server: Add metrics (pingcap#1729)

Add metrics for server package.
Update gitcookie.sh.

Author: shenli

gitcookie.sh

@@ -4,6 +4,7 @@ chmod 0600 ~/.gitcookies
 git config --global http.cookiefile ~/.gitcookies
 
 tr , \\t <<\__END__ >>~/.gitcookies
-go.googlesource.com,FALSE,/,TRUE,2147483647,o,git-z.pingcap.com=1/Xv6CBlnVpdrhYBXT5i_VexGocQcbgkKsrW938zgjqx0
-go-review.googlesource.com,FALSE,/,TRUE,2147483647,o,git-z.pingcap.com=1/Xv6CBlnVpdrhYBXT5i_VexGocQcbgkKsrW938zgjqx0
+go.googlesource.com,FALSE,/,TRUE,2147483647,o,git-shenli.pingcap.com=1/rGvVlvFq_x9rxOmXqQe_rfcrjbOk6NSOHIQKhhsfidM
+go-review.googlesource.com,FALSE,/,TRUE,2147483647,o,git-shenli.pingcap.com=1/rGvVlvFq_x9rxOmXqQe_rfcrjbOk6NSOHIQKhhsfidM
 __END__
+

server/conn.go

@@ -51,7 +51,6 @@ import (
 	"github.com/pingcap/tidb/terror"
 	"github.com/pingcap/tidb/util/arena"
 	"github.com/pingcap/tidb/util/hack"
-	"github.com/pingcap/tidb/util/metrics"
 )
 
 var defaultCapability = mysql.ClientLongPassword | mysql.ClientLongFlag |
@@ -113,6 +112,7 @@ func (cc *clientConn) Close() error {
 	delete(cc.server.clients, cc.connectionID)
 	cc.server.rwlock.Unlock()
 	cc.conn.Close()
+	connGauge.Dec()
 	if cc.ctx != nil {
 		return cc.ctx.Close()
 	}
@@ -305,6 +305,8 @@ func (cc *clientConn) Run() {
 		cc.Close()
 	}()
 
+	connGauge.Inc()
+
 	for {
 		cc.alloc.Reset()
 		data, err := cc.readPacket()
@@ -530,6 +532,16 @@ func (cc *clientConn) handleLoadData(loadDataInfo *executor.LoadDataInfo) error
 
 func (cc *clientConn) handleQuery(sql string) (err error) {
 	startTs := time.Now()
+	defer func() {
+		// Add metrics
+		queryHistgram.Observe(time.Since(startTs).Seconds())
+		label := querySucc
+		if err != nil {
+			label = queryFailed
+		}
+		queryCounter.WithLabelValues(label).Inc()
+	}()
+
 	rs, err := cc.ctx.Execute(sql)
 	if err != nil {
 		return errors.Trace(err)
@@ -558,7 +570,6 @@ func (cc *clientConn) handleQuery(sql string) (err error) {
 	} else {
 		log.Warnf("[TIME_QUERY] %v %s", costTime, sql)
 	}
-	metrics.Query(costTime)
 	return errors.Trace(err)
 }
 

util/metrics/metrics.go server/metrics.go

@@ -11,30 +11,45 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package metrics
+package server
 
 import (
-	"time"
-
 	"github.com/prometheus/client_golang/prometheus"
 )
 
 var (
-	queryMetric = prometheus.NewHistogram(
+	queryHistgram = prometheus.NewHistogram(
 		prometheus.HistogramOpts{
 			Namespace: "tidb",
-			Subsystem: "query",
+			Subsystem: "server",
 			Name:      "handle_query_duration_seconds",
 			Help:      "Bucketed histogram of processing time (s) of handled queries.",
 			Buckets:   prometheus.ExponentialBuckets(0.0005, 2, 13),
 		})
-)
 
-// Query is used for add query cost time into metrics.
-func Query(costTime time.Duration) {
-	queryMetric.Observe(float64(costTime))
-}
+	queryCounter = prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Namespace: "tidb",
+			Subsystem: "server",
+			Name:      "query_total",
+			Help:      "Counter of queries.",
+		}, []string{"type"})
+
+	// Query handle result status.
+	querySucc   = "query_succ"
+	queryFailed = "query_failed"
+
+	connGauge = prometheus.NewGauge(
+		prometheus.GaugeOpts{
+			Namespace: "tidb",
+			Subsystem: "server",
+			Name:      "connections",
+			Help:      "Number of connections.",
+		})
+)
 
 func init() {
-	prometheus.MustRegister(queryMetric)
+	prometheus.MustRegister(queryHistgram)
+	prometheus.MustRegister(queryCounter)
+	prometheus.MustRegister(connGauge)
 }

server/server.go

@@ -45,8 +45,6 @@ import (
 	"github.com/pingcap/tidb/terror"
 	"github.com/pingcap/tidb/util/arena"
 	"github.com/pingcap/tidb/util/printer"
-	// For prometheus init
-	_ "github.com/pingcap/tidb/util/metrics"
 	"github.com/prometheus/client_golang/prometheus"
 )