Meeting notes for Isabella, Oliver, Joy and me

000. Consistent Hashing

Meeting Date/Time: 07/25/2021

Speaker: XiuYi

Attendees: Oliver, Isabella, Joy

Meeting Notes:

Scalability
服务器的负载均衡算法
分布式缓存场景，3万张图片，3个缓存服务器
传统Hash取模算法，所有的缓存数据hash值改变，All cache miss
一致性hash算法，先hash服务器编号，然后hash文件/请求的名字，只有小部分缓存失效
数据倾斜/某台服务器宕机，请求分散
代码

001. 1) Oliver: 缓存简介，缓存更新策略（上）; 2) Joy：DDIA第一章;

Meeting Date/Time: 07/27/2021

Speaker: Oliver, Joy

Attendees: XiuYi, Isabella

Meeting Notes:

Oliver: 缓存简介，缓存更新策略（上）

Joy：DDIA第一章

Reliability
Scalability
Maintainability

002. 1) push/pull & Polling; 2) Inverted Index;

Meeting Date/Time: 07/30/2021

Speaker: Isabella, XiuYi

Attendees: Joy, Oliver

Meeting Notes:

push/pull & Polling

short polling/long polling/websocket
pull/pull各自适用场景

Inverted Index

关键词为key，出现地方为value
lucene，Solr/ElasticSearch

003. 1) 如何保证消息的时序性 2) 缓存简介，缓存更新策略（下）

Meeting Date/Time: 07/31/2021

Speaker: XiuYi, Oliver

Attendees: Isabella, Joy

Meeting Notes:

如何保证消息的时序性

分布式，集群化部署
全局ID generator
离线推送

缓存简介，缓存更新策略（下）

Weak/Eventual/Strong Consistency
data parition - tweet id
fail over / replication
cache aside(write around) / write back / write through / refresh ahead

004. 1) API设计要点 2) BQ准备，亚麻16条领导力准则

Meeting Date/Time: 08/05/2021

Speaker: Isabella, Xiuyi

Attendees: Oliver, Joy

Meeting Notes:

API设计要点

RPC
SOAP
REST
GraphQL

BQ准备，亚麻领导力准则

自我介绍
1）客户至上； 2）主人翁精神； 3）创新简化； 4）决策正确

005. 1) SDP - Database, RDBMS, NoSQL 2) DDIA第二章

Meeting Date/Time: 08/08/2021

Speaker: Oliver, Joy

Attendees: Isabella, Xiuyi

Meeting Notes: 1）Oli - SDP - Database

#1: Relational database management system (RDBMS)
- master-master, master-slave, federation, sharding
#2: NoSQL
- Key-Value Store, Documentation Store, Wide-Column Store, Graph Database
#3: SQL or NoSQL
SDP

2）Joy - DDIA Chapter II

SQL/Nosql
关系型文档型

006. 1）Design Chat Service (Grokking) 2）MicroService

Meeting Date/Time: 08/12/2021

Speaker: Joy, Isabella

Attendees: Oliver, Xiuyi

Meeting Notes:

Design Chat Service (Grokking)

polling - WS
consistency
store - column based
partitioning

2）MicroService

Introduction

007. 1)Xiuyi讲Chat Service补漏 2) Oliver分库分表

Meeting Date/Time: 08/15/2021

Speaker: Oliver, Xiuyi

Attendees: Joy, Isabella

Meeting Notes:

chat 补充

polling and websocket
push vs pull
流程图

分库分表

策略
join操作

008. 1）Joy讲IG， 2）Xiuyi复习Isabella的topics

Meeting Date/Time: 08/19/2021

Speaker: Joy, Xiuyi

Attendees: Isabella, Oliver

Meeting Notes: 1) * 2) *

009. 1）Oliver算法模板， 2）Isabella复习Joy的topics

Meeting Date/Time: 08/22/2021

Speaker: Oliver， Isabella

Attendees: Joy, Xiuyi

Meeting Notes:

算法模板

Binary Search
Two Pointer
BFS
BT/BST
DP
Heap
Union Find
Trie

010. 1）Joy复习Oliver的topics 2）Xiuyi - Load Balancer

Meeting Date/Time: 08/26/2021

Speaker: Joy, Xiuyi

Attendees: Oliver， Isabella

Meeting Notes:

From grokking

Load Balancer
caching
Data Partitioning
SQL/NoSQL
CAP
Long Polling, WB, Server sent events(SSE)

Load Balancer必知必会

011. 1）Isabella复习Facebook message和IG

Meeting Date/Time: 08/29/2021

Speaker: Isabella, Oliver

Attendees: Joy, Xiuyi

Meeting Notes: 1)

session ID 是否可以用全局ID生成器例如Redis？

012. 1）Desgin Youtube 2) pre sum

Meeting Date/Time: 09/02/2021

Speaker: Joy，Oliver，

Attendees: Isabella, Xiuyi

Meeting Notes: 1)

cache storage

tech blog

013. 1）Notification 2) Job Scheduler

Meeting Date/Time: 09/05/2021

Speaker: Xiuyi， Isabella

Attendees: Joy, Oliver

Meeting Notes: 1) * 2) *

014. 1）Joy复习Xiuyi的topics 2）多线程

Meeting Date/Time: 09/10/2021

Speaker: Joy, Xiuyi

Attendees: Oliver， Isabella

Meeting Notes:

复习topics

一致性hash
Inverted Index
Cookie, Session, Token
Load Balancer

015. 1）Isabella复习Xiuyi的topics

Meeting Date/Time: 09/12/2021

Speaker: Isabella

Attendees: Joy, Xiuyi

Meeting Notes:

复习topics

Learn and Be Curious
Earn Trust

016. 1）Tiny URL 2）Typeahead

Meeting Date/Time: 09/17/2021

Speaker: Joy, Oliver

Attendees: Xiuyi, Isabella

Meeting Notes:

Tiny URL

不同短网址在不同网站上，检测访问量
一个长网址对应多个短网址(Cassandra等column based)
服务器和用户可设置过期时间，不能被猜到
hash function
Key generation Service生成短网址的letters， 6个8个等

Typeahead

017. 1）网络安全基础 2）Design Parking lot

Meeting Date/Time: 09/19/2021

Speaker: Xiuyi, Isabella

Attendees: Oliver， Joy

Meeting Notes: 1) * 2) *

018. 1）图论，DP基础 2）Union Find

Meeting Date/Time: 09/28/2021

Speaker: Joy, Isabella

Attendees: Oliver， Xiuyi

Meeting Notes:

图论入门

Queue
Priority Queue

Union Find

019. 1）设计KV Store

Meeting Date/Time: 09/30/2021

Speaker: Xiuyi

Attendees: Oliver，Joy, Isabella and many others

Meeting Notes:

设计KV Store

020. 1）Grokking新的topics 2）Design Rate Limiter 3)

Meeting Date/Time: 08/22/2021

Speaker: Joy, Isabella, Oliver

Attendees: Xiu Yi

Meeting Notes: 1)

Redundancy (server) and Replication(data)
Bloom Filters - 不为1肯定没有，为1不保证一定有
Quorum
Leader and Follower
Heartbeat
Checksum - 对TCP/UDP的报文段进行校验/检测nodes之间数据复制是否完整

Design Rate Limiter

Token bucket

021. 1）Isabella复习LB/Consistent Hashing/Partitioning,Sharding 2）Blind 75

Meeting Date/Time: 10/07/2021

Speaker: Isabella, Oliver

Attendees: Joy, Xiuyi

Meeting Notes: 1) * * 2) *

022. 1）亚麻领导力LP学习4条

Meeting Date/Time: 10/12/2021

Speaker: Xiuyi

Attendees: Isabella, Oliver

Meeting Notes: 1)

Learn and Be Curious 好奇求知
Hire and Develop The Best 选育贤能
Insist on the Highest Standards 最高标准
Think Big 远见卓识

023. 1） Design Pastebin 2）复习2

Meeting Date/Time: 10/14/2021

Speaker: Joy，Isabella

Attendees: Xiuyi

Meeting Notes: 1)

paste table + user table
clean service

peer to peer / master slave
Cahce （缓存淘汰策略，缓存与DB一致性问题 - 先更新DB再删缓存，脏数据最少）

024. 1）API的设计 2）读书分享 - Working Effectively with Legacy Coding第一章

Meeting Date/Time: 10/19/2021

Speaker: Xiuyi, Oliver

Attendees: Isabella

Meeting Notes: 1) * * 2) *

025. 1）Design Dropbox 2）Idempotency幂等

Meeting Date/Time: 10/21/2021

Speaker: Joy, Xiuyi

Attendees: Oliver, Isabella

Meeting Notes: 1) * * 2) *

026. 1）Review basics III - databases 2）读书分享 - Working Effectively with Legacy Coding第二章

Meeting Date/Time: 10/24/2021

Speaker: Isabella, Oliver

Attendees: Joy, Xiuyi

Meeting Notes: 1) * * 2) *

027. 1）Mock Job Scheduler 2）Distirbuted Lock

Meeting Date/Time: 10/31/2021

Speaker: Isabella, Xiuyi

Attendees:

Meeting Notes: 1) * * 2) *

028. 1）设计Twitter的补充 2）TopK的设计 3) Multi-threading

Meeting Date/Time: 11/07/2021

Speaker: Joy, Isabella, Xiuyi

Attendees:

Meeting Notes: 1)

tweets的Sharding - 雪花算法ID
Cache
Twitter Search

MapReduce
Count-min Setch

可重入性的问题

029. 1）Mock Interview设计Amazon Price Tracker

Meeting Date/Time: 11/14/2021

Speaker: Xiuyi

Attendees: Isabella, Joy, Oliver

Meeting Notes: 1) Amazon price tracker

1k products

requirements:

grab the prices and store prices somewhere
we pop these date to customers

Amazon prices -> services to grab the prices -> to our own stores - > services to fetch data from our stores -> pop up for ASAP for real time for customer needs

pay Amazon to use APIs to get data - alternative for others, we may can use crawlers
rest/graphQL APIs to get data in our gateway layers - json objects
middle ware service to clean/aggregate/cluster data - pre-compute
store

shcema:

Product: productID, categoryID, price, timestamp;

Price: ID, productID, Array{{price1, time1},{price2, time2},{price3, time3}...}

Category: ID, categoryNames....

Select price From Product Where ProductID = "123"

sevices to grab data and do some computing - pick some products/category,save them in the cache -> speed reading for new customers
pop to clients

authozation -> free -> can access some limited resources (e.g, overal category prices change in past three months) vs VIP users (have more accesses to all tracks, like all historical data changes for all produces)

030. 1）点赞系统 2）Kafka入门图解

Meeting Date/Time: 11/18/2021

Speaker: Isabella, Xiuyi

Attendees: Joy, Oliver

Meeting Notes: 1) * * 2)

kafka不在一个consumer group的消费者怎么消费同一个消息？

031. 1）Design slack - 0

Meeting Date/Time: 12/02/2021

Speaker: Xiuyi

Attendees: Isabella, Oliver

Meeting Notes: 1) * * 2) *

032. 1）Neayby Friend; 2) 点赞系统 - 续 3) Manage up

Meeting Date/Time: 12/05/2021

Speaker: Joy, Isabella, Xiuyi

Attendees: Oliver

Meeting Notes: 1)

Quad Tree

033. 1）[Counting system](https://medium.com/pinterest-engineering/building-a-real-time-user-action-counting-system-for-ads-88a60d9c9a

); 2) GeoHash Meeting Date/Time: 12/05/2021

Speaker: Isabella, Xiuyi

Attendees: Joy, Oliver

Meeting Notes: 1) * * 2) * 3) *

034. 1）Partition之前的一些策略; 2) Design Snapchat/instagram Stories 3) DDIA summary - ch 1,2

Meeting Date/Time: 12/05/2021

Speaker: Joy, Isabella, Xiuyi

Attendees: Jasmine

Meeting Notes: 1) * * 2) * 3) *

035. 1）Design What's up app 2) Distributed System Summary + k8s

Meeting Date/Time: 01/02/2022

Speaker: Isabella, Xiuyi

Attendees:

Meeting Notes: 1) * * 2) *

036. 1）Design What's up app - leftover 2) DDIA ch 3

Meeting Date/Time: 01/09/2022

Speaker: Isabella, Xiuyi

Attendees: Joy, Oliver, Jasmine

Meeting Notes: 1) * * 2) *

037. 1）DDIA ch 4 2) In Memory DB 3) Design Leetcode

Meeting Date/Time: 01/16/2022

Speaker: Xiuyi, Nick, Isabella

Attendees: Joy

Meeting Notes: 1) * * 2) * 3)

038. 1）Twitter Architecture

Meeting Date/Time: 01/23/2022

Speaker: Xiuyi

Attendees: Jasmine, Nick, Isabella, Oliver

Meeting Notes: 1) * * 2) * 3)

039. 1）Zero Copy 2) Apache Flink 3) Cost Efficiency @ Scale in Big data File Format

Meeting Date/Time: 01/30/2022

Speaker: Xiuyi, Isabella, Oli

Attendees: Jasmine, Nick, Joy

Meeting Notes: 1) * * 2)

https://developer.aliyun.com/article/666052?spm=a2c6h.13262185.0.0.4c7b7e18EzjqIJ

https://eng.uber.com/cost-efficiency-big-data/

040. 1）即时通讯系统y 2) SQL to NoSQL 3) WebAssembly

Meeting Date/Time: 02/06/2022

Speaker: Nick, Joy

Attendees: Jasmine, Vickie, Isabella, Oli, Xiuyi

Meeting Notes: 1) * * 2) *

041. 1）Webassembly

Meeting Date/Time: 02/10/2022

Speaker: Xiuyi

Attendees: Jasmine, Vickie, Isabella, Oli, Nick, Joy, wenruo

Meeting Notes: 1) * * 2) *

042. 1）Apache Beam

Meeting Date/Time: 02/20/2022

Speaker: Xiuyi

Attendees: Jasmine, Isabella, Oli, Nick, Joy, wenruo

Meeting Notes: 1)

Python版本的'|'问题，应该是语法糖两个进程通信，而不是位操作的或操作

043. 1）FB Outage on 10/04/2021 2) Idempotency - 上

Meeting Date/Time: 02/27/2022

Speaker: Wenruo, Isabella

Attendees: Xiuyi, Nick, Jasmine, Vickie

Meeting Notes: 1) * * 2)

044. 1）DDIA Ch 5 - 1 2) SP and Trigger 3) MVND

Meeting Date/Time: 03/06/2022

Speaker: Nick, Joy, Xiuyi

Attendees: Wenruo, Isabella, Xiuyi, Jasmine, Vickie

Meeting Notes: 1)

Kafka从2.4版本开始可以从followers中读取数据，之前版本只能从leader中读；正常的数据库一般是leader只负责写入
WAL vs binlog

045. 1）DDIA Ch 5 - 2 2) Lyft Beam

Meeting Date/Time: 03/13/2022

Speaker: Ning, Xiuyi

Attendees: Yu, Xiuyi, Wenruo, Isabella, Jasmine, Vickie

Meeting Notes: 1) * * 2) * 3)

046. 1）Docker - 上 2) Idempotency - 下

Meeting Date/Time: 03/20/2022

Speaker: Xiuyi, Isabella，

Attendees: Ning, Yu, Xiuyi, Wenruo, , Jasmine, Vickie

Meeting Notes: 1) * * 2)

pre-PRC, rpc, post-RPC transaction最后一个步骤失败了怎么办？
Transaction的操作顺序问题
master和replicas在payments中同步问题

047. 1）Inorder 2) clean code 3) Payment system - 上

Meeting Date/Time: 03/27/2022

Speaker: Wenruo, Oli Xiuyi

Attendees: Ning, Yu, Joy, Isa, Jasmine

Meeting Notes: 1) * * 2) * 3)

048. 1）Inorder Payment system - 下

Meeting Date/Time: 04/03/2022

Speaker: Xiuyi

Attendees: Yu, Joy, Isa, Jasmine, Wenruo, Oli

Meeting Notes: 1)

是否可以将Kafka的partition指定给consumer消费？

049. 1）PostgresSQL 2) Webhooks

Meeting Date/Time: 04/10/2022

Speaker: Isabela Xiuyi

Attendees: Yu, Jasmine, Wenruo, Yibo, Vickie

BQ topics - customer obsession

Who was your most difficult customer?
Give me an example of a time when you did not meet a client’s expectation. What happened, and how did you attempt to rectify the situation?
When you’re working with a large number of customers, it’s tricky to deliver excellent service to them all. How do you go about prioritizing your customers’ needs?
Tell the story of the last time you had to apologize to someone.

Meeting Notes: 1) * *

050. 1）TCP - DB connections

Meeting Date/Time: 04/17/2022

Speaker:

Attendees: Isabela, Xiuyi, Yu, Jasmine, Wei, Yibo, Vickie

Meeting Notes: 1)

RST ARK

051. 1）支持亿级流量的高并发IM架构 2) OpenAPI简介

Meeting Date/Time: 04/24/2022

Speaker: Yu, Xiuxi

Attendees: Isabela, Jasmine, Wei, Wenruo, Nick, Oli

Meeting Notes: 1) * 2)

resources

052. 1）Learning OAuth2.0 2) DDIA Chapter 6

Meeting Date/Time: 04/24/2022

Speaker: Wei, Nick

Attendees: Yu, Xiuxi, Isabela, Jasmine, Yibo, Wenruo, Oli

Meeting Notes: 1) * 2)

resources

053 1) Design chat system.

Meeting Date/Time: 08/28/2022

Speaker: Joy

Attendees: Yu, Xiuxi, Isabela, Jasmine, Yibo, Wenruo, Oli

Meeting Notes:

Meeting Notes: Types of connections:

short polling; (close right after response) 2.long polling; (long and will timeout) 3.WebSocket. (Bi-directional and persistent) High-level design: Stateless: User > LB > services (AMI, Service discovery, User service, Group service) Stateful: via WS Storage: KV stores 用于水平scaling KV store 低延迟。关系型搞不定长尾问题。索引也是坑的一笔。 Table 设计: dbo.[message] dbo.[group_message] 只要保证group范围内ID唯一，即可躺平。

1.Message 1 to 1 chat workflows, 重点是有个message queue。面向消息队列编程。

如何跨设备同步，实现统一通信？手机PC（都记录各自收到哪一条了）然后都通过Chat Server1的session来catch up。
Small Group chat workflow：重点是有message queue，发是发给queue，收也是收那个queue。
Online Presence如何隐身 5s一个heartbeat，30s就当他掉了。 PS: WB开销很大，只考虑建立给active chatting，timeout即可回收资源。

Meeting Note三 1.Online Status fanout Pub-sub模式更新在线状态非常昂贵，让他们自己手动pull？ Wrap up 加分题： 1.支持文字以外的多媒体。 2.端到端加密。小心老旧机型性能问题。。。 3.Caching。历史数据本地存着？

关系数据库可以存下用户，setting等比较stable的基本数据（靠谱便于维护）。但是像一条条的即时消息，必须上KV store。 4.服务发现 PS：面试时把replica放在back pocket就好。太细节不用摆在桌面。 PS：拜占庭共识？？？

resources

056. 1）Jeopardy Game

Meeting Date/Time: 09/25/2022

Speaker: XiuYi

Attendees: Yu, Wei, Isabela, Vickie, Joy, Yibo, Oli, O.O, Wen, Ju, zhengda

Meeting Notes: 1)

Jeopardy Game 1

Num! Isabella Ju
Top1 Joy Zhengda
找工作 Wei Wen Yuan
YYV Yu Yibo Vickie

067. 1）Design Web Crawler 2)

Meeting Date/Time: 10/02/2022

Speaker: Zhengda Wu

Attendees: Yu, Wei, Isabela, Guilin, Yibo, Oli, Ning, Joy, Yuan

Meeting Notes:

Design a web crawler （搜索引擎）

如何防止死循环
MapReduce
NoSQL存储
抓取的数据隔一段时间不同如何处理？ - timestamp
PageRank
Load Balancer算法
缓存的地方（浏览器。redis，数据库层， CDN， Application）
Web Server/API Server
分布式爬虫? 数以亿计的网站
crawler在背后一直run，起点是什么？ - 有一些种子links，公司自己定；
热门网站如何决定 - 热门网站放在queues里面（deep dive）
反爬机制 - 文件/协议

068. 1）Design Web Crawler - 上 2)

Meeting Date/Time: 10/09/2022

Speaker: Joy, Ding

Attendees: Yu, Wei, Isabela, Guilin, Ning, Yuan, Zhengda，Oli

Meeting Notes:

Design a web crawler

种子URLs - 根据场景来选择
准备download的 - URL frontier
content比较防止重爬 - 文字比对效率太低，利用Hashing结果来对比，MD5比较慢，MurmurHash或者JenkinsHash可用，Lucene用的Lookup3Signature（by JenkinsHash）
比对hashing结果非常相近的时候，是否存两次或相同对待；只存关键词和links - fingerprints
Inverted Indices - 索引关键词，部分网页存cache大部分不存网页本身内容（no content storage）

Ding Q&A

国内国外工作最大的不同 - 科技类公司，国内工作怕普遍强度高很多

069. 1）Prometueus理解和实战

Meeting Date/Time: 10/16/2022

Speaker: Xiuyi

Attendees: Isabela, Oli, Ning, Ding, Zhengda

Meeting Notes:

Prometheus + Grafana + SpringBoot

联邦监控
tombstones文件
Prometheus高级功能

070. 1）Design Web Crawler - 下

Meeting Date/Time: 10/23/2022

Speaker: Joy

Attendees: Isabela, Xiuyi, Oli, Ning, Ding, Zhengda

Meeting Notes:

Design Web Crawler - 下

DFS vs BFS
Queue Selector - 设定优先级
防扒机制 - 大网站
不同domain但内容相同 - filter
Spider Traps - 黑名单
两个queues存放问题

071. 1）Review Consistent Hashing 和 KV store

Meeting Date/Time: 10/30/2022

Speaker: Joy

Attendees: Isabela, Xiuyi, Ning, Yu, Wei, Zhengda, Oli

Meeting Notes: 1) *

072. 1）Prometueus告警实战

Meeting Date/Time: 11/13/2022

Speaker: Xiuyi

Attendees: Isabela, Oli, Ning, Yu, Zhengda, Joy

Meeting Notes:

Prometheus + Grafana + Kafka

SlackBot token

073. 1）如何画架构图 - C4 Model

Meeting Date/Time: 11/20/2022

Speaker: Xiuyi

Attendees: Isabela, Wei, Yuan, Yu, Joy, Oli

Meeting Notes: 1)

通常我们会到container（起始）和component（局部展开）这两层

074. 1）Design Metrics and Alerting System

Meeting Date/Time: 12/04/2022

Speaker: Xiuyi

Attendees: Isabela, Wei, Ning, Yu, Joy, Oli, Zhengda

Meeting Notes: 1)

075. 1）DDIA - Chapter 3 Storage and Retrieval

Meeting Date/Time: 12/11/2022

Speaker: Wei

Attendees: Isabela, XiuYi, Ning, Yuan, Joy, Oli, Zhengda

Meeting Notes:

DDIA第三章笔记

what is clustered index?

076. 1）RDBMS Index

Meeting Date/Time: 12/18/2022

Speaker: XiuYi

Attendees: Isabela, Wei, Ning, Yu

Meeting Notes:

Index的创建和使用

-- 创建Person表
SHOW DATABASES;
USE testdb;

drop table IF EXISTS `person`;
create TABLE `person`
(
    `id`          bigint(20)   NOT NULL AUTO_INCREMENT,
    `name`        varchar(255) NOT NULL,
    `score`       int(11)      NOT NULL,
    `create_time` timestamp    NOT NULL,
    PRIMARY KEY (`id`),
    KEY `name_score` (`name`, `score`) USING BTREE,
    KEY `create_time` (`create_time`) USING BTREE
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8mb4;

-- 在本地机器上，循环sp创建100K测试数据，with MySQL8.0.31
-- maintain cost
create
    DEFINER = `root`@`localhost` PROCEDURE `insert_person`()
begin
    declare c_id integer default 1;
    while c_id <= 100000
        do
            insert into person values (c_id, concat('name', c_id), c_id + 100, date_sub(NOW(), interval c_id second));
            set c_id = c_id + 1;
        end while;
end;


-- space cost
select round(((DATA_LENGTH) / 1024 / 1024), 3)  `Data size in MB`,
       round(((INDEX_LENGTH) / 1024 / 1024), 3) `Index size in MB`
from information_schema.TABLES
where TABLE_NAME = 'person';
-- retrieves rows from a table using an index cost
explain select * from person where NAME = 'name1';
explain select NAME, SCORE from person where NAME = 'name1';

-- 索引匹配列前缀
EXPLAIN SELECT * FROM person WHERE NAME LIKE '%name123' LIMIT 100; -- not use index
EXPLAIN SELECT * FROM person WHERE NAME LIKE 'name123%' LIMIT 100; -- use index
-- where后的条件语句
EXPLAIN SELECT * FROM person WHERE LENGTH(NAME) = 7;

-- Joint Index只用一个
EXPLAIN SELECT * FROM person WHERE SCORE > 45678; -- not use index
EXPLAIN SELECT * FROM person WHERE NAME LIKE 'NAME45%'; -- use index
EXPLAIN SELECT * FROM person WHERE SCORE > 45678 AND NAME LIKE 'NAME45%'; -- use index

SHOW TABLE STATUS LIKE 'person';

-- check places for optimization
SET optimizer_trace="enabled=on";
SELECT * FROM person WHERE NAME >'name84059' AND create_time>'2022-12-17 15:00:00';
SELECT * FROM information_schema.OPTIMIZER_TRACE;
SET optimizer_trace="enabled=off";

077. 1）AWS Services

Meeting Date/Time: 01/08/2023

Speaker: Xiuyi

Attendees: Isabela, Wei, Ning, Yu, Joy, Oli, Zhengda, Jasmine

Meeting Notes:

geohash vs google s2 vs quadra tree

078. 1）Proximity Service

Meeting Date/Time: 01/22/2023

Speaker: Joy

Attendees: Isabela, Wei, Ning, Yu, Xiuyi, Oli

Meeting Notes:

Proximity Service (Yelp)

079. 1）Nearby Friends/People within x miles

Meeting Date/Time: 01/29/2023

Speaker: Joy

Attendees: Isabela, Wei, Ning, Yu, Xiuyi, Zhengda, Oli

Meeting Notes:

peer to peer vs shared backend
service discovery

080. 1）DDIA - Chapter 5 Replication

Meeting Date/Time: 02/05/2023

Speaker: Wei

Attendees: Joy, Isabela, Ning, Yu, Xiuyi, Zhengda, Oli

Meeting Notes:

Leaders and Followers replication
Single Leader replication Logs: Statement based logging; Write ahead logging(WAL); logical (row based) logging; Trigger based logging
Multi-leader replication: Performance; Conflict resolution; Network;

Conflict-free replicated data types (CRDTs);
Mergeable persistent data structures (MPDSs);
Operational transformation (OT);

Leaderless replication:

081. 1）Review System Design basics

Meeting Date/Time: 02/12/2023

Speaker: Isabela

Attendees: Joy, Yu, Xiuyi, Zhengda, Oli

Meeting Notes:

Load Balancer - Least connection/Least response time/Least Bandwidth/Least Packets/Round Robin/Weighted Round Robin/IP Hash/URL Hash
Cache - Client side cache/CDN/Server side cache, Global cache/Distributed Cache (with Request Cache), Local cache

Cache Invalidation - Write through (Cache and DB sametime)/Write Around (Write only DB)/Write Back (Write Cache first and then DB)/Cache Aside (Read from Cache first, if not found, read from DB and then write to Cache)
Cache Eviction - FIFO/LIFO/LRU/LFU/MRU/RR
先更新数据库再更新缓存 vs 先删除缓存再更新数据库 vs 先更新数据库再删除缓存（根据不用的use cases来选择）

082. 1）Docker Full Course 101

Meeting Date/Time: 02/19/2023

Speaker: Xiuyi

Attendees: Joy, Yu, Ning, Zhengda, Oli, Jasmine, Isabella

Meeting Notes:

Container - hotfix mechanism; which to control this process
Docker uses Linux Container on Windows - LCOW (not Linux Container - LXC, LCOW refers Hyper-V) to run Linux containers on Windows
TODO: K8S

083. 1）Google Map (from Alex Xu)

Meeting Date/Time: 02/26/2023

Speaker: Joy

Attendees: Joy, Yu, Xiuyi, Ning, Oli, Jasmine, Isabella

Meeting Notes:

Functional Requirements: User location service, Navigation service including ETA, Map redering
Non-functional Requirements: Accuracy, Smoothness, Data and Battery usage, General Availability and scalability
Map 101: Geocoding vs Reverse Geocoding; Geohashing, Map rendering (Hirachical routing tiles: zoom in/out, 4个方向，小块为4的n次方)
Road data processing for navigation service: Dijistra algorithm, A* algorithm
Google Map Architecture:

Frontend: Map rendering, Navigation, Search, User location service
Backend: Map data, Navigation data, Search data, User location data
Map data: Map tiles, Map features, Map labels, Map images
Navigation Service: Navigation routes, Navigation labels, Navigation images
Search data: Search index, Search labels, Search images
User location Service: User location, User location labels, User location images
CDN for location service

Data Models: Routing tiles/Object DB(s3), , user location data/column based(cassandra), geocoding data路的信息/redis, map tiles图片信息
Shortest-path service - A* algorithm, BFS
ETA service, Ranking service, Updator service
Delivery protocol: Websocket, Server-Send Events(SSE)

084. 1）Learn Design Patterns

Meeting Date/Time: 03/05/2023

Speaker: Joy

Attendees: Yu, Xiuyi, Isabella, Ruichen, Zhengda, Joy, Ning, Oli

Meeting Notes:

SOLID
Proxy Pattern
Command Pattern

085. 1）Cache

Meeting Date/Time: 03/12/2023

Speaker: Isabella

Attendees: Yu, Xiuyi, Zhengda, Ning, Joy

Meeting Notes:

Recovery Time Objective (RTO) vs Recovery Point Objective (RPO)
Weak consistency vs Strong consistency
Reverse Proxy vs Forward Proxy
Redis vs Other in-memory cache
supplement - Crash cource in Caching

085. 1）Kubernetes 101 - 0

Meeting Date/Time: 03/19/2023

Speaker: Xiuyi

Attendees: Isabella, Yu, Ruichen, Ning, Joy, Oli

Meeting Notes:

Is K8s Node same as distributed system Node?
How do K8s nodes isaolate from each other?
sidecar pattern

085. 1）Design Distributed MQ

Meeting Date/Time: 03/26/2023

Speaker: Joy

Attendees: Isabella, Xiuyi, Yu, Zhengda, Oli

Meeting Notes:

Design Distributed MQ
Benefits of Distributed MQ

086. 1）Design Distributed MQ - Kafka Consumer groups

Meeting Date/Time: 04/02/2023

Speaker: Joy

Attendees: Isabella, Xiuyi, Ning, Oli, Ruichen

Meeting Notes:

Delayed Message Delivery

087. 1）Infrastructure and tooling for MLOPS

Meeting Date/Time: 04/09/2023

Speaker: Xiuyi

Attendees: Isabella, Oli, Ruichen, Zhengda

Meeting Notes: 1)

088. 1）Transactions

Meeting Date/Time: 04/23/2023

Speaker: Isabella

Attendees: Xiuyi, Ning, Oli, Ruichen, Zhengda, Joy

Meeting Notes:

转账的transaction，不同accounts之间，先减后加还是先加后见，讨论觉得先减后加，但DDIA ch7的例子是先加后减 2）Isolation level: Read Uncommitted vs Read Committed vs Repeatable Read (Snapshot Isolation) vs Serializable

089. Metrics and Alerting System

Meeting Date/Time: 04/30/2023

Speaker: Joy

Attendees: Isabella, Xiuyi, Ning, Oli, Ruichen, Zhengda

Meeting Notes:

Topic: 2023-04-30 Metrics Monitoring & Alerting System

Metrics Collections
Alerting Systems

Data retention policy: raw data for 7 days, 1 min resolution for 30 days 1 hour resolution for 1 year Non-functional requirements Scalability Low latency Reliability Flexibility

Pull v.s. Push

Aggregations: 一般习惯用Flink，Spark来aggregte (用kafka功能非常少，kafka做aggregate很少用，社区讨论啊，支持啊都很少)。 Kafka Streams natively supports "incremental" aggregation functions, in which the aggregation result is updated based on the values captured by each window. Incremental functions include count(), sum(), min(), and max().

Handle storage: Down Sampling Cold Storage

PagerDuty v.s. Prometheus

089. Ad Click Event Aggregation

2023-05-07 Ad Click Event Aggregation

Architectures: Lambda v.s. KAPPA

Real-time Streaming v.s. Batching

Online v.s. Offline aggregations

Scaling: YARN, and the Cassandra built-in

Partition tolerance: refer to the Swimlane Diagram > keep a record of your offset in the HDFS, and also group the (send aggregated result + save new offset + reply ACK to the Kafka) transaction.

Fault tolerance: keep the partial results.

Correctness: Reconciliation

090. Ad Click Event Aggregation

Meeting Date/Time: 05/07/2023

Speaker: Joy

Attendees: Isabella, Xiuyi, Ning, Oli, Zhengda, Jeff

Meeting Notes:

Ad Click Event Aggregation

Architectures: Lambda v.s. KAPPA

Real-time Streaming v.s. Batching

Online v.s. Offline aggregations

Scaling: YARN, and the Cassandra built-in

Partition tolerance: refer to the Swimlane Diagram > keep a record of your offset in the HDFS, and also group the (send aggregated result + save new offset + reply ACK to the Kafka) transaction.

Fault tolerance: keep the partial results.

Correctness: Reconciliation

091. 1）Transactions - 续

Meeting Date/Time: 05/14/2023

Speaker: Isabella

Attendees: Joy, Xiuyi, Ning, Oli, Ruichen, Yu

Meeting Notes:

Lost update - write write conflict - Atomic write operation/Explict locking
Write skew and phantoms - constraint locking / predicate locking
Serializability Isolation - Two phase locking

shared mode / exclusive mode
growing phase - 可以获得锁，不能释放锁
shrinking phase - 可以释放锁，不能获得锁
bad for performance
serializable snapshot isolation (SSI) - 读写锁分离, optimistic concurrency control (OCC)

092. 1）k8s - 1, Pod and ReplicaSet

Meeting Date/Time: 05/21/2023

Speaker: Xiuyi

Attendees: Isabella, Joy, Oli, Ruichen, Yu, Zhengda

Meeting Notes: 1)

093. 1）Overview of Distributed Systems

Meeting Date/Time: 05/28/2023

Speaker: Xiuyi

Attendees: Isabella, Joy, Oli, Yu, Zhengda

Meeting Notes:

System Desing Components

DNS (Domain Name System)
Load Balancer
API Gateway
CDN (Content Delivery Network)
Forward Proxy v.s. Reverse Proxy
Caching
Data Partitioning
Sharding
Database Replication (Async v.s. semi-sync v.s. synchronous) Quorum ()
Distributed Messaging System
Distributed File Systems
Notification System
Full-text Search
Data Warehouse

094. 1）System Design - Hotel Reservation System (Airbnb)

Meeting Date/Time: 06/04/2023

Speaker: Joy

Attendees: Xiuyi, Isabella, Ning, Yu, Zhengda

Meeting Notes:

System Design - Hotel Reservation System (Airbnb)

instead of room id, use room type
reservation id
idenpotence for reservation id, idempotent API
pessimistic locking v.s. optimistic locking
- pessimistic locking - lock the resource before you use it
- optimistic locking - version number, compare and check outdated or not
2 phase commit and 3 phase commit

094. 1）Messaging System

Meeting Date/Time: 06/11/2023

Speaker: Isabella

Attendees: Xiuyi, Yu, Ruichen, Oli, Zhengda

Meeting Notes:

Distributed transaction - 2 phase commit and 3 phase commit
Atomic transaction protocol

095. 1）Kubernetes - 2, Deployment, replicaSet and deamonSet

Meeting Date/Time: 06/18/2023

Speaker: Xiuyi

Attendees: Isabella, Yu, Ruichen, Oli, Zhengda

Meeting Notes: 1)

096. 1）Overview for Coding Interview

Meeting Date/Time: 06/25/2023

Speaker: Xiuyi

Attendees: Isabella, Yu, Joy, Ruichen, Oli, Zhengda

Meeting Notes: 1)

097. 1）Microsoft AI for Beginners (part1)

Meeting Date/Time: 07/02/2023

Speaker: Ruichen

Attendees: Isabella, Xiuyi, Wenruo

Meeting Notes:

Microsoft Course - AI for Beginners

098. 1）An incomplete list of skills senior+ engineers need, beyond coding

Meeting Date/Time: 07/09/2023

Speaker: Xiuyi

Attendees: Isabella, Ning, Oli, Ruichen, Yu, Zhengda

Meeting Notes:

Senior+ Engineer
Treat your team as a company, treat other teams as customers;
Divide and conquer: 5 years -> 1 year -> 6 months -> 1 month -> 1 week -> 1 day; soft goals;
How to persuade other teams to adopt your solutions in real work?
In Interviews?

099. 1）An incomplete list of skills senior+ engineers need, beyond coding

Meeting Date/Time: 07/16/2023

Speaker: Xiuyi

Attendees: Joy, Oli, Ruichen, Yu, Zhengda

Meeting Notes: 31 Startup business models you must know - with examples

100. 1）Distributed Email System

Meeting Date/Time: 07/23/2023

Speaker: Joy

Attendees: Isa, Xiuyi, Oli, Yu, Ning

Meeting Notes:

101. 1）Review Senarios for System Design Terms; 2) Improve your visibility

Meeting Date/Time: 07/30/2023

Speaker: Xiuyi

Attendees: Isa, Joy, Oli, Yu, Ruichen, Yu, Zhengda

Meeting Notes: 1) Review Senarios for System Design Terms 2) Improve your visibility

102. Tiny URL System Design

Meeting Date/Time: 08/06/2023

Speaker: Isa

Attendees: Xiuyi, Joy, Ning, Ruichen, Yu, Zhengda

Meeting Notes:

encoding vs encryption
delete longURL?

103. Real-time Gaming Leaderboard System Design

Meeting Date/Time: 08/13/2023

Speaker: Joy

Attendees: Xiuyi, Isa, Oli, Ruichen, Ning,

Meeting Notes:

Real-time Gaming Leaderboard
Requirement: Display top 10 players on the leaderboard.
Show a user’s specific rank.
Display players who are four places above and below the desired user (bonus).
Non-functional requirements Real-time update on scores.
5M DAU QPS : if user play 10 games per day on average.
API Design POST /v1/scores [user id, points]
GET /v1/scores
GET /v1/scores/{:userId}

104.

105. 106. K8s Service and Ingress

Meeting Date/Time: 09/10/2023

Speaker: Xiuyi

Attendees: Joy, Isa, Oli, Yu, Ruichen, Ning, Zhengda

107. Digital Wallet

Meeting Date/Time: 09/17/2023

Speaker: Joy

Attendees: Isa, Xiuyi, Yu, Ning

108. Partition

Meeting Date/Time: 09/24/2023

Speaker: Isa

Attendees: Xiuyi, Yu, Joy, Zhengda

109. Database transaction concurrency control

Meeting Date/Time: 10/01/2023

Speaker: Xiuyi

Attendees: Isa, Yu, Oli, Ruichen, Ning

110. 四个问题

Meeting Date/Time: 10/08/2023

Speaker: Ning, Yu, Isa, Ruichen

Attendees: Xiuyi，Joy 1）分布式系统中API设计的幂等性设计应该考虑哪些因素？ 2）分布式系统中请求之间的顺序性如何保证？（例如用MQ做例子） 3）Zookeeper的使用场景和竞品有哪些？ 4）简述cookie，session，token之间的联系和区别？讲述分布式session和sticky session

111. Stock Exchange

Meeting Date/Time: 10/15/2023

Speaker: Joy

Attendees: Xiuyi，Oli, Yu, Isa, Ruichen, Zhengda

111. Consistency

Meeting Date/Time: 10/22/2023

Speaker: Isa

Attendees: Xiuyi，Oli, Joy, Yu, Ning

Linearizability
Serializability

112. 四个问题

Meeting Date/Time: 11/05/2023

Speaker: Ning, Yu, Sophia, Norman

Attendees: Xiuyi, Ruichen, Joy

2 Phase Commit - XA 方案 - participant状态提交的阻塞问题；cordiantor单点问题；在网络分区或协调者故障的情况下不保证一致性；悲观锁
3 Phase Commit - TCC方案 - 悲观锁，解决coordinator的单点问题 - 应用场景？
简述MySQL, Redis，ZK实现分布式锁 - zk如何解决service的死锁问题？
业界常见的分布式锁解决方案 - Chubby, Curator, ZK, DynamoDB, Redis, etcd, etcd-recipes, Consul

113. 数据存储与检索 Index in DDIA

Meeting Date/Time: 11/12/2023

Speaker: Joy

Attendees: Xiuyi, Isa, Ning, Yu, Sophia, Norman, Oli, Ruichen

In LSM, how to know which segments are new and which are old? - TimeStamp, Serial Number, Tiered Compaction, Bloom Filter Tier, etc
sequential write v.s. random write, use WAL to protect data
B-Tree v.s. LSM
B+ Tree, many DBs have 3~4 levels, use "latch" or "copy on write" to protect the tree

114. DDIA

Meeting Date/Time: 11/19/2023

Speaker: Isa Attendees: Xiuyi, Joy, Ning, Yu, Sophia, Norman, Oli, Ruichen

115. Websocket and devops

Meeting Date/Time: 11/26/2023

Speaker: Xiuyi Attendees: Joy, xiao, jeff, Ning, Sophia, Norman, Oli, Ziwei

how many users/sessions can 1 websocket handle? 1 websocket connection for 1 user

116. 四个问题

Meeting Date/Time: 12/03/2023 Speaker: Ning, Yu, Sophia, Ruichen Attendees: Xiuyi, Joy, Zhengda, Norman, Ziwei

@柠檬综合各个方面，例如应用场景，格式，效率，安全性等等，对比API架构类型 SOAP, REST, RPC，GraphQL； 2）@yugege 结合自己工作经验，介绍企业中一个系统向另外一个系统同步数据的方式，例如何种场景使用了RPC，为什么使用RPC，为什么选择JSON/protocol buffer/avro作为数据传输格式，等等； 3）@Sophia Lu 当我们设计面向customers的API时，通常需要做什么样的措施来保护我们的APIs? 例如 OAuth2， Versioning， Rate Limiting， Input Validation， API Gateway等等； 4）@Ruichen Rong 常见的API接口测试方法有哪些，各适用于什么场景？例如Integration Testing, Functional Testing, Smoke Testing, Load Testing, Regression Testing等等。

117. DDIA chapter 2 - Replication - 1 - Single Leader

Meeting Date/Time: 12/10/2023 Speaker: Joy Attendees: Isa, Xiuyi, Ning, Sophia, Norman, Oli, Ziwei, Zhengda, Ruichen

Replication - single leader v.s. multi-leader v.s. leaderless
leaders to followers -> logs

118. DDIA chapter 2 - Replication - 2 - Multi Leader and Leaderless

Meeting Date/Time: 12/17/2023 Speaker: Joy Attendees: Xiuyi, Sophia, Ziwei, Zhengda 1)

119. Idempontence

Meeting Date/Time: 12/24/2023 Speaker: Guilin Attendees: Joy, Ruichen 1)

120. New year goals

Meeting Date/Time: 01/07/2024 Speaker: Attendees: Guilin, Ruichen 1)

121. CI with Github Actions

Meeting Date/Time: 01/14/2024 Speaker: Guilin Attendees: Sophia, Joy, Ruichen, Ziwei, Zhengda 1)

122. Top K problem

Meeting Date/Time: 01/21/2024 Speaker: Attendees: Norman, Sophia, Guilin, Oli, Ziwei, Zhengda

Bloom Filter
Count-Min Sketch

123. 1）Some Reviews

Meeting Date/Time: 02/04/2024 Speaker: Guilin Attendees: Ning, Oli, Sophia, Wenruo, Ruichen, Ziwei, Zhengda

Monolith v.s. Microservice
Separate Frontend and Backend
A BQ template

124. 1）Free talks

Meeting Date/Time: 03/10/2024 Speaker: Guilin Attendees: Ning, Norman, Isabella, Ziwei, Zhengda

AI - https://mp.weixin.qq.com/s/M5K49T2CGcUb5yh6bWnXZg

125. 1）From Container to Wasm on Kubernetes

Meeting Date/Time: 03/17/2024 Speaker: Guilin Attendees: Sophia, Zhengda

https://www.cncf.io/blog/2024/03/12/webassembly-on-kubernetes-from-containers-to-wasm-part-01/

126. 1）整合市面上AI产品并部署

Meeting Date/Time: 03/24/2024 Speaker: Guilin Attendees: Sophia, Zhengda, Norman, Oli

127. 1）Applications in Artificial Intelligence

Meeting Date/Time: 03/31/2024 Speaker: Guilin Attendees: Zhengda, Ning

128. 1）Overview of Distributed Systems

Meeting Date/Time: 04/07/2024 Speaker: Guilin Attendees: Zhengda, Ning, Norman, Oli

129. 1）CICD with Github Actions and argoCD

Meeting Date/Time: 04/14/2024 Speaker: Guilin Attendees: Zhengda, Ning, Oli

130. 1）Introduction to Llama3

Meeting Date/Time: 04/21/2024 Speaker: Guilin Attendees: Zhengda, Ning, Oli

131. 1）Design Metrics & Alerting System 0 - Overview

Meeting Date/Time: 05/05/2024 Speaker: Guilin Attendees: Oli

Logging v.s. Metrics v.s. Tracing
Prometheus v.s. Zabbix vs Nightingale

132. 1）Design Metrics & Alerting System 1 - Glossary and Architecture

Meeting Date/Time: 05/12/2024 Speaker: Guilin Attendees: Oli, Zhengda

Metrics - 3 identifiers: global unique name, timestamp, influxdb way
Metrics - Counter, Gauge, Histogram, Summary

132. 1）Design Metrics & Alerting System 2 - Monitoring Architecture

Meeting Date/Time: 05/19/2024 Speaker: Guilin Attendees: Oli, Ning

Exporters, TSDB, Alerting, Visualization

133. 1）Design Metrics & Alerting System 3 - Start Prometheus cluster and key concepts

Meeting Date/Time: 06/02/2024 Speaker: Guilin Attendees: Oli, Zhengda

Start Prometheus cluster and key concepts

134. 1）AI RAG and Langchain

Meeting Date/Time: 06/23/2024 Speaker: Guilin Attendees: Oli, Norman

AI RAG and Langchain

135. 1）Neuroplatform

Meeting Date/Time: 06/30/2024 Speaker: Guilin Attendees: Zhengda, Ning

Neuroplatform

136. 1）Deploy Kafka on Kubernetes; 2) RAG - AnythingLLM

Meeting Date/Time: 07/14/2024 Speaker: Guilin Attendees: Norman, Ruicheng, Will

137. 1）Graphrag

Meeting Date/Time: 07/21/2024 Speaker: Guilin Attendees: Oli

guilindev / studybuddy Goto Github PK

studybuddy's Introduction

000. Consistent Hashing

001. 1) Oliver: 缓存简介，缓存更新策略（上）; 2) Joy：DDIA第一章;

002. 1) push/pull & Polling; 2) Inverted Index;

003. 1) 如何保证消息的时序性 2) 缓存简介，缓存更新策略（下）

004. 1) API设计要点 2) BQ准备，亚麻16条领导力准则

005. 1) SDP - Database, RDBMS, NoSQL 2) DDIA第二章

006. 1）Design Chat Service (Grokking) 2）MicroService

007. 1)Xiuyi讲Chat Service补漏 2) Oliver分库分表

008. 1）Joy讲IG， 2）Xiuyi复习Isabella的topics

009. 1）Oliver算法模板， 2）Isabella复习Joy的topics

010. 1）Joy复习Oliver的topics 2）Xiuyi - Load Balancer

011. 1）Isabella复习Facebook message和IG

012. 1）Desgin Youtube 2) pre sum

013. 1）Notification 2) Job Scheduler

014. 1）Joy复习Xiuyi的topics 2）多线程

015. 1）Isabella复习Xiuyi的topics

016. 1）Tiny URL 2）Typeahead

017. 1）网络安全基础 2）Design Parking lot

018. 1）图论，DP基础 2）Union Find

019. 1）设计KV Store

020. 1）Grokking新的topics 2）Design Rate Limiter 3)

021. 1）Isabella复习LB/Consistent Hashing/Partitioning,Sharding 2）Blind 75

022. 1）亚麻领导力LP学习4条

023. 1） Design Pastebin 2）复习2

024. 1）API的设计 2）读书分享 - Working Effectively with Legacy Coding第一章

025. 1）Design Dropbox 2）Idempotency幂等

026. 1）Review basics III - databases 2）读书分享 - Working Effectively with Legacy Coding第二章

027. 1）Mock Job Scheduler 2）Distirbuted Lock

028. 1）设计Twitter的补充 2）TopK的设计 3) Multi-threading

029. 1）Mock Interview设计Amazon Price Tracker

030. 1）点赞系统 2）Kafka入门图解

031. 1）Design slack - 0

032. 1）Neayby Friend; 2) 点赞系统 - 续 3) Manage up

033. 1）[Counting system](https://medium.com/pinterest-engineering/building-a-real-time-user-action-counting-system-for-ads-88a60d9c9a

034. 1）Partition之前的一些策略; 2) Design Snapchat/instagram Stories 3) DDIA summary - ch 1,2

035. 1）Design What's up app 2) Distributed System Summary + k8s

036. 1）Design What's up app - leftover 2) DDIA ch 3

037. 1）DDIA ch 4 2) In Memory DB 3) Design Leetcode

038. 1）Twitter Architecture

039. 1）Zero Copy 2) Apache Flink 3) Cost Efficiency @ Scale in Big data File Format

040. 1）即时通讯系统y 2) SQL to NoSQL 3) WebAssembly

041. 1）Webassembly

042. 1）Apache Beam

043. 1）FB Outage on 10/04/2021 2) Idempotency - 上

044. 1）DDIA Ch 5 - 1 2) SP and Trigger 3) MVND

045. 1）DDIA Ch 5 - 2 2) Lyft Beam

046. 1）Docker - 上 2) Idempotency - 下

047. 1）Inorder 2) clean code 3) Payment system - 上

048. 1）Inorder Payment system - 下

049. 1）PostgresSQL 2) Webhooks

050. 1）TCP - DB connections

051. 1）支持亿级流量的高并发IM架构 2) OpenAPI简介

052. 1）Learning OAuth2.0 2) DDIA Chapter 6

053 1) Design chat system.

056. 1）Jeopardy Game

067. 1）Design Web Crawler 2)

068. 1）Design Web Crawler - 上 2)

069. 1）Prometueus理解和实战

070. 1）Design Web Crawler - 下

071. 1）Review Consistent Hashing 和 KV store

072. 1）Prometueus告警实战

073. 1）如何画架构图 - C4 Model

074. 1）Design Metrics and Alerting System

075. 1）DDIA - Chapter 3 Storage and Retrieval

what is clustered index?

076. 1）RDBMS Index

077. 1）AWS Services

078. 1）Proximity Service

079. 1）Nearby Friends/People within x miles

080. 1）DDIA - Chapter 5 Replication

081. 1）Review System Design basics

082. 1）Docker Full Course 101

083. 1）Google Map (from Alex Xu)

084. 1）Learn Design Patterns

085. 1）Cache

085. 1）Kubernetes 101 - 0

085. 1）Design Distributed MQ

086. 1）Design Distributed MQ - Kafka Consumer groups