Web application troubleshooting

網站應用程式技術問題排除

Web script level

• Understanding the meaning of critical HTTP status codes 4xx, 5xx Troubleshooting of HTTP errors
• Javascript
• Backend script

Database level

• 確認資料庫連線有建立？
• 確認資料庫 SQL 查詢語法是否正確？或者逾時？ MySQL :: MySQL 5.7 Reference Manual :: 5.4.2 The Error Log

Web server level

• Log Files - Apache HTTP Server Version 2.4 on Win & Linux
• Configuring Logging | NGINX Plus on Win & Linux
• IIS 記錄 - Win32 apps | Microsoft Docs on Win

Example command: This command is used to view the last few lines of the Nginx server's error log file.

sudo tail /var/log/nginx/error.log

• sudo: Execute with administrator privileges
• tail: Display the end portion of a file
• /var/log/nginx/error.log: Default path for Nginx error log file

You can add -f parameter to monitor the log file in real-time:

OS level

• Win 系統管理工具 (Administrative Tools) -> 事件檢視器 (Event Viewer)
• Linux

Troubleshooting of ...

• Troubleshooting of Excel errors

• PHP, cUrl, Python, selenium, HTTP status code errors

• Database: SQL syntax debug, MySQL errors, MySQLTuner errors or PostgreSQL errors

• Troubleshooting of regular expression

• HTML/Javascript: Troubleshooting of javascript, XPath

• Software: Mediawiki, Docker, FTP problems, online conference software

• Test connectivity for the web service, Web Ping, Network problem, Web user behavior, Web scrape troubleshooting

Template

• Bug report template