Tier 1 is showing some stochastic behavior

[maximusunc]

Give the following query, it will usually return 134 results, but every 5 or 6 queries, it will return 171 results. Is it sometimes hitting some per-hop timeout?

curl -X POST https://dev.retriever.biothings.io/query \
  -H 'accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{
    "message": {
      "query_graph": {
        "nodes": {
          "SN": { "categories": ["biolink:ChemicalEntity"] },
          "ON": {
            "ids": ["MONDO:0007186"],
            "categories": ["biolink:DiseaseOrPhenotypicFeature"]
          },
          "h": { "categories": ["biolink:Disease"] }
        },
        "edges": {
          "edge_0": {
            "subject": "SN",
            "object": "ON",
            "predicates": ["biolink:treats_or_applied_or_studied_to_treat"]
          },
          "edge_1": {
            "subject": "SN",
            "object": "h",
            "predicates": ["biolink:treats_or_applied_or_studied_to_treat"]
          },
          "edge_2": {
            "subject": "h",
            "object": "ON",
            "predicates": ["biolink:has_phenotype"]
          }
        }
      }
    },
    "parameters": {
      "tiers": [1]
    }
  }' > retriever_response.json