From f2db05a86901daac2a1a057ff465618b0d0a402e Mon Sep 17 00:00:00 2001
From: Gyuho Lee <gyuhox@gmail.com>
Date: Thu, 7 Jun 2018 10:22:51 -0700
Subject: [PATCH] mvcc: server db size with "etcd_debugging" namespace for
 backward compatibility

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>
---
 mvcc/kvstore.go |  3 +++
 mvcc/metrics.go | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/mvcc/kvstore.go b/mvcc/kvstore.go
index a445f6a4a..9c7f5c3ad 100644
--- a/mvcc/kvstore.go
+++ b/mvcc/kvstore.go
@@ -323,6 +323,9 @@ func (s *store) restore() error {
 	reportDbTotalSizeInBytesMu.Lock()
 	reportDbTotalSizeInBytes = func() float64 { return float64(b.Size()) }
 	reportDbTotalSizeInBytesMu.Unlock()
+	reportDbTotalSizeInBytesDebuggingMu.Lock()
+	reportDbTotalSizeInBytesDebugging = func() float64 { return float64(b.Size()) }
+	reportDbTotalSizeInBytesDebuggingMu.Unlock()
 	reportDbTotalSizeInUseInBytesMu.Lock()
 	reportDbTotalSizeInUseInBytes = func() float64 { return float64(b.SizeInUse()) }
 	reportDbTotalSizeInUseInBytesMu.Unlock()
diff --git a/mvcc/metrics.go b/mvcc/metrics.go
index c7ea0ce4c..9163cc7c6 100644
--- a/mvcc/metrics.go
+++ b/mvcc/metrics.go
@@ -161,6 +161,23 @@ var (
 	reportDbTotalSizeInBytesMu sync.RWMutex
 	reportDbTotalSizeInBytes   = func() float64 { return 0 }
 
+	// TODO: remove this in v3.5
+	dbTotalSizeDebugging = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
+		Namespace: "etcd_debugging",
+		Subsystem: "mvcc",
+		Name:      "db_total_size_in_bytes",
+		Help:      "Total size of the underlying database physically allocated in bytes.",
+	},
+		func() float64 {
+			reportDbTotalSizeInBytesDebuggingMu.RLock()
+			defer reportDbTotalSizeInBytesDebuggingMu.RUnlock()
+			return reportDbTotalSizeInBytesDebugging()
+		},
+	)
+	// overridden by mvcc initialization
+	reportDbTotalSizeInBytesDebuggingMu sync.RWMutex
+	reportDbTotalSizeInBytesDebugging   = func() float64 { return 0 }
+
 	dbTotalSizeInUse = prometheus.NewGaugeFunc(prometheus.GaugeOpts{
 		Namespace: "etcd",
 		Subsystem: "mvcc",
@@ -218,6 +235,7 @@ func init() {
 	prometheus.MustRegister(dbCompactionTotalMs)
 	prometheus.MustRegister(dbCompactionKeysCounter)
 	prometheus.MustRegister(dbTotalSize)
+	prometheus.MustRegister(dbTotalSizeDebugging)
 	prometheus.MustRegister(dbTotalSizeInUse)
 	prometheus.MustRegister(hashSec)
 	prometheus.MustRegister(hashRevSec)