CHANGES_SUMMARY.md

Summary of Changes

1. Added TODO Comment in Code

File: obp-api/src/main/scala/code/api/util/RateLimitingUtil.scala

Added a TODO comment at line 154 explaining the optimization opportunity:

• Remove redundant EXISTS check since GET returns None for non-existent keys
• This would reduce Redis operations from 2 to 1 (25% reduction per request)
• Includes example of simplified code

Change: Only added comment lines, no formatting changes.

2. Documentation Created

File: REDIS_RATE_LIMITING_DOCUMENTATION.md

Comprehensive documentation covering:

• Overview and architecture
• Configuration parameters
• Rate limiting mechanisms (authorized and anonymous)
• Redis data structure (keys, values, TTL)
• Implementation details of core functions
• API response headers
• Monitoring and debugging commands
• Error handling
• Performance considerations

Note: All Lua script references have been removed as requested.

3. Files Removed

• REDIS_OPTIMIZATION_ANSWER.md - Deleted (contained Lua-based optimization suggestions)

Key Insight

Q: Can we just use INCR instead of SET, INCR, and EXISTS?

A: Partially, yes:

• ✅ EXISTS is redundant - GET returns None when key doesn't exist (25% reduction)
• ❌ Can't eliminate SETEX - INCR doesn't set TTL, and we need TTL for automatic counter reset
• Current pattern (SETEX for first call, INCR for subsequent calls) is correct for the Jedis wrapper

The TODO comment marks where the EXISTS optimization should be implemented.