From e560b5ecc10302b6a3539be57f4f16ad9fd24f63 Mon Sep 17 00:00:00 2001
From: "R.B. Boyer" <rb@hashicorp.com>
Date: Fri, 31 Jan 2025 22:12:30 +0000
Subject: [PATCH 1/4] backport of commit
 fcf694d32e63e2478842f70e84fceec671220e84

---
 agent/metadata/build.go | 41 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/agent/metadata/build.go b/agent/metadata/build.go
index 76a432d9a38..b42beae32f8 100644
--- a/agent/metadata/build.go
+++ b/agent/metadata/build.go
@@ -4,12 +4,51 @@
 package metadata
 
 import (
+	"sync"
+
 	"github.com/hashicorp/go-version"
 	"github.com/hashicorp/serf/serf"
 )
 
+type versionTuple struct {
+	Value *version.Version
+	Err   error
+}
+
+var versionCache sync.Map // string->versionTuple
+
 // Build extracts the Consul version info for a member.
 func Build(m *serf.Member) (*version.Version, error) {
-	str := versionFormat.FindString(m.Tags["build"])
+	build := m.Tags["build"]
+
+	ok, v, err := getMemoizedBuildVersion(build)
+	if ok {
+		return v, err
+	}
+
+	v, err = parseBuildAsVersion(build)
+
+	versionCache.Store(build, versionTuple{Value: v, Err: err})
+
+	return v, err
+}
+
+func getMemoizedBuildVersion(build string) (bool, *version.Version, error) {
+	rawTuple, ok := versionCache.Load(build)
+	if !ok {
+		return false, nil, nil
+	}
+	tuple, ok := rawTuple.(versionTuple)
+	if !ok {
+		return false, nil, nil
+	}
+	if tuple.Err != nil {
+		return true, nil, tuple.Err
+	}
+	return true, tuple.Value, nil
+}
+
+func parseBuildAsVersion(build string) (*version.Version, error) {
+	str := versionFormat.FindString(build)
 	return version.NewVersion(str)
 }

From ede956c22d11cef42c96f9dee3c988aaea378c47 Mon Sep 17 00:00:00 2001
From: "R.B. Boyer" <rb@hashicorp.com>
Date: Fri, 31 Jan 2025 22:31:07 +0000
Subject: [PATCH 2/4] backport of commit
 ba856addf7f37ca9777cb7361e0258dbb91bf2ac

---
 .changelog/22113.txt | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 .changelog/22113.txt

diff --git a/.changelog/22113.txt b/.changelog/22113.txt
new file mode 100644
index 00000000000..c97fff1a4a3
--- /dev/null
+++ b/.changelog/22113.txt
@@ -0,0 +1,3 @@
+```release-note:improvement
+metadata: memoize the parsed build versions
+```

From e3e6b0032389b48d3a27f1139130261378358c89 Mon Sep 17 00:00:00 2001
From: "R.B. Boyer" <4903+rboyer@users.noreply.github.com>
Date: Fri, 31 Jan 2025 22:32:07 +0000
Subject: [PATCH 3/4] backport of commit
 1f21f81e83f0c72d7e22b1c3e12c05e2c4474859

---
 agent/metadata/build.go | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/agent/metadata/build.go b/agent/metadata/build.go
index b42beae32f8..880132b9db0 100644
--- a/agent/metadata/build.go
+++ b/agent/metadata/build.go
@@ -42,10 +42,7 @@ func getMemoizedBuildVersion(build string) (bool, *version.Version, error) {
 	if !ok {
 		return false, nil, nil
 	}
-	if tuple.Err != nil {
-		return true, nil, tuple.Err
-	}
-	return true, tuple.Value, nil
+	return true, tuple.Value, tuple.Err
 }
 
 func parseBuildAsVersion(build string) (*version.Version, error) {

From 561d2cc4927c5d78af3cd3094a160213fb2cddb4 Mon Sep 17 00:00:00 2001
From: "R.B. Boyer" <rb@hashicorp.com>
Date: Fri, 31 Jan 2025 22:37:19 +0000
Subject: [PATCH 4/4] backport of commit
 760167dc426345be6ed94e4a0568f78f3564eb7b

---
 agent/metadata/server.go | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/agent/metadata/server.go b/agent/metadata/server.go
index 2e626787bdf..19dba6e2cc9 100644
--- a/agent/metadata/server.go
+++ b/agent/metadata/server.go
@@ -127,11 +127,6 @@ func IsConsulServer(m serf.Member) (bool, *Server) {
 		}
 	}
 
-	buildVersion, err := Build(&m)
-	if err != nil {
-		return false, nil
-	}
-
 	wanJoinPort := 0
 	wanJoinPortStr, ok := m.Tags["wan_join_port"]
 	if ok {
@@ -180,6 +175,11 @@ func IsConsulServer(m serf.Member) (bool, *Server) {
 
 	addr := &net.TCPAddr{IP: m.Addr, Port: port}
 
+	buildVersion, err := Build(&m)
+	if err != nil {
+		return false, nil
+	}
+
 	parts := &Server{
 		Name:                m.Name,
 		ShortName:           strings.TrimSuffix(m.Name, "."+datacenter),