出包的是 container/cgroup ，看來 kernel 要常更新才行。
k8s 雖然是多了一層，但奇特的是你把 control plane 整個關掉， container 其實還會繼續跑，只是不能更新而已。從這角度來看 k8s 其實和真正部署的 app 隔的很開
SQL 有標準，因此 JPA 的意義少了一半。但雲端平台一直沒有標準 ，好不容易大家都服了 k8s，紛紛抬轎，長遠來看還是優點大於缺點。
其實進入 k8s 後就有 service discovery，不需要這層了，等於是多出來。
另外 format 應該是各子團隊開始 refactor 成統一格式才對，而不是再做一層轉換層 (都已經變慢了還不做最佳化？)
Introduction on SAP Fiori Initially, SAP customers used to complain about the static and old-fashioned look and feel of the screen. Also, SAP was only accessible via its GUI for most of the transactions. SAP decided to launch a set of applications that included the most widely used transactions like purchase order approval, sales order creation and many more.
Watch this SAP Fiori Tutorial For Beginners Video: https://www.youtube.com/watch?v=SgoYw3AWbHA
This collection of apps is named as Fiori, which is based on the HTML5 framework. The main advantage of this is, it can be accessed across desktops, tablets, and smartphones. Introduction on SAP Fiori What Is SAP Fiori? SAP Fiori is a new type of user experience (UX) for SAP applications and software. Fiori provides a set of applications that can be used in regular business functions like financial apps, calculation apps, work approvals, and various self-service apps. Fiori Apps were developed by SAP, based on the user interface, UI5. As mentioned, SAP Fiori is a new user experience which contains a collection of applications that are used in regular functions. SAP Fiori provides various role-based applications like HR, manufacturing, finance, etc. Below image depicts the concepts contained in the home page of SAP Fiori. What Is SAP Fiori With respect to the designing aspects of SAP Fiori, there are five design principles that make SAP Fiori simple and easily accessible. The image that is represented below depicts these five different design principles of SAP Fiori. principles of SAP Fiori. Role based: In this case, SAP transactions have been converted into a beautiful user-interactive application. This shows only the relevant information of a user. Responsiveness: This provides an unmatched application response and query execution time by combining SAP Fiori with the power of SAP HANA. Simple: To meet the user’s requirements, SAP has designed a simple scenario called 1-1-3 scenario which means: 1 user, Introduction on SAP Fiori Initially, SAP customers used to complain about the static and old-fashioned look and feel of the screen. Also, SAP was only accessible via its GUI for most of the transactions. SAP decided to launch a set of applications that included the most widely used transactions like purchase order approval, sales order creation and many more. Watch this SAP Fiori Tutorial For Beginners Video: https://www.youtube.com/watch?v=SgoYw3AWbHA This collection of apps is named as Fiori, which is based on the HTML5 framework. The main advantage of this is, it can be accessed across desktops, tablets, and smartphones.
What Is SAP Fiori? SAP Fiori is a new type of user experience (UX) for SAP applications and software. Fiori provides a set of applications that can be used in regular business functions like financial apps, calculation apps, work approvals, and various self-service apps. Fiori Apps were developed by SAP, based on the user interface, UI5. As mentioned, SAP Fiori is a new user experience which contains a collection of applications that are used in regular functions. SAP Fiori provides various role-based applications like HR, manufacturing, finance, etc. Below image depicts the concepts contained in the home page of SAP Fiori.
For more information about the SAP Fiori Visit: https://intellipaat.com/blog/tutorial/s4-hana-logistics-tutorial/introduction-to-sap-fiori/
With respect to the designing aspects of SAP Fiori, there are five design principles that make SAP Fiori simple and easily accessible. The image that is represented below depicts these five different design principles of SAP Fiori.
• Role based: In this case, SAP transactions have been converted into a beautiful user-interactive application. This shows only the relevant information of a user. • Responsiveness: This provides an unmatched application response and query execution time by combining SAP Fiori with the power of SAP HANA. • Simple: To meet the user’s requirements, SAP has designed a simple scenario called 1-1-3 scenario which means: 1 user, 1 use case, and 3 screens. • Seamless
看來大公司都會走 CRD，這也是 k8s 的優點之一，容許擴充但不會擴充到用起來不像 k8s.
可惜沒看到部署的機器數。
engineer team 很多華人/韓國人的樣子
從 ec2 instance 搬到 k8s 之後發現，現在 cluster 一死掉，就是全部服務一起死。不像以前 ec2 個個虛擬主機是獨立的，隨便掛一個都沒差
k8s 適合跑的應用都是 stateless，更廣泛一點說，就是 cloud native app。因為這樣，所以Pod、Job…等等元件要 scale 和重啟都好輕鬆啊！但其實有另一大塊是 stateful app 很難搞定，許多人乾脆 stateful 的通通不放 k8s 裡了。然後更妙的是 k8s cluster 本身就是個 stateful app，而且不符合 cloud native 的定義。這算是呼應第一點，當 cluster 壞掉時，你沒辦法很容易啟動新的 cluster 原地復活。
k8s 太複雜了，而且未來只會更複雜，因為目前不斷有新的標準產生。依照過去十幾年的經驗，過度複雜的系統最後會被簡化過的新架構取代，感覺 k8s 也是個過渡性產品。
與 k8s 成對的是 microservice，甚至有人還說: 如果沒要要用 microservice，何必用 k8s ? 問題是 microservice 這種分散式泡沫一定很快就會消失，因為前例太多了，像是 EJB、WebService、SOA... 等等
k8s 現在有很多小廠商提供產品和服務，大廠則是不斷推出相關的新產品，然後又有証照可考，未來很多企業都會導入的。從這角度來看似乎很正面，但這個超級像過去的 J2EE，有標準、有証照、有一堆免費和商用 container 可選 (以前 J2EE server 也叫 container，這不是巧合)。你看看 J2EE 現在還剩什麼廠商吧…
當然啦，技術本來就會隨時代迭代，這個十年可能就是 k8s 稱霸，而十年也夠久了，投身這門技術可以讓自己有競爭力，企業也會因為標準化，尋求人材時會簡單許多。要說短期內會出現的缺失，就是因為 k8s 變成顯學、標準化，造成大家不適用 k8s 的系統也會硬套，然後又難學難管理，白白增加成本。
現在k8s好像是顯學，但偶爾也會看到一些如 Maybe You Don't Need Kubernetes1 這類的文章，所以有機會想多方聽聽各種經驗，可以請教一下為什麼嗎?