Add cmdstat metrics to redis input (#5926)

plugins/inputs/redis/README.md

@@ -120,6 +120,13 @@ Additionally the plugin also calculates the hit/miss ratio (keyspace\_hitrate) a
     - expires(int, number)
     - avg_ttl(int, number)
 
+- redis_cmdstat
+    Every Redis used command will have 3 new fields:
+    - calls(int, number)
+    - usec(int, mircoseconds)
+    - usec_per_call(float, microseconds)
+
+
 ### Tags:
 
 - All measurements have the following tags:
@@ -130,6 +137,9 @@ Additionally the plugin also calculates the hit/miss ratio (keyspace\_hitrate) a
 - The redis_keyspace measurement has an additional database tag:
     - database
 
+- The redis_cmdstat measurement has an additional tag:
+    - command
+
 ### Example Output:
 
 Using this configuration:
@@ -161,3 +171,8 @@ redis_keyspace:
 ```
 > redis_keyspace,database=db1,host=host,server=localhost,port=6379,replication_role=master keys=1i,expires=0i,avg_ttl=0i 1493101350000000000
 ```
+
+redis_command:
+```
+> redis_cmdstat,command=publish,host=host,port=6379,replication_role=master,server=localhost calls=68113i,usec=325146i,usec_per_call=4.77 1559227136000000000
+```

plugins/inputs/redis/redis.go

@@ -37,7 +37,7 @@ type RedisClient struct {
 }
 
 func (r *RedisClient) Info() *redis.StringCmd {
-	return r.client.Info()
+	return r.client.Info("ALL")
 }
 
 func (r *RedisClient) BaseTags() map[string]string {
@@ -248,6 +248,11 @@ func gatherInfoOutput(
 				gatherKeyspaceLine(name, kline, acc, tags)
 				continue
 			}
+			if section == "Commandstats" {
+				kline := strings.TrimSpace(parts[1])
+				gatherCommandstateLine(name, kline, acc, tags)
+				continue
+			}
 			metric = name
 		}
 
@@ -324,6 +329,51 @@ func gatherKeyspaceLine(
 	}
 }
 
+// Parse the special cmdstat lines.
+// Example:
+//     cmdstat_publish:calls=33791,usec=208789,usec_per_call=6.18
+// Tag: cmdstat=publish; Fields: calls=33791i,usec=208789i,usec_per_call=6.18
+func gatherCommandstateLine(
+	name string,
+	line string,
+	acc telegraf.Accumulator,
+	global_tags map[string]string,
+) {
+	if !strings.HasPrefix(name, "cmdstat") {
+		return
+	}
+
+	fields := make(map[string]interface{})
+	tags := make(map[string]string)
+	for k, v := range global_tags {
+		tags[k] = v
+	}
+	tags["command"] = strings.TrimPrefix(name, "cmdstat_")
+	parts := strings.Split(line, ",")
+	for _, part := range parts {
+		kv := strings.Split(part, "=")
+		if len(kv) != 2 {
+			continue
+		}
+
+		switch kv[0] {
+		case "calls":
+			fallthrough
+		case "usec":
+			ival, err := strconv.ParseInt(kv[1], 10, 64)
+			if err == nil {
+				fields[kv[0]] = ival
+			}
+		case "usec_per_call":
+			fval, err := strconv.ParseFloat(kv[1], 64)
+			if err == nil {
+				fields[kv[0]] = fval
+			}
+		}
+	}
+	acc.AddFields("redis_cmdstat", fields, tags)
+}
+
 func init() {
 	inputs.Add("redis", func() telegraf.Input {
 		return &Redis{}

plugins/inputs/redis/redis_test.go

@@ -118,6 +118,22 @@ func TestRedis_ParseMetrics(t *testing.T) {
 	}
 	acc.AssertContainsTaggedFields(t, "redis", fields, tags)
 	acc.AssertContainsTaggedFields(t, "redis_keyspace", keyspaceFields, keyspaceTags)
+
+	cmdstatSetTags := map[string]string{"host": "redis.net", "replication_role": "master", "command": "set"}
+	cmdstatSetFields := map[string]interface{}{
+		"calls":         int64(261265),
+		"usec":          int64(1634157),
+		"usec_per_call": float64(6.25),
+	}
+	acc.AssertContainsTaggedFields(t, "redis_cmdstat", cmdstatSetFields, cmdstatSetTags)
+
+	cmdstatCommandTags := map[string]string{"host": "redis.net", "replication_role": "master", "command": "command"}
+	cmdstatCommandFields := map[string]interface{}{
+		"calls":         int64(1),
+		"usec":          int64(990),
+		"usec_per_call": float64(990.0),
+	}
+	acc.AssertContainsTaggedFields(t, "redis_cmdstat", cmdstatCommandFields, cmdstatCommandTags)
 }
 
 const testOutput = `# Server
@@ -209,6 +225,10 @@ used_cpu_user:0.05
 used_cpu_sys_children:0.00
 used_cpu_user_children:0.00
 
+# Commandstats
+cmdstat_set:calls=261265,usec=1634157,usec_per_call=6.25
+cmdstat_command:calls=1,usec=990,usec_per_call=990.00
+
 # Keyspace
 db0:keys=2,expires=0,avg_ttl=0