What is the purpose of Tenant Identifier in tenants.json ?

[hung-doan]

In my scenario, I backup a database from the remote server

• Then setup a fresh machine to start the development or debug on my local machine:
  • Local File shell
  • Multiple developers
  • App_Data is excluded from the source version control.
  • Single Tenant app
• Point the connectionString to the local database that I have restored from the backup file.

However, I see that:

• If there is no tenants.json in App_Data. It will ask us to go to the Setup screen.
• Then I copied my tenants.json into the App_Data, all works.

I also tried to change the Identifier in tenants.json. It stills works.

{
  "Default": {
    "Identifier": ".......",
    "State": "Running"
  }
}

I wonder what is the purpose of Identifier, is that ok if I change it ?.

[jtkech]

@hung-doan

Because of the following

OrchardCore/src/OrchardCore/OrchardCore/Shell/ShellHost.cs

Lines 219 to 223 in 8ff2453

	// Consistency: We may have been the last to add the shell but not with the last settings.
	if (settings.VersionId == currentVersionId)
	{
	return;
	}

Notice that it is now named VersionId

[hung-doan]

cool, thanks you @jtkech.
I dive a little more into the source code and see that these line of codes are executed via the setup process.

That means the Identifier is just a flag that is used during the setup to avoid the race condition issue.
The modification on this filed, logically doesn't cause any issues to our application ?

[jtkech]

Yes, used to keep in sync for a given OC instance the in memory id to the one in tenants.json. Note: If there are multiple OC running instances, these settings should be in a shared store e.g. the database, not in the local tenants.json.

Not only on setup, each time a given instance saves the settings, e.g. we can change a tenant prefix through the admin UI (with the tenants feature). No problem to change this Id if all the related OC instances are restarted.