Update docs/overview/architecture.md

docs/overview/architecture.md

@@ -88,7 +88,7 @@ When the user searches a vector from Vald:
 4. After the request is processed by the user-defined Vald Ingress Filter, the result will return to the Vald Filter Gateway.
 5. Vald Filter Gateway will forward the request to the Vald Meta Gateway. Vald Meta Gateway is used to resolve the internal used UUID to the user inserted vector ID in step 10-11.
 6. Vald Meta Gateway will forward the request to the Vald LB Gateway. Vald LB Gateway will preform the post-processing of the result in step 9 after the Vald Agent(s) return in step 8.
-7. Vald LB Gateway will forward the request to all Vald Agents in parallel. Each Vald Agent will search the _k_ nearest neighbor vectors in an on memory cache.
+7. Vald LB Gateway will forward the request to all Vald Agents in parallel. Each Vald Agent will search the _k_ nearest neighbor vectors in an on memory graph index.
 8. Vald Agent returns the searching result to the Vald LB Gateway. The searching result includes the UUID, the vector distance, and the vector. The number of the result will be the same as requested.
 9. Vald LB Gateway will aggregate all searching results from all Vald Agents, rank the result by the vector distance, and return the ranked result to the Vald Meta Gateway.
 10. Vald Meta Gateway will forward the searching result to the Vald Meta to resolve the user-defined vector IDs from the internal used UUIDs.