Embedded & Distributed System

I was organising and cleaning up my Google Drive and found this pdf file about Android Graphic System I wrote back in 2014. It is 62 pages. I will never be able to update it and make it better and/or up to date, since I have moved to other area recently. I'm not not sure how useful it is now, but anyway I will share it here. https://drive.google.com/file/d/0BxzOKllGjbpdOVd4UlpOWUlxM2c/view?usp=sharing

The  index page of understand container    had a very good page view after being created. Then I was thinking if anyone would be interested in a more polished, extended, and easier to read version. So I started a book called "understand container".  Let me know if you will be interested in the work by subscribing  here  and I'll send the first draft version which will include all the 8 articles here. The free subscription will end at 31th, Oct, 2018. * Remember to click  " Share email with author (optional)", so that I can send the book to your email directly. 

This is an index page to a series of 8 articles on container implementation. OCI Specification Linux Namespaces Linux Cgroup Linux Capability Mount and Jail User and Root Network and Hook Network and CNI Update: This page has a very good page view after being created. Then I was thinking if anyone would be interested in a more polished, extended, and easier to read version. So I started a book called "understand container".  Let me know if you will be interested in the work by subscribing here  and I'll send the first draft version which will include all the 8 articles here. The free subscription will end at 31th, Oct, 2018. * Remember to click " Share email with author (optional)", so that I can send the book to your email directly.  Cheers,

Controllers  in k8s assumes the same role and responsibility as the Controller in the classic  Model-View-Controller （whereras the  Model  are the various API objects stored in the  etcd ） architecture. What's kind of unique about the controller in k8s is will  constantly  reconcile the system desired state to current state, not just a one time task.

The most known job of a container orchestration is to "Assign Pods to Nodes", or so-called  scheduling . If all the Pods and Nodes are the same, it becomes a trivial problem to solve - a round robin policy would do the job. In practice, However, Pods have different resource requirements, and less obvious that the nodes may have different capabilities - thinking machines purchased 5 years ago and brand new ones.

In the last article, we said there was a  statetore  in the master node; in practice, it is implemented using  etcd .  etcd  is open source distributed key-value store (from coreOs) using the  raft  consensus algorithm. You can find a good introduction of etcd  here .  k8s  use  etcd  to store all the cluster information and is the only stateful component in the whole k8s (we don't count in the stateful components of the application itself).

In the last article, we focus on the components in the work nodes. In this one, we'll switch our focus to the  user  and the component in  master  node. Operation Model From user's perspective, the model is quite simple:  User  declare a  State  he wants the system to be in, and then it is k8s's job to achieve that.