From 6e762be4fb91ef6366221fa706b07faced9b5dba Mon Sep 17 00:00:00 2001
From: Hongqin-Li <ihongqinli@gmail.com>
Date: Wed, 28 Dec 2022 13:38:07 +0000
Subject: [PATCH] Consider task count for ddl delay scheduling

---
 src/rootserver/ddl_task/ob_ddl_scheduler.cpp | 2 +-
 src/rootserver/ddl_task/ob_ddl_scheduler.h   | 1 +
 src/rootserver/ddl_task/ob_ddl_task.cpp      | 8 +++++---
 src/rootserver/ddl_task/ob_ddl_task.h        | 2 +-
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/rootserver/ddl_task/ob_ddl_scheduler.cpp b/src/rootserver/ddl_task/ob_ddl_scheduler.cpp
index b1e20482a..d4a9b32ca 100644
--- a/src/rootserver/ddl_task/ob_ddl_scheduler.cpp
+++ b/src/rootserver/ddl_task/ob_ddl_scheduler.cpp
@@ -337,7 +337,7 @@ void ObDDLScheduler::run1()
         } else {
           ObCurTraceId::set(task->get_trace_id());
           int task_ret = task->process();
-          task->calc_next_schedule_ts(task_ret);
+          task->calc_next_schedule_ts(task_ret, task_queue_.get_task_cnt());
           if (task->need_retry() && !has_set_stop()) {
             if (OB_FAIL(task_queue_.add_task_to_last(task))) {
               STORAGE_LOG(ERROR, "fail to add task to last, which should not happen", K(ret), K(*task));
diff --git a/src/rootserver/ddl_task/ob_ddl_scheduler.h b/src/rootserver/ddl_task/ob_ddl_scheduler.h
index 261791920..595665bfd 100644
--- a/src/rootserver/ddl_task/ob_ddl_scheduler.h
+++ b/src/rootserver/ddl_task/ob_ddl_scheduler.h
@@ -61,6 +61,7 @@ public:
   int add_task_to_last(ObDDLTask *task);
   int get_task(const ObDDLTaskKey &task_key, ObDDLTask *&task);
   int get_task(const int64_t task_id, ObDDLTask *&task);
+  int64_t get_task_cnt() const { return task_list_.get_size(); }
   void destroy();
 private:
   typedef common::ObDList<ObDDLTask> TaskList;
diff --git a/src/rootserver/ddl_task/ob_ddl_task.cpp b/src/rootserver/ddl_task/ob_ddl_task.cpp
index dee28b1b9..60348ec3e 100644
--- a/src/rootserver/ddl_task/ob_ddl_task.cpp
+++ b/src/rootserver/ddl_task/ob_ddl_task.cpp
@@ -623,13 +623,15 @@ int ObDDLTask::push_execution_id()
   return ret;
 }
 
-void ObDDLTask::calc_next_schedule_ts(int ret_code)
+// The length of [min_dt, max_dt] controls the execution rate of ddl tasks.
+void ObDDLTask::calc_next_schedule_ts(const int ret_code, const int64_t total_task_cnt)
 {
   if (OB_TIMEOUT == ret_code) {
     const int64_t SEC = 1000000;
-    delay_schedule_time_ = std::min(delay_schedule_time_ * 6/5 + SEC/10, 30*SEC);
+    const int64_t max_delay = total_task_cnt * ObDDLUtil::get_ddl_rpc_timeout() * 10;
+    delay_schedule_time_ = std::min(delay_schedule_time_ * 6/5 + SEC/10, max_delay);
     const int64_t max_dt = delay_schedule_time_;
-    const int64_t min_dt = std::max(0L, max_dt - 3*SEC);
+    const int64_t min_dt = max_dt / 2;
     next_schedule_ts_ = ObTimeUtility::current_time() + ObRandom::rand(min_dt, max_dt);
   } else {
     delay_schedule_time_ = 0;
diff --git a/src/rootserver/ddl_task/ob_ddl_task.h b/src/rootserver/ddl_task/ob_ddl_task.h
index 335a9d3e9..571ebaf2c 100644
--- a/src/rootserver/ddl_task/ob_ddl_task.h
+++ b/src/rootserver/ddl_task/ob_ddl_task.h
@@ -323,7 +323,7 @@ public:
   void set_sys_task_id(const TraceId &sys_task_id) { sys_task_id_ = sys_task_id; }
   void set_sql_exec_addr(const common::ObAddr &addr) { sql_exec_addr_ = addr; }
   const TraceId &get_sys_task_id() const { return sys_task_id_; }
-  void calc_next_schedule_ts(int ret_code);
+  void calc_next_schedule_ts(const int ret_code, const int64_t total_task_cnt);
   bool need_schedule() { return next_schedule_ts_ <= ObTimeUtility::current_time(); }
   bool is_replica_build_need_retry(const int ret_code);
   int push_execution_id();