From e6ac4924735ffb84a68c965549a4ee36499620bd Mon Sep 17 00:00:00 2001
From: Miguel Angel Rojo Fernandez <miguel.rojo@vechain.org>
Date: Sat, 11 Jan 2025 12:30:43 +0000
Subject: [PATCH] batch writes performance

---
 muxdb/engine/leveldb.go |  9 ++++++++-
 muxdb/engine/metrics.go | 17 +++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 muxdb/engine/metrics.go

diff --git a/muxdb/engine/leveldb.go b/muxdb/engine/leveldb.go
index b26d7acff..33a1804ac 100644
--- a/muxdb/engine/leveldb.go
+++ b/muxdb/engine/leveldb.go
@@ -8,7 +8,9 @@ package engine
 import (
 	"context"
 	"sync"
+	"time"
 
+	"github.com/ethereum/go-ethereum/common/mclock"
 	"github.com/syndtr/goleveldb/leveldb"
 	"github.com/syndtr/goleveldb/leveldb/opt"
 	"github.com/syndtr/goleveldb/leveldb/util"
@@ -112,11 +114,16 @@ func (ldb *levelEngine) Bulk() kv.Bulk {
 		return batch
 	}
 	flush := func(minSize int) error {
-		if batch != nil && len(batch.Dump()) >= minSize {
+		batchBytesNo := len(batch.Dump())
+		if batch != nil && batchBytesNo >= minSize {
 			if batch.Len() > 0 {
+				startTime := mclock.Now()
 				if err := ldb.db.Write(batch, &writeOpt); err != nil {
 					return err
 				}
+				metricBatchWriteBytes().Set(int64(batchBytesNo))
+				batchWriteElapsed := mclock.Now() - startTime
+				metricBatchWriteDuration().Observe(time.Duration(batchWriteElapsed).Milliseconds())
 			}
 			ldb.batchPool.Put(batch)
 			batch = nil
diff --git a/muxdb/engine/metrics.go b/muxdb/engine/metrics.go
new file mode 100644
index 000000000..bc29baf47
--- /dev/null
+++ b/muxdb/engine/metrics.go
@@ -0,0 +1,17 @@
+// Copyright (c) 2024 The VeChainThor developers
+
+// Distributed under the GNU Lesser General Public License v3.0 software license, see the accompanying
+// file LICENSE or <https://www.gnu.org/licenses/lgpl-3.0.html>
+
+// Package muxdb implements the storage layer for block-chain.
+// It manages instance of merkle-patricia-trie, and general purpose named kv-store.
+package engine
+
+import (
+	"github.com/vechain/thor/v2/metrics"
+)
+
+var (
+	metricBatchWriteBytes    = metrics.LazyLoadGauge("batch_write_bytes")
+	metricBatchWriteDuration = metrics.LazyLoadHistogram("batch_write_duration_ms", metrics.Bucket10s)
+)