[CP] Fix circular wait between row lock and tenant rpc thread

oceanbase · Nov 8, 2023 · cd1eea4 · cd1eea4
1 parent 5198a80
commit cd1eea4
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Showing 4 changed files with 18 additions and 7 deletions.
diff --git a/src/rootserver/ddl_task/ob_ddl_task.cpp b/src/rootserver/ddl_task/ob_ddl_task.cpp
@@ -3253,7 +3253,7 @@ int ObDDLTaskRecordOperator::select_for_update(
   } else {
     SMART_VAR(ObMySQLProxy::MySQLResult, res) {
       sqlclient::ObMySQLResult *result = NULL;
-      if (OB_FAIL(sql_string.assign_fmt("SELECT status, execution_id FROM %s WHERE task_id = %lu FOR UPDATE",
+      if (OB_FAIL(sql_string.assign_fmt("SELECT status, execution_id FROM %s WHERE task_id = %lu FOR UPDATE NOWAIT",
           OB_ALL_DDL_TASK_STATUS_TNAME, task_id))) {
         LOG_WARN("assign sql string failed", K(ret), K(task_id), K(tenant_id));
       } else if (OB_FAIL(trans.read(res, tenant_id, sql_string.ptr()))) {

diff --git a/src/share/ob_global_stat_proxy.cpp b/src/share/ob_global_stat_proxy.cpp
@@ -483,27 +483,35 @@ int ObGlobalStatProxy::get(
   return ret;
 }
 
+int ObGlobalStatProxy::select_snapshot_gc_scn_for_update_nowait(
+    common::ObISQLClient &sql_client,
+    const uint64_t tenant_id,
+    SCN &snapshot_gc_scn)
+{
+  return inner_get_snapshot_gc_scn_(sql_client, tenant_id, snapshot_gc_scn, "FOR UPDATE NOWAIT");
+}
+
 int ObGlobalStatProxy::select_snapshot_gc_scn_for_update(
     common::ObISQLClient &sql_client,
     const uint64_t tenant_id,
     SCN &snapshot_gc_scn)
 {
-  return inner_get_snapshot_gc_scn_(sql_client, tenant_id, snapshot_gc_scn, true);
+  return inner_get_snapshot_gc_scn_(sql_client, tenant_id, snapshot_gc_scn, "FOR UPDATE");
 }
 
 int ObGlobalStatProxy::get_snapshot_gc_scn(
     common::ObISQLClient &sql_client,
     const uint64_t tenant_id,
     SCN &snapshot_gc_scn)
 {
-  return inner_get_snapshot_gc_scn_(sql_client, tenant_id, snapshot_gc_scn, false);
+  return inner_get_snapshot_gc_scn_(sql_client, tenant_id, snapshot_gc_scn, "");
 }
 
 int ObGlobalStatProxy::inner_get_snapshot_gc_scn_(
     common::ObISQLClient &sql_client,
     const uint64_t tenant_id,
     SCN &snapshot_gc_scn,
-    const bool is_for_update)
+    const char *for_update_str)
 {
   int ret = OB_SUCCESS;
   uint64_t snapshot_gc_scn_val = 0;
@@ -512,7 +520,7 @@ int ObGlobalStatProxy::inner_get_snapshot_gc_scn_(
     ObSqlString sql;
     if (OB_FAIL(sql.assign_fmt(
                 "SELECT column_value FROM %s WHERE TABLE_NAME = '__all_global_stat' AND COLUMN_NAME"
-                " = 'snapshot_gc_scn' %s", OB_ALL_CORE_TABLE_TNAME, (is_for_update ? "FOR UPDATE" : "")))) {
+                " = 'snapshot_gc_scn' %s", OB_ALL_CORE_TABLE_TNAME, for_update_str))) {
       LOG_WARN("assign sql failed", K(ret));
     } else if (OB_FAIL(sql_client.read(res, tenant_id, sql.ptr()))) {
       LOG_WARN("execute sql failed", K(ret), K(sql));

diff --git a/src/share/ob_global_stat_proxy.h b/src/share/ob_global_stat_proxy.h
@@ -82,6 +82,9 @@ class ObGlobalStatProxy
 
   virtual int get_snapshot_info(int64_t &snapshot_gc_scn,
                                 int64_t &gc_schema_version);
+  static int select_snapshot_gc_scn_for_update_nowait(common::ObISQLClient &sql_client,
+                                               const uint64_t tenant_id,
+                                               SCN &snapshot_gc_scn);
   static int select_snapshot_gc_scn_for_update(common::ObISQLClient &sql_client,
                                                const uint64_t tenant_id,
                                                SCN &snapshot_gc_scn);
@@ -107,7 +110,7 @@ class ObGlobalStatProxy
   static int inner_get_snapshot_gc_scn_(common::ObISQLClient &sql_client,
                                         const uint64_t tenant_id,
                                         SCN &snapshot_gc_scn,
-                                        const bool is_for_update);
+                                        const char *for_update_str);
   int update(const ObGlobalStatItem::ItemList &list, const bool is_incremental = false);
   int get(ObGlobalStatItem::ItemList &list, bool for_update = false);
 

diff --git a/src/share/ob_snapshot_table_proxy.cpp b/src/share/ob_snapshot_table_proxy.cpp
@@ -204,7 +204,7 @@ int ObSnapshotTableProxy::batch_add_snapshot(
     info.snapshot_scn_ = snapshot_scn;
     info.schema_version_ = schema_version;
     info.comment_ = comment;
-    if (OB_FAIL(ObGlobalStatProxy::select_snapshot_gc_scn_for_update(trans, tenant_id, snapshot_gc_scn))) {
+    if (OB_FAIL(ObGlobalStatProxy::select_snapshot_gc_scn_for_update_nowait(trans, tenant_id, snapshot_gc_scn))) {
       LOG_WARN("fail to select gc timstamp for update", KR(ret), K(info), K(tenant_id));
     }
     while (OB_SUCC(ret) && report_idx < tablet_id_array.count()) {