Knock 🚪

Internal Document Search Service for B2B SaaS

1. Search

• #ThingsYouCan’tAskCoworkers #WhatYouMissed
• Don’t hesitate—ask Knock!
• Posts highly related to your query are quickly retrieved using morpheme analysis and importance ranking.

2. Security

• #InternalDocuments #SecurityIsKey
• Each company has its own Admin, and only the Admin can register Members.
• Read/edit permissions can be assigned based on employee rank.

3. Community

• Categorize and manage documents by use case.
• Easily check the edit status of a post, and receive notifications once a colleague finishes editing.
• Foster a collaborative work environment through comments and edit logs!

4. D.I.Y

• #YourWay #CustomizeFreely #DocumentDecorNotPlannerDecor
• Use the favorites feature to save posts into your own folders, organized just the way you want!
• Favorite folders are private, so you can save freely with peace of mind.
  
  
  
  

Knock Backend Team

📚 Knock Team Notion

	Name	Github
BE Lead	Yeowon Kim	https://github.com/YeowonKIM
BE Member	Nahyun Kim	https://github.com/hunny-A
BE Member	Jaeyong Park	https://github.com/jyparkDev
BE Member	Sunyeon Jeong	https://github.com/sunyeon-Jeong

Project Details

• Demo Video
  

  • Final Presentation 📷
    

• Implementation Goals

  • Search Performance: Fast and accurate results using morpheme analysis
  • Edit Status Notifications: Show editing status and notify when edits are complete
  • Personal Document Management: Manage your own posts and organize internal documents in folders
  • Post Sharing Community: Comment-based communication and access to edit history
  • Log Functionality: View past and current versions of edited posts

• Features Implemented

  • Search and category-based filtering
  • Post detail page
  • My Page and Favorites
  • Admin page (managing companies, employees, categories, etc.)
  • Comments and edit logs

• Duration

  • 2023.03.10 ~ 2023.04.21

Tech Stack

Service Architecture

ERD

View ERD

API Documentation

📄 Go to API Docs

Key Features

Document Search & Filtering	Edit Status Tracking
- High performance search by title, content, and keywords - Category-specific search - Search filters (relevance, comments, views, recency)	- View edit status - Notify users if a completed post is reopened for edits

Admin Page	Comments & Edit Logs
- Manage employee roles and permissions - Manage document categories	- Communicate via comments - Compare before/after versions via logs

Trouble Shooting

💡 For details, data, and statistics, check the links under each toggle.

Improving Search Performance

(1) [STEP1] Identifying and addressing performance issues

• Problem: Speed and performance varied by environment (Local, EC2).
• Cause: Inefficient library usage and redundant queries
• Solution: Introduced JMeter for load testing and AOP Execution Timer for performance tracking 👉 https://www.notion.so/STEP1-fad9129c662e44859f1ff7d4df0dd75f

(2) [STEP2] Optimizing morpheme analysis settings

• Issue: Komoran library was too slow and used excessive memory
• Solution: Adjusted settings to optimize memory usage
• Result: Load threads increased 10x (40 → 400); execution time reduced to 1/10 (1.5s → 0.5s) 👉 https://www.notion.so/STEP2-4bd04dd85a6e4edb9b5e8dc47f6fcc27

(3) [STEP3] Query optimization with QueryDSL

• Problem: Still slow (500ms) even with a lighter library
• Cause: Inefficient queries for keyword/category search
• Fix: Combined separate queries into a single dynamic query
• Result: Load capacity increased (700 → 2500 threads); time reduced to ~300ms 👉 https://www.notion.so/STEP3-Query-DSL-939026377148406f93c7a571b767cd42

(4) [STEP4] Improving sorting query performance

• Problem: Poor query structure when applying filters
• Fix: Used dynamic queries with OrderSpecifier for sorting (e.g., by interest, views, comments, date)
• Result: Execution time reduced to <100ms, stable under 2500 threads 👉 https://www.notion.so/STEP4-Query-b142f6187b964433a73e4118458bc35c

SSE

(1) Needed real-time edit status notifications without frequent API calls (2) Used SSE for one-way, persistent communication from server to client 👉 https://www.notion.so/SSE-d46754926bdd4ba2a69be6a6e94405a2

Temporary Auth Code Storage

(1) Needed short-term storage for password recovery codes (2) Used Redis due to its in-memory efficiency and automatic expiration 👉 https://www.notion.so/Redis-5f74e46c591d47108d4bf692b29ba3aa

CI / CD

- Issue: Docker image failed to run from Github Actions on EC2 - Cause: SSH connection to Knock EC2 server was refused - Fix: Resolved by adjusting `secrets` settings in Github Actions (pem.key and EC2 password) 👉 https://www.notion.so/CI-CD-78da8d9f7b4f4f6bba947b7e7ffda2b1