bug: session_key args has no null check #735
Description
Describe the bug
The session_key args under KvawareRouter has no null check before accessing it.
To Reproduce
Run the vllm production stack with below args
--host │
│ 0.0.0.0 │
│ --port │
│ 8000 │
│ --service-discovery │
│ k8s │
│ --k8s-namespace │
│ vllm │
│ --k8s-label-selector │
│ environment=test,release=test │
│ --routing-logic │
│ kvaware │
│ --engine-stats-interval │
│ 15 │
│ --request-stats-window │
│ 60 │
│ --lmcache-controller-port │
│ 9000
Expected behavior
No response
Additional context
No response