How to debug Server.isOnline()

[Dan Korneff]

I'm using Server.isOnline() to check for an internet connection before I perform some networks tasks. It's implemented in a function like this:

	// Check Internet Connection
	function checkInternetConnection()
	{
		if(!Server.isOnline())
		{
			sendEvent(ErrorCode.NO_INTERNET);
			return false;
		}		
		return true;
	}

This is returning false on some users systems even though they have internet.
Server.isOnine() appears to just ping Google and Amazon as a test.

bool ScriptingApi::Server::isOnline()
{
	const char* urlsToTry[] = { "http://google.com/generate_204", "https://amazon.com", nullptr };

	for (const char** url = urlsToTry; *url != nullptr; ++url)
	{
		URL u(*url);

		auto ms = Time::getMillisecondCounter();
		std::unique_ptr<InputStream> in(u.createInputStream(false, nullptr, nullptr, String(), HISE_SCRIPT_SERVER_TIMEOUT, nullptr));
		dynamic_cast<JavascriptProcessor*>(getScriptProcessor())->getScriptEngine()->extendTimeout(Time::getMillisecondCounter() - ms);

		if (in != nullptr)
			return true;
	}

	return false;
}

So I've had the end users perform this task manually via command prompt, and they get a response.

curl -I http://google.com/generate_204
returns:
HTTP/1.1 204 No Content
Content-Length: 0
Cross-Origin-Resource-Policy: cross-origin
Date: Wed, 03 Jan 2024 13:23:15 GMT

and 
ping -c 4 google.com
returns:
Pinging google.com [142.250.81.238] with 32 bytes of data:
Reply from 142.250.81.238: bytes=32 time=13ms TTL=116
Reply from 142.250.81.238: bytes=32 time=10ms TTL=116
Reply from 142.250.81.238: bytes=32 time=10ms TTL=116
Reply from 142.250.81.238: bytes=32 time=17ms TTL=116

Ping statistics for 142.250.81.238:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 10ms, Maximum = 17ms, Average = 12ms

It seems that they have an internet connection. What method can I use to gather information from the Server function to see where it's failing? Is there something similar to the Server Controller that can be tapped in to?

[d.healey]

@Dan-Korneff Are those users in China?

[Dan Korneff]

@d-healey They are not in China. And the manual test shows that they can reach the isOnline endpoints.

[d.healey]

@Dan-Korneff Have you set a short timeout value? HISE_SCRIPT_SERVER_TIMEOUT=20000

[Christoph Hart]

What happens if you change the URL in the C++ code to use SSL:

"https://google.com/generate_204"

I know that sometimes on macOS there is an issue with connecting to non SSL domains.

[d.healey]

@Christoph-Hart said in How to debug Server.isOnline():

I know that sometimes on macOS there is an issue with connecting to non SSL domains.

That might be why I did this

https://github.com/christophhart/HISE/pull/328/files#diff-16813562fe191a1534f1f835248ab9446725ab9ffa0543f31d84d9743adaf874R114