關鍵字: EKS, AWS CNI Plugin
影響: 連結服務時頻繁地看到連線失敗

今天這個案例是作者團隊想要嘗試從 kops 轉移到 EKS 上遇到的問題，最初的症狀是整個平台運作起來非常慢。作者提到最初想要轉移到 EKS 上的一個理由就是其擁有更好的網路效能，然而當前的問題症狀很像網路問題，因此團隊最後直接諮詢 AWS 支援來尋求網路專家的支援。

再錄製封包之後終於觀察到了一些現況。所有叢集內的網路流量都運作得非常良好沒有問題，然而外界與叢集內的封包則沒有如此順利，觀察到大量的 TCP 重送封包。

中間與 AWS 來來回回長達一個月，協助錄製各種封包但是還是沒有解決問題，最後作者觀察到一些現象，有些節點會有存取變慢的問題，但是上面的Pod卻沒有事情。而有些則是節點本身沒有問題，但是上面的Pod卻有問題。

後面又有一次的視訊多人會議，中間弄弄整個網路全壞光了，這時候聽從 AWS 的建議開啟了一個 AWS_VPC_K8S_CNI_EXTERNALSNAT=true 的設定，然後網路就全面好了..

文章最後介紹一下整個事情的發生的原因，以及為什麼開啟 AWS_VPC_K8S_CNI_EXTERNALSNAT=true 就一切沒有問題了，有興趣的可以點選全文研究研究

https://yashmehrotra.com/post/2020-03-16-case-of-missing-packet/

Kubernetes 維運經驗分享篇
主題: 解除 CPU 來提升服務效能
關鍵字: CPU Limit, CPU throtting, 高延遲性

本篇文章是探討的是使用 CPU Limit 的經驗，熟悉這個機制的讀者應該都知道能夠這個設定來確保每個 Container 能夠使用的 CPU 數量，同時也可以透過這個機制去確保每個節點上都有足夠的 CPU 資源供原生服務，譬如 kubelet, kubeproxy 來使用。

本篇作者團隊要分享的是設定 CPU Limit 卻導致效能更差的故事，當 CPU 設定為 800ms 的時候，卻發現實際運行的效能最高只有 200ms，反覆查找卻得到是 Linux Kernel 的臭蟲導致。

一個直接的做法就是針對那些本來就沒有過高 CPU 使用量服務取消其 CPU Limit，作者於文章中也探討了一些機制要如何保護與應對這些被移除 CPU 限制的服務。

這個臭蟲於 Linux Kernel 4.19 後已經修復，但是要注意你使用的發行版本是否有有包含這個修復，作者也於文章中列出一些已知的發行版本修復狀況

原文: https://erickhun.com/posts/kubernetes-faster-services-no-cpu-limits/

今天要分享的是來自 lambda 的團隊根據其多年 Kubernetes 的經驗分享，該篇文章篇長，閱讀可能需要15分鐘左右，這邊幫大家重點整理，有興趣的別錯過完整內容，我個人滿推薦細讀的

# 重點整理
1. 團隊一開始是透過 Ansible + Valut + Consul 來管理整個架構＋應用程式的部署。
2. 作者認為一個非常重要的東西就是， 想清楚你為什麼需要 Kubernetes，不要隨便盲目的使用
3. Kubernetes 的學習曲線非常高，除了 Kubernetes 本身之外，還有很多整合的東西都需要一起學習，譬如 Monitoring, Logging, CI/CD, Secret Management, Tracing 等，每個領域都不簡單
4. Kubernetes 的導入，並非只有營運團隊需要處理，實際上是整個產品團隊都會連帶影響，譬如對於開發者來說，本地開發要怎麼做，本地測試要怎麼做？
CI/CD 如果要考慮 Kuberntees，有哪些部分需要注意？ 應用程式如何打包與上版本？ 更新策略是什麼？
這中間有超多的議題需要整個團隊一起學習與克服，才能夠真正享受到 Kubernetes 帶來的好處
5. 轉移到 Kubernets 中間的過渡期很辛苦，同時維護兩種架構，這需要時間去處理，沒有辦法馬上完成，也不可能一步到位
6. 文章中也有提到作者團隊於各領域所採取的解決方案，這邊就大概列一下

Prometheus, Grafana Loki, Vault, Tekton, Argo Workflow, Telepresence, Skaffold, Kustomize, AWS, Kops

註: 我個人認為裡面最重要的一點就是第二點，任何領域都一定，不要盲目追求潮流，而是要有充分的理由去說服自己為什麼需要使用某產品。對我來說一個很重要的行動準則是，要先說服自己，才有辦法說服別人

https://lambda.grofers.com/learnings-from-two-years-of-kubernetes-in-production-b0ec21aa2814

Joel, a ruthless survivor with few moral lines left to cross, lives in one of the last remaining Quarantine Zones. These walled-off, oppressive cities are run by what's left of the military. Despite the strict martial law, Joel operates in the black market of the city, smuggling contraband for the right price.

Joel is asked by a dying friend to look after Ellie, a fourteen-year-old girl with courage beyond her years. What starts out as a simple job to deliver Ellie to another Quarantine Zone, soon transforms into a profound journey that will forever change Joel and Ellie.

As they journey across a post-pandemic United States, Joel and Ellie will encounter different factions of survivors that have each found a unique way of dealing with the infected humans, the lack of supplies, and the threat of other survivors. As Joel and Ellie struggle to persevere, they must learn to trust each other and work together in order to survive the realities of this new world.

✦ Facebook臉書: https://www.facebook.com/ejonstyle/
✦ Donate贊助: https://www.twitchalerts.com/donate/jonstyle69
✦ Website網站: http://www.jonstyle.com/
✦ Twitter: https://twitter.com/jonstyle68
✦ Instagram: https://www.instagram.com/jonstyle69

More Videos 更多影片:
❤ GTA5 Funny moments: https://goo.gl/TTrjAc
❤ Uncharted 4 | 秘境探險4 : https://goo.gl/FHsHlw
❤ Uncharted 4 Treasures: https://goo.gl/kI5VaR
❤ DQB: https://goo.gl/ip4weW
❤ 火影忍者疾風傳 終極風暴4: https://goo.gl/SIFUV1
❤ The Division | 全境封鎖: https://goo.gl/se0x3z
❤ COC | 部落衝突: https://goo.gl/F5NGfC


謝謝你的收看，如果沒有第一時間回覆，歡迎至粉絲專頁留言給我喔!
如果你喜歡我的影片 ❤請訂閱❤ 是支持我最大動力！

Joel, a ruthless survivor with few moral lines left to cross, lives in one of the last remaining Quarantine Zones. These walled-off, oppressive cities are run by what's left of the military. Despite the strict martial law, Joel operates in the black market of the city, smuggling contraband for the right price.

Joel is asked by a dying friend to look after Ellie, a fourteen-year-old girl with courage beyond her years. What starts out as a simple job to deliver Ellie to another Quarantine Zone, soon transforms into a profound journey that will forever change Joel and Ellie.

As they journey across a post-pandemic United States, Joel and Ellie will encounter different factions of survivors that have each found a unique way of dealing with the infected humans, the lack of supplies, and the threat of other survivors. As Joel and Ellie struggle to persevere, they must learn to trust each other and work together in order to survive the realities of this new world.

✦ Facebook臉書: https://www.facebook.com/ejonstyle/
✦ Donate贊助: https://www.twitchalerts.com/donate/jonstyle69
✦ Website網站: http://www.jonstyle.com/
✦ Twitter: https://twitter.com/jonstyle68
✦ Instagram: https://www.instagram.com/jonstyle69

More Videos 更多影片:
❤ GTA5 Funny moments: https://goo.gl/TTrjAc
❤ Uncharted 4 | 秘境探險4 : https://goo.gl/FHsHlw
❤ Uncharted 4 Treasures: https://goo.gl/kI5VaR
❤ DQB: https://goo.gl/ip4weW
❤ 火影忍者疾風傳 終極風暴4: https://goo.gl/SIFUV1
❤ The Division | 全境封鎖: https://goo.gl/se0x3z
❤ COC | 部落衝突: https://goo.gl/F5NGfC


謝謝你的收看，如果沒有第一時間回覆，歡迎至粉絲專頁留言給我喔!
如果你喜歡我的影片 ❤請訂閱❤ 是支持我最大動力！

Joel, a ruthless survivor with few moral lines left to cross, lives in one of the last remaining Quarantine Zones. These walled-off, oppressive cities are run by what's left of the military. Despite the strict martial law, Joel operates in the black market of the city, smuggling contraband for the right price.

Joel is asked by a dying friend to look after Ellie, a fourteen-year-old girl with courage beyond her years. What starts out as a simple job to deliver Ellie to another Quarantine Zone, soon transforms into a profound journey that will forever change Joel and Ellie.

As they journey across a post-pandemic United States, Joel and Ellie will encounter different factions of survivors that have each found a unique way of dealing with the infected humans, the lack of supplies, and the threat of other survivors. As Joel and Ellie struggle to persevere, they must learn to trust each other and work together in order to survive the realities of this new world.

✦ Facebook臉書: https://www.facebook.com/ejonstyle/
✦ Donate贊助: https://www.twitchalerts.com/donate/jonstyle69
✦ Website網站: http://www.jonstyle.com/
✦ Twitter: https://twitter.com/jonstyle68
✦ Instagram: https://www.instagram.com/jonstyle69

More Videos 更多影片:
❤ GTA5 Funny moments: https://goo.gl/TTrjAc
❤ Uncharted 4 | 秘境探險4 : https://goo.gl/FHsHlw
❤ Uncharted 4 Treasures: https://goo.gl/kI5VaR
❤ DQB: https://goo.gl/ip4weW
❤ 火影忍者疾風傳 終極風暴4: https://goo.gl/SIFUV1
❤ The Division | 全境封鎖: https://goo.gl/se0x3z
❤ COC | 部落衝突: https://goo.gl/F5NGfC


謝謝你的收看，如果沒有第一時間回覆，歡迎至粉絲專頁留言給我喔!
如果你喜歡我的影片 ❤請訂閱❤ 是支持我最大動力！