From f4400ef8778fe7b454e7a0b0b8f13ca0007bb59c Mon Sep 17 00:00:00 2001
From: watermelo <80680489@qq.com>
Date: Sat, 6 Jun 2020 17:52:21 +0800
Subject: [PATCH 1/5] Add: add comments for metadata direcotory

---
 metadata/identifier/base_metadata_identifier.go      | 7 ++-----
 metadata/identifier/metadata_identifier.go           | 5 +++--
 metadata/identifier/service_metadata_identifier.go   | 8 ++++----
 metadata/identifier/subscribe_metadata_identifier.go | 4 ++--
 metadata/service.go                                  | 3 +++
 5 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/metadata/identifier/base_metadata_identifier.go b/metadata/identifier/base_metadata_identifier.go
index a314671055..963c3d1a56 100644
--- a/metadata/identifier/base_metadata_identifier.go
+++ b/metadata/identifier/base_metadata_identifier.go
@@ -37,7 +37,6 @@ type BaseServiceMetadataIdentifier struct {
 	side             string
 }
 
-// joinParams...
 func joinParams(joinChar string, params []string) string {
 	var joinedStr string
 	for _, param := range params {
@@ -47,7 +46,7 @@ func joinParams(joinChar string, params []string) string {
 	return joinedStr
 }
 
-// getIdentifierKey...
+// getIdentifierKey gets metadata identifier key by @params
 func (mdi *BaseServiceMetadataIdentifier) getIdentifierKey(params ...string) string {
 	return mdi.serviceInterface +
 		constant.KEY_SEPARATOR + mdi.version +
@@ -56,7 +55,7 @@ func (mdi *BaseServiceMetadataIdentifier) getIdentifierKey(params ...string) str
 		joinParams(constant.KEY_SEPARATOR, params)
 }
 
-// getFilePathKey...
+// getFilePathKey gets metadata file path key by @params
 func (mdi *BaseServiceMetadataIdentifier) getFilePathKey(params ...string) string {
 	path := serviceToPath(mdi.serviceInterface)
 
@@ -69,7 +68,6 @@ func (mdi *BaseServiceMetadataIdentifier) getFilePathKey(params ...string) strin
 
 }
 
-// serviceToPath...
 func serviceToPath(serviceInterface string) string {
 	if serviceInterface == constant.ANY_VALUE {
 		return ""
@@ -83,7 +81,6 @@ func serviceToPath(serviceInterface string) string {
 
 }
 
-//withPathSeparator...
 func withPathSeparator(path string) string {
 	if len(path) != 0 {
 		path = constant.PATH_SEPARATOR + path
diff --git a/metadata/identifier/metadata_identifier.go b/metadata/identifier/metadata_identifier.go
index f3df8f3654..e97795b4cf 100644
--- a/metadata/identifier/metadata_identifier.go
+++ b/metadata/identifier/metadata_identifier.go
@@ -17,17 +17,18 @@
 
 package identifier
 
+// The MetadataIdentifier is used to store method descriptor
 type MetadataIdentifier struct {
 	application string
 	BaseMetadataIdentifier
 }
 
-// getIdentifierKey...
+// getIdentifierKey gets metadata identifier key by @mdi.application
 func (mdi *MetadataIdentifier) getIdentifierKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.application)
 }
 
-// getIdentifierKey...
+// getIdentifierKey gets metadata file path key by @mdi.application
 func (mdi *MetadataIdentifier) getFilePathKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.application)
 }
diff --git a/metadata/identifier/service_metadata_identifier.go b/metadata/identifier/service_metadata_identifier.go
index 373df0130d..b89641caac 100644
--- a/metadata/identifier/service_metadata_identifier.go
+++ b/metadata/identifier/service_metadata_identifier.go
@@ -27,12 +27,12 @@ type ServiceMetadataIdentifier struct {
 	BaseMetadataIdentifier
 }
 
-// getIdentifierKey...
+// getIdentifierKey gets metadata identifier key by @mdi.protocol and @mdi.revision
 func (mdi *ServiceMetadataIdentifier) getIdentifierKey(params ...string) string {
-	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.protocol + constant.KEY_REVISON_PREFIX + mdi.revision)
+	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.protocol, constant.KEY_REVISON_PREFIX, mdi.revision)
 }
 
-// getIdentifierKey...
+// getFilePathKey gets metadata file path key by @mdi.protocol and @mdi.revision
 func (mdi *ServiceMetadataIdentifier) getFilePathKey(params ...string) string {
-	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.protocol + constant.KEY_REVISON_PREFIX + mdi.revision)
+	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.protocol, constant.KEY_REVISON_PREFIX, mdi.revision)
 }
diff --git a/metadata/identifier/subscribe_metadata_identifier.go b/metadata/identifier/subscribe_metadata_identifier.go
index 321a216a3e..917e8e6308 100644
--- a/metadata/identifier/subscribe_metadata_identifier.go
+++ b/metadata/identifier/subscribe_metadata_identifier.go
@@ -22,12 +22,12 @@ type SubscriberMetadataIdentifier struct {
 	BaseMetadataIdentifier
 }
 
-// getIdentifierKey...
+// getIdentifierKey gets metadata identifier key by @mdi.revision
 func (mdi *SubscriberMetadataIdentifier) getIdentifierKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.revision)
 }
 
-// getIdentifierKey...
+// getFilePathKey gets metadata file path key by @mdi.revision
 func (mdi *SubscriberMetadataIdentifier) getFilePathKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.revision)
 }
diff --git a/metadata/service.go b/metadata/service.go
index d85703c95a..89df68fb31 100644
--- a/metadata/service.go
+++ b/metadata/service.go
@@ -22,6 +22,9 @@ import (
 	gxset "github.com/dubbogo/gost/container/set"
 )
 
+// Metadata service is a built-in service around the metadata of Dubbo services,
+// whose interface is provided by Dubbo Framework and exported automatically before subscription after other services exporting,
+// which may be used for Dubbo subscribers and admin.
 type MetadataService interface {
 	ServiceName() string
 	ExportURL(url *common.URL) bool

From 51405f61c754516ebe9ccbc1b709ef0c5c9f347c Mon Sep 17 00:00:00 2001
From: watermelo <80680489@qq.com>
Date: Mon, 8 Jun 2020 12:44:08 +0800
Subject: [PATCH 2/5]     Mod: modify inappropriate comments after review

---
 metadata/identifier/base_metadata_identifier.go      | 7 +++++--
 metadata/identifier/metadata_identifier.go           | 6 +++---
 metadata/identifier/service_metadata_identifier.go   | 9 +++++----
 metadata/identifier/subscribe_metadata_identifier.go | 5 +++--
 4 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/metadata/identifier/base_metadata_identifier.go b/metadata/identifier/base_metadata_identifier.go
index 963c3d1a56..3eca5e1bb3 100644
--- a/metadata/identifier/base_metadata_identifier.go
+++ b/metadata/identifier/base_metadata_identifier.go
@@ -25,11 +25,13 @@ import (
 	"github.com/apache/dubbo-go/common/constant"
 )
 
+// BaseMetadataIdentifier defined for describe the Metadata base identify
 type BaseMetadataIdentifier interface {
 	getFilePathKey(params ...string) string
 	getIdentifierKey(params ...string) string
 }
 
+// BaseMetadataIdentifier is the base implement of BaseMetadataIdentifier interface
 type BaseServiceMetadataIdentifier struct {
 	serviceInterface string
 	version          string
@@ -37,6 +39,7 @@ type BaseServiceMetadataIdentifier struct {
 	side             string
 }
 
+// joinParams will join the specified char in slice, and build as string
 func joinParams(joinChar string, params []string) string {
 	var joinedStr string
 	for _, param := range params {
@@ -46,7 +49,7 @@ func joinParams(joinChar string, params []string) string {
 	return joinedStr
 }
 
-// getIdentifierKey gets metadata identifier key by @params
+// getIdentifierKey will return string format as service:Version:Group:Side:param1:param2...
 func (mdi *BaseServiceMetadataIdentifier) getIdentifierKey(params ...string) string {
 	return mdi.serviceInterface +
 		constant.KEY_SEPARATOR + mdi.version +
@@ -55,7 +58,7 @@ func (mdi *BaseServiceMetadataIdentifier) getIdentifierKey(params ...string) str
 		joinParams(constant.KEY_SEPARATOR, params)
 }
 
-// getFilePathKey gets metadata file path key by @params
+// getFilePathKey will return string format as metadata/path/Version/Group/Side/param1/param2...
 func (mdi *BaseServiceMetadataIdentifier) getFilePathKey(params ...string) string {
 	path := serviceToPath(mdi.serviceInterface)
 
diff --git a/metadata/identifier/metadata_identifier.go b/metadata/identifier/metadata_identifier.go
index e97795b4cf..03b150c6b0 100644
--- a/metadata/identifier/metadata_identifier.go
+++ b/metadata/identifier/metadata_identifier.go
@@ -17,18 +17,18 @@
 
 package identifier
 
-// The MetadataIdentifier is used to store method descriptor
+// MetadataIdentifier is inherit baseMetaIdentifier with Application name
 type MetadataIdentifier struct {
 	application string
 	BaseMetadataIdentifier
 }
 
-// getIdentifierKey gets metadata identifier key by @mdi.application
+// GetIdentifierKey will return string format as service:Version:Group:Side:Application
 func (mdi *MetadataIdentifier) getIdentifierKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.application)
 }
 
-// getIdentifierKey gets metadata file path key by @mdi.application
+// GetFilePathKey will return string format as metadata/path/Version/Group/Side/Application
 func (mdi *MetadataIdentifier) getFilePathKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.application)
 }
diff --git a/metadata/identifier/service_metadata_identifier.go b/metadata/identifier/service_metadata_identifier.go
index b89641caac..9325719c4c 100644
--- a/metadata/identifier/service_metadata_identifier.go
+++ b/metadata/identifier/service_metadata_identifier.go
@@ -21,18 +21,19 @@ import (
 	"github.com/apache/dubbo-go/common/constant"
 )
 
+// ServiceMetadataIdentifier is inherit baseMetaIdentifier with service params: Revision and Protocol
 type ServiceMetadataIdentifier struct {
 	revision string
 	protocol string
 	BaseMetadataIdentifier
 }
 
-// getIdentifierKey gets metadata identifier key by @mdi.protocol and @mdi.revision
+// GetIdentifierKey will return string format as service:Version:Group:Side:Protocol:"revision"+Revision
 func (mdi *ServiceMetadataIdentifier) getIdentifierKey(params ...string) string {
-	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.protocol, constant.KEY_REVISON_PREFIX, mdi.revision)
+	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.protocol, constant.KEY_REVISON_PREFIX+mdi.revision)
 }
 
-// getFilePathKey gets metadata file path key by @mdi.protocol and @mdi.revision
+// GetFilePathKey will return string format as metadata/path/Version/Group/Side/Protocol/"revision"+Revision
 func (mdi *ServiceMetadataIdentifier) getFilePathKey(params ...string) string {
-	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.protocol, constant.KEY_REVISON_PREFIX, mdi.revision)
+	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.protocol, constant.KEY_REVISON_PREFIX+mdi.revision)
 }
diff --git a/metadata/identifier/subscribe_metadata_identifier.go b/metadata/identifier/subscribe_metadata_identifier.go
index 917e8e6308..dd0923d67b 100644
--- a/metadata/identifier/subscribe_metadata_identifier.go
+++ b/metadata/identifier/subscribe_metadata_identifier.go
@@ -17,17 +17,18 @@
 
 package identifier
 
+// SubscriberMetadataIdentifier is inherit baseMetaIdentifier with service params: Revision
 type SubscriberMetadataIdentifier struct {
 	revision string
 	BaseMetadataIdentifier
 }
 
-// getIdentifierKey gets metadata identifier key by @mdi.revision
+// GetIdentifierKey will return string format as service:Version:Group:Side:Revision
 func (mdi *SubscriberMetadataIdentifier) getIdentifierKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.revision)
 }
 
-// getFilePathKey gets metadata file path key by @mdi.revision
+// GetFilePathKey will return string format as metadata/path/Version/Group/Side/Revision
 func (mdi *SubscriberMetadataIdentifier) getFilePathKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.revision)
 }

From aebe31225c4c90a8705f8181ae91f3e73656c61a Mon Sep 17 00:00:00 2001
From: watermelo <80680489@qq.com>
Date: Mon, 8 Jun 2020 12:44:08 +0800
Subject: [PATCH 3/5]     Mod: modify inappropriate comments after review

---
 metadata/identifier/base_metadata_identifier.go      | 7 +++++--
 metadata/identifier/metadata_identifier.go           | 6 +++---
 metadata/identifier/service_metadata_identifier.go   | 9 +++++----
 metadata/identifier/subscribe_metadata_identifier.go | 5 +++--
 4 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/metadata/identifier/base_metadata_identifier.go b/metadata/identifier/base_metadata_identifier.go
index 963c3d1a56..3eca5e1bb3 100644
--- a/metadata/identifier/base_metadata_identifier.go
+++ b/metadata/identifier/base_metadata_identifier.go
@@ -25,11 +25,13 @@ import (
 	"github.com/apache/dubbo-go/common/constant"
 )
 
+// BaseMetadataIdentifier defined for describe the Metadata base identify
 type BaseMetadataIdentifier interface {
 	getFilePathKey(params ...string) string
 	getIdentifierKey(params ...string) string
 }
 
+// BaseMetadataIdentifier is the base implement of BaseMetadataIdentifier interface
 type BaseServiceMetadataIdentifier struct {
 	serviceInterface string
 	version          string
@@ -37,6 +39,7 @@ type BaseServiceMetadataIdentifier struct {
 	side             string
 }
 
+// joinParams will join the specified char in slice, and build as string
 func joinParams(joinChar string, params []string) string {
 	var joinedStr string
 	for _, param := range params {
@@ -46,7 +49,7 @@ func joinParams(joinChar string, params []string) string {
 	return joinedStr
 }
 
-// getIdentifierKey gets metadata identifier key by @params
+// getIdentifierKey will return string format as service:Version:Group:Side:param1:param2...
 func (mdi *BaseServiceMetadataIdentifier) getIdentifierKey(params ...string) string {
 	return mdi.serviceInterface +
 		constant.KEY_SEPARATOR + mdi.version +
@@ -55,7 +58,7 @@ func (mdi *BaseServiceMetadataIdentifier) getIdentifierKey(params ...string) str
 		joinParams(constant.KEY_SEPARATOR, params)
 }
 
-// getFilePathKey gets metadata file path key by @params
+// getFilePathKey will return string format as metadata/path/Version/Group/Side/param1/param2...
 func (mdi *BaseServiceMetadataIdentifier) getFilePathKey(params ...string) string {
 	path := serviceToPath(mdi.serviceInterface)
 
diff --git a/metadata/identifier/metadata_identifier.go b/metadata/identifier/metadata_identifier.go
index e97795b4cf..03b150c6b0 100644
--- a/metadata/identifier/metadata_identifier.go
+++ b/metadata/identifier/metadata_identifier.go
@@ -17,18 +17,18 @@
 
 package identifier
 
-// The MetadataIdentifier is used to store method descriptor
+// MetadataIdentifier is inherit baseMetaIdentifier with Application name
 type MetadataIdentifier struct {
 	application string
 	BaseMetadataIdentifier
 }
 
-// getIdentifierKey gets metadata identifier key by @mdi.application
+// GetIdentifierKey will return string format as service:Version:Group:Side:Application
 func (mdi *MetadataIdentifier) getIdentifierKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.application)
 }
 
-// getIdentifierKey gets metadata file path key by @mdi.application
+// GetFilePathKey will return string format as metadata/path/Version/Group/Side/Application
 func (mdi *MetadataIdentifier) getFilePathKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.application)
 }
diff --git a/metadata/identifier/service_metadata_identifier.go b/metadata/identifier/service_metadata_identifier.go
index b89641caac..9325719c4c 100644
--- a/metadata/identifier/service_metadata_identifier.go
+++ b/metadata/identifier/service_metadata_identifier.go
@@ -21,18 +21,19 @@ import (
 	"github.com/apache/dubbo-go/common/constant"
 )
 
+// ServiceMetadataIdentifier is inherit baseMetaIdentifier with service params: Revision and Protocol
 type ServiceMetadataIdentifier struct {
 	revision string
 	protocol string
 	BaseMetadataIdentifier
 }
 
-// getIdentifierKey gets metadata identifier key by @mdi.protocol and @mdi.revision
+// GetIdentifierKey will return string format as service:Version:Group:Side:Protocol:"revision"+Revision
 func (mdi *ServiceMetadataIdentifier) getIdentifierKey(params ...string) string {
-	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.protocol, constant.KEY_REVISON_PREFIX, mdi.revision)
+	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.protocol, constant.KEY_REVISON_PREFIX+mdi.revision)
 }
 
-// getFilePathKey gets metadata file path key by @mdi.protocol and @mdi.revision
+// GetFilePathKey will return string format as metadata/path/Version/Group/Side/Protocol/"revision"+Revision
 func (mdi *ServiceMetadataIdentifier) getFilePathKey(params ...string) string {
-	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.protocol, constant.KEY_REVISON_PREFIX, mdi.revision)
+	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.protocol, constant.KEY_REVISON_PREFIX+mdi.revision)
 }
diff --git a/metadata/identifier/subscribe_metadata_identifier.go b/metadata/identifier/subscribe_metadata_identifier.go
index 917e8e6308..dd0923d67b 100644
--- a/metadata/identifier/subscribe_metadata_identifier.go
+++ b/metadata/identifier/subscribe_metadata_identifier.go
@@ -17,17 +17,18 @@
 
 package identifier
 
+// SubscriberMetadataIdentifier is inherit baseMetaIdentifier with service params: Revision
 type SubscriberMetadataIdentifier struct {
 	revision string
 	BaseMetadataIdentifier
 }
 
-// getIdentifierKey gets metadata identifier key by @mdi.revision
+// GetIdentifierKey will return string format as service:Version:Group:Side:Revision
 func (mdi *SubscriberMetadataIdentifier) getIdentifierKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.revision)
 }
 
-// getFilePathKey gets metadata file path key by @mdi.revision
+// GetFilePathKey will return string format as metadata/path/Version/Group/Side/Revision
 func (mdi *SubscriberMetadataIdentifier) getFilePathKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.revision)
 }

From 1169ebfd539900ff07d16b75266cace9639efb5c Mon Sep 17 00:00:00 2001
From: watermelo <80680489@qq.com>
Date: Tue, 9 Jun 2020 17:43:14 +0800
Subject: [PATCH 4/5] Mod: modify comments for metadata direcotory

---
 metadata/identifier/base_metadata_identifier.go    | 4 ++--
 metadata/identifier/service_metadata_identifier.go | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/metadata/identifier/base_metadata_identifier.go b/metadata/identifier/base_metadata_identifier.go
index 3eca5e1bb3..9b2ac6eb97 100644
--- a/metadata/identifier/base_metadata_identifier.go
+++ b/metadata/identifier/base_metadata_identifier.go
@@ -25,7 +25,7 @@ import (
 	"github.com/apache/dubbo-go/common/constant"
 )
 
-// BaseMetadataIdentifier defined for describe the Metadata base identify
+// BaseMetadataIdentifier defined for description the Metadata base identify
 type BaseMetadataIdentifier interface {
 	getFilePathKey(params ...string) string
 	getIdentifierKey(params ...string) string
@@ -39,7 +39,7 @@ type BaseServiceMetadataIdentifier struct {
 	side             string
 }
 
-// joinParams will join the specified char in slice, and build as string
+// joinParams will join the specified char in slice, and return a string
 func joinParams(joinChar string, params []string) string {
 	var joinedStr string
 	for _, param := range params {
diff --git a/metadata/identifier/service_metadata_identifier.go b/metadata/identifier/service_metadata_identifier.go
index 9325719c4c..6a1c40c018 100644
--- a/metadata/identifier/service_metadata_identifier.go
+++ b/metadata/identifier/service_metadata_identifier.go
@@ -30,10 +30,10 @@ type ServiceMetadataIdentifier struct {
 
 // GetIdentifierKey will return string format as service:Version:Group:Side:Protocol:"revision"+Revision
 func (mdi *ServiceMetadataIdentifier) getIdentifierKey(params ...string) string {
-	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.protocol, constant.KEY_REVISON_PREFIX+mdi.revision)
+	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.protocol + constant.KEY_REVISON_PREFIX + mdi.revision)
 }
 
 // GetFilePathKey will return string format as metadata/path/Version/Group/Side/Protocol/"revision"+Revision
 func (mdi *ServiceMetadataIdentifier) getFilePathKey(params ...string) string {
-	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.protocol, constant.KEY_REVISON_PREFIX+mdi.revision)
+	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.protocol + constant.KEY_REVISON_PREFIX + mdi.revision)
 }

From b7371f745388230f2cdfb1746186a0f4bd83ee2b Mon Sep 17 00:00:00 2001
From: watermelo <80680489@qq.com>
Date: Tue, 9 Jun 2020 17:43:14 +0800
Subject: [PATCH 5/5] Mod: modify comments for metadata direcotory

---
 metadata/identifier/base_metadata_identifier.go      | 8 ++++----
 metadata/identifier/metadata_identifier.go           | 4 ++--
 metadata/identifier/service_metadata_identifier.go   | 8 ++++----
 metadata/identifier/subscribe_metadata_identifier.go | 4 ++--
 4 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/metadata/identifier/base_metadata_identifier.go b/metadata/identifier/base_metadata_identifier.go
index 3eca5e1bb3..3e67f14640 100644
--- a/metadata/identifier/base_metadata_identifier.go
+++ b/metadata/identifier/base_metadata_identifier.go
@@ -25,7 +25,7 @@ import (
 	"github.com/apache/dubbo-go/common/constant"
 )
 
-// BaseMetadataIdentifier defined for describe the Metadata base identify
+// BaseMetadataIdentifier defined for description the Metadata base identify
 type BaseMetadataIdentifier interface {
 	getFilePathKey(params ...string) string
 	getIdentifierKey(params ...string) string
@@ -39,7 +39,7 @@ type BaseServiceMetadataIdentifier struct {
 	side             string
 }
 
-// joinParams will join the specified char in slice, and build as string
+// joinParams will join the specified char in slice, and return a string
 func joinParams(joinChar string, params []string) string {
 	var joinedStr string
 	for _, param := range params {
@@ -49,7 +49,7 @@ func joinParams(joinChar string, params []string) string {
 	return joinedStr
 }
 
-// getIdentifierKey will return string format as service:Version:Group:Side:param1:param2...
+// getIdentifierKey will return string format is service:Version:Group:Side:param1:param2...
 func (mdi *BaseServiceMetadataIdentifier) getIdentifierKey(params ...string) string {
 	return mdi.serviceInterface +
 		constant.KEY_SEPARATOR + mdi.version +
@@ -58,7 +58,7 @@ func (mdi *BaseServiceMetadataIdentifier) getIdentifierKey(params ...string) str
 		joinParams(constant.KEY_SEPARATOR, params)
 }
 
-// getFilePathKey will return string format as metadata/path/Version/Group/Side/param1/param2...
+// getFilePathKey will return string format is metadata/path/Version/Group/Side/param1/param2...
 func (mdi *BaseServiceMetadataIdentifier) getFilePathKey(params ...string) string {
 	path := serviceToPath(mdi.serviceInterface)
 
diff --git a/metadata/identifier/metadata_identifier.go b/metadata/identifier/metadata_identifier.go
index 03b150c6b0..c3e8dc1a21 100644
--- a/metadata/identifier/metadata_identifier.go
+++ b/metadata/identifier/metadata_identifier.go
@@ -23,12 +23,12 @@ type MetadataIdentifier struct {
 	BaseMetadataIdentifier
 }
 
-// GetIdentifierKey will return string format as service:Version:Group:Side:Application
+// GetIdentifierKey will return string format is service:Version:Group:Side:Application
 func (mdi *MetadataIdentifier) getIdentifierKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.application)
 }
 
-// GetFilePathKey will return string format as metadata/path/Version/Group/Side/Application
+// GetFilePathKey will return string format is metadata/path/Version/Group/Side/Application
 func (mdi *MetadataIdentifier) getFilePathKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.application)
 }
diff --git a/metadata/identifier/service_metadata_identifier.go b/metadata/identifier/service_metadata_identifier.go
index 9325719c4c..96c0419ed6 100644
--- a/metadata/identifier/service_metadata_identifier.go
+++ b/metadata/identifier/service_metadata_identifier.go
@@ -28,12 +28,12 @@ type ServiceMetadataIdentifier struct {
 	BaseMetadataIdentifier
 }
 
-// GetIdentifierKey will return string format as service:Version:Group:Side:Protocol:"revision"+Revision
+// GetIdentifierKey will return string format is service:Version:Group:Side:Protocol:"revision"+Revision
 func (mdi *ServiceMetadataIdentifier) getIdentifierKey(params ...string) string {
-	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.protocol, constant.KEY_REVISON_PREFIX+mdi.revision)
+	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.protocol + constant.KEY_REVISON_PREFIX + mdi.revision)
 }
 
-// GetFilePathKey will return string format as metadata/path/Version/Group/Side/Protocol/"revision"+Revision
+// GetFilePathKey will return string format is metadata/path/Version/Group/Side/Protocol/"revision"+Revision
 func (mdi *ServiceMetadataIdentifier) getFilePathKey(params ...string) string {
-	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.protocol, constant.KEY_REVISON_PREFIX+mdi.revision)
+	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.protocol + constant.KEY_REVISON_PREFIX + mdi.revision)
 }
diff --git a/metadata/identifier/subscribe_metadata_identifier.go b/metadata/identifier/subscribe_metadata_identifier.go
index dd0923d67b..3dc5006f63 100644
--- a/metadata/identifier/subscribe_metadata_identifier.go
+++ b/metadata/identifier/subscribe_metadata_identifier.go
@@ -23,12 +23,12 @@ type SubscriberMetadataIdentifier struct {
 	BaseMetadataIdentifier
 }
 
-// GetIdentifierKey will return string format as service:Version:Group:Side:Revision
+// GetIdentifierKey will return string format is service:Version:Group:Side:Revision
 func (mdi *SubscriberMetadataIdentifier) getIdentifierKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getIdentifierKey(mdi.revision)
 }
 
-// GetFilePathKey will return string format as metadata/path/Version/Group/Side/Revision
+// GetFilePathKey will return string format is metadata/path/Version/Group/Side/Revision
 func (mdi *SubscriberMetadataIdentifier) getFilePathKey(params ...string) string {
 	return mdi.BaseMetadataIdentifier.getFilePathKey(mdi.revision)
 }