dremio backend webserver 简单说明-CFANZ编程社区

dremio 的webserver 是基于jetty+jersey 开发的web server 同时也和标准的dremio 服务一样实现了service 接口方便服务的启动

具体是由DACDaemon 调用触发的启动

webserver start 服务

  
 @Override

  public void start() throws Exception {

   // 使用了DremioServer 服务进行实际的启动

    server.startDremioServer(

      registry,

      config,

      credentialsServiceProvider,

      uiType,

      this::registerEndpoints

    );

  }

jetty+jersey 服务的启动

DremioServer 类中


public void startDremioServer(

    SingletonRegistry registry,

    DACConfig config,

    Provider<CredentialsService> credentialsServiceProvider,

    String uiType,

    Consumer<ServletContextHandler> servletRegistrer

  ) throws Exception {

    this.credentialsServiceProvider = credentialsServiceProvider;

    try {

      if (!embeddedJetty.isRunning()) {

       // 创建jetty 的connector  
        createConnector(config);

      // 添加handlers，包含了不少dremio 内部的服务

        addHandlers();

      }

  
      if (config.verboseAccessLog) {

        accessLogFilter = new AccessLogFilter();

       // 此处servletContextHandler 是在addHandlers 中初始化的

        servletContextHandler.addFilter(

          new FilterHolder(accessLogFilter),

          "/*",

          EnumSet.of(DispatcherType.REQUEST));

      }

  
      if (config.serveUI) {

        final String basePath = "rest/dremio_static/";

        final String markerPath = String.format("META-INF/%s.properties", uiType);

       // dremio 自己的一个servlet

        final ServletHolder fallbackServletHolder = new ServletHolder("fallback-servlet", registry.lookup(DremioServlet.class));

        addStaticPath(fallbackServletHolder, basePath, markerPath);

        servletContextHandler.addServlet(fallbackServletHolder, "/*");

      }

  
      if (servletRegistrer != null) {

        servletRegistrer.accept(servletContextHandler);

      }

  
      if (!embeddedJetty.isRunning()) {

        embeddedJetty.start();

      }

  
      setPortFromConnector();

      logger.info("Started on {}://localhost:" + port, config.webSSLEnabled() ? "https" : "http");

  
      serviceStarted = true;

    } catch (Exception ex) {

      throw new ServerErrorException(ex);

    }

  }

其他api endpoint 的注册

WebServer 类中，基于了DremioServer 提供的一个函数接口，注册了不少dremio 的api 接口

使用了jetty 提供的ServletHolder 动态的servlet 注册接口，同时利用了ResourceConfig

protected void registerEndpoints(ServletContextHandler servletContextHandler) {

  // security header filters

  SecurityHeadersFilter securityHeadersFilter = new SecurityHeadersFilter(registry.provider(OptionManager.class));

  servletContextHandler.addFilter(new FilterHolder(securityHeadersFilter), "/*", EnumSet.of(DispatcherType.REQUEST));

  
  // Generic Response Headers filter for api responses

  servletContextHandler.addFilter(GenericResponseHeadersFilter.class.getName(), "/apiv2/*", EnumSet.of(DispatcherType.REQUEST));

  servletContextHandler.addFilter(GenericResponseHeadersFilter.class.getName(), "/api/*", EnumSet.of(DispatcherType.REQUEST));

  
  // add the font mime type.

  final MimeTypes mimeTypes = servletContextHandler.getMimeTypes();

  mimeTypes.addMimeMapping("woff2", "application/font-woff2; charset=utf-8");

  servletContextHandler.setMimeTypes(mimeTypes);

  
  // WebSocket API

  final SocketServlet servlet = new SocketServlet(registry.lookup(JobsService.class), registry.lookup(TokenManager.class),

    registry.provider(OptionManager.class));

  final ServletHolder wsHolder = new ServletHolder(servlet);

  wsHolder.setInitOrder(1);

  servletContextHandler.addServlet(wsHolder, "/apiv2/socket");

  
  // Rest API

  ResourceConfig restServer = restServerProvider.get();

  
  restServer.property(RestServerV2.ERROR_STACKTRACE_ENABLE, config.sendStackTraceToClient);

  restServer.property(RestServerV2.TEST_API_ENABLE, config.allowTestApis);

  restServer.property(RestServerV2.FIRST_TIME_API_ENABLE, isInternalUS);

  
  restServer.register(dremioBinder);

  restServer.register((DynamicFeature) (resourceInfo, context) -> context.register(DremioServer.TracingFilter.class));

  
  final ServletHolder restHolder = new ServletHolder(new ServletContainer(restServer));

  restHolder.setInitOrder(2);

  servletContextHandler.addServlet(restHolder, "/apiv2/*");

  
  // Public API

  ResourceConfig apiServer = apiServerProvider.get();

  apiServer.register(dremioBinder);

  apiServer.register((DynamicFeature) (resourceInfo, context) -> context.register(DremioServer.TracingFilter.class));

  
  final ServletHolder apiHolder = new ServletHolder(new ServletContainer(apiServer));

  apiHolder.setInitOrder(3);

  servletContextHandler.addServlet(apiHolder, "/api/v3/*");

  }

dremio 自己的实现

包含了APIServer以及RestServerV2

参考类图

基于了ResourceConfig 进行了动态扩展

dremio backend webserver 简单说明_ide

有一个灵活的设计是，dremio 基于了注解实现动态注册，比如api 以及rest 都包含了自己的注解扩展

protected void init(ScanResult result) {

    // FILTERS

    register(JSONPrettyPrintFilter.class);

    register(MediaTypeFilter.class);

  
    // RESOURCES

   // 基于APIResource 注解，通过调用register 动态注册接口服务

    for (Class<?> resource : result.getAnnotatedClasses(APIResource.class)) {

      register(resource);

    }

  
    // FEATURES

    register(DACAuthFilterFeature.class);

    register(DACJacksonJaxbJsonFeature.class);

    register(DACExceptionMapperFeature.class);

  
    // EXCEPTION MAPPERS

    register(JsonParseExceptionMapper.class);

    register(JsonMappingExceptionMapper.class);

  
    // PROPERTIES

    property(ServerProperties.RESPONSE_SET_STATUS_OVER_SEND_ERROR, "true");

    property(RestServerV2.TEST_API_ENABLE, "true");

  
    final String disableMoxy = PropertiesHelper.getPropertyNameForRuntime(CommonProperties.MOXY_JSON_FEATURE_DISABLE,

      getConfiguration().getRuntimeType());

    property(disableMoxy, true);

  }