How can I check that how many applications have subscribed to a product in a catalog ?
One way is to check the subscription of all application in that catalog however in my case there are so many application that why it's very time consuming to use this approach. Any feasible approach for this case ?
There are two ways that I know of.
One is to enable catalog search: Login to API Manager and navigate to your provider org. Append "/ff" to the URL and hit enter. Enable the search feature. Once enabled, you'll see a search bar at the top of the screen. Search for your product, making sure you set options for the correct catalog. Click on the "Catalog Products" tab and you will see your product and subscription count. Click on the ellipsis and you can choose the option to view all subscriptions.
The second way is through the APIC rest API. If you want to go down that route, use their API Explorer here: https://apic-api.apiconnect.ibmcloud.com/v2018/