diff --git a/server/rpc/connecthelper/useragent.go b/server/rpc/connecthelper/useragent.go
index 02b5e41ee..07116a414 100644
--- a/server/rpc/connecthelper/useragent.go
+++ b/server/rpc/connecthelper/useragent.go
@@ -27,10 +27,14 @@ import (
 // metadata.
 func SDKTypeAndVersion(header http.Header) (string, string) {
 	yorkieUserAgent := header.Get(types.UserAgentKey)
-	if len(yorkieUserAgent) == 0 {
+	if yorkieUserAgent == "" {
 		return "", ""
 	}
 
-	agent := strings.Split(yorkieUserAgent, "/")
-	return agent[0], agent[1]
+	split := strings.Split(yorkieUserAgent, "/")
+	if len(split) != 2 {
+		return "", ""
+	}
+
+	return split[0], split[1]
 }
diff --git a/server/rpc/interceptors/admin_auth.go b/server/rpc/interceptors/admin_auth.go
index 4940b19ac..2855d308c 100644
--- a/server/rpc/interceptors/admin_auth.go
+++ b/server/rpc/interceptors/admin_auth.go
@@ -76,12 +76,14 @@ func (i *AdminAuthInterceptor) WrapUnary(next connect.UnaryFunc) connect.UnaryFu
 			req.Spec().Procedure,
 		)
 
-		i.backend.Metrics.AddServerHandledCounter(
-			"unary",
-			strings.Split(req.Spec().Procedure, "/")[1],
-			strings.Split(req.Spec().Procedure, "/")[2],
-			connecthelper.ToRPCCodeString(err),
-		)
+		if split := strings.Split(req.Spec().Procedure, "/"); len(split) == 3 {
+			i.backend.Metrics.AddServerHandledCounter(
+				"unary",
+				split[1],
+				split[2],
+				connecthelper.ToRPCCodeString(err),
+			)
+		}
 
 		return res, err
 	}
@@ -126,12 +128,14 @@ func (i *AdminAuthInterceptor) WrapStreamingHandler(next connect.StreamingHandle
 			conn.Spec().Procedure,
 		)
 
-		i.backend.Metrics.AddServerHandledCounter(
-			"server_stream",
-			strings.Split(conn.Spec().Procedure, "/")[1],
-			strings.Split(conn.Spec().Procedure, "/")[2],
-			connecthelper.ToRPCCodeString(err),
-		)
+		if split := strings.Split(conn.Spec().Procedure, "/"); len(split) == 3 {
+			i.backend.Metrics.AddServerHandledCounter(
+				"server_stream",
+				split[1],
+				split[2],
+				connecthelper.ToRPCCodeString(err),
+			)
+		}
 
 		return err
 	}
diff --git a/server/rpc/interceptors/context.go b/server/rpc/interceptors/context.go
index 753112570..076b15a55 100644
--- a/server/rpc/interceptors/context.go
+++ b/server/rpc/interceptors/context.go
@@ -79,12 +79,14 @@ func (i *ContextInterceptor) WrapUnary(next connect.UnaryFunc) connect.UnaryFunc
 			req.Spec().Procedure,
 		)
 
-		i.backend.Metrics.AddServerHandledCounter(
-			"unary",
-			strings.Split(req.Spec().Procedure, "/")[1],
-			strings.Split(req.Spec().Procedure, "/")[2],
-			connecthelper.ToRPCCodeString(err),
-		)
+		if split := strings.Split(req.Spec().Procedure, "/"); len(split) == 3 {
+			i.backend.Metrics.AddServerHandledCounter(
+				"unary",
+				split[1],
+				split[2],
+				connecthelper.ToRPCCodeString(err),
+			)
+		}
 
 		return res, err
 	}
@@ -126,12 +128,14 @@ func (i *ContextInterceptor) WrapStreamingHandler(next connect.StreamingHandlerF
 			conn.Spec().Procedure,
 		)
 
-		i.backend.Metrics.AddServerHandledCounter(
-			"server_stream",
-			strings.Split(conn.Spec().Procedure, "/")[1],
-			strings.Split(conn.Spec().Procedure, "/")[2],
-			connecthelper.ToRPCCodeString(err),
-		)
+		if split := strings.Split(conn.Spec().Procedure, "/"); len(split) == 3 {
+			i.backend.Metrics.AddServerHandledCounter(
+				"server_stream",
+				split[1],
+				split[2],
+				connecthelper.ToRPCCodeString(err),
+			)
+		}
 
 		return err
 	}
@@ -155,8 +159,7 @@ func (i *ContextInterceptor) buildContext(ctx context.Context, header http.Heade
 		md.APIKey = apiKey
 	}
 
-	authorization := header.Get(types.AuthorizationKey)
-	if authorization != "" {
+	if authorization := header.Get(types.AuthorizationKey); authorization != "" {
 		md.Authorization = authorization
 	}
 	ctx = metadata.With(ctx, md)
diff --git a/test/integration/agent_test.go b/test/integration/server_test.go
similarity index 85%
rename from test/integration/agent_test.go
rename to test/integration/server_test.go
index 2f21c8df2..93c53eb99 100644
--- a/test/integration/agent_test.go
+++ b/test/integration/server_test.go
@@ -20,7 +20,6 @@ package integration
 
 import (
 	"context"
-	"io"
 	"sync"
 	"testing"
 
@@ -56,7 +55,10 @@ func TestServer(t *testing.T) {
 					assert.Fail(t, "unexpected ctx done")
 					return
 				case wr := <-wrch:
-					if wr.Err == io.EOF || connect.CodeOf(wr.Err) == connect.CodeCanceled {
+					// TODO(hackerwins): Define ClientError instead of using ConnectError later.
+					// For now, we use ConnectError to check whether the stream is closed. To
+					// simplify the interface, we will define ClientError later.
+					if connect.CodeOf(wr.Err) == connect.CodeCanceled {
 						assert.Len(t, wr.Presences, 0)
 						wg.Done()
 						return