metrics: update distsql_copr_resp_size unit (#59991)

ref #59990

Author: zimulala

pkg/metrics/distsql.go

@@ -89,6 +89,6 @@ func InitDistSQLMetrics() {
 			Subsystem: "distsql",
 			Name:      "copr_resp_size",
 			Help:      "copr task response data size in bytes.",
-			Buckets:   prometheus.ExponentialBuckets(1024, 2, 20),
+			Buckets:   prometheus.ExponentialBuckets(1, 2, 10),
 		}, []string{LblStore})
 }

pkg/metrics/grafana/tidb.json

@@ -23717,7 +23717,9 @@
           "datasource": "${DS_TEST-CLUSTER}",
           "description": "The total coprocessor response size between each tidb and tikv",
           "fieldConfig": {
-            "defaults": {},
+            "defaults": {
+              "unit": "KiBs"
+            },
             "overrides": []
           },
           "fill": 0,
@@ -23787,7 +23789,7 @@
           "yaxes": [
             {
               "$$hashKey": "object:394",
-              "format": "binBps",
+              "format": "KiBs",
               "label": "",
               "logBase": 1,
               "max": null,
@@ -23817,7 +23819,9 @@
           "datasource": "${DS_TEST-CLUSTER}",
           "description": "Histogram of coprocessor response size in bytes between tidb and tikv",
           "fieldConfig": {
-            "defaults": {},
+            "defaults": {
+              "unit": "kbytes"
+            },
             "overrides": []
           },
           "fill": 0,
@@ -23914,7 +23918,7 @@
           "yaxes": [
             {
               "$$hashKey": "object:394",
-              "format": "bytes",
+              "format": "kbytes",
               "label": "",
               "logBase": 1,
               "max": null,

pkg/store/copr/coprocessor.go

@@ -1453,7 +1453,7 @@ func (worker *copIteratorWorker) handleTaskOnce(bo *Backoffer, task *copTask) (*
 	}
 	metrics.TiKVCoprocessorHistogram.WithLabelValues(storeID, strconv.FormatBool(staleRead), scope).Observe(costTime.Seconds())
 	if copResp != nil {
-		tidbmetrics.DistSQLCoprRespBodySize.WithLabelValues(storeAddr).Observe(float64(len(copResp.Data)))
+		tidbmetrics.DistSQLCoprRespBodySize.WithLabelValues(storeAddr).Observe(float64(len(copResp.Data) / 1024))
 	}
 
 	var result *copTaskResult