Spring - Angular - SseEmitter 仅适用于本地机器

Question

I'm using event emitters to notify my clients of a change in their company. My production environment is on the google cloud .

For that purpose on login, I create for each one of them a SseEmitter via this endpoint:

    @GetMapping(value = "/notifications", headers = "Accept=*/*", consumes = MediaType.ALL_VALUE, produces = MediaType.TEXT_EVENT_STREAM_VALUE)
    public SseEmitter getCurrentUserNotificationsEmitter() {
        return companyNotifierService.createEmitter(SessionUtils.getCurrentCompanyUuid(), SessionUtils.getCurrentUserUuid());
    }

I consume this endpoint on the angular side like this:

listen(): void {
  const eventSource = new EventSource(`/webfront${this.serviceUrl}/notifications`, { 
                         withCredentials: true });
  eventSource.addEventListener('update', () => //do stuff);
  eventSource.onmessage(() => console.log('heartbeat'));
  //keep listening on error
  eventSource.onerror(() => { eventSource.close(); listen(); })
  }

My service sends the message like this:

 void notifyUser(String userId, String companyUuid){
    final SseEmitter emitter;
    //find the user emitter in a data structure
     emitter.send(SseEmitter.event()
                   .reconnectTime(30000)
                   .data("company-updated", MediaType.TEXT_PLAIN)
                   .id(UUID.randomUUID().toString())
                   .name("update"));
 }

My webserver production configuration:

 //this webserver is needed on production, and to test IE11, for the other reasons use ng server itself const express = require('express'); const https = require('https'); const path = require('path'); const fs = require('fs'); const httpProxy = require('http-proxy'); const logger = require('morgan'); const errorHandler = require('errorhandler'); const _httpsOptions = { key: fs.readFileSync('../security/localhost.key'), cert: fs.readFileSync('../security/localhost.crt') }; const app = express(); // eslint-disable-next-line new-cap const proxy = new httpProxy.createProxyServer({target: 'https://localhost:8763', secure: false}); app.set('port', process.env.PORT || 8773); app.use(logger('dev')); app.use(express.static(path.join(__dirname, '../../dist/clientng'))); if (app.get('env') === 'development') { app.use(errorHandler()); } app.all('/auto/*', function (req, res) { console.log(req.protocol); console.log(req.hostname); const url = req.protocol + '://' + req.hostname + ':' + app.get('port') + '/#' + req.url; res.redirect(url); }); app.all('/*', function (req, res) { proxy.web(req, res, function (err) { console.log(err); if (err) throw err; }); }); https.createServer(_httpsOptions, app).listen(app.get('port'), function () { console.log('Express server listening on port ' + app.get('port')); fs.writeFile('node.pid', process.pid.toString(), function (err) { if (err) { console.log(err); } }); });

My spring MVC configuration:

  mvc:
    async:
      request-timeout: 210000 # ms

Some times I get these exception on the spring server log:

org.springframework.web.context.request.async.AsyncRequestTimeoutException: null
        at org.springframework.web.context.request.async.TimeoutDeferredResultProcessingInterceptor.handleTimeout(TimeoutDeferredResultProcessingInterceptor.java:42)
        at org.springframework.web.context.request.async.DeferredResultInterceptorChain.triggerAfterTimeout(DeferredResultInterceptorChain.java:79)
        at org.springframework.web.context.request.async.WebAsyncManager.lambda$startDeferredResultProcessing$5(WebAsyncManager.java:424)
        at java.util.ArrayList.forEach(ArrayList.java:1259)
        at org.springframework.web.context.request.async.StandardServletAsyncWebRequest.onTimeout(StandardServletAsyncWebRequest.java:150)
        at org.apache.catalina.core.AsyncListenerWrapper.fireOnTimeout(AsyncListenerWrapper.java:44)
        at org.apache.catalina.core.AsyncContextImpl.timeout(AsyncContextImpl.java:132)
        at org.apache.catalina.connector.CoyoteAdapter.asyncDispatch(CoyoteAdapter.java:153)
        at org.apache.coyote.AbstractProcessor.dispatch(AbstractProcessor.java:241)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:53)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:791)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1417)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Thread.java:750)
14:11:21.354 [http-nio-8080-exec-6] WARN  o.s.w.s.m.m.a.ExceptionHandlerExceptionResolver - Failure in @ExceptionHandler public lu.legitech.lexnow.json.common.BasicErrorMessage lu.legitech.lexnow.controller.ErrorController.uncaughtException(java.lang.Exception)
org.springframework.web.HttpMediaTypeNotAcceptableException: Could not find acceptable representation
        at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:306)
        at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:180)
        at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:82)
        at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:119)
        at org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver.doResolveHandlerMethodException(ExceptionHandlerExceptionResolver.java:412)
        at org.springframework.web.servlet.handler.AbstractHandlerMethodExceptionResolver.doResolveException(AbstractHandlerMethodExceptionResolver.java:61)
        at org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver.resolveException(AbstractHandlerExceptionResolver.java:136)
        at org.springframework.web.servlet.handler.HandlerExceptionResolverComposite.resolveException(HandlerExceptionResolverComposite.java:80)
        at org.springframework.web.servlet.DispatcherServlet.processHandlerException(DispatcherServlet.java:1297)
        at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1109)
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1055)
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
        at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:320)
        at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:116)
        at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:91)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
        at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:119)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
        at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:84)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
        at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
        at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:170)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
        at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
        at org.springframework.security.web.session.ConcurrentSessionFilter.doFilter(ConcurrentSessionFilter.java:155)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
        at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:200)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
        at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:116)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
        at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334)
        at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215)
        at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178)
        at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:357)
        at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:270)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:117)
        at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:106)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:712)
        at org.apache.catalina.core.ApplicationDispatcher.doDispatch(ApplicationDispatcher.java:633)
        at org.apache.catalina.core.ApplicationDispatcher.dispatch(ApplicationDispatcher.java:601)
        at org.apache.catalina.core.AsyncContextImpl$AsyncRunnable.run(AsyncContextImpl.java:547)
        at org.apache.catalina.core.AsyncContextImpl.doInternalDispatch(AsyncContextImpl.java:347)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:196)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
        at org.apache.catalina.connector.CoyoteAdapter.asyncDispatch(CoyoteAdapter.java:235)
        at org.apache.coyote.AbstractProcessor.dispatch(AbstractProcessor.java:241)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:53)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:791)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1417)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Thread.java:750)

What is really weird is that in localhost it works perfectly. I also compiled it for production and deployed it in my localhost and it works fine. However, in the google cloud platform, it doesn't. The messages never arrive.

What could be the issue?

Answer 1

The problem was related to my nginx configuration. By default nginx does some kind of buffering which prevents the messages from arriving to the client. Here is a post with a better explanation:

https://serverfault.com/questions/801628/for-server-sent-events-sse-what-nginx-proxy-configuration-is-appropriate

Nginx configuration for this endpoint should contain this:

proxy_http_version 1.1;
proxy_set_header Connection "";

Also as suggested in the post add this to your response headers:

    SseEmitter endpoint(HttpServletResponse response) {
            response.addHeader("Content-Type", "text/event-stream");
            response.addHeader("Cache-Control", "no-cache");
            response.addHeader("X-Accel-Buffering", "no");
     SseEmitter emitter = service.getEmitter();
     return emitter;
}