From 68d54f5f42eb16afa98846d00f6a8cc4f091eb2f Mon Sep 17 00:00:00 2001
From: Chunzhu Li <lichunzhu@stu.xjtu.edu.cn>
Date: Wed, 8 Feb 2023 22:54:53 +0800
Subject: [PATCH] address comments

---
 br/pkg/lightning/restore/table_restore.go     |  7 ++++++-
 .../run.sh                                    | 21 ++++++++++++++++++-
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/br/pkg/lightning/restore/table_restore.go b/br/pkg/lightning/restore/table_restore.go
index bb607245d27e5..fc669a271b2a6 100644
--- a/br/pkg/lightning/restore/table_restore.go
+++ b/br/pkg/lightning/restore/table_restore.go
@@ -794,7 +794,12 @@ func (tr *TableRestore) postProcess(
 			}
 			hasDupe = hasLocalDupe
 		}
-		failpoint.Inject("SlowDownCheckDupe", func() {})
+		failpoint.Inject("SlowDownCheckDupe", func(v failpoint.Value) {
+			sec := v.(int)
+			tr.logger.Warn("start to sleep several seconds before checking other dupe",
+				zap.Int("seconds", sec))
+			time.Sleep(time.Duration(sec) * time.Second)
+		})
 
 		otherHasDupe, needRemoteDupe, baseTotalChecksum, err := metaMgr.CheckAndUpdateLocalChecksum(ctx, &localChecksum, hasDupe)
 		if err != nil {
diff --git a/br/tests/lightning_duplicate_resolution_incremental/run.sh b/br/tests/lightning_duplicate_resolution_incremental/run.sh
index feef4da8f609b..b1bf1e3869d27 100644
--- a/br/tests/lightning_duplicate_resolution_incremental/run.sh
+++ b/br/tests/lightning_duplicate_resolution_incremental/run.sh
@@ -22,14 +22,33 @@ LOG_FILE1="$TEST_DIR/lightning-duplicate-resolution1.log"
 LOG_FILE2="$TEST_DIR/lightning-duplicate-resolution2.log"
 
 # let lightning run a bit slow to avoid some table in the first lightning finish too fast.
-export GO_FAILPOINTS="github.com/pingcap/tidb/br/pkg/lightning/restore/SlowDownCheckDupe=sleep(5000)"
+export GO_FAILPOINTS="github.com/pingcap/tidb/br/pkg/lightning/restore/SlowDownCheckDupe=return(10)"
 run_lightning --backend local --sorted-kv-dir "$TEST_DIR/lightning_duplicate_resolution_incremental.sorted1" \
   --enable-checkpoint=1 --log-file "$LOG_FILE1" --config "tests/$TEST_NAME/config1.toml" &
+
+counter=0
+while [ $counter -lt 10 ]; do
+    if grep -Fq "start to sleep several seconds before checking other dupe" "$LOG_FILE1"; then
+        echo "lightning 1 already starts waiting for dupe"
+        break
+    fi
+    ((counter += 1))
+    echo "waiting for lightning 1 starts"
+    sleep 1
+done
+
+if [ $counter -ge 10 ]; then
+  echo "fail to wait for lightning 1 starts"
+  exit 1
+fi
+
 run_lightning --backend local --sorted-kv-dir "$TEST_DIR/lightning_duplicate_resolution_incremental.sorted2" \
   --enable-checkpoint=1 --log-file "$LOG_FILE2" --config "tests/$TEST_NAME/config2.toml" &
 
 wait
 
+export GO_FAILPOINTS=""
+
 # Ensure table is consistent.
 run_sql 'admin check table dup_resolve_detect.ta'