# Detect if a stream goes online or offline

**URL:** <https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294>\
**Category:** Wowza Developer Dojo\
**Tags:** wowza-streaming-server-java-api\
**Created:** [May 5, 2013, 10:42am UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294 "2013-05-05T10:42:21Z")\
**Posts on this page:** 16\
**Page:** 1

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**Author:** ![ruben\_docter](https://avatars.discourse-cdn.com/v4/letter/r/7993a0/32.png) [@ruben\_docter](https://community.wowza.com/u/ruben_docter)\
**Post date:** [May 5, 2013, 10:42am UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/1 "2013-05-05T10:42:21Z")

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If I want to start a webcam platform with multiple cams, is there a module or which module can I use to detect if a stream goes online or offline, so I can save the status to a database? Is something possible or is there a module that can do this?

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**Author:** ![Richard\_Lanham](https://avatars.discourse-cdn.com/v4/letter/r/c68b51/32.png) [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)\
**Post date:** [May 5, 2013, 2:44pm UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/2 "2013-05-05T14:44:50Z")

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Take a look at IMediaStreamActionNotify.onUnPublish():

[https://www.wowza.com/docs/how-to-use-imediastreamactionnotify3-interface-to-listen-for-rtmp-stream-events-includes-codec-info](https://www.wowza.com/docs/how-to-use-imediastreamactionnotify3-interface-to-listen-for-rtmp-stream-events-includes-codec-info)

Refer to this post for database connectivity in Wowza:

[https://www.wowza.com/docs/how-to-do-user-authentication-for-flash-rtmp-client-using-jdbc-connection-to-mysql-database](https://www.wowza.com/docs/how-to-do-user-authentication-for-flash-rtmp-client-using-jdbc-connection-to-mysql-database)

Don’t over-use JDBC connections in Wowza. A quick connect in the onUnPublish handler should be okay.

And take a look at the IOPerformanceCounter in the Wowza API.

Richard

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**Author:** ![Richard\_Lanham](https://avatars.discourse-cdn.com/v4/letter/r/c68b51/32.png) [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)\
**Post date:** [May 7, 2013, 2:44pm UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/3 "2013-05-07T14:44:10Z")

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Take a look at the HTTPUtils api in the Wowza api. Use with caution, http calls are not recommended. It would be best if you not make Wowza wait, make the call and, if necessary, process a response in its own thread. If you must process a response to proceed, that is where things get dicey with http calls.

Richard

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**Author:** ![Richard\_Lanham](https://avatars.discourse-cdn.com/v4/letter/r/c68b51/32.png) [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)\
**Post date:** [May 7, 2013, 6:18pm UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/4 "2013-05-07T18:18:01Z")

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<div class="post-metadata">

**Author:** ![Richard\_Lanham](https://avatars.discourse-cdn.com/v4/letter/r/c68b51/32.png) [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)\
**Post date:** [May 8, 2013, 1:20pm UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/5 "2013-05-08T13:20:25Z")

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You can use IMediaStreamActionNotify3 events (including .onPublish and .onUnPublish):

[https://www.wowza.com/docs/how-to-use-imediastreamactionnotify3-interface-to-listen-for-rtmp-stream-events-includes-codec-info](https://www.wowza.com/docs/how-to-use-imediastreamactionnotify3-interface-to-listen-for-rtmp-stream-events-includes-codec-info)

Richard

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<div class="post-metadata">

**Author:** ![Richard\_Lanham](https://avatars.discourse-cdn.com/v4/letter/r/c68b51/32.png) [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)\
**Post date:** [May 8, 2013, 1:43pm UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/6 "2013-05-08T13:43:47Z")

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There is something else to add to this, a ThreadPoolExecutor, but I have not yet.

Richard

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<div class="post-metadata">

**Author:** ![Richard\_Lanham](https://avatars.discourse-cdn.com/v4/letter/r/c68b51/32.png) [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)\
**Post date:** [May 8, 2013, 2:00pm UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/7 "2013-05-08T14:00:07Z")

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Actually, I am not sure about this. I am going to delete it for now.

Richard

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<div class="post-metadata">

**Author:** ![Richard\_Lanham](https://avatars.discourse-cdn.com/v4/letter/r/c68b51/32.png) [@Richard\_Lanham](https://community.wowza.com/u/Richard_Lanham)\
**Post date:** [May 8, 2013, 6:03pm UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/8 "2013-05-08T18:03:07Z")

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I’m unsure. I’ll get back to you.

Richard

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**Author:** ![ruben\_docter](https://avatars.discourse-cdn.com/v4/letter/r/7993a0/32.png) [@ruben\_docter](https://community.wowza.com/u/ruben_docter)\
**Post date:** [May 7, 2013, 3:15pm UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/9 "2013-05-07T15:15:15Z")

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What is the best method to call an url, for example: [http://domainname/online?streamname=name](http://domainname/online?streamname=name) in the onPublish and onUnpublish methods? Is this possible in that module? I need to ping a node js server to notify it if a cam is online or not.

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<div class="post-metadata">

**Author:** ![ruben\_docter](https://avatars.discourse-cdn.com/v4/letter/r/7993a0/32.png) [@ruben\_docter](https://community.wowza.com/u/ruben_docter)\
**Post date:** [May 7, 2013, 5:45pm UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/10 "2013-05-07T17:45:52Z")

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Something like the following would do, without problems? I don’t have to process the response.

try {

URL url = new URL(“[http://www.example.com](http://www.example.com)”);

try {

HttpURLConnection con = (HttpURLConnection) url.openConnection();

} catch(IOException e) {

System.out.println("IOException: " + e.getMessage());

}

} catch(MalformedURLException e) {

System.out.println("MalformedURLException: " + e.getMessage());

} }

The above doesn’t seem to work and the following also doesn’t work":

HTTPUtils.HTTPRequestToByteArray(“[http://www.example.com/test.php",“GET”,"wowza=](http://www.example.com/test.php%22,%22GET%22,%22wowza=)”+streamName,null);

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<div class="post-metadata">

**Author:** ![ruben\_docter](https://avatars.discourse-cdn.com/v4/letter/r/7993a0/32.png) [@ruben\_docter](https://community.wowza.com/u/ruben_docter)\
**Post date:** [May 7, 2013, 6:42pm UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/11 "2013-05-07T18:42:32Z")

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If i use the post method:

HTTPUtils.HTTPRequestToByteArray(“[http://www.example.com/test.php",“POST”,"wowza=](http://www.example.com/test.php%22,%22POST%22,%22wowza=)”+streamName,null);

it is working like a charm!

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<div class="post-metadata">

**Author:** ![ruben\_docter](https://avatars.discourse-cdn.com/v4/letter/r/7993a0/32.png) [@ruben\_docter](https://community.wowza.com/u/ruben_docter)\
**Post date:** [May 8, 2013, 9:38am UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/12 "2013-05-08T09:38:45Z")

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Well, this looks very good, but is it possible to open a new thread in the IMediaStreamActionNotify onUnpublish and unPublish events, because then the stream is published and unpublished for sure.

I mean what happens if the publish function is invoked (the HTTPWorker is also invoked), but it returns an error. Now the stream isn’t working but the stream in the database is set to being live.

Can I be sure that when publish is invoked, the stream is really wokring?

What function can I use for unPublish? I couldn’t find an unPublish function, only something like deleteStream or closeStream?

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<div class="post-metadata">

**Author:** ![ruben\_docter](https://avatars.discourse-cdn.com/v4/letter/r/7993a0/32.png) [@ruben\_docter](https://community.wowza.com/u/ruben_docter)\
**Post date:** [May 8, 2013, 2:31pm UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/13 "2013-05-08T14:31:33Z")

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Ok thanks, now I see how it works, just have to add the following class: public class HTTPWorker implements Runnable to the Module base where the actionnotifier also is. Many thanks!

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<div class="post-metadata">

**Author:** ![ruben\_docter](https://avatars.discourse-cdn.com/v4/letter/r/7993a0/32.png) [@ruben\_docter](https://community.wowza.com/u/ruben_docter)\
**Post date:** [May 8, 2013, 6:12pm UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/14 "2013-05-08T18:12:01Z")

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What is the solution then?

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<div class="post-metadata">

**Author:** ![Roger\_Littin1](https://avatars.discourse-cdn.com/v4/letter/r/c89c15/32.png) [@Roger\_Littin1](https://community.wowza.com/u/Roger_Littin1)\
**Post date:** [May 9, 2013, 9:21am UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/15 "2013-05-09T09:21:48Z")

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Hi,

Here is a more complete example that Richard was trying to show in the previously removed post.

```auto
package com.wowza.wms.test;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import com.wowza.util.HTTPUtils;
import com.wowza.wms.amf.AMFDataList;
import com.wowza.wms.client.IClient;
import com.wowza.wms.module.*;
import com.wowza.wms.request.RequestFunction;
public class ModuleHTTPSafeCall extends ModuleBase {
	private interface IResponseListener {
		public void onResponse(byte[] response);
	}
	
	private class HTTPWorker implements Runnable {
		String url;
		IResponseListener listener = null;
		
		public HTTPWorker(String url, IResponseListener listener) {
			this.url = url;
			this.listener = listener;
		}
		@Override
		public void run() {
			byte[] response = HTTPUtils.HTTPRequestToByteArray(url, "get", null, null);
			if(listener != null) {
				listener.onResponse(response);
			}
			
			getLogger().info("ModuleHTTPSafeCall url: " + url);
		}
		
	}
	
	private class ResponseListener implements IResponseListener {
		private IClient client;
		public ResponseListener(IClient client)
		{
			this.client = client;
		}
		@Override
		public void onResponse(byte[] response)
		{
			// do something here with response if needed.
			getLogger().info("Response: " + new String(response));
		}
		
	}
	private ThreadPoolExecutor runner = new ThreadPoolExecutor(1, 1, 3000, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>());
	public void publish(IClient client, RequestFunction function, AMFDataList params) {
		runner.execute(new HTTPWorker("http://localhost/test.html", new ResponseListener(client)));
		invokePrevious(this, client, function, params);
	}
}

```

What Richard was trying to show is that it is important, when doing remote calls that could take a while to return, that you do not stall the current thread while waiting. It is best practice to use a separate thread pool to run the remote calls.

This example also adds a response listener to capture the response value from the remote call so you can work with it. If you do not need to use the response value then you can use

```auto
runner.execute(new HTTPWorker("http://localhost/test.html", null));

```

Roger.

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<div class="post-metadata">

**Author:** ![Roger\_Stewart](https://avatars.discourse-cdn.com/v4/letter/r/ee59a6/32.png) [@Roger\_Stewart](https://community.wowza.com/u/Roger_Stewart)\
**Post date:** [January 15, 2020, 7:22am UTC](https://community.wowza.com/t/detect-if-a-stream-goes-online-or-offline/39294/16 "2020-01-15T07:22:32Z")

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I have a question regarding Disney plus streaming service, I just installed a few days back & now start facing the buffering issue, I know this service is ongoing with infancy period. Any thoughts?

[https://getsolved.org/know-about-disney-plus-streaming-service/](https://getsolved.org/know-about-disney-plus-streaming-service/)