fix adjust_global_merge_info when max_frozen_status.frozen_scn_ = 1

src/rootserver/freeze/ob_major_merge_scheduler.cpp

@@ -314,7 +314,7 @@ int ObMajorMergeScheduler::do_one_round_major_merge(const int64_t expected_epoch
         // no new zone to merge
         LOG_INFO("no more zone need to merge", K_(tenant_id));
       } else if (OB_FAIL(schedule_zones_to_merge(to_merge_zone, expected_epoch))) {
-        LOG_WARN("fail to get next merge zones", KR(ret), K(to_merge_zone), K(expected_epoch));
+        LOG_WARN("fail to schedule zones to merge", KR(ret), K(to_merge_zone), K(expected_epoch));
       }
       // Need to update_merge_status, even though to_merge_zone is empty.
       // E.g., in the 1st loop, already schedule all zones to merge, but not finish major merge.

src/rootserver/freeze/ob_zone_merge_manager.cpp

@@ -915,11 +915,12 @@ int ObZoneMergeManagerBase::adjust_global_merge_info()
   } else {
     // Adjust global_merge_info in memory with (max_frozen_status.frozen_scn_ - 1).
     // So as to launch one major freeze with max_frozen_status.frozen_scn_.
-    inner_adjust_global_merge_info(SCN::minus(max_frozen_status.frozen_scn_, 1));
-  }
-  if (OB_SUCC(ret)) {
-    LOG_INFO("succ to adjust global merge info", K_(tenant_id), "max_frozen_scn",
-      max_frozen_status.frozen_scn_);
+    // Note: only launch major freezes with frozen_scn > 1
+    if (max_frozen_status.frozen_scn_ > SCN::base_scn()) {
+      inner_adjust_global_merge_info(SCN::minus(max_frozen_status.frozen_scn_, 1));
+      LOG_INFO("succ to adjust global merge info", K_(tenant_id), "max_frozen_scn",
+               max_frozen_status.frozen_scn_, K_(global_merge_info));
+    }
   }
   return ret;
 }