The issue
I’ve got a Rest API in Spring-Boot where i’m listening to an event-source stream from html like so:
eventSource = new EventSource("/api/events/receive", {
xhrHeaders: {
'Content-Type': 'text/event-stream',
'Connection': 'keep-alive'
}
});
eventSource.onmessage = function (evt) { ... };
The EventSource returns 503 after a while!
Works perfectly on localhost but not on remote host!
Things i’ve tried
- add keep-alive on the
@RestControllerviaHttpServletResponseObject
@GetMapping(path = "/api/events/receive", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
public Flux<Ambulance> receiveAmbulance(HttpServletResponse resp) {
resp.addHeader("Connection", "keep-alive");
return Flux.create(sink -> {
ambulanceProcessor.register(sink::next);
});
}
- add to that template a
keep-aliveheader via@Controller
@GetMapping("/dashboard")
public String getResource(Model model, HttpServletResponse response) {
response.addHeader("Connection", "keep-alive");
return "view";
}
Related posted i’ve visited
503 After a few seconds
Note: I’ve tried almost everything and nothing seems to work for me…
Answer
I manage to keep it alive by creating a new @Service with this @Bean
@Bean
public void KeepAliveEvt()
{
ExecutorService sseMvcExecutor = Executors.newSingleThreadExecutor();
sseMvcExecutor.execute(() -> {
try {
for (int i = 0; true; i++) {
Thread.sleep(120000);
ambulanceProcessor.process(new Event());
System.out.println("Kept Alive");
}
} catch (Exception ex) {
}
});
}
Basically I’m keeping it alive with a Dummy Event every 2 minutes