[UT] Fix unstable ut (backport #50672) (#50677)

Signed-off-by: sevev <[email protected]>
Co-authored-by: zhangqiang <[email protected]>

be/src/storage/tablet_updates.h

@@ -466,6 +466,8 @@ class TabletUpdates {
         }
     }
 
+    bool compaction_running() { return _compaction_running; }
+
     void check_for_apply() { _check_for_apply(); }
 
     std::timed_mutex* get_index_lock() { return &_index_lock; }

be/test/storage/tablet_updates_test.cpp

@@ -2282,8 +2282,16 @@ void TabletUpdatesTest::test_vertical_compaction(bool enable_persistent_index) {
         rs1->rowset_meta()->set_segments_overlap_pb(NONOVERLAPPING);
         ASSERT_TRUE(_tablet2->rowset_commit(2, rs1).ok());
         std::this_thread::sleep_for(std::chrono::milliseconds(200));
+        ASSERT_EQ(100, read_tablet(_tablet, 2));
         ASSERT_TRUE(_tablet2->updates()->compaction(_compaction_mem_tracker.get()).ok());
-        std::this_thread::sleep_for(std::chrono::seconds(1));
+        int32_t count = 0;
+        while (_tablet->updates()->compaction_running()) {
+            std::this_thread::sleep_for(std::chrono::seconds(1));
+            // wait for compaction finish at most 60 seconds
+            if (++count > 60) {
+                break;
+            }
+        }
 
         ASSERT_EQ(_tablet2->updates()->num_rowsets(), 1);
         ASSERT_EQ(_tablet2->updates()->version_history_count(), 3);