[refactor](loadmemlimit) remove load memlimit since it is never used (apache#39536)

It is needed to pick to branch 21, because we will depend on it to do
spill disk.

Co-authored-by: yiguolei <yiguolei@gmail.com>

Author: yiguolei

be/src/runtime/runtime_state.cpp

@@ -463,15 +463,6 @@ Status RuntimeState::append_error_msg_to_file(std::function<std::string()> line,
     return Status::OK();
 }
 
-int64_t RuntimeState::get_load_mem_limit() {
-    // TODO: the code is abandoned, it can be deleted after v1.3
-    if (_query_options.__isset.load_mem_limit && _query_options.load_mem_limit > 0) {
-        return _query_options.load_mem_limit;
-    } else {
-        return _query_mem_tracker->limit();
-    }
-}
-
 void RuntimeState::resize_op_id_to_local_state(int operator_size) {
     _op_id_to_local_state.resize(-operator_size);
 }

be/src/runtime/runtime_state.h

@@ -466,10 +466,6 @@ class RuntimeState {
 
     std::vector<TErrorTabletInfo>& error_tablet_infos() { return _error_tablet_infos; }
 
-    // get mem limit for load channel
-    // if load mem limit is not set, or is zero, using query mem limit instead.
-    int64_t get_load_mem_limit();
-
     // local runtime filter mgr, the runtime filter do not have remote target or
     // not need local merge should regist here. the instance exec finish, the local
     // runtime filter mgr can release the memory of local runtime filter

be/src/vec/sink/writer/vtablet_writer.cpp

@@ -413,7 +413,6 @@ void VNodeChannel::_open_internal(bool is_incremental) {
 
     request->set_num_senders(_parent->_num_senders);
     request->set_need_gen_rollup(false); // Useless but it is a required field in pb
-    request->set_load_mem_limit(_parent->_load_mem_limit);
     request->set_load_channel_timeout_s(_parent->_load_channel_timeout_s);
     request->set_is_high_priority(_parent->_is_high_priority);
     request->set_sender_ip(BackendOptions::get_localhost());
@@ -1245,7 +1244,6 @@ Status VTabletWriter::_init(RuntimeState* state, RuntimeProfile* profile) {
     _max_wait_exec_timer = ADD_TIMER(profile, "MaxWaitExecTime");
     _add_batch_number = ADD_COUNTER(profile, "NumberBatchAdded", TUnit::UNIT);
     _num_node_channels = ADD_COUNTER(profile, "NumberNodeChannels", TUnit::UNIT);
-    _load_mem_limit = state->get_load_mem_limit();
 
 #ifdef DEBUG
     // check: tablet ids should be unique

be/src/vec/sink/writer/vtablet_writer.h

@@ -660,9 +660,6 @@ class VTabletWriter final : public AsyncResultWriter {
     RuntimeProfile::Counter* _add_batch_number = nullptr;
     RuntimeProfile::Counter* _num_node_channels = nullptr;
 
-    // load mem limit is for remote load channel
-    int64_t _load_mem_limit = -1;
-
     // the timeout of load channels opened by this tablet sink. in second
     int64_t _load_channel_timeout_s = 0;
 

fe/fe-core/src/main/java/org/apache/doris/load/loadv2/LoadLoadingTask.java

@@ -152,14 +152,6 @@ private void executeOnce() throws Exception {
         curCoordinator.setExecMemoryLimit(execMemLimit);
         curCoordinator.setExecPipEngine(Config.enable_pipeline_load);
 
-        /*
-         * For broker load job, user only need to set mem limit by 'exec_mem_limit' property.
-         * And the variable 'load_mem_limit' does not make any effect.
-         * However, in order to ensure the consistency of semantics when executing on the BE side,
-         * and to prevent subsequent modification from incorrectly setting the load_mem_limit,
-         * here we use exec_mem_limit to directly override the load_mem_limit property.
-         */
-        curCoordinator.setLoadMemLimit(execMemLimit);
         curCoordinator.setMemTableOnSinkNode(enableMemTableOnSinkNode);
 
         long leftTimeMs = getLeftTimeMs();