Firefox can’t establish a connection to the server at https://example.com

user_9048111 0
Viewed 104

I have a webserver and I want to implement server-event Source via: EventSource("API.php") but I ran into error on random requests! For example After 120 Requests I get the error or the other time after 31 requests! what is the problem and how to solve that?

Site CODE:

<!DocType 'html'>
<html>
<head></head>
<body>
<div id="result"></div>

<script>
if(typeof(EventSource) !== "undefined") {
  // Yes! Server-sent events support!
  // Some code.....
var source = new EventSource("Example.php");
source.onmessage = function(event) {
  document.getElementById("result").innerHTML += event.data + "<br>";
}; 


} else {
  alert("Use FireFox to Load This Page! Your Browser is not supported...")
} 


</script>

</body>
<footer></footer>
</html>

sample image

server-sent-events javascript
1 Answers

This ("521") is apparently a cloudflare-specific error. So your problem is server-side, not with your JavaScript.

There are plenty of suggestions online; I suggest your search terms should be "cloudflare 521". Or "cloudflare server sent events". Don't search for "cloudflare SSE" as that abbreviation has multiple meanings in that context.

It seems what people normally do is create a rule to not use Cloudflare for your SSE endpoints.

user_8418300
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