Unregistering multiple applications doesn't work while unregistering single application works.

[seonWKim]

Description:
When I try to unregister multiple applications using group actions, it throws NPE occasionally. I looked into the stack trace and found the code which was throwing the error.

if (streamDeploymentPropertiesMap.containsKey(appName)) {
	Map<String, String> appDeploymentProperties = streamDeploymentPropertiesMap.get(streamAppName);
	if (appDeploymentProperties.containsKey(SkipperStream.SKIPPER_SPEC_VERSION)) {
		String version = appDeploymentProperties.get(SkipperStream.SKIPPER_SPEC_VERSION);
		if (version != null && version.equals(appVersion)) {
			return streamDefinition.getName();
		}
	}
}

NullPointerException is being thrown by AppRegistryController at line 342

• line 342: if (appDeploymentProperties.containsKey(SkipperStream.SKIPPER_SPEC_VERSION))

I don't have deep understanding in this code but I think NullPointerException is being thrown because streamDeploymentPropertiesMap.containsKey(appName) is not checking appropriate key(appName). You can see that on the next line streamDeploymentPropertiesMap.get(streamAppName), streamDeploymentPropertiesMap is retrieving a value from different key(streamAppName). I wonder if this is a bug or something that should work properly.

Release versions:
The version is 2.10.0

Custom apps:
Not related to custom apps.

Steps to reproduce:
Use dataflow version 2.10.0.
Register multiple applications. Then unregister applications using group action.

Screenshots:

Additional context:
Add any other context about the problem here.

[onobc]

Hi @seonwoo960000

Thanks for the super detailed report and sleuthing - much appreciated. It does look like the map key is incorrect. Because of your detailed report, we should be able to get this fixed and make it into the 2.10.3 release.

[onobc]

Hi @seonwoo960000 ,

After digging in a bit further, the appName and streamAppName will always be the same as the streamAppName is the registered app name. It does read inconsistent though and I will make them the same variable.

I am having trouble reproducing this. Could you give me any details about the stream app definitions you are attempting to delete in a group as well as the streams definitions that contains those apps?

[seonWKim]

@onobc Sure ! 😄
I reproduced by following below steps.

1. Import stream application starters for Kafka/Docker
   
2. Apps are registered.
3. It seems that when trying to remove http or log module by using group delete action, it returned NPE

Hmm weird things is when I'm trying to reproduce this, it seems to work fine again. I'm now able to delete http or log using group actions 🤔

Maybe group actions seemed to be not working because some of our team members were able to manipulate the database tables used by spring cloud dataflow. I'll have to dig some more into this and let you know what might was the reason for this mess.

[onobc]

I will go ahead and close this @seonwoo960000. If you start to see the behavior again please re-open and we will dig in. Thanks.