台股老k

Life Gamer

[台股老k @KevinBird61]

@BlockMaple 最近這種文章越來越多

[台股老k @KevinBird61]

@sehui2534690907 @ezshine @HuoQubot

[台股老k @KevinBird61]

@sehui2534690907 @ezshine @HuoQubot

[Jim Huang @jserv]

MicroBPF-Kernel is a RISC-V edge-device unikernel built from first principles to combine seL4's formal verification, Unikraft-style efficiency and in-kernel eBPF programmability. Each application is compiled into a minimal unikernel image (<2 MB) that boots in under 10 ms, safe!

[柴郡🔔｜Crypto+AI Plus @0xCheshire]

所有人都说欧洲在科技领域无法与美国竞争。

但就在 48 小时前，Mistral 推出的 Le Chat 证明了他们错了：

• 速度比 ChatGPT 快 13 倍
• 完全开源
• 完全免费（相比之下，ChatGPT Plus 订阅费每月 20 美元）

硅谷完全没有预料到的欧洲 AI 突破：🧵

[Atal @ZabihullahAtal]

C++ Course from Beginning to Advance!

Download Link:
https://t.co/uNrOEn9ZcU

[Alex Xu @alexxubyte]

🎁 Giving Away 100 Digital System Design, ML System Design, & Newsletter Subscriptions 🎁

𝐇𝐨𝐰 𝐭𝐨 𝐩𝐚𝐫𝐭𝐢𝐜𝐢𝐩𝐚𝐭𝐞:
✅ Like & retweet
✅ Subscribe to our free weekly newsletter: https://t.co/5teyU77Kjr
✅ Winners get all 3

Happy Thanksgiving ❤️

⏰ The giveaway ends in 72 hours.

Winners will receive an email on how to redeem the rewards on Nov 26.

[Bytebytego @bytebytego]

IBM MQ -> RabbitMQ -> Kafka ->Pulsar, How do message queue architectures evolve?

�� IBM MQ
IBM MQ was launched in 1993. It was originally called MQSeries and was renamed WebSphere MQ in 2002. It was renamed to IBM MQ in 2014. IBM MQ is a very successful product widely used in the financial sector. Its revenue still reached 1 billion dollars in 2020.

🔹 RabbitMQ
RabbitMQ architecture differs from IBM MQ and is more similar to Kafka concepts. The producer publishes a message to an exchange with a specified exchange type. It can be direct, topic, or fanout. The exchange then routes the message into the queues based on different message attributes and the exchange type. The consumers pick up the message accordingly.

🔹 Kafka
In early 2011, LinkedIn open sourced Kafka, which is a distributed event streaming platform. It was named after Franz Kafka. As the name suggested, Kafka is optimized for writing. It offers a high-throughput, low-latency platform for handling real-time data feeds. It provides a unified event log to enable event streaming and is widely used in internet companies.

Kafka defines producer, broker, topic, partition, and consumer. Its simplicity and fault tolerance allow it to replace previous products like AMQP-based message queues.

🔹 Pulsar
Pulsar, developed originally by Yahoo, is an all-in-one messaging and streaming platform. Compared with Kafka, Pulsar incorporates many useful features from other products and supports a wide range of capabilities. Also, Pulsar architecture is more cloud-native, providing better support for cluster scaling and partition migration, etc.

There are two layers in Pulsar architecture: the serving layer and the persistent layer. Pulsar natively supports tiered storage, where we can leverage cheaper object storage like AWS S3 to persist messages for a longer term.

Over to you: which message queues have you used?

–
Subscribe to our weekly newsletter to get a Free System Design PDF (158 pages): https://t.co/FIzCeaWsZV

[Alex Xu @alexxubyte]

We are often asked to design for high availability, high scalability, and high throughput. What do they mean exactly? The method to download the high-resolution PDF is available at the end.

The diagram below is a system design cheat sheet with common solutions.

1. High Availability
This means we need to ensure a high agreed level of uptime. We often describe the design target as “3 nines” or “4 nines”. “4 nines”, 99.99% uptime, means the service can only be down 8.64 seconds per day.

To achieve high availability, we need to design redundancy in the system. There are several ways to do this:

- Hot-hot: two instances receive the same input and send the output to the downstream service. In case one side is down, the other side can immediately take over. Since both sides send output to the downstream, the downstream system needs to dedupe.

- Hot-warm: two instances receive the same input and only the hot side sends the output to the downstream service. In case the hot side is down, the warm side takes over and starts to send output to the downstream service.

- Single-leader cluster: one leader instance receives data from the upstream system and replicates to other replicas.

- Leaderless cluster: there is no leader in this type of cluster. Any write will get replicated to other instances. As long as the number of write instances plus the number of read instances are larger than the total number of instances, we should get valid data.

2. High Throughput
This means the service needs to handle a high number of requests given a period of time. Commonly used metrics are QPS (query per second) or TPS (transaction per second).

To achieve high throughput, we often add caches to the architecture so that the request can return without hitting slower I/O devices like databases or disks. We can also increase the number of threads for computation-intensive tasks. However, adding too many threads can deteriorate the performance. We then need to identify the bottlenecks in the system and increase its throughput. Using asynchronous processing can often effectively isolate heavy-lifting components.

3. High Scalability
This means a system can quickly and easily extend to accommodate more volume (horizontal scalability) or more functionalities (vertical scalability). Normally we watch the response time to decide if we need to scale the system.

To achieve high scalability, it is important to segregate the responsibilities of the services. Microservices are widely adopted for this purpose. We also leverage the service registry and load balancer to route requests to the proper instance.

Over to you: Do you have other things to share in your design toolbox?

–
Subscribe to our newsletter to download the 𝐡𝐢𝐠𝐡-𝐫𝐞𝐬𝐨𝐥𝐮𝐭𝐢𝐨𝐧 𝐏𝐃𝐅. After signing up, find the download link on the success page: https://t.co/5w1YCB3vOJ

[Simon Willison @simonw]

Found the system prompt that drives this thing here: https://t.co/UdSV5rUY2S

It works by generating a base64 encoded PNG of the drawn components, then passing that to GPT-4 Vision with that system prompt and instructions to "Turn this into a single html file using tailwind"

[Alex Xu @alexxubyte]

Top 3 API Gateway Use Cases.

API gateway sits between the clients and services, providing API communications between them.

1. API gateway helps build an ecosystem.
The users can leverage an API gateway to access a wider set of tools. The partners in the ecosystem collaborate with each other to provide better integrations for the users.

2. API gateway builds API marketplace
The API marketplace hosts fundamental functionalities for everyone. The developers and businesses can easily develop or innovate in this ecosystem and sell APIs on the marketplace.

3. API gateway provides compatibility with multiple platforms
When dealing with multiple platforms, an API gateway can help work across multiple complex architectures.

–
Subscribe to our weekly newsletter to get a Free System Design PDF (158 pages): https://t.co/uc5M7CdXXC

[Dr Milan Milanović @milan_milanovic]

𝗙𝗮𝗰𝗲𝗯𝗼𝗼𝗸 𝗰𝗿𝗲𝗮𝘁𝗲𝗱 𝗮 𝘁𝗼𝗼𝗹 𝘄𝗵𝗶𝗰𝗵 𝗱𝗲𝘁𝗲𝗰𝘁 𝗮𝗻𝗱 𝗿𝗲𝗽𝗮𝗶𝗿 𝗯𝘂𝗴𝘀 𝗮𝘂𝘁𝗼𝗺𝗮𝘁𝗶𝗰𝗮𝗹𝗹𝘆

The recent document by engineers from Facebook explains how they wrote a tool that can automatically fix bugs. In the paper, they introduced 𝗦𝗔𝗣𝗙𝗜𝗫, an automated tool designed to detect and repair bugs in software. The tool has suggested fixes for six essential Android apps in the Facebook App Family: Facebook, Messenger, Instagram, FBLite, Workplace, and Workchat.

How Does It Work?

𝗦𝘁𝗲𝗽 𝟭: Detect a Crash - Another tool, 𝗦𝗮𝗽𝗶𝗲𝗻𝘇, finds app crashes. When Sapienz identifies a crash, it is logged into a database.

𝗦𝘁𝗲𝗽 𝟮: Identify the Problem - SAPFIX pinpoints the exact line of code causing the issue. It first checks if the crash is reproducible. If it's not reproducible, the crash is discarded. It uses a technique called "spectrum-based fault localization" to identify the most likely lines of code responsible for the crash.

𝗦𝘁𝗲𝗽 𝟯: Suggest a Fix - Using predefined templates or code mutations, SAPFIX proposes a solution. After identifying the fault location, SAPFIX attempts to generate a patch. It employs two strategies:

🔹 𝗧𝗲𝗺𝗽𝗹𝗮𝘁𝗲-𝗯𝗮𝘀𝗲𝗱 𝗙𝗶𝘅𝗶𝗻𝗴: SAPFIX uses predefined templates to suggest fixes for common bugs. These templates are designed based on standard developer practices.

🔹 𝗠𝘂𝘁𝗮𝘁𝗶𝗼𝗻-𝗯𝗮𝘀𝗲𝗱 𝗙𝗶𝘅𝗶𝗻𝗴: SAPFIX resorts to a mutation-based system if the template-based approach fails. It systematically applies a series of code mutations to the fault location to generate potential fixes.

𝗦𝘁𝗲𝗽 𝟰: Test the Fix - The proposed solution is tested to ensure it's valid. It uses the test cases from 𝗦𝗮𝗽𝗶𝗲𝗻𝘇 to check the validity of the patch. If the patch passes all tests, it's considered a good fix. After patch validation, SAPFIX uses 𝗜𝗻𝗳𝗲𝗿 (a static analysis tool) to analyze the proposed fix further. Infer checks if the patch introduces any new potential issues.

𝗦𝘁𝗲𝗽 𝟱: Review - Developers get the final say, reviewing and approving the fix.

Check the entire document in the comments.

Image credits: Facebook.

What do you think about this?

_______
If you like my posts, please follow me, @milan_milanovic, and hit the 🔔 on my profile to get a notification for all my new posts.

Grow with me 🚀!

#technology #softwareengineering #programming #techworldwithmilan #coding

[Alex Xu @alexxubyte]

My recommended materials for cracking your next technical interview:

Coding
- Leetcode
- Cracking the coding interview book
- Neetcode

System Design Interview
- System Design Interview book 1, 2 by Alex Xu
- Grokking the system design by Design Guru
- Design Data-intensive Application book

Behavioral interview
- Tech Interview Handbook (Github repo)
- A Life Engineered (YT)
- STAR method (general method)

OOD Interview
- Interviewready
- OOD by educative
- Head First Design Patterns Book

Mock interviews
- Interviewingio
- Pramp
- Meetapro

Apply for Jobs
- Linkedin
- Monster
- Indeed

Over to you: What is your favorite interview prep material?

–
Subscribe to our weekly newsletter to get a Free System Design PDF (158 pages): https://t.co/uc5M7Cdq84

[fox hsiao @pirrer]

"二十多年前，鮮為人知的兩岸三地合作計畫，建立電腦中文重要基礎"

兩岸三地深恐漢字被日韓主導，中華兒女顏面盡失，於是加速合作。國際組織後來採用聰明的包容思維，讓Unicode成為集大成的標準碼總匯。

二十多年前，一個鮮為人知的兩岸三地合作計畫，建立了中文電腦重要的基礎，今天全球所有華人能夠如此順利上網、搜尋中文內容，以及利用電郵、微信或Line互傳訊息，要歸功於當初那群電腦專家和工程師們，若非他們的努力，今天的中文網路世界將是什麼情景是難以想像的。

話說早期的電腦由於記憶體有限，只適合處理字母型的文字，英文、法文、西班牙文等西方語系的國家受惠於文字的結構，率先享用電腦帶來的好處。中文方面只爭取到注音符號列入主要的碼頁，在個人電腦沒有出現以前，絕大多數台灣使用的電腦都用英文做資料處理。後來由於市場的強烈需求，宏碁、神通和倚天等公司投入中文化電腦的研究。基本上那時是將西方語文為主的電腦架構加以改裝，廠商設計的中文輸入設備和內碼處理軟體變成附加的商品。

然而，由於缺少標準，不同廠牌的電腦採用的內碼五花八門，在台灣至少就有電信碼、四角號碼、倉頡碼、Big5碼等，若加上大陸GB和香港不同的方案，要從不同的電腦間傳中文資料簡直比登天還難。那時使用電腦的朋友都記得：假如不想讓對方收到一堆亂碼，寧願用英文寫電子信。

個人電腦發明後，使用人數大增，歐美日本的電腦公司要進軍華人市場，開始積極討論將中文納入基本的架構中，台灣的電腦公司在電腦中文化上有較豐富的經驗，經常成為外商合作的��伴，我們的人才就成為中文電腦的技術尖兵。

在電腦科技方面，在當時兩岸雖已有初步的交流互動，但是官方的來往仍屬敏感的議題，我和一群電腦專家學者組成的開放系統協會COSA接受政府私下委託，在資策會的積極協助下，展開了與香港和大陸的協商。我們和對岸一組專家及技術人員在香港中文大學的協助下在香港低調聚會，為提供國際組織的中文內碼標準而集思廣益，中國大陸固然希望以簡體字優先，但是也同意在歷史和古書的閱讀上，繁體字仍有其用途。台灣方面，我們做了深入調查，以便了解我們希望多少繁體字能夠納入。據我的記憶：閱讀報紙約要五千字、戶政機關期望有四、五萬字，圖書館界則認為要涵蓋所有古字，恐怕要七萬多字。幾經折衝協商，大家覺得先以一萬五到兩萬字做為爭取的起點。

當時兩岸的專家採取了務實的技術觀點，把意識形態放在一邊，先同意用一些原則讓字數控制在較少的範圍：

一、 簡繁體系的字體完全一樣的當然就成為共同用字

二、 簡體字和繁體字寫法不同、意義完全相同的，只佔一個內碼的位置，此內碼在簡體字的系統呈現簡體字型，在繁體字的系統則呈現繁體字型。兩邊溝通時我送繁體，你讀簡體，暢通無礙。這種情形好像台灣有些家庭，阿公講台語，孫子聽得懂，但是只會用國語回答，還好阿公也會聽國語，只是表達要用台語才流利。

三、 兩岸都各自剔除沒有必要的重複：有些字明明是同一字，只是寫法不同，例如「強」與「强」只能���出一個。

四、 若兩字寫法不同，也不完全同樣意義，才允許占用不同的內碼。

至於總共要提出多少字數呢？提得太少，以後電腦常有無法輸入或讀不出來的字，用途將會大打折扣；提出的字數太多則擔心國際標準組織不會同意，幾經調查和辯論，選擇了國際組織會同意的一萬六千多個字。在當時兩岸氛圍還不是那麼明朗和友善的情形下，政府不便出面，以民間為主的協會和學術界扮演了舉足輕重的腳色，我有幸躬逢盛會，盡了棉薄之力。

香港的中文大學很恰當地扮演了搭橋的工作，香港跟台灣同樣用繁體字，更重要的是：他們並沒有台灣那麼多有中文電腦設計經驗的工程師，所以自然願意和台灣合作一起跟大陸協商。大陸那時雖然有自己的電腦廠商，但是在國際上尚未累積足夠的人脈和經驗，所以，雖然市場遠大於���灣，還願意和台灣協商，展現出大中華文化的氣度。

當時還有一段插曲，日韓準備共同提出包含漢字的東亞文字方案，兩岸三地深恐漢字被日韓主導，中華兒女顏面盡失，於是加速合作。國際組織後來採用聰明的包容思維，讓Unicode成為集大成的標準碼總匯，以華人世界所使用的中文內碼提案，加進了日韓所需，圓滿地達成大家共同的心願，圖示如下：

由於兩岸三地的提案為聯合國國際標轉組織ISO接受，電腦廠商共同支持的Unicode也決定採用跟ISO一樣的標準，中國人從此在電腦的輸入、儲存、傳輸和呈現上居於跟世界上絕大多數使用者同等地位，中文在全球十萬個標準內碼中被採納了一萬六千多個字！世界各地華人的智慧得以貢獻到網路上，真是一件令人振奮的事情。存在一段時間的中文紛亂情形也由於Unicode幫忙解決了兩岸間文字呈現間可能的爭執，最後全世界通用的萬國碼(或稱為統一碼)很快為兩岸三地所接受。

今天我們在台灣的朋友傳送e-mail給大陸朋友可以用���己孰悉的繁體字，對方收到的是她或他孰悉的簡體字，溝通無誤。在搜尋上更是因為同樣的內碼，只要意義相同，兩岸符合搜尋詞語的網頁都可以搜到，完全避開了無謂的意識形態之爭。現在華人全世界上網人數保守估計有八、九億人，除了英文被認同為世界語之外，中文毫無疑問是挑戰英文的最佳語文。

我們由衷地感謝這群默默做事的專家學者和工程師，你們的貢獻不只在技術表準的制定，也為華人的生活、商務和文化提供難以估算的價值！

[まり @mariii_a7iv]

大正ロマン溢れる銀山温泉の雪景色が美しい

[Tech Burrito @TechBurritoUno]

The history of Bluetooth technology name.

[Donglu @DongluYu]

Sketch. Final.

[Alex Xu @alexxubyte]

/1 8 Data Structures That Power Your Databases. Which one should we pick?

[Kalan ◂Ⓘ▸ @kalanyei]

收入級距在 453 萬以上的族群，可以發現薪資所得佔比降低之外，股利所得的佔比最高來到 38%。越有錢的族群薪資所得比例越少，獲利往往來自於投資，也就是所謂的錢滾錢。

資料來源：綜稅各類所得金額百分比各級距申報統計表

[cts🌸 @gf_256]

Choose your fighter (Advent of Code)