High Sierra, Sierra’s dispatching bug, and iTunes 12.7

New versions of iTunes are well-known for causing anguish. Yesterday’s release of version 12.7 is no exception, as it removes access to the iTunes App Store, to purchase and install iOS apps, as well as access to Ringtones.

Users were aghast at this, asking how they were to maintain their multiple iOS devices without being able to download updates and new purchases onto their Macs, then sync each iOS device using iTunes.

Apple’s answer, I suspect, is in the new Content Caching feature in High Sierra, although that doesn’t appear to be offered as a retrofit for Sierra. Apple hasn’t yet provided full details, but what I think is intended is that those with multiple iOS devices use their Mac as a local app and update server.

To do this in High Sierra seems straightforward: you turn Content Caching on in the Sharing pane, and configure whatever options that may entail. You then need to leave that Mac running at all times, without it going to sleep, so that when you connect an iOS device to it (by USB), it can deliver all newly purchased apps and updates through the App Store app on that device.

In many ways, this is a much neater solution than poor, overburdened iTunes has been.

There is one quite major snag, as things stand: the long-standing dispatching bug which has plagued Sierra.

Relatively few Sierra users leave their Macs on for long periods (a week or more) without letting the system sleep. Those who do have run into a problem, most noticeably with automatic Time Machine backups. After a week or so without being started up, or going to sleep, the systems in macOS Sierra which are responsible for scheduling and dispatching background activities, such as backups, stop working properly.

In removing functionality from iTunes and putting it in the new Content Caching feature in High Sierra, Apple will be drawing many more Mac users to leave their Macs running without system sleep for long periods. If the bug which is in Sierra persists in High Sierra, the number of users affected by it will rise very greatly.

Of course, Apple may have fixed that bug in High Sierra. If it hasn’t, I can see a tsunami of reports and complaints starting at the beginning of October, when it is likely to start manifesting itself on the first Macs to be upgraded to High Sierra.

Watch this space, with great interest.