CACHE_INVALIDATION_FIX_IMPLEMENTED.md

Cache Invalidation Fix - Implementation Summary

Overview

Implemented targeted fixes for interaction context retrieval failures by adding proper cache invalidation. All changes only affect cache management and do not modify application functionality.

Issues Fixed

Issue 1: Primary - Cache Not Invalidated After Interaction Context Generation ✅

Location: src/orchestrator_engine.py (lines 449-457)

Fix: After successfully generating and storing an interaction context, invalidate both caches to force fresh retrieval on next request.

Changes:

• Call invalidate_session_cache() after generate_interaction_context()
• Also clear orchestrator-level _context_cache
• Added logging for cache invalidation

Impact: Next request will query database instead of using stale cache, retrieving newly generated interaction contexts.

Issue 2: Secondary - Orchestrator Cache Not Cleared ✅

Location: src/orchestrator_engine.py (lines 453-457)

Fix: When invalidating session cache, also clear orchestrator-level cache (_context_cache).

Changes:

• Check if _context_cache exists and contains entry for session
• Delete orchestrator cache entry if present
• Added debug logging

Impact: Prevents orchestrator cache from returning stale data even if session cache is cleared.

Issue 3: Tertiary - Context Reference Mismatch Detection ✅

Location: src/orchestrator_engine.py (lines 174-195)

Fix: Detect when users reference previous context but cache shows 0 contexts, then force cache refresh.

Changes:

• Detect phrases like "based on above inputs", "previous response", etc.
• If user references previous context but has 0 interaction contexts, invalidate both caches
• Force re-retrieval of context from database
• Log warning when mismatch detected and info when refreshed

Impact: When users explicitly reference previous context, system will refresh cache and retrieve stored interaction contexts.

Issue 4: Cache Invalidation Method Added ✅

Location: src/context_manager.py (lines 1045-1053)

Fix: Added dedicated method for cache invalidation.

Changes:

• Added invalidate_session_cache(session_id) method
• Method safely checks if cache entry exists before deletion
• Added logging for cache invalidation

Impact: Provides clean API for cache invalidation that can be reused throughout codebase.

Code Changes Summary

File: src/context_manager.py

Added Method (lines 1045-1053):

def invalidate_session_cache(self, session_id: str):
    """
    Invalidate cached context for a session to force fresh retrieval
    Only affects cache management - does not change application functionality
    """
    session_cache_key = f"session_{session_id}"
    if session_cache_key in self.session_cache:
        del self.session_cache[session_cache_key]
        logger.info(f"Cache invalidated for session {session_id} to ensure fresh context retrieval")

File: src/orchestrator_engine.py

Change 1 - Cache invalidation after interaction context generation (lines 449-457):

# After generate_interaction_context()
# Invalidate caches to ensure fresh context retrieval on next request
# Only affects cache management - does not change application functionality
self.context_manager.invalidate_session_cache(session_id)
# Also clear orchestrator-level cache
if hasattr(self, '_context_cache'):
    orchestrator_cache_key = f"context_{session_id}"
    if orchestrator_cache_key in self._context_cache:
        del self._context_cache[orchestrator_cache_key]
        logger.debug(f"Orchestrator cache invalidated for session {session_id}")

Change 2 - Context reference mismatch detection (lines 174-195):

# Detect context reference mismatches and force cache refresh if needed
# Only affects cache management - does not change application functionality
user_input_lower = user_input.lower()
references_previous = any(phrase in user_input_lower for phrase in [
    'based on above', 'based on previous', 'above inputs', 'previous response',
    'last response', 'earlier', 'before', 'mentioned above', 'as discussed',
    'from above', 'from previous', 'the above', 'the previous'
])

interaction_contexts_count = len(context.get('interaction_contexts', []))
if references_previous and interaction_contexts_count == 0:
    logger.warning(f"User references previous context but cache shows 0 contexts - forcing cache refresh")
    # Invalidate both caches and re-retrieve
    self.context_manager.invalidate_session_cache(session_id)
    if hasattr(self, '_context_cache'):
        orchestrator_cache_key = f"context_{session_id}"
        if orchestrator_cache_key in self._context_cache:
            del self._context_cache[orchestrator_cache_key]
    # Force fresh context retrieval
    context = await self._get_or_create_context(session_id, user_input, user_id)
    interaction_contexts_count = len(context.get('interaction_contexts', []))
    logger.info(f"Context refreshed after cache invalidation: {interaction_contexts_count} interaction contexts")

Impact Assessment

Application Functionality

• NO CHANGES: All existing functionality preserved
• Only cache management logic modified
• Database operations unchanged
• Agent execution unchanged
• Response generation unchanged

Cache Behavior

• IMPROVED: Cache now invalidated at appropriate times
• Fresh data retrieved when needed
• Stale cache no longer prevents context retrieval

Performance

• MINIMAL IMPACT: Cache invalidation is O(1) operation
• May result in one extra database query per request (only when cache invalidated)
• Trade-off: Better accuracy vs. minimal performance cost

Expected Behavior After Fix

Scenario 1: Normal Request Flow

Request 1: "Tell me about Excel handling"
  → Generate response
  → Store interaction context in DB
  → Invalidate cache ✅
Request 2: "Create a prototype"
  → Cache miss (invalidated)
  → Query database
  → Retrieve interaction context from DB ✅
  → Use context for response generation

Scenario 2: Context Reference Detection

Request 1: "Tell me about Excel handling"
  → Generate response
  → Store interaction context in DB
  → Invalidate cache ✅
Request 2: "Based on above inputs, create prototype"
  → Cache miss (invalidated) OR cache hit with 0 contexts
  → Detect "based on above" reference ✅
  → Force cache invalidation ✅
  → Query database
  → Retrieve interaction context from DB ✅
  → Use context for response generation

Testing Recommendations

1. Test Normal Flow:

   • Send request 1 → Verify cache invalidated in logs
   • Send request 2 → Verify interaction context retrieved (> 0)
   • Verify response correctly references previous discussion

2. Test Context Reference Detection:

   • Send request 1
   • Send request 2 with "based on above inputs"
   • Verify log: "forcing cache refresh"
   • Verify log: "Context refreshed after cache invalidation: X interaction contexts"
   • Verify response correctly references previous discussion

3. Verify No Functionality Regression:

   • All existing features work as before
   • Response quality unchanged
   • Performance acceptable (may have 1 extra DB query)

Logging Changes

New log entries to monitor:

• "Cache invalidated for session {session_id} to ensure fresh context retrieval"
• "Orchestrator cache invalidated for session {session_id}" (debug level)
• "User references previous context but cache shows 0 contexts - forcing cache refresh" (warning)
• "Context refreshed after cache invalidation: X interaction contexts"

Related Documentation

• See INTERACTION_CONTEXT_FAILURE_ANALYSIS.md for detailed root cause analysis
• Changes only affect cache management as identified in analysis