Cfrgtkky

I have a requirement to send notification from SQL database to the user as Server sent events in Spring Boot. I have used SseEmitter to implement this.

1) @GetMapping(value = "/v2/user/notifications/event",produces = MediaType.TEXT_EVENT_STREAM_VALUE)

    public ResponseEntity<SseEmitter> sendNotification(@RequestHeader(value = "Authorization") final String token) {



        HttpHeaders headers = new HttpHeaders();

        headers.add("Connection","keep-alive");

        headers.add("Cache-Control", "no-cache");

        List<HttpStatus> httpStatuses = new ArrayList<>();

        httpStatuses.add(0, HttpStatus.OK);





        SseEmitter sseEmitter = new SseEmitter(Long.MAX_VALUE);

        Integer nextEventFireTime = appConfig.getConfiguration().getInteger("sse.nextEventFireTime");



        ScheduledExecutorService scheduledExecutorService =

                Executors.newScheduledThreadPool(Constants.MAX_THREAD_POOL_SSE);



        scheduledExecutorService.scheduleAtFixedRate(() -> {

            try {

                service.sendNotification(sseEmitter, token);

            } catch (BaseException e) {

                httpStatuses.add(0, HttpStatus.INTERNAL_SERVER_ERROR);

                sseEmitter.completeWithError(e);

                scheduledExecutorService.shutdown();

            }

        } , 0, nextEventFireTime, TimeUnit.SECONDS);



        return new ResponseEntity<>(sseEmitter, headers, httpStatuses.get(0));

    }

*nextEventFireTime is configured as 15

2)@Override

    public synchronized void sendNotification(SseEmitter emitter, String token) throws BaseException {



        NotificationMetadata notificationMetadata =

                getUnreadNotificationCount(token);



        List<Notification2> notificationList;

        notificationList =

                getSseNotifications(token);



        SseEmitter.SseEventBuilder event = SseEmitter.event();



        NotificationResponse2 notificationResponse2 = new NotificationResponse2();

        notificationResponse2.setData(notificationList);

        notificationResponse2.setMetadata(notificationMetadata);



        event.name(Constants.SSE_EVENT_NAME).data(notificationResponse2)

                .build();

        try {

            emitter.send(event.reconnectTime(15000L));

        } catch (Exception e) {

            throw new BaseException("Failed to send notification event.. "+e.getMessage(), Constants.ERROR_CODE_INTERNAL_ERROR,

                    "sendNotification", HttpStatus.INTERNAL_SERVER_ERROR);

        }

    }

The client is waiting for the response and it is taking close to 17 minutes when there is no data in db for notification but count query is fetching the data and when there is data then also it is taking 4-5 minutes to give the response.

I am using SseEmitter first time and when I debug the code at server is executed but the response is still pending.

Can someone help me with this issue?