We are using the Microsoft Azure NotificationHub with templated installations.

I’m trying to use the Android PNS-handle itself as the installation id for a new installation. To do that, we remove certain characters ([<>{}&%#@:;]) and use the remaining string as the InstallationId for the new installation. For PushChannel, we use the original PNS-handle.

Registering an installation like this doesn’t show any errors, and we can successfully send messages to the registered tags.

But when we want to GET or DELETE an installation, the NotificationHub can’t find the installation.

I’ve done some testing with custom installation id’s and found out that only if the Id has a max length of 102 characters, the registered installation can later be retrieved or deleted.

Can anyone point to any documentation which confirms this is an actual maximum length? Or are you able to do use id’s longer than that?

The only thing I’ve found so far is that a tag has a maximum length of 120 characters, and the NotificationHub automatically adds a tag named $InstallationId:{INSTALLATION_ID}. For this tag to not exceed 120 chars, the INSTALLATION_ID can’t be longer than 102 characters.
But the installation itself does get registered, as we are able to send templated messages to the tags registered with the installation.