Why to use a cell schema

The practice of Micro Bo fan service platform in the cell architecture has been told in Qcon, this time I wrote the article again, I think the dissemination of knowledge is not so important (the cell structure is not innovation, will be introduced in detail later), but more importantly, I hope to be able to arouse your thinking, to be able to put more effort into thinking and trying at the architectural level.

Why should there be architectural practice?

Many people like the details, because there is a famous saying that the Devil in the details, so go to the details to find the devil. But can you see an angel if you beat the devil? Not necessarily. The details are actually the easiest part, and there's a lot more to it than that. As with cement and sand, you can make concrete, but you have a long way to go to build a high-rise, you have to learn to design the architecture.

But things are not finished, just as there is no single truth, and architecture is not just one. You can't once learn to be invincible. If you want to disaster relief, you need a tent, if you want to rebuild, you need is the tile-roofed. Different dwellings require a different structure.

Different services also require different architectural designs, which is why we need architectural practices. The reason behind this is that we do any service, and we have to consider the performance and cost of the service.

But there are many ways to optimize, why is the architecture? Admittedly, from the hardware to the operating system, from the shared library to the application software, from the algorithm to the architecture, each layer can be optimized, but each layer does the work and the benefits are different. Architecture may be the most energy-focused, but in many cases it is also very rare to provide more than the order of magnitude of ascension.

So, the change of mindset is the part that you should care about most, the cell is just an example, and the fan service platform is just an example of this example.

To get to the point, the next article will introduce the practice from three questions, what the cell is, why and how we do it.

1. What is the cell?

The cellular architecture is developed from the field of parallel computing. In the field of distributed service design, a unit (cell) is a self-contained installation that satisfies all business operations of a partition. A partition (Shard) is a subset of the overall dataset, and if you use tail to divide the user, that same tail of users can be considered a partition. Cell is the process of transforming a service design to conform to the unit characteristics.

Figure 1: The microscope screenshot of the onion cells, the purpose of the cell is to make each cell work independently as a cell.

Under the traditional service architecture (pictured below), services are layered, each layer uses different partitioning algorithms, each layer has a different number of nodes, and the upper nodes randomly select the lower nodes. Of course, this random is comparatively speaking.

Figure 2: Traditional service architecture, for scalability design, the upper node randomly select the lower node