You can be available, or you can be consistent. The higher guarantee of consistency you demand, lowers your availability. Imagine a small database with a milli

You can be available, or you can be consistent. The higher guarantee of consistency you demand, lowers your availability. Imagine a small database with a million copies on a million machines. when I write something, i'm going to have to wait a bit while all million machines acknowledge the write is complete. If i have a lower threshold, say 1, the write completes real fast but the million machines aren't consistent. Real systems balance consistency and availability.