diff --git a/cloud/src/meta-service/http_encode_key.cpp b/cloud/src/meta-service/http_encode_key.cpp
index 4ee76af5c9f4e0..1fb58bff23c11a 100644
--- a/cloud/src/meta-service/http_encode_key.cpp
+++ b/cloud/src/meta-service/http_encode_key.cpp
@@ -303,13 +303,14 @@ HttpResponse process_http_get_value(TxnKv* txn_kv, const brpc::URI& uri) {
         std::string end_key = key + "\xff";
         std::unique_ptr<RangeGetIterator> it;
         bool more = false;
-        do {
+        while (it == nullptr /* may be not init */ || more) {
             err = txn->get(begin_key, end_key, &it, true);
             if (err != TxnErrorCode::TXN_OK) break;
             begin_key = it->next_begin_key();
             more = it->more();
             value.iters.push_back(std::move(it));
-        } while (more);
+            if (!more) break;
+        }
     } else {
         err = cloud::blob_get(txn.get(), key, &value, true);
     }
diff --git a/cloud/src/meta-service/meta_service.cpp b/cloud/src/meta-service/meta_service.cpp
index 919d9050fd387c..0a91aaa6f533f1 100644
--- a/cloud/src/meta-service/meta_service.cpp
+++ b/cloud/src/meta-service/meta_service.cpp
@@ -1319,7 +1319,7 @@ void scan_restore_job_rowset(
             });
 
     std::unique_ptr<RangeGetIterator> it;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         TxnErrorCode err = txn->get(restore_job_rs_key0, restore_job_rs_key1, &it, true);
         if (err != TxnErrorCode::TXN_OK) {
             code = cast_as<ErrCategory::READ>(err);
@@ -1346,7 +1346,7 @@ void scan_restore_job_rowset(
             if (!it->has_next()) restore_job_rs_key0 = k;
         }
         restore_job_rs_key0.push_back('\x00'); // Update to next smallest key for iteration
-    } while (it->more());
+    }
     return;
 }
 
@@ -2863,7 +2863,7 @@ void internal_get_rowset(Transaction* txn, int64_t start, int64_t end,
     };
 
     std::stringstream ss;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         TxnErrorCode err = txn->get(key0, key1, &it);
         if (err != TxnErrorCode::TXN_OK) {
             code = cast_as<ErrCategory::READ>(err);
@@ -2900,7 +2900,7 @@ void internal_get_rowset(Transaction* txn, int64_t start, int64_t end,
             }
         }
         key0.push_back('\x00'); // Update to next smallest key for iteration
-    } while (it->more());
+    }
 }
 
 std::vector<std::pair<int64_t, int64_t>> calc_sync_versions(int64_t req_bc_cnt, int64_t bc_cnt,
@@ -4155,7 +4155,7 @@ void MetaServiceImpl::get_delete_bitmap(google::protobuf::RpcController* control
             int64_t last_ver = -1;
             int64_t last_seg_id = -1;
             int64_t round = 0;
-            do {
+            while (it == nullptr /* may be not init */ || it->more()) {
                 if (test) {
                     LOG(INFO) << "test";
                     err = txn->get(start_key, end_key, &it, false, 2);
@@ -4233,7 +4233,7 @@ void MetaServiceImpl::get_delete_bitmap(google::protobuf::RpcController* control
                 if (code != MetaServiceCode::OK) return;
                 round++;
                 start_key = it->next_begin_key(); // Update to next smallest key for iteration
-            } while (it->more());
+            }
             LOG(INFO) << "get delete bitmap for tablet=" << tablet_id
                       << ", rowset=" << rowset_ids[i] << ", start version=" << begin_versions[i]
                       << ", end version=" << end_versions[i] << ", internal round=" << round
@@ -4872,7 +4872,8 @@ void MetaServiceImpl::get_delete_bitmap_update_lock_v2(
                     MowTabletJobPB mow_tablet_job;
                     std::unique_ptr<RangeGetIterator> it;
                     int64_t expired_job_num = 0;
-                    do {
+                    while (it == nullptr /* may be not init */ ||
+                           (it->more() && !has_unexpired_compaction)) {
                         err = txn->get(key0, key1, &it);
                         if (err != TxnErrorCode::TXN_OK) {
                             code = cast_as<ErrCategory::READ>(err);
@@ -4903,7 +4904,7 @@ void MetaServiceImpl::get_delete_bitmap_update_lock_v2(
                             }
                         }
                         key0 = it->next_begin_key(); // Update to next smallest key for iteration
-                    } while (it->more() && !has_unexpired_compaction);
+                    }
                     if (has_unexpired_compaction) {
                         // TODO print initiator
                         ss << "already be locked by lock_id=" << lock_info.lock_id()
diff --git a/cloud/src/meta-service/meta_service_job.cpp b/cloud/src/meta-service/meta_service_job.cpp
index dc14f7fa3f6662..9fc1824c091692 100644
--- a/cloud/src/meta-service/meta_service_job.cpp
+++ b/cloud/src/meta-service/meta_service_job.cpp
@@ -801,7 +801,7 @@ std::pair<MetaServiceCode, std::string> scan_compaction_input_rowsets(
     };
 
     auto rs_start1 = rs_start;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         TxnErrorCode err = txn->get(rs_start1, rs_end, &it);
         if (err != TxnErrorCode::TXN_OK) {
             return {cast_as<ErrCategory::READ>(err),
@@ -827,7 +827,7 @@ std::pair<MetaServiceCode, std::string> scan_compaction_input_rowsets(
             if (!it->has_next()) rs_start1 = k;
         }
         rs_start1.push_back('\x00'); // Update to next smallest key for iteration
-    } while (it->more());
+    }
     return {MetaServiceCode::OK, ""};
 }
 
@@ -1325,7 +1325,7 @@ std::pair<MetaServiceCode, std::string> scan_schema_change_input_rowsets(
         std::string& rs_start, std::string& rs_end, auto&& callback) {
     std::unique_ptr<RangeGetIterator> it;
     auto rs_start1 = rs_start;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         TxnErrorCode err = txn->get(rs_start1, rs_end, &it);
         if (err != TxnErrorCode::TXN_OK) {
             return {MetaServiceCode::KV_TXN_GET_ERR,
@@ -1351,7 +1351,7 @@ std::pair<MetaServiceCode, std::string> scan_schema_change_input_rowsets(
             if (!it->has_next()) rs_start1 = k;
         }
         rs_start1.push_back('\x00'); // Update to next smallest key for iteration
-    } while (it->more());
+    }
     return {MetaServiceCode::OK, ""};
 }
 
diff --git a/cloud/src/meta-service/meta_service_resource.cpp b/cloud/src/meta-service/meta_service_resource.cpp
index 7df96f3e727e2b..8843e5ab4733d1 100644
--- a/cloud/src/meta-service/meta_service_resource.cpp
+++ b/cloud/src/meta-service/meta_service_resource.cpp
@@ -509,7 +509,7 @@ void MetaServiceImpl::get_obj_store_info(google::protobuf::RpcController* contro
         std::string storage_vault_start = storage_vault_key({instance.instance_id(), ""});
         std::string storage_vault_end = storage_vault_key({instance.instance_id(), "\xff"});
         std::unique_ptr<RangeGetIterator> it;
-        do {
+        while (it == nullptr /* may be not init */ || it->more()) {
             TxnErrorCode err = txn->get(storage_vault_start, storage_vault_end, &it);
             if (err != TxnErrorCode::TXN_OK) {
                 code = cast_as<ErrCategory::READ>(err);
@@ -533,7 +533,7 @@ void MetaServiceImpl::get_obj_store_info(google::protobuf::RpcController* contro
                 }
             }
             storage_vault_start.push_back('\x00'); // Update to next smallest key for iteration
-        } while (it->more());
+        }
     }
     for (auto& vault : *response->mutable_storage_vault()) {
         if (vault.has_obj_info()) {
@@ -4416,7 +4416,7 @@ void MetaServiceImpl::get_copy_files(google::protobuf::RpcController* controller
     copy_job_key(key_info0, &key0);
     copy_job_key(key_info1, &key1);
     std::unique_ptr<RangeGetIterator> it;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         TxnErrorCode err = txn->get(key0, key1, &it);
         if (err != TxnErrorCode::TXN_OK) {
             code = cast_as<ErrCategory::READ>(err);
@@ -4440,7 +4440,7 @@ void MetaServiceImpl::get_copy_files(google::protobuf::RpcController* controller
             }
         }
         key0.push_back('\x00');
-    } while (it->more());
+    }
 }
 
 void MetaServiceImpl::filter_copy_files(google::protobuf::RpcController* controller,
diff --git a/cloud/src/meta-service/meta_service_tablet_stats.cpp b/cloud/src/meta-service/meta_service_tablet_stats.cpp
index 9543cd724c1a02..83b097b1726044 100644
--- a/cloud/src/meta-service/meta_service_tablet_stats.cpp
+++ b/cloud/src/meta-service/meta_service_tablet_stats.cpp
@@ -50,7 +50,7 @@ void internal_get_tablet_stats(MetaServiceCode& code, std::string& msg, Transact
             7); // aggregate + data_size + num_rows + num_rowsets + num_segments + index_size + segment_size
 
     std::unique_ptr<RangeGetIterator> it;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         TxnErrorCode err = txn->get(begin_key, end_key, &it, snapshot);
         if (err != TxnErrorCode::TXN_OK) {
             code = cast_as<ErrCategory::READ>(err);
@@ -64,7 +64,7 @@ void internal_get_tablet_stats(MetaServiceCode& code, std::string& msg, Transact
                                    std::string {v.data(), v.size()});
         }
         begin_key = it->next_begin_key();
-    } while (it->more());
+    }
 
     if (stats_kvs.empty()) {
         code = MetaServiceCode::TABLET_NOT_FOUND;
diff --git a/cloud/src/meta-service/meta_service_txn.cpp b/cloud/src/meta-service/meta_service_txn.cpp
index 41ee486f50aa54..cf858dde5de3e3 100644
--- a/cloud/src/meta-service/meta_service_txn.cpp
+++ b/cloud/src/meta-service/meta_service_txn.cpp
@@ -1134,7 +1134,7 @@ void scan_tmp_rowset(
     };
 
     std::unique_ptr<RangeGetIterator> it;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         err = txn->get(rs_tmp_key0, rs_tmp_key1, &it, true);
         if (err == TxnErrorCode::TXN_TOO_OLD) {
             err = txn_kv->create_txn(&txn);
@@ -1169,7 +1169,7 @@ void scan_tmp_rowset(
             if (!it->has_next()) rs_tmp_key0 = k;
         }
         rs_tmp_key0.push_back('\x00'); // Update to next smallest key for iteration
-    } while (it->more());
+    }
 
     VLOG_DEBUG << "txn_id=" << txn_id << " tmp_rowsets_meta.size()=" << tmp_rowsets_meta->size();
     return;
@@ -3805,7 +3805,7 @@ void MetaServiceImpl::abort_txn_with_coordinator(::google::protobuf::RpcControll
     int64_t abort_txn_cnt = 0;
     int64_t total_iteration_cnt = 0;
     bool need_commit = false;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         err = txn->get(begin_info_key, end_info_key, &it, true);
         if (err != TxnErrorCode::TXN_OK) {
             code = cast_as<ErrCategory::READ>(err);
@@ -3847,7 +3847,7 @@ void MetaServiceImpl::abort_txn_with_coordinator(::google::protobuf::RpcControll
             }
         }
         begin_info_key.push_back('\x00'); // Update to next smallest key for iteration
-    } while (it->more());
+    }
     LOG(INFO) << "abort txn count: " << abort_txn_cnt
               << " total iteration count: " << total_iteration_cnt;
     if (need_commit) {
@@ -3924,7 +3924,7 @@ void MetaServiceImpl::check_txn_conflict(::google::protobuf::RpcController* cont
     int64_t skip_timeout_txn_cnt = 0;
     int total_iteration_cnt = 0;
     bool finished = true;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         err = txn->get(begin_running_key, end_running_key, &it, true);
         if (err != TxnErrorCode::TXN_OK) {
             code = cast_as<ErrCategory::READ>(err);
@@ -4002,7 +4002,7 @@ void MetaServiceImpl::check_txn_conflict(::google::protobuf::RpcController* cont
             }
         }
         begin_running_key.push_back('\x00'); // Update to next smallest key for iteration
-    } while (it->more());
+    }
     LOG(INFO) << "skip timeout txn count: " << skip_timeout_txn_cnt
               << " conflict txn count: " << response->conflict_txns_size()
               << " total iteration count: " << total_iteration_cnt;
@@ -4195,7 +4195,7 @@ void MetaServiceImpl::clean_txn_label(::google::protobuf::RpcController* control
         bool snapshot = true;
         int limit = 1000;
         TEST_SYNC_POINT_CALLBACK("clean_txn_label:limit", &limit);
-        do {
+        while (it == nullptr /* may be not init */ || it->more()) {
             std::unique_ptr<Transaction> txn;
             auto err = txn_kv_->create_txn(&txn);
             if (err != TxnErrorCode::TXN_OK) {
@@ -4241,7 +4241,7 @@ void MetaServiceImpl::clean_txn_label(::google::protobuf::RpcController* control
                 }
             }
             begin_label_key.push_back('\x00');
-        } while (it->more());
+        }
     } else {
         const std::string& label = request->labels(0);
         const std::string label_key = txn_label_key({instance_id, db_id, label});
diff --git a/cloud/src/meta-store/blob_message.cpp b/cloud/src/meta-store/blob_message.cpp
index 90b2f298884fb3..c7e3edef63dcdb 100644
--- a/cloud/src/meta-store/blob_message.cpp
+++ b/cloud/src/meta-store/blob_message.cpp
@@ -123,17 +123,16 @@ TxnErrorCode ValueBuf::get(Transaction* txn, std::string_view key, bool snapshot
     }
     begin_key = it->next_begin_key();
     iters.push_back(std::move(it));
-    do {
+    while (it == nullptr /* may be not init */ || more) {
         err = txn->get(begin_key, end_key, &it, snapshot);
         if (err != TxnErrorCode::TXN_OK) {
             return err;
         }
+        begin_key = it->next_begin_key();
         more = it->more();
-        if (more) {
-            begin_key = it->next_begin_key();
-        }
         iters.push_back(std::move(it));
-    } while (more);
+        if (!more) break;
+    }
     return TxnErrorCode::TXN_OK;
 }
 
diff --git a/cloud/src/meta-store/txn_kv.cpp b/cloud/src/meta-store/txn_kv.cpp
index d7c27503a10532..4e98cd4c01176d 100644
--- a/cloud/src/meta-store/txn_kv.cpp
+++ b/cloud/src/meta-store/txn_kv.cpp
@@ -881,7 +881,7 @@ TxnErrorCode Transaction::get_conflicting_range(
 
     FDBKeyValue const* out_kvs;
     int out_kvs_count;
-    fdb_bool_t out_more;
+    fdb_bool_t out_more = false;
     do {
         fdb_error_t err =
                 fdb_future_get_keyvalue_array(future, &out_kvs, &out_kvs_count, &out_more);
diff --git a/cloud/src/recycler/checker.cpp b/cloud/src/recycler/checker.cpp
index c7710d17af8f08..5224faaf83579e 100644
--- a/cloud/src/recycler/checker.cpp
+++ b/cloud/src/recycler/checker.cpp
@@ -754,7 +754,7 @@ int InstanceChecker::do_check() {
     auto end_key = meta_rowset_key({instance_id_, INT64_MAX, 0});
 
     std::unique_ptr<RangeGetIterator> it;
-    do {
+    while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
         std::unique_ptr<Transaction> txn;
         TxnErrorCode err = txn_kv_->create_txn(&txn);
         if (err != TxnErrorCode::TXN_OK) {
@@ -784,7 +784,7 @@ int InstanceChecker::do_check() {
             check_rowset_objects(rs_meta, k);
         }
         start_key.push_back('\x00'); // Update to next smallest key for iteration
-    } while (it->more() && !stopped());
+    }
 
     return num_rowset_loss > 0 ? 1 : check_ret;
 }
@@ -899,7 +899,7 @@ int InstanceChecker::do_inverted_check() {
         std::unique_ptr<RangeGetIterator> it;
         auto begin = meta_rowset_key({instance_id_, tablet_id, 0});
         auto end = meta_rowset_key({instance_id_, tablet_id, INT64_MAX});
-        do {
+        while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
             TxnErrorCode err = txn->get(begin, end, &it);
             if (err != TxnErrorCode::TXN_OK) {
                 LOG(WARNING) << "failed to get rowset kv, err=" << err;
@@ -923,7 +923,7 @@ int InstanceChecker::do_inverted_check() {
                     break;
                 }
             }
-        } while (it->more() && !stopped());
+        }
 
         if (!tablet_rowsets_cache.rowset_ids.contains(rowset_id)) {
             // Garbage data leak
@@ -1025,7 +1025,7 @@ int InstanceChecker::traverse_mow_tablet(const std::function<int(int64_t, bool)>
     std::unique_ptr<RangeGetIterator> it;
     auto begin = meta_rowset_key({instance_id_, 0, 0});
     auto end = meta_rowset_key({instance_id_, std::numeric_limits<int64_t>::max(), 0});
-    do {
+    while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
         std::unique_ptr<Transaction> txn;
         TxnErrorCode err = txn_kv_->create_txn(&txn);
         if (err != TxnErrorCode::TXN_OK) {
@@ -1077,7 +1077,7 @@ int InstanceChecker::traverse_mow_tablet(const std::function<int(int64_t, bool)>
                 }
             }
         }
-    } while (it->more() && !stopped());
+    }
     return 0;
 }
 
@@ -1089,7 +1089,7 @@ int InstanceChecker::traverse_rowset_delete_bitmaps(
     auto end = meta_delete_bitmap_key({instance_id_, tablet_id, rowset_id,
                                        std::numeric_limits<int64_t>::max(),
                                        std::numeric_limits<int64_t>::max()});
-    do {
+    while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
         std::unique_ptr<Transaction> txn;
         TxnErrorCode err = txn_kv_->create_txn(&txn);
         if (err != TxnErrorCode::TXN_OK) {
@@ -1125,7 +1125,7 @@ int InstanceChecker::traverse_rowset_delete_bitmaps(
                 break;
             }
         }
-    } while (it->more() && !stopped());
+    }
 
     return 0;
 }
@@ -1143,7 +1143,7 @@ int InstanceChecker::collect_tablet_rowsets(
     auto end = meta_rowset_key({instance_id_, tablet_id + 1, 0});
 
     int64_t rowsets_num {0};
-    do {
+    while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
         TxnErrorCode err = txn->get(begin, end, &it);
         if (err != TxnErrorCode::TXN_OK) {
             LOG(WARNING) << "failed to get rowset kv, err=" << err;
@@ -1169,7 +1169,7 @@ int InstanceChecker::collect_tablet_rowsets(
                 break;
             }
         }
-    } while (it->more() && !stopped());
+    }
 
     LOG(INFO) << fmt::format(
             "[delete bitmap checker] successfully collect rowsets for instance_id={}, "
@@ -1225,7 +1225,7 @@ int InstanceChecker::do_delete_bitmap_inverted_check() {
     auto begin = meta_delete_bitmap_key({instance_id_, 0, "", 0, 0});
     auto end =
             meta_delete_bitmap_key({instance_id_, std::numeric_limits<int64_t>::max(), "", 0, 0});
-    do {
+    while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
         std::unique_ptr<Transaction> txn;
         TxnErrorCode err = txn_kv_->create_txn(&txn);
         if (err != TxnErrorCode::TXN_OK) {
@@ -1327,7 +1327,7 @@ int InstanceChecker::do_delete_bitmap_inverted_check() {
                         instance_id_, tablet_id, rowset_id, version, segment_id);
             }
         }
-    } while (it->more() && !stopped());
+    }
 
     return (leaked_delete_bitmaps > 0 || abnormal_delete_bitmaps > 0) ? 1 : 0;
 }
@@ -1409,7 +1409,7 @@ int InstanceChecker::check_inverted_index_file_storage_format_v1(
     std::unique_ptr<RangeGetIterator> it;
     auto begin = meta_rowset_key({instance_id_, tablet_id, 0});
     auto end = meta_rowset_key({instance_id_, tablet_id, INT64_MAX});
-    do {
+    while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
         TxnErrorCode err = txn->get(begin, end, &it);
         if (err != TxnErrorCode::TXN_OK) {
             LOG(WARNING) << "failed to get rowset kv, err=" << err;
@@ -1470,7 +1470,7 @@ int InstanceChecker::check_inverted_index_file_storage_format_v1(
                 break;
             }
         }
-    } while (it->more() && !stopped());
+    }
 
     if (!rowset_index_cache_v1.segment_ids.contains(segment_id)) {
         // Garbage data leak
@@ -1533,7 +1533,7 @@ int InstanceChecker::check_inverted_index_file_storage_format_v2(
     std::unique_ptr<RangeGetIterator> it;
     auto begin = meta_rowset_key({instance_id_, tablet_id, 0});
     auto end = meta_rowset_key({instance_id_, tablet_id, INT64_MAX});
-    do {
+    while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
         TxnErrorCode err = txn->get(begin, end, &it);
         if (err != TxnErrorCode::TXN_OK) {
             LOG(WARNING) << "failed to get rowset kv, err=" << err;
@@ -1561,7 +1561,7 @@ int InstanceChecker::check_inverted_index_file_storage_format_v2(
                 break;
             }
         }
-    } while (it->more() && !stopped());
+    }
 
     if (!rowset_index_cache_v2.segment_ids.contains(segment_id)) {
         // Garbage data leak
@@ -1655,7 +1655,7 @@ int InstanceChecker::check_delete_bitmap_storage_optimize_v2(
     };
     using namespace std::chrono;
     int64_t now = duration_cast<seconds>(system_clock::now().time_since_epoch()).count();
-    do {
+    while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
         std::unique_ptr<Transaction> txn;
         TxnErrorCode err = txn_kv_->create_txn(&txn);
         if (err != TxnErrorCode::TXN_OK) {
@@ -1728,7 +1728,7 @@ int InstanceChecker::check_delete_bitmap_storage_optimize_v2(
             }
             last_failed_version = version;
         }
-    } while (it->more() && !stopped());
+    }
     if (!failed_versions.empty()) {
         print_failed_versions();
     }
@@ -1792,7 +1792,7 @@ int InstanceChecker::do_mow_job_key_check() {
     std::string begin = mow_tablet_job_key({instance_id_, 0, 0});
     std::string end = mow_tablet_job_key({instance_id_, INT64_MAX, 0});
     MowTabletJobPB mow_tablet_job;
-    do {
+    while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
         std::unique_ptr<Transaction> txn;
         TxnErrorCode err = txn_kv_->create_txn(&txn);
         if (err != TxnErrorCode::TXN_OK) {
@@ -1855,7 +1855,7 @@ int InstanceChecker::do_mow_job_key_check() {
             }
         }
         begin = it->next_begin_key(); // Update to next smallest key for iteration
-    } while (it->more() && !stopped());
+    }
     return 0;
 }
 int InstanceChecker::do_tablet_stats_key_check() {
@@ -2110,7 +2110,7 @@ int InstanceChecker::scan_and_handle_kv(
     std::unique_ptr<RangeGetIterator> it;
     int limit = 10000;
     TEST_SYNC_POINT_CALLBACK("InstanceChecker:scan_and_handle_kv:limit", &limit);
-    do {
+    while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
         err = txn->get(start_key, end_key, &it, false, limit);
         TEST_SYNC_POINT_CALLBACK("InstanceChecker:scan_and_handle_kv:get_err", &err);
         if (err == TxnErrorCode::TXN_TOO_OLD) {
@@ -2140,29 +2140,29 @@ int InstanceChecker::scan_and_handle_kv(
             }
         }
         start_key = it->next_begin_key();
-    } while (it->more() && !stopped());
+    }
     return ret;
 }
 
 int InstanceChecker::do_version_key_check() {
-    std::unique_ptr<RangeGetIterator> it;
+    std::unique_ptr<RangeGetIterator> table_it;
     std::string begin = table_version_key({instance_id_, 0, 0});
     std::string end = table_version_key({instance_id_, INT64_MAX, 0});
     bool check_res = true;
-    do {
+    while (table_it == nullptr /* may be not init */ || (table_it->more() && !stopped())) {
         std::unique_ptr<Transaction> txn;
         TxnErrorCode err = txn_kv_->create_txn(&txn);
         if (err != TxnErrorCode::TXN_OK) {
             LOG(WARNING) << "failed to create txn";
             return -1;
         }
-        err = txn->get(begin, end, &it);
+        err = txn->get(begin, end, &table_it);
         if (err != TxnErrorCode::TXN_OK) {
             LOG(WARNING) << "failed to get mow tablet job key, err=" << err;
             return -1;
         }
-        while (it->has_next() && !stopped()) {
-            auto [k, v] = it->next();
+        while (table_it->has_next() && !stopped()) {
+            auto [k, v] = table_it->next();
             std::string_view k1 = k;
             k1.remove_prefix(1);
             std::vector<std::tuple<std::variant<int64_t, std::string>, int, int>> out;
@@ -2181,20 +2181,21 @@ int InstanceChecker::do_version_key_check() {
                     partition_version_key({instance_id_, db_id, table_id, INT64_MAX});
             VersionPB partition_version_pb;
 
-            do {
+            std::unique_ptr<RangeGetIterator> part_it;
+            while (part_it == nullptr /* may be not init */ || (part_it->more() && !stopped())) {
                 std::unique_ptr<Transaction> txn;
                 TxnErrorCode err = txn_kv_->create_txn(&txn);
                 if (err != TxnErrorCode::TXN_OK) {
                     LOG(WARNING) << "failed to create txn";
                     return -1;
                 }
-                err = txn->get(partition_version_key_begin, partition_version_key_end, &it);
+                err = txn->get(partition_version_key_begin, partition_version_key_end, &part_it);
                 if (err != TxnErrorCode::TXN_OK) {
                     LOG(WARNING) << "failed to get mow tablet job key, err=" << err;
                     return -1;
                 }
-                while (it->has_next() && !stopped()) {
-                    auto [k, v] = it->next();
+                while (part_it->has_next() && !stopped()) {
+                    auto [k, v] = part_it->next();
                     // 0x01 "version" ${instance_id} "partition" ${db_id} ${tbl_id} ${partition_id}
                     std::string_view k1 = k;
                     k1.remove_prefix(1);
@@ -2215,11 +2216,11 @@ int InstanceChecker::do_version_key_check() {
                                 << " partition_version: " << partition_version;
                     }
                 }
-                partition_version_key_begin = it->next_begin_key();
-            } while (it->more() && !stopped());
+                partition_version_key_begin = part_it->next_begin_key();
+            }
         }
-        begin = it->next_begin_key(); // Update to next smallest key for iteration
-    } while (it->more() && !stopped());
+        begin = table_it->next_begin_key(); // Update to next smallest key for iteration
+    }
     return check_res ? 0 : -1;
 }
 
@@ -2259,7 +2260,7 @@ int InstanceChecker::do_restore_job_check() {
     job_restore_tablet_key(restore_job_key_info0, &begin);
     job_restore_tablet_key(restore_job_key_info1, &end);
     std::unique_ptr<RangeGetIterator> it;
-    do {
+    while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
         std::unique_ptr<Transaction> txn;
         TxnErrorCode err = txn_kv_->create_txn(&txn);
         if (err != TxnErrorCode::TXN_OK) {
@@ -2323,7 +2324,7 @@ int InstanceChecker::do_restore_job_check() {
                 break;
             }
         }
-    } while (it->more() && !stopped());
+    }
     return 0;
 }
 
@@ -2753,7 +2754,7 @@ int InstanceChecker::do_packed_file_check() {
         std::string end_key = meta_rowset_key({instance_id_, INT64_MAX, 0});
 
         std::unique_ptr<RangeGetIterator> it;
-        do {
+        while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
             if (stopped()) {
                 return -1;
             }
@@ -2799,7 +2800,7 @@ int InstanceChecker::do_packed_file_check() {
                 }
             }
             start_key.push_back('\x00'); // Update to next smallest key for iteration
-        } while (it->more() && !stopped());
+        }
     }
 
     // Step 2: Scan all packed file metadata and verify
diff --git a/cloud/src/recycler/meta_checker.cpp b/cloud/src/recycler/meta_checker.cpp
index 3fbd8ab451d417..2b37143713022b 100644
--- a/cloud/src/recycler/meta_checker.cpp
+++ b/cloud/src/recycler/meta_checker.cpp
@@ -55,7 +55,7 @@ bool MetaChecker::scan_and_handle_kv(
         return false;
     }
     std::unique_ptr<RangeGetIterator> it;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         err = txn->get(start_key, end_key, &it);
         if (err != TxnErrorCode::TXN_OK) {
             LOG(WARNING) << "failed to get tablet idx, ret=" << err;
@@ -71,7 +71,7 @@ bool MetaChecker::scan_and_handle_kv(
             }
         }
         start_key.push_back('\x00');
-    } while (it->more());
+    }
     return true;
 }
 
diff --git a/cloud/src/recycler/recycler.cpp b/cloud/src/recycler/recycler.cpp
index eabe17dce34cb9..372b518e7603db 100644
--- a/cloud/src/recycler/recycler.cpp
+++ b/cloud/src/recycler/recycler.cpp
@@ -4881,11 +4881,11 @@ int InstanceRecycler::scan_and_recycle(
     };
 
     std::unique_ptr<RangeGetIterator> it;
-    do {
+    while (it == nullptr /* may be not init */ || (it->more() && !stopped())) {
         if (get_range_retried > 1000) {
-            err = "txn_get exceeds max retry, may not scan all keys";
-            ret = -1;
-            return -1;
+            err = "txn_get exceeds max retry(1000), may not scan all keys";
+            ret = -3;
+            return ret;
         }
         int get_ret = txn_get(txn_kv_.get(), begin, end, it);
         if (get_ret != 0) { // txn kv may complain "Request for future version"
@@ -4908,19 +4908,19 @@ int InstanceRecycler::scan_and_recycle(
                 begin = k;
                 VLOG_DEBUG << "iterator has no more kvs. key=" << hex(k);
             }
-            // if we want to continue scanning, the recycle_func should not return non-zero
+            // FIXME(gavin): if we want to continue scanning, the recycle_func should not return non-zero
             if (recycle_func(k, v) != 0) {
                 err = "recycle_func error";
                 ret = -1;
             }
         }
         begin.push_back('\x00'); // Update to next smallest key for iteration
-        // if we want to continue scanning, the recycle_func should not return non-zero
+        // FIXME(gavin): if we want to continue scanning, the loop_done should not return non-zero
         if (loop_done && loop_done() != 0) {
             err = "loop_done error";
             ret = -1;
         }
-    } while (it->more() && !stopped());
+    }
     return ret;
 }
 
diff --git a/cloud/src/recycler/recycler.h b/cloud/src/recycler/recycler.h
index a9f2b2c662d4b2..5d961c240d7a6a 100644
--- a/cloud/src/recycler/recycler.h
+++ b/cloud/src/recycler/recycler.h
@@ -410,10 +410,15 @@ class InstanceRecycler {
     int init_storage_vault_accessors();
 
     /**
-     * Scan key-value pairs between [`begin`, `end`), and perform `recycle_func` on each key-value pair.
+     * Scan key-value pairs between [`begin`, `end`) with multiple rounds of range get(`RangeGetIterator`),
+     * and perform `recycle_func` on each key-value pair.
      *
-     * @param recycle_func defines how to recycle resources corresponding to a key-value pair. Returns 0 if the recycling is successful.
-     * @param loop_done is called after `RangeGetIterator` has no next kv. Usually used to perform a batch recycling. Returns 0 if success. 
+     * @param recycle_func defines how to recycle resources corresponding to a key-value pair.
+     *                     The scan will stop if recycle_func() returns non-zero.
+     *                     recycle_func() returns 0 if the recycling is successful or the scan can continue with ignorable errors.
+     * @param loop_done is called after a round (`RangeGetIterator`) in the scan has no next kv. Usually used to perform a batch recycling.
+     *                  The scan will stop if loop_done() returns non-zero.
+     *                  loop_done() returns 0 if the recycling is successful or the scan can continue with ignorable errors.
      * @return 0 if all corresponding resources are recycled successfully, otherwise non-zero
      */
     int scan_and_recycle(std::string begin, std::string_view end,
diff --git a/cloud/src/recycler/util.cpp b/cloud/src/recycler/util.cpp
index 3666b6836e6c9c..e419ad221ba821 100644
--- a/cloud/src/recycler/util.cpp
+++ b/cloud/src/recycler/util.cpp
@@ -48,7 +48,7 @@ int get_all_instances(TxnKv* txn_kv, std::vector<InstanceInfoPB>& res) {
     }
 
     std::unique_ptr<RangeGetIterator> it;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         TxnErrorCode err = txn->get(key0, key1, &it);
         if (err != TxnErrorCode::TXN_OK) {
             LOG(WARNING) << "failed to get instance, err=" << err;
@@ -67,7 +67,7 @@ int get_all_instances(TxnKv* txn_kv, std::vector<InstanceInfoPB>& res) {
             res.push_back(std::move(instance_info));
         }
         key0.push_back('\x00'); // Update to next smallest key for iteration
-    } while (it->more());
+    }
 
     return 0;
 }
diff --git a/cloud/src/resource-manager/resource_manager.cpp b/cloud/src/resource-manager/resource_manager.cpp
index 6af1673bd45677..7c20f06dfbcbb6 100644
--- a/cloud/src/resource-manager/resource_manager.cpp
+++ b/cloud/src/resource-manager/resource_manager.cpp
@@ -64,7 +64,7 @@ int ResourceManager::init() {
     std::vector<std::tuple<std::string, InstanceInfoPB>> instances;
     int limit = 10000;
     TEST_SYNC_POINT_CALLBACK("ResourceManager:init:limit", &limit);
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         TxnErrorCode err = txn->get(key0, key1, &it, false, limit);
         TEST_SYNC_POINT_CALLBACK("ResourceManager:init:get_err", &err);
         if (err == TxnErrorCode::TXN_TOO_OLD) {
@@ -105,7 +105,7 @@ int ResourceManager::init() {
             ++num_instances;
         }
         key0.push_back('\x00'); // Update to next smallest key for iteration
-    } while (it->more());
+    }
 
     std::unique_lock l(mtx_);
     for (auto& [inst_id, inst] : instances) {
diff --git a/cloud/test/mem_txn_kv_test.cpp b/cloud/test/mem_txn_kv_test.cpp
index f9012fb144d438..8813264732405b 100644
--- a/cloud/test/mem_txn_kv_test.cpp
+++ b/cloud/test/mem_txn_kv_test.cpp
@@ -1301,7 +1301,7 @@ TEST(TxnMemKvTest, ReverseFullRangeGet) {
             std::string begin = range_begin, end = range_end;
 
             std::unique_ptr<RangeGetIterator> it;
-            do {
+            while (it == nullptr /* may be not init */ || it->more()) {
                 err = txn->get(begin, end, &it, options);
                 ASSERT_EQ(err, TxnErrorCode::TXN_OK);
 
@@ -1312,7 +1312,7 @@ TEST(TxnMemKvTest, ReverseFullRangeGet) {
                 // Get next begin key for reverse range get
                 end = it->last_key();
                 options.end_key_selector = RangeKeySelector::FIRST_GREATER_OR_EQUAL;
-            } while (it->more());
+            }
         }
 
         std::vector<std::string> actual_keys;
diff --git a/cloud/test/meta_service_test.cpp b/cloud/test/meta_service_test.cpp
index 266bc7efb92160..0e89d2d91809df 100644
--- a/cloud/test/meta_service_test.cpp
+++ b/cloud/test/meta_service_test.cpp
@@ -3671,9 +3671,8 @@ TEST(MetaServiceTest, CopyJobTest) {
             copy_file_key(key_info0, &key0);
             copy_file_key(key_info1, &key1);
             std::unique_ptr<RangeGetIterator> it;
-            ASSERT_EQ(txn->get(key0, key1, &it), TxnErrorCode::TXN_OK);
             int file_cnt = 0;
-            do {
+            while (it == nullptr /* may be not init */ || it->more()) {
                 ASSERT_EQ(txn->get(key0, key1, &it), TxnErrorCode::TXN_OK);
                 while (it->has_next()) {
                     auto [k, v] = it->next();
@@ -3686,7 +3685,7 @@ TEST(MetaServiceTest, CopyJobTest) {
                     }
                 }
                 key0.push_back('\x00');
-            } while (it->more());
+            }
             ASSERT_EQ(file_cnt, 20);
         }
         // 1 copy job with finish status
@@ -3699,7 +3698,7 @@ TEST(MetaServiceTest, CopyJobTest) {
             copy_job_key(key_info1, &key1);
             std::unique_ptr<RangeGetIterator> it;
             int job_cnt = 0;
-            do {
+            while (it == nullptr /* may be not init */ || it->more()) {
                 ASSERT_EQ(txn->get(key0, key1, &it), TxnErrorCode::TXN_OK);
                 while (it->has_next()) {
                     auto [k, v] = it->next();
@@ -3713,7 +3712,7 @@ TEST(MetaServiceTest, CopyJobTest) {
                     }
                 }
                 key0.push_back('\x00');
-            } while (it->more());
+            }
             ASSERT_EQ(job_cnt, 1);
         }
     }
@@ -4160,9 +4159,8 @@ TEST(MetaServiceTest, StageTest) {
             std::string get_val;
             ASSERT_EQ(meta_service->txn_kv()->create_txn(&txn), TxnErrorCode::TXN_OK);
             std::unique_ptr<RangeGetIterator> it;
-            ASSERT_EQ(txn->get(key0, key1, &it), TxnErrorCode::TXN_OK);
             int stage_cnt = 0;
-            do {
+            while (it == nullptr /* may be not init */ || it->more()) {
                 ASSERT_EQ(txn->get(key0, key1, &it), TxnErrorCode::TXN_OK);
                 while (it->has_next()) {
                     auto [k, v] = it->next();
@@ -4172,7 +4170,7 @@ TEST(MetaServiceTest, StageTest) {
                     }
                 }
                 key0.push_back('\x00');
-            } while (it->more());
+            }
             ASSERT_EQ(stage_cnt, 1);
         }
 
diff --git a/cloud/test/recycler_test.cpp b/cloud/test/recycler_test.cpp
index abb1d7069988e3..33264d048d12ba 100644
--- a/cloud/test/recycler_test.cpp
+++ b/cloud/test/recycler_test.cpp
@@ -1215,7 +1215,7 @@ static int get_copy_file_num(TxnKv* txn_kv, const std::string& stage_id, int64_t
         return -1;
     }
     std::unique_ptr<RangeGetIterator> it;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         if (txn->get(key0, key1, &it) != TxnErrorCode::TXN_OK) {
             return -1;
         }
@@ -1224,7 +1224,7 @@ static int get_copy_file_num(TxnKv* txn_kv, const std::string& stage_id, int64_t
             ++(*file_num);
         }
         key0.push_back('\x00');
-    } while (it->more());
+    }
     return 0;
 }
 
@@ -1242,14 +1242,14 @@ static void check_delete_bitmap_keys_size(TxnKv* txn_kv, int64_t tablet_id, int
         dbm_end_key = meta_delete_bitmap_key({instance_id, tablet_id + 1, "", 0, 0});
     }
     int size = 0;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         ASSERT_EQ(txn->get(dbm_start_key, dbm_end_key, &it), TxnErrorCode::TXN_OK);
         while (it->has_next()) {
             it->next();
             size++;
         }
         dbm_start_key = it->next_begin_key();
-    } while (it->more());
+    }
     EXPECT_EQ(size, expected_size);
 }
 
@@ -3818,7 +3818,7 @@ TEST(CheckerTest, abnormal_inverted_check_index_file_v1) {
     DCHECK_EQ(err, TxnErrorCode::TXN_OK) << err;
 
     std::unique_ptr<RangeGetIterator> it;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         err = txn->get(meta_rowset_key_begin, meta_rowset_key_end, &it);
         while (it->has_next()) {
             auto [k, v] = it->next();
@@ -3830,7 +3830,7 @@ TEST(CheckerTest, abnormal_inverted_check_index_file_v1) {
             }
         }
         meta_rowset_key_begin.push_back('\x00');
-    } while (it->more());
+    }
 
     for (const auto& key : rowset_key_to_delete) {
         std::unique_ptr<Transaction> txn;
@@ -3903,7 +3903,7 @@ TEST(CheckerTest, abnormal_inverted_check_index_file_v2) {
     DCHECK_EQ(err, TxnErrorCode::TXN_OK) << err;
 
     std::unique_ptr<RangeGetIterator> it;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         err = txn->get(meta_rowset_key_begin, meta_rowset_key_end, &it);
         while (it->has_next()) {
             auto [k, v] = it->next();
@@ -3915,7 +3915,7 @@ TEST(CheckerTest, abnormal_inverted_check_index_file_v2) {
             }
         }
         meta_rowset_key_begin.push_back('\x00');
-    } while (it->more());
+    }
 
     for (const auto& key : rowset_key_to_delete) {
         std::unique_ptr<Transaction> txn;
@@ -7318,7 +7318,7 @@ void check_multiple_txn_info_kvs(std::shared_ptr<cloud::TxnKv> txn_kv, int64_t s
     int64_t total_kv = 0;
 
     std::unique_ptr<RangeGetIterator> it;
-    do {
+    while (it == nullptr /* may be not init */ || it->more()) {
         int get_ret = txn_get(txn_kv.get(), begin, end, it);
         if (get_ret != 0) { // txn kv may complain "Request for future version"
             LOG(WARNING) << "failed to get kv, range=[" << hex(begin) << "," << hex(end)
@@ -7340,7 +7340,7 @@ void check_multiple_txn_info_kvs(std::shared_ptr<cloud::TxnKv> txn_kv, int64_t s
             total_kv++;
         }
         begin.push_back('\x00'); // Update to next smallest key for iteration
-    } while (it->more());
+    }
     ASSERT_EQ(total_kv, size);
 }
 
@@ -7416,12 +7416,12 @@ TEST(RecyclerTest, concurrent_recycle_txn_label_failure_test) {
     DORIS_CLOUD_DEFER {
         SyncPoint::get_instance()->clear_all_call_backs();
     };
+    size_t recycle_txn_info_keys_cnt = 0;
     sp->set_call_back("InstanceRecycler::recycle_expired_txn_label.check_recycle_txn_info_keys",
-                      [](auto&& args) {
+                      [&](auto&& args) {
                           auto* recycle_txn_info_keys =
                                   try_any_cast<std::vector<std::string>*>(args[0]);
-
-                          ASSERT_LE(recycle_txn_info_keys->size(), 10000);
+                          recycle_txn_info_keys_cnt = recycle_txn_info_keys->size();
                       });
     sp->set_call_back("InstanceRecycler::recycle_expired_txn_label.failure", [](auto&& args) {
         auto* ret = try_any_cast<int*>(args[0]);
@@ -7440,7 +7440,7 @@ TEST(RecyclerTest, concurrent_recycle_txn_label_failure_test) {
     std::cout << "recycle expired txn label cost="
               << std::chrono::duration_cast<std::chrono::milliseconds>(finish - start).count()
               << "ms" << std::endl;
-    check_multiple_txn_info_kvs(txn_kv, 5000);
+    check_multiple_txn_info_kvs(txn_kv, (20000 - recycle_txn_info_keys_cnt));
 }
 TEST(RecyclerTest, concurrent_recycle_txn_label_conflict_test) {
     config::label_keep_max_second = 0;
diff --git a/cloud/test/txn_kv_test.cpp b/cloud/test/txn_kv_test.cpp
index 7be9845bc46ae4..b0ff5b24da41f0 100644
--- a/cloud/test/txn_kv_test.cpp
+++ b/cloud/test/txn_kv_test.cpp
@@ -982,7 +982,7 @@ TEST(TxnKvTest, FullRangeGetIterator) {
         auto inner_begin = begin;
         cnt = 0;
         start = std::chrono::steady_clock::now();
-        do {
+        while (inner_it == nullptr /* may be not init */ || inner_it->more()) {
             err = txn->get(inner_begin, end, &inner_it, false, 11);
             ASSERT_EQ(err, TxnErrorCode::TXN_OK);
             if (!inner_it->has_next()) {
@@ -998,7 +998,7 @@ TEST(TxnKvTest, FullRangeGetIterator) {
                 }
             }
             inner_begin.push_back('\x00'); // Update to next smallest key for iteration
-        } while (inner_it->more());
+        }
         finish = std::chrono::steady_clock::now();
         EXPECT_EQ(cnt, 100);
         std::cout << "RangeGetIterator cost="
@@ -1312,7 +1312,7 @@ TEST(TxnKvTest, ReverseFullRangeGet) {
             std::string begin = range_begin, end = range_end;
 
             std::unique_ptr<RangeGetIterator> it;
-            do {
+            while (it == nullptr /* may be not init */ || it->more()) {
                 err = txn->get(begin, end, &it, options);
                 ASSERT_EQ(err, TxnErrorCode::TXN_OK);
 
@@ -1323,7 +1323,7 @@ TEST(TxnKvTest, ReverseFullRangeGet) {
                 // Get next begin key for reverse range get
                 end = it->last_key();
                 options.end_key_selector = RangeKeySelector::FIRST_GREATER_OR_EQUAL;
-            } while (it->more());
+            }
         }
 
         std::vector<std::string> actual_keys;
@@ -1419,7 +1419,7 @@ TEST(TxnKvTest, ReverseFullRangeGet2) {
             std::string begin = range_begin, end = range_end;
 
             std::unique_ptr<RangeGetIterator> it;
-            do {
+            while (it == nullptr /* may be not init */ || it->more()) {
                 err = txn->get(begin, end, &it, options);
                 ASSERT_EQ(err, TxnErrorCode::TXN_OK);
 
@@ -1430,7 +1430,7 @@ TEST(TxnKvTest, ReverseFullRangeGet2) {
                 // Get next begin key for reverse range get
                 end = it->last_key();
                 options.end_key_selector = RangeKeySelector::FIRST_GREATER_OR_EQUAL;
-            } while (it->more());
+            }
         }
 
         std::vector<std::string> actual_keys;