With balanced session-sticky routing:
LRU APC = 49.2% (only 1.8pp below infinite 51.0%)
LFU APC = 43.5% (worse than LRU!)
SessionProtLRU = 49.0% (no improvement)
The previous 10.1pp gap was from routing imbalance (all traffic to inst_0),
not from cache eviction policy. Balanced routing recovers 5.9pp of the gap.
Multi-turn sessions get 80.1% APC with simple LRU + session-sticky routing
because inter-turn gap is only 2 requests (LRU naturally keeps it warm).
Conclusion: fix routing balance, not cache policy.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
