From 523c4115177e887e65745547a74777f09aba013a Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Tue, 18 Oct 2016 09:12:12 +0200
Subject: [PATCH] core: Add metrics collection for transaction events;
 replace/discard for pending and future queues, as well as invalid
 transactions

---
 core/tx_pool.go | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/core/tx_pool.go b/core/tx_pool.go
index 2c8a5c396c..540c8514d4 100644
--- a/core/tx_pool.go
+++ b/core/tx_pool.go
@@ -30,6 +30,7 @@ import (
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/ethereum/go-ethereum/metrics"
 	"gopkg.in/karalabe/cookiejar.v2/collections/prque"
 )
 
@@ -55,6 +56,15 @@ var (
 	evictionInterval     = time.Minute   // Time interval to check for evictable transactions
 )
 
+var (
+	// Metrics
+	pendingDiscardMeter    = metrics.NewMeter("core/txpool/transactions/pending/discard")
+	pendingReplaceMeter    = metrics.NewMeter("core/txpool/transactions/pending/replace")
+	queuedDiscardMeter     = metrics.NewMeter("core/txpool/transactions/queued/discard")
+	queuedReplaceMeter     = metrics.NewMeter("core/txpool/transactions/queued/replace")
+	invalidTxMeter         = metrics.NewMeter("core/txpool/transactions/invalid")
+)
+
 type stateFn func() (*state.StateDB, error)
 
 // TxPool contains all currently known transactions. Transactions
@@ -306,6 +316,7 @@ func (pool *TxPool) add(tx *types.Transaction) error {
 	}
 	// Otherwise ensure basic validation passes and queue it up
 	if err := pool.validateTx(tx); err != nil {
+		invalidTxMeter.Mark(1)
 		return err
 	}
 	pool.enqueueTx(hash, tx)
@@ -333,11 +344,13 @@ func (pool *TxPool) enqueueTx(hash common.Hash, tx *types.Transaction) {
 	}
 	inserted, old := pool.queue[from].Add(tx)
 	if !inserted {
+		queuedDiscardMeter.Mark(1)
 		return // An older transaction was better, discard this
 	}
 	// Discard any previous transaction and mark this
 	if old != nil {
 		delete(pool.all, old.Hash())
+		queuedReplaceMeter.Mark(1)
 	}
 	pool.all[hash] = tx
 }
@@ -360,11 +373,13 @@ func (pool *TxPool) promoteTx(addr common.Address, hash common.Hash, tx *types.T
 	if !inserted {
 		// An older transaction was better, discard this
 		delete(pool.all, hash)
+		pendingDiscardMeter.Mark(1)
 		return
 	}
 	// Otherwise discard any previous transaction and mark this
 	if old != nil {
 		delete(pool.all, old.Hash())
+		pendingReplaceMeter.Mark(1)
 	}
 	pool.all[hash] = tx // Failsafe to work around direct pending inserts (tests)