},
          "expr": "label_join((histogram_quantile(0.50, sum(rate(istio_request_duration_milliseconds_bucket{reporter=\"source\"}[1m])) by (le, destination_workload, destination_workload_namespace)) / 1000) or histogram_quantile(0.50, sum(rate(istio_request_duration_seconds_bucket{reporter=\"source\"}[1m])) by (le, destination_workload, destination_workload_namespace)), \"destination_workload_var\", \".\", \"destination_workload\", \"destination_workload_namespace\")",