreakerService(settingsModule.getSettings(),
                settingsModule.getClusterSettings());
            resourcesToClose.add(circuitBreakerService);
            modules.add(new GatewayModule());

            PageCacheRecycler pageCacheRecycler = createPageCacheRecycler(settings);
            BigArrays bigArrays = createBigArrays(pageCacheRecycler, circuitBreakerService);
            resourcesToClose.add(bigArrays);
            modules.add(settingsModule);
            List<NamedWriteableRegistry.Entry> namedWriteables = Stream.of(
                NetworkModule.getNamedWriteables().stream(),
                indicesModule.getNamedWriteables().stream(),
                searchModule.getNamedWriteables().stream(),
                pluginsService.filterPlugins(Plugin.class).stream()
                    .flatMap(p -> p.getNamedWriteables().stream()),
                ClusterModule.getNamedWriteables().stream())
                .flatMap(Function.identity()).collect(Collectors.toList());
            final NamedWriteableRegistry namedWriteableRegistry = new NamedWriteableRegistry(namedWriteables);
            NamedXContentRegistry xContentRegistry = new NamedXContentRegistry(Stream.of(
                NetworkModule.getNamedXContents().stream(),
                indicesModule.getNamedXContents().stream(),
                searchModule.getNamedXContents().stream(),
                pluginsService.filterPlugins(Plugin.class).stream()
                    .flatMap(p -> p.getNamedXContent().stream()),
                ClusterModule.getNamedXWriteables().stream())
                .flatMap(Function.identity()).collect(toList()));
            modules.add(new RepositoriesModule(this.environment, pluginsService.filterPlugins(RepositoryPlugin.class), xContentRegistry));
            final MetaStateService metaStateService = new MetaStateService(settings, nodeEnvironment, xContentRegistry);

            // collect engine factory providers from server and from plugins
            final Collection<EnginePlugin> enginePlugins = pluginsService.filterPlugins(EnginePlugin.class);
            final Collection<Function<IndexSettings, Optional<EngineFactory>>> engineFactoryProviders =
                    Stream.concat(
                            indicesModule.getEngineFactories().stream(),
                            enginePlugins.stream().map(plugin -> plugin::getEngineFactory))
                    .collect(Collectors.toList());

            final Map<String, Function<IndexSettings, IndexStore>> indexStoreFactories =
                    pluginsService.filterPlugins(IndexStorePlugin.class)
                            .stream()
                            .map(IndexStorePlugin::getIndexStoreFactories)
                            .flatMap(m -> m.entrySet().stream())
                            .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));

            final IndicesService indicesService =
                    new IndicesService(settings, pluginsService, nodeEnvironment, xContentRegistry, analysisModule.getAnalysisRegistry(),
                            clusterModule.getIndexNameExpressionResolver(), indicesModule.getMapperRegistry(), namedWriteableRegistry,
                            threadPool, settingsModule.getIndexScopedSettings(), circuitBreakerService, bigArrays,
                            scriptModule.getScriptService(), client, metaStateService, engineFactoryProviders, indexStoreFactories);

            final AliasValidator aliasValidator = new AliasValidator(settings);

            final MetaDataCreateIndexService metaDataCreateIndexService = new MetaDataCreateIndexService(
                    settings,
                    clusterService,
                    indicesService,
                    clusterModule.getAllocationService(),
                    aliasValidator,
                    environment,
                    settingsModule.getIndexScopedSettings(),
                    threadPool,
                    xContentRegistry,
                    forbidPrivateIndexSettings);

            Collection<Object> pluginComponents = pluginsService.filterPlugins(Plugin.class).stream()
                .flatMap(p -> p.createComponents(client, clusterService, threadPool, resourceWatcherService,
                                                 scriptModule.getScriptService(), xContentRegistry, environment, nodeEnvironment,
                                                 namedWriteableRegistry).stream())
                .collect(Collectors.toList());

            ActionModule actionModule = new ActionModule(false, settings, clusterModule.getIndexNameExpressionResolver(),
                settingsModule.getIndexScopedSettings(), settingsModule.getClusterSettings(), settingsModule.getSettingsFilter(),
                threadPool, pluginsService.filterPlugins(ActionPlugin.class), client, circuitBreakerService, usageService);
            modules.add(actionModule);

            final RestController restController = actionModule.getRestController();
            final NetworkModule networkModule = new NetworkModule(settings, false, pluginsService.filterPlugins(NetworkPlugin.class),
                threadPool, bigArrays, pageCacheRecycler, circuitBreakerService, namedWriteableRegistry, xContentRegistry,
                networkService, restController);
            Collection<UnaryOperator<Map<String, MetaData.Custom>>> customMetaDataUpgraders =
                pluginsService.filterPlugins(Plugin.class).stream()
                    .map(Plugin::getCustomMetaDataUpgrader)
                    .collect(Collectors.toList());
            Collection<UnaryOperator<Map<String, IndexTemplateMetaData>>> indexTemplateMetaDataUpgraders =
                pluginsService.filterPlugins(Plugin.class).stream()
                    .map(Plugin::getIndexTemplateMetaDataUpgrader)
                    .collect(Collectors.toList());
            Collection<UnaryOperator<IndexMetaData>> indexMetaDataUpgraders = pluginsService.filterPlugins(Plugin.class).stream()
                    .map(Plugin::getIndexMetaDataUpgrader).collect(Collectors.toList());
            final MetaDataUpgrader metaDataUpgrader = new MetaDataUpgrader(customMetaDataUpgraders, indexTemplateMetaDataUpgraders);
            final MetaDataIndexUpgradeService metaDataIndexUpgradeService = new MetaDataIndexUpgradeService(settings, xContentRegistry,
                indicesModule.getMapperRegistry(), settingsModule.getIndexScopedSettings(), indexMetaDataUpgraders);
            final GatewayMetaState gatewayMetaState = new GatewayMetaState(settings, nodeEnvironment, metaStateService,
                metaDataIndexUpgradeService, metaDataUpgrader);
            new TemplateUpgradeService(settings, client, clusterService, threadPool, indexTemplateMetaDataUpgraders);
            final Transport transport = networkModule.getTransportSupplier().get();
            Set<String> taskHeaders = Stream.concat(
                pluginsService.filterPlugins(ActionPlugin.class).stream().flatMap(p -> p.getTaskHeaders().stream()),
                Stream.of(Task.X_OPAQUE_ID)
            ).collect(Collectors.toSet());
            final TransportService transportService = newTransportService(settings, transport, threadPool,
                networkModule.getTransportInterceptor(), localNodeFactory, settingsModule.getClusterSettings(), taskHeaders);
            final ResponseCollectorService responseCollectorService = new ResponseCollectorService(this.settings, clusterService);
            final SearchTransportService searchTransportService =  new SearchTransportService(settings, transportService,
                SearchExecutionStatsCollector.makeWrapper(responseCollectorService));
            final HttpServerTransport httpServerTransport = newHttpTransport(networkModule);

            final DiscoveryModule discoveryModule = new DiscoveryModule(this.settings, threadPool, transportService, namedWriteableRegistry,
                networkService, clusterService.getMasterService(), clusterService.getClusterApplierService(),
                clusterService.getClusterSettings(), pluginsService.filterPlugins(DiscoveryPlugin.class),
                clusterModule.getAllocationService(), environment.configFile());
            this.nodeService = new NodeService(settings, threadPool, monitorService, discoveryModule.getDiscovery(),
                transportService, indicesService, pluginsService, circuitBreakerService, scriptModule.getScriptService(),
                httpServerTransport, ingestService, clusterService, settingsModule.getSettingsFilter(), responseCollectorService,
                searchTransportService);

            final SearchService searchService = newSearchService(clusterService, indicesService,
                threadPool, scriptModule.getScriptService(), bigArrays, searchModule.getFetchPhase(),
                responseCollectorService);

            final List<PersistentTasksExecutor<?>> tasksExecutors = pluginsService
                .filterPlugins(PersistentTaskPlugin.class).stream()
                .map(p -> p.getPersistentTasksExecutor(clusterService, threadPool, client))
                .flatMap(List::stream)
                .collect(toList());

            final PersistentTasksExecutorRegistry registry = new PersistentTasksExecutorRegistry(settings, tasksExecutors);
            final PersistentTasksClusterService persistentTasksClusterService =
                new PersistentTasksClusterService(settings, registry, clusterService);
            final PersistentTasksService persistentTasksService = new PersistentTasksService(settings, clusterService, threadPool, client);

            modules.add(b -> {
                    b.bind(Node.class).toInstance(this);
                    b.bind(NodeService.class).toInstance(nodeService);
                    b.bind(NamedXContentRegistry.class).toInstance(xContentRegistry);
                    b.bind(PluginsService.class).toInstance(pluginsService);
                    b.bind(Client.class).toInstance(client);
                    b.bind(NodeClient.class).toInstance(client);
                    b.bind(Environment.class).toInstance(this.environment);
                    b.bind(ThreadPool.class).toInstance(threadPool);
                    b.bind(NodeEnvironment.class).toInstance(nodeEnvironment);
                    b.bind(ResourceWatcherService.class).toInstance(resourceWatcherService);
                    b.bind(CircuitBreakerService.class).toInstance(circuitBreakerService);
                    b.bind(BigArrays.class).toInstance(bigArrays);
                    b.bind(ScriptService.class).toInstance(scriptModule.getScriptService());
                    b.bind(AnalysisRegistry.class).toInstance(analysisModule.getAnalysisRegistry());
                    b.bind(IngestService.class).toInstance(ingestService);
                    b.bind(UsageService.class).toInstance(usageService);
                    b.bind(NamedWriteableRegistry.class).toInstance(namedWriteableRegistry);
                    b.bind(MetaDataUpgrader.class).toInstance(metaDataUpgrader);
                    b.bind(MetaStateService.class).toInstance(metaStateService);
                    b.bind(IndicesService.class).toInstance(indicesService);
                    b.bind(AliasValidator.class).toInstance(aliasValidator);
                    b.bind(MetaDataCreateIndexService.class).toInstance(metaDataCreateIndexService);
                    b.bind(SearchService.class).toInstance(searchService);
                    b.bind(SearchTransportService.class).toInstance(searchTransportService);
                    b.bind(SearchPhaseController.class).toInstance(new SearchPhaseController(settings,
                        searchService::createReduceContext));
                    b.bind(Transport.class).toInstance(transport);
                    b.bind(TransportService.class).toInstance(transportService);
                    b.bind(NetworkService.class).toInstance(networkService);
                    b.bind(UpdateHelper.class).toInstance(new UpdateHelper(settings, scriptModule.getScriptService()));
                    b.bind(MetaDataIndexUpgradeService.class).toInstance(metaDataIndexUpgradeService);
                    b.bind(ClusterInfoService.class).toInstance(clusterInfoService);
                    b.bind(GatewayMetaState.class).toInstance(gatewayMetaState);
                    b.bind(Discovery.class).toInstance(discoveryModule.getDiscovery());
                    {
                        RecoverySettings recoverySettings = new RecoverySettings(settings, settingsModule.getClusterSettings());
                        processRecoverySettings(settingsModule.getClusterSettings(), recoverySettings);
                        b.bind(PeerRecoverySourceService.class).toInstance(new PeerRecoverySourceService(settings, transportService,
                                indicesService, recoverySettings));
                        b.bind(PeerRecoveryTargetService.class).toInstance(new PeerRecoveryTargetService(settings, threadPool,
                                transportService, recoverySettings, clusterService));
                    }
                    b.bind(HttpServerTransport.class).toInstance(httpServerTransport);
                    pluginComponents.stream().forEach(p -> b.bind((Class) p.getClass()).toInstance(p));
                    b.bind(PersistentTasksService.class).toInstance(persistentTasksService);
                    b.bind(PersistentTasksClusterService.class).toInstance(persistentTasksClusterService);
                    b.bind(PersistentTasksExecutorRegistry.class).toInstance(registry);
                }
            );
            injector = modules.createInjector();

            // TODO hack around circular dependencies problems in AllocationService
            clusterModule.getAllocationService().setGatewayAllocator(injector.getInstance(GatewayAllocator.class));

            List<LifecycleComponent> pluginLifecycleComponents = pluginComponents.stream()
                .filter(p -> p instanceof LifecycleComponent)
                .map(p -> (LifecycleComponent) p).collect(Collectors.toList());
            pluginLifecycleComponents.addAll(pluginsService.getGuiceServiceClasses().stream()
                .map(injector::getInstance).collect(Collectors.toList()));
            resourcesToClose.addAll(pluginLifecycleComponents);
            this.pluginLifecycleComponents = Collections.unmodifiableList(pluginLifecycleComponents);
            client.initialize(injector.getInstance(new Key<Map<Action, TransportAction>>() {}),
                    () -> clusterService.localNode().getId(), transportService.getRemoteClusterService());

            logger.debug("initializing HTTP handlers ...");
            actionModule.initRestHandlers(() -> clusterService.state().nodes());
            logger.info("initialized");

            success = true;
        } catch (IOException ex) {
            throw new ElasticsearchException("failed to bind service", ex);
        } finally {
            if (!success) {
                IOUtils.closeWhileHandlingException(resourcesToClose);
            }
        }
    }

涉及的主要模块

上图的文本如下;

ClusterModule
GatewayAllocator
AllocationService
ClusterService
NodeConnectionsService
MetaDataDeleteIndexService
MetaDataIndexStateService
MetaDataMappingService
MetaDataIndexAliasesService
MetaDataUpdateSettingsService
MetaDataIndexTemplateService
IndexNameExpressionResolver
RoutingService
DelayedAllocationService
ShardStateAction
NodeMappingRefreshAction
MappingUpdatedAction
TaskResultsService
AllocationDeciders
ShardsAllocator

IndicesModule
IndicesStore
IndicesClusterStateService
SyncedFlushService
TransportNodesListShardStoreMetaData
GlobalCheckpointSyncAction
TransportResyncReplicationAction
PrimaryReplicaSyncer

其他
Node
NodeService
NamedXContentRegistry
PluginsService
Client
NodeClient
Environment
ThreadPool
NodeEnvironment
ResourceWatcherService
CircuitBreakerService
BigArrays
ScriptService
AnalysisRegistry
IngestService
UsageService
NamedWriteableRegistry
MetaDataUpgrader
MetaStateService
IndicesService
AliasValidator
MetaDataCreateIndexService
SearchService
SearchTransportService
SearchPhaseController
Transport
TransportService
NetworkService
UpdateHelper
MetaDataIndexUpgradeService
ClusterInfoService
GatewayMetaState
Discovery
PeerRecoverySourceService
PeerRecoveryTargetService
HttpServerTransport
PersistentTasksService
PersistentTasksClusterService
PersistentTasksExecutorRegistry

pluginModule

GatewayModule
DanglingIndicesState
GatewayService
TransportNodesListGatewayMetaState
TransportNodesListGatewayStartedShards
LocalAllocateDangledIndices

SettingsModule
Settings
SettingsFilter
ClusterSettings
IndexScopedSettings

ActionModule
ActionFilters
DestructiveOperations
AutoCreateIndex
TransportLivenessAction
TransportAction
supportAction

RepositoriesModule
RepositoriesService
SnapshotsService
SnapshotShardsService
TransportNodesSnapshotsStatus
RestoreService