[CP][Bugfix][OBKV]fix session pool hold too much memory when login frequently

src/observer/table/ob_table_session_pool.cpp

@@ -33,7 +33,7 @@ int ObTableApiSessPoolMgr::mtl_init(ObTableApiSessPoolMgr *&mgr)
 
 /*
   start tableapi retired session task
-  - 60 second interval
+  - 5 second interval
   - repeated
 */
 int ObTableApiSessPoolMgr::start()
@@ -45,7 +45,7 @@ int ObTableApiSessPoolMgr::start()
     LOG_WARN("table api session pool mgr isn't inited", K(ret));
   } else if (OB_FAIL(TG_SCHEDULE(MTL(omt::ObSharedTimer*)->get_tg_id(),
                                  elimination_task_,
-                                 ELIMINATE_SESSION_DELAY/* 60s */,
+                                 ELIMINATE_SESSION_DELAY/* 5s */,
                                  true/* repeat */))) {
     LOG_WARN("failed to schedule tableapi retired session task", K(ret));
   } else {
@@ -377,7 +377,7 @@ int ObTableApiSessPool::move_node_to_retired_list(ObTableApiSessNode *node)
   1. remove session val in free_list.
   2. remove session node from retired_nodes_ when node is empty.
   3. free node memory.
-  4. delete 1000 session nodes per times
+  4. delete 2000 session nodes per times
 */
 int ObTableApiSessPool::evict_retired_sess()
 {
@@ -387,7 +387,7 @@ int ObTableApiSessPool::evict_retired_sess()
   ObLockGuard<ObSpinLock> guard(retired_nodes_lock_); // lock retired_nodes_
 
   DLIST_FOREACH_REMOVESAFE_X(node, retired_nodes_, delete_count < BACKCROUND_TASK_DELETE_SESS_NUM) {
-    if (cur_time - node->get_last_active_ts() < SESS_RETIRE_TIME) {
+    if (cur_time - node->get_last_active_ts() < SESS_UPDATE_TIME_INTERVAL) {
       // do nothing, this node maybe is from ObTableApiSessNodeReplaceOp, some threads maybe is using it.
       // we remove it next retire task.
     } else if (OB_FAIL(node->remove_unused_sess())) {
@@ -545,23 +545,31 @@ int ObTableApiSessPool::create_and_add_node_safe(ObTableApiCredential &credentia
 /*
   1. only call in login
   2. move old to retired list when node exist, create new node otherwise.
+  3. if the update interval is less than 5 seconds, ignore this update.
 */
 int ObTableApiSessPool::update_sess(ObTableApiCredential &credential)
 {
   int ret = OB_SUCCESS;
-
   ObTableApiSessNode *node = nullptr;
   const uint64_t key = credential.hash_val_;
+  int64_t cur_time = ObTimeUtility::current_time();
+
   if (OB_FAIL(get_sess_node(key, node))) {
     if (OB_HASH_NOT_EXIST == ret) { // not exist, create
       if (OB_FAIL(create_and_add_node_safe(credential))) {
         LOG_WARN("fail to create and add node", K(ret), K(credential));
+      } else {
+        ATOMIC_STORE(&last_update_ts_, cur_time);
       }
     } else {
       LOG_WARN("fail to get session node", K(ret), K(key));
     }
+  } else if (cur_time - last_update_ts_ < SESS_UPDATE_TIME_INTERVAL) {
+    // if the update interval is less than 5 seconds, ignore this update.
   } else if (OB_FAIL(replace_sess_node_safe(credential))) { // exist, create and replace old node
     LOG_WARN("fail to replace session node", K(ret), K(credential));
+  } else {
+    ATOMIC_STORE(&last_update_ts_, cur_time);
   }
 
   return ret;

src/observer/table/ob_table_session_pool.h

@@ -70,7 +70,7 @@ private:
   int create_session_pool_safe();
   int create_session_pool_unsafe();
 private:
-  static const int64_t ELIMINATE_SESSION_DELAY = 60 * 1000 * 1000; // 60s
+  static const int64_t ELIMINATE_SESSION_DELAY = 5 * 1000 * 1000; // 5s
   bool is_inited_;
   common::ObArenaAllocator allocator_;
   ObTableApiSessPool *pool_;
@@ -87,13 +87,15 @@ class ObTableApiSessPool final
 public:
   // key is ObTableApiCredential.hash_val_
   typedef common::hash::ObHashMap<uint64_t, ObTableApiSessNode*> CacheKeyNodeMap;
-  static const int64_t SESS_POOL_DEFAULT_BUCKET_NUM = 10; // 取决于客户端登录的用户数量
+  static const int64_t SESS_POOL_DEFAULT_BUCKET_NUM = 10; // default user number
-  static const int64_t SESS_RETIRE_TIME = 300 * 1000000; // 超过300s未被访问的session会被标记淘汰
+  static const int64_t SESS_RETIRE_TIME = 300 * 1000 * 1000; // marked as retired more than 300 seconds are not accessed
-  static const int64_t BACKCROUND_TASK_DELETE_SESS_NUM = 1000; // 后台任务每次删除淘汰的session node数量
+  static const int64_t BACKCROUND_TASK_DELETE_SESS_NUM = 2000; // number of eliminated session nodes in background task per time
+  static const int64_t SESS_UPDATE_TIME_INTERVAL = 5 * 1000 * 1000; // the update interval cannot exceed 5 seconds
 public:
   explicit ObTableApiSessPool()
       : allocator_("TbSessPool", OB_MALLOC_NORMAL_BLOCK_SIZE, MTL_ID()),
-        is_inited_(false)
+        is_inited_(false),
+        last_update_ts_(0)
   {}
   ~ObTableApiSessPool() { destroy(); };
   TO_STRING_KV(K_(is_inited),
@@ -120,6 +122,7 @@ private:
   // 前台login时、后台淘汰时都会操作retired_nodes_，因此需要加锁
   common::ObDList<ObTableApiSessNode> retired_nodes_;
   ObSpinLock retired_nodes_lock_; // for lock retired_nodes_
+  int64_t last_update_ts_;
 private:
   DISALLOW_COPY_AND_ASSIGN(ObTableApiSessPool);
 };

unittest/observer/table/test_table_sess_pool.cpp

@@ -170,8 +170,7 @@ TEST_F(TestTableSessPool, mgr_update_session)
   ASSERT_NE(nullptr, mgr->pool_);
   ASSERT_TRUE(mgr->pool_->is_inited_);
   ASSERT_EQ(1, mgr->pool_->key_node_map_.size());
-  ASSERT_EQ(1, mgr->pool_->retired_nodes_.size_);
+  ASSERT_EQ(0, mgr->pool_->retired_nodes_.size_);
-  ASSERT_EQ(node, mgr->pool_->retired_nodes_.get_last());
   ASSERT_EQ(OB_SUCCESS, mgr->pool_->get_sess_node(new_cred->hash_val_, node));
   ASSERT_NE(nullptr, node);
   ASSERT_TRUE(node->sess_lists_.free_list_.is_empty());
@@ -184,7 +183,7 @@ TEST_F(TestTableSessPool, mgr_update_session)
   ASSERT_NE(nullptr, mgr->pool_);
   ASSERT_TRUE(mgr->pool_->is_inited_);
   ASSERT_EQ(2, mgr->pool_->key_node_map_.size());
-  ASSERT_EQ(1, mgr->pool_->retired_nodes_.size_);
+  ASSERT_EQ(0, mgr->pool_->retired_nodes_.size_);
   ASSERT_EQ(OB_SUCCESS, mgr->pool_->get_sess_node(new_cred->hash_val_, node));
   ASSERT_NE(nullptr, node);
   ASSERT_TRUE(node->sess_lists_.free_list_.is_empty());