The fallacy of “cloud storage”

Something happened in the world of Minecraft; an opportunity to illustrate my favorite pet peeve against “cloud storage”.

When someone opens their Google Mail interface, they will expect to see the same list of e-mails (or more) as they saw the last time they opened the interface, even possibly from a different computer.

When someone connects their Dropbox client, they will expect their Dropbox folder to contain the same files as they saw the last time they used Dropbox, even possibly from a different computer.

The technical term is “transparent automatic synchronization.” For most users, it’s just called “cloud storage”: the impression that the data is stored out of the material world, without the need to burden oneself with the technical knowledge of where, how and by whom the data is actually stored.

Meanwhile, Jeb at Mojang has released a new version of Minecraft.

To keep a long story short, Minecraft is this game/toy where the players can explore, mine, craft items and build structures in a world generated for them automatically. A sort of digital Lego on steroids. Among other items, one can build in Minecraft a chest using wood planks. A chest is a block which, when placed, can serve as a container for other items. When you click on a chest in game, you expect to find in it the same items you saw (or placed into it) the last time you used the same chest. Intuitively, separate chests have separate contents; the items are, from the player’s perspective, in the particular chest where they were last placed. Their location is, more or less consciously, understood by the player to be congruent with the location of the particular chest.

A recent version of Minecraft, named “12w21a,” introduces a new sort of item called the Ender chest, invented a while ago on Reddit. This chest is made of obsidian instead of wood, and purple sparkles around it indicate it has magical properties. In this case, the magic corresponds to a practical need for advanced players: the contents placed into one Ender chest can be retrieved from any other Ender chest in the world. For a single player, it feels like a teleport: if the player places items into one Ender chest, then travels across the world and builds another Ender chest, they will see their items appear automatically in the new chest, as if they have been teleported there. However it is slightly more powerful than this: if there are multiple players in the same world, and they each build their own Ender chest, and they open it at the same time, they will see the same items! As CaptainSparklez puts it in his latest video review, this is cloud storage for chests. The analogy is brilliant.

It is not only brilliant; it is also instructive. For one of the first questions asked by many players is whether the content of the Ender chests in one world can be retrieved from another world. The answer, in Minecraft, is negative: contrary to Diablo’s stash whose contents are shared across all quests and avatars, the Ender chest’s contents is actually located in the world’s savefile where the world’s data is stored on the user’s computer (or game server in multiplayer games). The corollary, as many players have now found out, is that erasing a world also discards the Ender chest’s contents. The magic of the cloud is limited: the service offered, persistence, is only as good as the persistence of the actual location of the data and the goodwill of its operators.

With Google Mail, this service is offered by Google’s datacenters, dependent on the goodwill of Google employees. With Dropbox, this service is offered by Amazon’s datacenters, dependent on the goodwill of both Amazon and Dropbox employees. With any “cloud storage” facility, the scope of the persistence service can be identified by asking where the data is and who is in charge.

Minecraft players feel the physical concreteness of the scope of persistence by exercising control over their own worlds’ savefiles. As I see it, most Internet cloud storage users persist in blissfully ignoring issues of scope and abandon control of their data to the hands of strangers; I predict most will feel surprised, and even cheated, when, as technical incidents causes large-scale data loss, they come to realize that the ”cloud” is just made of machines and people.