branch-4.1: [perf](load) Optimize write performance with improved backpressure control

be/src/cloud/cloud_delta_writer.cpp

@@ -25,6 +25,8 @@
 #include "load/memtable/memtable_memory_limiter.h"
 #include "runtime/exec_env.h"
 #include "runtime/thread_context.h"
+#include "storage/adaptive_thread_pool_controller.h"
+#include "util/threadpool.h"
 
 namespace doris {
 
@@ -86,8 +88,18 @@ Status CloudDeltaWriter::write(const Block* block, const DorisVector<uint32_t>&
     CHECK(_is_init || _is_cancelled);
     {
         SCOPED_TIMER(_wait_flush_limit_timer);
-        while (_memtable_writer->flush_running_count() >=
-               config::memtable_flush_running_count_limit) {
+        auto* s3_file_upload_pool = rowset_builder()->is_s3_storage()
+                                            ? ExecEnv::GetInstance()->s3_file_upload_thread_pool()
+                                            : nullptr;
+        const auto need_backpressure = [this, s3_file_upload_pool] {
+            if (s3_file_upload_pool != nullptr) {
+                return s3_file_upload_pool->get_queue_size() >
+                       AdaptiveThreadPoolController::kS3QueueBusyThreshold;
+            }
+            return _memtable_writer->flush_running_count() >=
+                   config::memtable_flush_running_count_limit;
+        };
+        while (need_backpressure()) {
             std::this_thread::sleep_for(std::chrono::milliseconds(10));
         }
     }

be/src/cloud/cloud_rowset_builder.cpp

@@ -21,6 +21,7 @@
 #include "cloud/cloud_storage_engine.h"
 #include "cloud/cloud_tablet.h"
 #include "cloud/cloud_tablet_mgr.h"
+#include "io/fs/file_system.h"
 #include "storage/storage_policy.h"
 
 namespace doris {
@@ -135,6 +136,13 @@ const RowsetMetaSharedPtr& CloudRowsetBuilder::rowset_meta() {
     return _rowset_writer->rowset_meta();
 }
 
+bool CloudRowsetBuilder::is_s3_storage() const {
+    if (_rowset_writer == nullptr) {
+        return false;
+    }
+    return _rowset_writer->context().fs()->type() == io::FileSystemType::S3;
+}
+
 Status CloudRowsetBuilder::set_txn_related_info() {
     if (_tablet->enable_unique_key_merge_on_write()) {
         // For empty rowsets when skip_writing_empty_rowset_metadata=true,

be/src/cloud/cloud_rowset_builder.h

@@ -37,6 +37,8 @@ class CloudRowsetBuilder final : public BaseRowsetBuilder {
 
     const RowsetMetaSharedPtr& rowset_meta();
 
+    bool is_s3_storage() const;
+
     Status set_txn_related_info();
 
     void set_skip_writing_rowset_metadata(bool skip) { _skip_writing_rowset_metadata = skip; }