mempool size metric

mempool/mempool.go

@@ -83,10 +83,12 @@ type Mempool struct {
 	wal *auto.AutoFile
 
 	logger log.Logger
+
+	metrics *Metrics
 }
 
 // NewMempool returns a new Mempool with the given configuration and connection to an application.
-func NewMempool(config *cfg.MempoolConfig, proxyAppConn proxy.AppConnMempool, height int64) *Mempool {
+func NewMempool(config *cfg.MempoolConfig, proxyAppConn proxy.AppConnMempool, height int64, metrics *Metrics) *Mempool {
 	mempool := &Mempool{
 		config:        config,
 		proxyAppConn:  proxyAppConn,
@@ -98,6 +100,7 @@ func NewMempool(config *cfg.MempoolConfig, proxyAppConn proxy.AppConnMempool, he
 		recheckEnd:    nil,
 		logger:        log.NewNopLogger(),
 		cache:         newTxCache(config.CacheSize),
+		metrics:       metrics,
 	}
 	proxyAppConn.SetResponseCallback(mempool.resCb)
 	return mempool
@@ -250,6 +253,7 @@ func (mem *Mempool) resCb(req *abci.Request, res *abci.Response) {
 	} else {
 		mem.resCbRecheck(req, res)
 	}
+	mem.metrics.Size.Set(float64(mem.Size()))
 }
 
 func (mem *Mempool) resCbNormal(req *abci.Request, res *abci.Response) {
@@ -393,6 +397,7 @@ func (mem *Mempool) Update(height int64, txs types.Txs) error {
 		// mem.recheckCursor re-scans mem.txs and possibly removes some txs.
 		// Before mem.Reap(), we should wait for mem.recheckCursor to be nil.
 	}
+	mem.metrics.Size.Set(float64(mem.Size()))
 	return nil
 }
 

mempool/mempool_test.go

@@ -33,7 +33,7 @@ func newMempoolWithApp(cc proxy.ClientCreator) *Mempool {
 	if err != nil {
 		panic(err)
 	}
-	mempool := NewMempool(config.Mempool, appConnMem, 0)
+	mempool := NewMempool(config.Mempool, appConnMem, 0, NopMetrics())
 	mempool.SetLogger(log.TestingLogger())
 	return mempool
 }
@@ -241,7 +241,7 @@ func TestMempoolCloseWAL(t *testing.T) {
 	app := kvstore.NewKVStoreApplication()
 	cc := proxy.NewLocalClientCreator(app)
 	appConnMem, _ := cc.NewABCIClient()
-	mempool := NewMempool(wcfg, appConnMem, 10)
+	mempool := NewMempool(wcfg, appConnMem, 10, NopMetrics())
 	mempool.InitWAL()
 
 	// 4. Ensure that the directory contains the WAL file

mempool/metrics.go

@@ -0,0 +1,17 @@
+package mempool
+
+import "github.com/go-kit/kit/metrics"
+import "github.com/go-kit/kit/metrics/discard"
+
+// Metrics contains metrics exposed by this package.
+// see MetricsProvider for descriptions.
+type Metrics struct {
+	Size metrics.Gauge
+}
+
+// NopMetrics returns no-op Metrics.
+func NopMetrics() *Metrics {
+	return &Metrics{
+		Size: discard.NewGauge(),
+	}
+}