引入：從雲計算到Serverless

原創

2021-05-01 16:03

問題	機會
服務的可用性	選用多個雲計算提供商；利用彈性來防範DDOS攻擊
數據丟失	標準化的API；使用兼容的軟硬件以進行波動計算
數據安全性和可審計性	採用加密技術，VLANs和防火牆；跨地域的數據存儲
數據傳輸瓶頸	快遞硬盤；數據備份/獲取；更加低的廣域網路由開銷；更高帶寬的LAN交換機
性能不可預知性	改進虛擬機支持；閃存；支持HPC應用的虛擬集羣
可伸縮的存儲	發明可伸縮的存儲
大規模分佈式系統中的錯誤	發明基於分佈式虛擬機的調試工具
快速伸縮	基於機器學習的計算自動伸縮；使用快照以節約資源
聲譽和法律危機	採用特定的服務進行保護
軟件許可	使用即用即付許可；批量銷售

"}}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" ","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在UC Berkeley的這篇文章中，作者不僅僅對雲計算進行了一個比較明確和細膩的定義，提出了面臨的挑戰和存在的機遇，更對雲計算的未來發展方向等進行大膽預測。同年，阿里軟件在江蘇南京建立首個“電子商務雲計算中心”（即現在的阿里雲）。至此，雲計算進入到了更加快速的發展階段。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/41/41fa733f39c55ebfaa6b55eff5760369.webp","alt":"圖片","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"圖2 雲計算髮展歷程","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" ","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如圖2所示，雲計算飛速發展的階段，雲計算的形態也在不斷的演進，從IaaS到PaaS，再到SaaS，雲計算逐漸的“找到了正確的發展方向”，2012年由Iron.io的副總裁Ken Form所寫的一篇名爲","attrs":{}},{"type":"text","marks":[{"type":"italic","attrs":{}}],"text":"Why The Future of Software and Apps is Serverless","attrs":{}},{"type":"text","text":"的文章中，提出了一個新的觀點：即使雲計算的已經逐漸的興起，但是大家仍然在圍繞着服務器轉。不過，這不會持續太久，雲應用正在朝着無服務器方向發展，這將對應用程序的創建和分發產生重大影響。並首次將“Serverless”這個詞帶進了大衆的視野。2014年Amazon發佈了AWS Lambda讓“Serverless”這一範式提高到一個全新的層面，爲雲中運行的應用程序提供了一種全新的系統體系結構，至此再也不需要在服務器上持續運行進程以等待HTTP請求或API調用，而是可以通過某種事件機制觸發代碼執行，通常這隻需要在AWS的某臺服務器上配置一個簡單的功能。此後Ant Stanley 在2015年7月名爲","attrs":{}},{"type":"text","marks":[{"type":"italic","attrs":{}}],"text":"Server are Dead…","attrs":{}},{"type":"text","text":"的文章中更是圍繞着AWS Lambda及剛剛發佈的AWS API Gateway這兩個服務解釋了他心目中的Serverless，並說Servers are dead … they just don’t know it yet.","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"到了2015年，在AWS的re:Invent大會上，Serverless的這個概念更是反覆的出現，其中包括了The Serverless Company Using AWS Lambda 和JAWS：The Monstrously Scalable Serverless Framework的這些演講。隨着Serverless這個概念的進一步發酵，2016年10月在倫敦舉辦了第一屆的ServerlessConf，在兩天時間裏面，來自全世界40多位演講嘉賓爲開發者分享了關於這個領域進展，並且對未來進行了展望，提出來了Serverless的發展機會以及所面臨的挑戰，這場大會是針對Serverless領域的第一場具有較大規模的會議，在Serverless的發展史上具有里程碑的意義。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" ","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/ba/bae877da2559eece9bc929be409e4902.webp","alt":"圖片","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"圖3 部分Serverless產品發佈時間","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如圖3所示，而截止到2017年，各大雲廠商基本上都已經在Serverless進行了基礎的佈局，尤其是國內的幾大雲廠商，也都先後在這一年邁入“Serverless時代”。從IaaS到PaaS再到SaaS的過程中，如圖4所示，雲計算所表現出的去服務器化越來越明顯，那麼Ken Form所提出來的Serverless又是什麼，它在雲計算髮展的過程中，又在扮演什麼角色呢，它的去服務器化又到了什麼程度呢？","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" ","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/26/26be8608fb6438adc0abfb9722d77553.webp","alt":"圖片","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"圖4 IaaS、PaaS、SaaS的區別","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" ","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Serverless翻譯成中文是無服務器，所謂的無服務器並非是說不需要依靠服務器等資源，而是說開發者再也不用過多考慮服務器的問題，可以更專注在產品代碼上，同時計算資源也開始作爲服務出現，而不是作爲服務器的概念出現，Serverless是一種構建和管理基於微服務架構的完整流程，允許用戶在服務部署級別而不是服務器部署級別來管理用戶的應用部署。與傳統架構的不同之處在於，它完全由第三方管理，由事件觸發，存在於無狀態（Stateless），暫存（可能只存在於一次調用的過程中）在計算容器內，Serverless部署應用無須涉及更多的基礎設施建設，就可以基本實現自動構建、部署和啓動服務。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"近些年來，微服務（Micro Service）是軟件架構領域另一個熱門的話題，如果說微服務是以專注於單一責任與功能的小型功能塊爲基礎，利用模組化的方式組合出複雜的大型應用程序，那麼可以進一步認爲Serverless架構可以提供一種更加“代碼碎片化”的軟件架構範式，而這一部分稱之爲Function as a Services（FaaS）。而所謂的“函數”提供的是相比微服務更加細小的程序單元。例如，可以通過微服務代表爲某個客戶執行所有CRUD操作所需的代碼，而FaaS中的函數可以代表客戶所要執行的每個操作：創建、讀取、更新以及刪除。當觸發“創建賬戶”事件後，將通過函數的方式執行相應的“函數”。單就這一層意思來說，可以簡單地將Serverless架構與FaaS概念等同起來。但是就具體的概念深刻探索的話，Serverless和FaaS還是不同的，Serverless和FaaS被廣爲接受的關係是：","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"Serverless = FaaS + BaaS （+ .....）","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在這個關係中，可以看到Serverless的組成除了FaaS和BaaS之外，還有一系列的省略號，其實這是Serverless給予給大家的遐想空間，給予這個時代的一些期待。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"隨着各大廠商逐漸佈局Serverless領域，Serverless也逐漸的從啓蒙階段，市場教育階段向更深一步生產應用，最佳實踐階段前進。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"同樣在2017年，CNCF Serverless WG成立了，並且開始以社區的力量推動Serverless快速前行，包括CNCF Serverless Whitepaper、CloudEvents等相關的立項研究與探索，2017年年末，eWEEK的Chris J. Preimesberger發表文章","attrs":{}},{"type":"text","marks":[{"type":"italic","attrs":{}}],"text":"Predictions 2018: Why Serverless Processing May Be Wave of the Future","attrs":{}},{"type":"text","text":"來表達在“全新的階段下”大家對Serverless的看法和期盼，在這篇文章中有來自知名團隊以及公司的相關負責人對Serverless表達了自己的想法：","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l Sumo Logic產品營銷副總裁Kalyan Ramanathan：Serverless可能是繼容器之後的未來。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l Avere Systems技術總監Dan Nydick：我們將看到更多Serverless技術和託管服務。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l Atlassian平臺負責人Steve Deasy：2018年將改變軟件的構建方式。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l Evident.io的首席執行官Tim Prendergast和客戶解決方案副總裁John Martinez：容器和Serverless正在興起，但它們會帶來安全問題。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l Contino美國總裁Jason McDonald：Serverless將繼續增加其影響力。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l 美國OVH的現場佈道者兼原理系統工程師Paul Stephenson：（2018年）將會更清楚地認識到Serverless可以解決哪些問題。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l 數據探險首席執行官Seth Noble：Serverless將在2018年與其他技術進行集成。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l Platform9首席執行官Sirish Raghuram：Kubernetes將在Serverless產品-AWS Lambda部署中發揮更大的影響力。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l Accelerite首席執行官Nara Rajagopalan：Serverless將改變開發模式。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"而到了2018年，Serverless的發展速度要比想象中的更加快速，在這一年，Google 發佈了 Knative，一個基於 Kubernetes 的開源 Serverless 框架，具備構建容器、流量調配、彈性伸縮、零實例、函數事件等能力。AWS 發佈了 Firecracker，一個開源的虛擬化技術，面向基於函數的服務，創建和管控安全的、多租戶的容器。Firecracker 的目標是把傳統虛擬機安全性和隔離性，和容器的訴求,資源效率結合起來。在這一年，CNCF也正式發佈了Serverless領域的白皮書：","attrs":{}},{"type":"text","marks":[{"type":"italic","attrs":{}}],"text":"CNCF Serverless Whitepaper V1.0","attrs":{}},{"type":"text","text":"，闡明Serverless技術概況、生態系統狀態,爲 CNCF 的下一步動作做指導，同時CloudEvnent規範，進入CNCF Sandbox；在這一年，UC Berkeley發文","attrs":{}},{"type":"text","marks":[{"type":"italic","attrs":{}}],"text":"Serverless Computing: One Step Forward, Two Steps Back","attrs":{}},{"type":"text","text":"，表達了對Serverless的擔憂和挑戰，在這篇文章中，作者認爲 Serverless 會對開源服務創新有所阻塞，作者認爲Serverless是：One Step Forward，Two Steps Back，關於這個部分內容的描述如下：","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong","attrs":{}}],"text":"One Step Forward：","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"通過提供自動縮放功能，今天的FaaS產品在雲編程方面邁出了一大步，它提供了一種實際上可管理的，看似無限的計算平臺。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong","attrs":{}}],"text":"Two Steps Back：","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"首先，他們忽略了高效數據處理的重要性；其次，它們阻礙了分佈式系統的開發。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"任何一個新的技術、概念出現都會遇到一定的挑戰和擔憂，就如同當年雲計算出現時，也被一些人（如Oracle公司總裁Larry Ellison、GNU發起人Richard Stallman）認爲只是又一個商業炒作的概念，毫無新意，甚至蠢不可及。當然，事實也證明，任何一個新的事物，都只有在經歷各種挑戰和質疑之後，才能更茁壯的成長，Serverless也不例外，從2019年開始，Serverless進入到了一個真正意義上的生產應用，最佳實踐快速發展階段而2019年對Serverless而言是非常關鍵的一年，也是Serverless具有里程碑式發展的一年，被很多人定義爲“Serverless正式發展的元年”。在這一年不僅有KubeCon在中國上海的CloudNativeCon中關於Serverless的“海量主題演講”，這些演講包括來自Captial One銀行的Kevin Hoffman的《WebAssembly、無服務器和雲》，IBM的Doug Davis的《CNCF CloudEvents項目：邁向無服務器互操作的一步》等；在這一年，更有UC Berkeley最新的文章，也被稱之爲Serverless領域的UC Berkeley斷言：","attrs":{}},{"type":"text","marks":[{"type":"italic","attrs":{}}],"text":"Cloud Programming Simplified: A Berkeley View on Serverless Computing","attrs":{}},{"type":"text","text":"，在這篇文章中，經歷了一年的發展，作者也從UC Berkeley的學者們也從1年前的質疑，悲觀轉變成了一種自信與期待，這篇文章中，作者犀利斷言Serverless 將會在接下來的十年，迅速的被採用，將會得到飛速的發展，並且說出了一些觀點：","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l 新的BaaS存儲服務會被髮明，以擴展在Serverless計算上能夠運行更加適配的應用程序類型。這樣的存儲能夠與本地塊存儲的性能相匹配，而且具有臨時和持久可供選擇。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l 比現有的 x86 微處理器更多的異構計算機。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l 更加安全、易用的編程，不僅具有高級語言的抽象能力，還有很好的細粒度的隔離性。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l 基於 Serverless 計算的價格將低於 Serverful 計算，至少不會高於 Serverful 計算。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l Serverless 將會接入更多的後臺支撐服務，如 OLTP 數據庫、消息隊列服務等。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l Serverless 計算一旦取得技術上的突破，將會導致 Serverful 服務的下滑。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"l Serverless 將會成爲雲時代默認的計算範式，將會取代 Serverful 計算，因此也意味着服務器 - 客戶端模式的終結。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"除了這些斷言，伯克利也對什麼是“Serverless\"給出了自己的想法：Put simply, Serverless computing = FaaS + BaaS. In our definition, for a service to be considered serverless, it must scale automatically with no need for explicit provisioning, and be billed based on usage. ","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在學術界，不僅僅UC Berkeley對Serverless發表過多篇論文，其實很多國內外高校，都已經在Serverless領域，投入足夠的精力進行科研探索，就目前來看， Serverless 已經成爲學術界的研究熱點，從 2017 年開始，每年相關論文數呈2倍速增長。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" ","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/7f/7f7e8b0c84d15b323828b1f073d39355.webp","alt":"圖片","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"圖5 Serverless發展歷程","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" ","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如圖5所示，從2012年，Serverless概念被正式提出之後，2014年AWS帶領Lambda開啓了Serverless的商業化，再到2017年各大廠商紛紛佈局Serverless領域，再到2019年，Serverless成爲熱點議題在KubeCon中被衆多人蔘與探討，UC Berkeley發文斷言Serverless將引領雲計算的下一個十年，Serverless隨着時間的不斷推進，各種技術部的不斷進步，正在逐漸的朝着更完整，更清晰的方向發展，隨着5G時代的到來，Serverless將會在更多領域發揮至關重要的作用。","attrs":{}}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"從IaaS到FaaS再到SaaS，再到如今的Serverless，雲計算的發展在近十餘年中發生了翻天覆地的變化，從虛擬空間到雲主機，從自建數據庫等業務，到雲數據庫等服務，雲計算的發展是迅速的，未來的方向和形態卻是模糊的，沒人知道雲計算的終態是什麼。誠然，現在有人說Serverless實現了當初了雲計算目標，Serverless纔是真正的雲計算，但是沒人可以肯定的說，Serverless就是雲計算的終態表現，或許，Serverless也僅僅是一個過渡的產物，但是這就要交個時間去驗證了，目前就不得而知了。","attrs":{}}]}]}