are being achieved. iii. Logging Levels 1. Debug – anything that happens in the program 2. Info – user driven actions or system specific 3. Warn – conditions that could become an error and will likely Faults & errors 10. Circuit breaker trips 11. Delays 12. Backup success/failure d. USE TELEMETRY TO GUIDE PROBLEM-SOLVING i. Don’t practice “Mean Time until Declared Innocent” – culture of blame encourages INTEGRATING A/B TESTING INTO OUR FEATURE TESTING i. Random subset of users shown differing versions. User groups define a cohort. Statistical analysis of cohort’s outcomes from differing versions used to

/iptables -P FORWARD ACCEPT # systemctl daemon-reload # systemctl restart docker ★默认还加了DOCKER-USER这个forward链，默认全部return，导致不通，也得 放开，具体得看下iptables规则），以下操作目的为 在系统启动后等待60秒待 k8s把iptables规则设置完毕再在以下几个chain里放通所有流量，如果对防火墙 sleep 60 /usr/sbin/iptables -I DOCKER 1 -s 0.0.0.0/0 -j ACCEPT /usr/sbin/iptables -I DOCKER-USER 1 -s 0.0.0.0/0 -j ACCEPT /usr/sbin/iptables -I DOCKER-ISOLATION-STAGE-1 1 -s 0.0.0.0/0 -j service-ip：是虚拟的ip，是由kube-proxy去建立相应的iptables/ipvs规则进行流量 的转发 ★kube-proxy的代理规则模式有： 代理模式 k8s版本要求 User Space proxy mode v1.0 + iptables proxy mode v1.1 + ipvs proxy mode v1.8 + 需要在所有k8s服务器上加载ipvs内核

schema 下 的 pg_hba_file_rules表里： INSERT INTO "pg_hba_file_rules" ("line_number", "type", "database", "user_name", "address", "netmask", "auth_method", "options", "error") VALUES (94, 'host', '{all}', '{all}' #初次登录需要切换为postgres用户，直接登录，无 需密码 postgres=# alter user postgres with password 'passwdxxyy'; #修改管理员账号 postgres的密码 postgres=# postgres=# create user cof with password 'passwdxxyy2'; #创建一个名为cof的 库的所有权限 postgres=# postgres=# revoke all on database db_test from cof; #撤销用户权限 postgres=# drop user xxx; #删除用户 postgres=# exit;

息，不用于身份验证 #全局设置信息保存在 ~/.gitconfig 文件里 # git config --global user.name cof #设置用户名 # git config --global user.email cof@cof-lee.com #设置邮箱 # git config --global #初始化仓库，将在当前路径下生成.git子目录，子目录里有 此git仓库的相关信息 # git config --local user.name cof #设置用户名 # git config --local user.email cof@cof-lee.com #设置邮箱 # git config --local h�p.sslVerify #查看本地设置 ★系统设置 系统设置信息保存在/etc/gitconfig文件里 # git config --system user.name cof # git config --system user.email cof@cof-lee.com # git config --system --list

有时我们使用shi�切换输入法，若不小心按的次数多了（按2次shi� 键），结果就弹出全局搜索框，不太友好，可以关闭此功能 File → Se�ngs → Advanced Se�ngs → 右 侧 的 User Interface ， 勾 选 Disable double modifier key shortcuts ★设置每行最大长度 File → Se�ngs → Editor → Code 禁用javascript chrome_options.add_argument('--disable-javascript') # 设置UserAgent user_agent = ["--user-agent=Mozilla/5.0 (Windows NT 10.0; Win64; x64)", "AppleWebKit/537.36 (KHTML "Chrome/120.0.0.0", "Safari/537.36"] chrome_options.add_argument(" ".join(user_agent)) # 创建一个浏览器驱动 driver = webdriver.Chrome(options=chrome_options) driver.maximize_window()

of buying off the shelf.  The risk of developing a system incrementally and altering it based on user feedback is often lower than that of buying a finished product that is hard to change.  The advantages product that does not fit our business and customize it until it does.  We offer our business users a user interface that is clunky because it was designed for users in the abstract across many possible companies get feedback, and then adjust what they have produced. As a result, the code can be developed in a user-centric way and match the enterprise’s needs precisely. Risk is low, because the team is constantly

must maintain a big picture, long-term view and focus on the next six-month release.  DO epics and user stories to concisely define the desired system functions and provide the foundation for Agile estimation estimation and planning. o They describe what the users want to accomplish with the resulting system. User stories help ensure that users, acquirers, developers, testers, and other stakeholders have a clear is established to help estimate the level of work for each requirement (i.e., as translated into user stories)

the-heck-do-you-start  The myth of the single metric  Four roles (CEO, Operations, Developer, User)  Sunburst chart how do visitors move through my siteLinux Performance Tools by Brendan Gregg (Netflix) process, entropy  Actively discourage email: it is exclusive Where there any key themes?  Real User Monitoring: more valuable than any other metric  Web Performance: 2 seconds is the magic number

ExecStart=/usr/local/bin/redis-server /root/redis-6.2.13/redis.conf PrivateTmp=true [Install] WantedBy=mul�-user.target EOF # systemctl daemon-reload # systemctl enable redis # systemctl start redis # systemctl

operations will derive NFRs. Codify these into the tests and pipeline f. BUILD REUSABLE OPERATIONS USER STORIES INTO DEVELOPMENT i. Goal – make recurring work as repeatable and deterministic as possible;