From 3777c384feb13fcaf7c77378fa4ded888a34f6e4 Mon Sep 17 00:00:00 2001
From: ShuNing <nolouch@gmail.com>
Date: Fri, 13 Sep 2024 17:05:12 +0800
Subject: [PATCH] [pick-8.1] region_request: ignore resource group errors that
 not relative storage layer (#1354) (#1463)

ref tikv/client-go#1322

Signed-off-by: nolouch <nolouch@gmail.com>
---
 internal/locate/region_request.go      | 30 +++++++++++++++---------
 internal/locate/region_request_test.go | 32 ++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 11 deletions(-)

diff --git a/internal/locate/region_request.go b/internal/locate/region_request.go
index 8bb277d43..a5b207d2b 100644
--- a/internal/locate/region_request.go
+++ b/internal/locate/region_request.go
@@ -65,6 +65,7 @@ import (
 	"github.com/tikv/client-go/v2/metrics"
 	"github.com/tikv/client-go/v2/tikvrpc"
 	"github.com/tikv/client-go/v2/util"
+	"github.com/tikv/pd/client/errs"
 	pderr "github.com/tikv/pd/client/errs"
 )
 
@@ -2124,7 +2125,9 @@ func (s *RegionRequestSender) sendReqToRegion(
 	}
 
 	if err != nil {
-		s.rpcError = err
+		if isRPCError(err) {
+			s.rpcError = err
+		}
 		if s.Stats != nil {
 			errStr := getErrMsg(err)
 			s.Stats.RecordRPCErrorStats(errStr)
@@ -2151,6 +2154,11 @@ func (s *RegionRequestSender) sendReqToRegion(
 	return
 }
 
+func isRPCError(err error) bool {
+	// exclude ErrClientResourceGroupThrottled
+	return err != nil && errs.ErrClientResourceGroupThrottled.NotEqual(err)
+}
+
 func storeIDLabel(rpcCtx *RPCContext) string {
 	if rpcCtx != nil && rpcCtx.Store != nil {
 		return strconv.FormatUint(rpcCtx.Store.storeID, 10)
@@ -2228,16 +2236,6 @@ func (s *RegionRequestSender) onSendFail(bo *retry.Backoffer, ctx *RPCContext, r
 		metrics.TiKVRPCErrorCounter.WithLabelValues("unknown", storeLabel).Inc()
 	}
 
-	if ctx.Store != nil && ctx.Store.storeType == tikvrpc.TiFlashCompute {
-		s.regionCache.InvalidateTiFlashComputeStoresIfGRPCError(err)
-	} else if ctx.Meta != nil {
-		if s.replicaSelector != nil {
-			s.replicaSelector.onSendFailure(bo, err)
-		} else {
-			s.regionCache.OnSendFail(bo, ctx, s.NeedReloadRegion(ctx), err)
-		}
-	}
-
 	// don't need to retry for ResourceGroup error
 	if errors.Is(err, pderr.ErrClientResourceGroupThrottled) {
 		return err
@@ -2250,6 +2248,16 @@ func (s *RegionRequestSender) onSendFail(bo *retry.Backoffer, ctx *RPCContext, r
 		return err
 	}
 
+	if ctx.Store != nil && ctx.Store.storeType == tikvrpc.TiFlashCompute {
+		s.regionCache.InvalidateTiFlashComputeStoresIfGRPCError(err)
+	} else if ctx.Meta != nil {
+		if s.replicaSelector != nil {
+			s.replicaSelector.onSendFailure(bo, err)
+		} else {
+			s.regionCache.OnSendFail(bo, ctx, s.NeedReloadRegion(ctx), err)
+		}
+	}
+
 	// Retry on send request failure when it's not canceled.
 	// When a store is not available, the leader of related region should be elected quickly.
 	// TODO: the number of retry time should be limited:since region may be unavailable
diff --git a/internal/locate/region_request_test.go b/internal/locate/region_request_test.go
index 230bb9a51..5a66645f7 100644
--- a/internal/locate/region_request_test.go
+++ b/internal/locate/region_request_test.go
@@ -65,6 +65,7 @@ import (
 	"github.com/tikv/client-go/v2/internal/client/mockserver"
 	"github.com/tikv/client-go/v2/internal/mockstore/mocktikv"
 	"github.com/tikv/client-go/v2/tikvrpc"
+	pderr "github.com/tikv/pd/client/errs"
 	"google.golang.org/grpc"
 )
 
@@ -160,6 +161,37 @@ func (s *testRegionRequestToSingleStoreSuite) TestOnRegionError() {
 	}()
 }
 
+func (s *testRegionRequestToSingleStoreSuite) TestOnSendFailByResourceGroupThrottled() {
+	req := tikvrpc.NewRequest(tikvrpc.CmdRawPut, &kvrpcpb.RawPutRequest{
+		Key:   []byte("key"),
+		Value: []byte("value"),
+	})
+	region, err := s.cache.LocateRegionByID(s.bo, s.region)
+	s.Nil(err)
+	s.NotNil(region)
+
+	// test ErrClientResourceGroupThrottled handled by regionRequestSender
+	func() {
+		oc := s.regionRequestSender.client
+		defer func() {
+			s.regionRequestSender.client = oc
+		}()
+		storeOld, _ := s.regionRequestSender.regionCache.stores.get(1)
+		epoch := storeOld.epoch
+		s.regionRequestSender.client = &fnClient{fn: func(ctx context.Context, addr string, req *tikvrpc.Request, timeout time.Duration) (response *tikvrpc.Response, err error) {
+			return nil, pderr.ErrClientResourceGroupThrottled
+		}}
+		bo := retry.NewBackofferWithVars(context.Background(), 5, nil)
+		_, _, err := s.regionRequestSender.SendReq(bo, req, region.Region, time.Second)
+		s.NotNil(err)
+		storeNew, _ := s.regionRequestSender.regionCache.stores.get(1)
+		//  not mark the store need be refill, then the epoch should not be changed.
+		s.Equal(epoch, storeNew.epoch)
+		// no rpc error if the error is ErrClientResourceGroupThrottled
+		s.Nil(s.regionRequestSender.rpcError)
+	}()
+}
+
 func (s *testRegionRequestToSingleStoreSuite) TestOnSendFailedWithStoreRestart() {
 	req := tikvrpc.NewRequest(tikvrpc.CmdRawPut, &kvrpcpb.RawPutRequest{
 		Key:   []byte("key"),