Merge branch 'mysql-5.7' into mysql-8.0

Author: karthik-kamath

sql/rpl_context.cc

@@ -132,6 +132,11 @@ bool Session_consistency_gtids_ctx::notify_after_gtid_executed_update(
   return res;
 }
 
+void Session_consistency_gtids_ctx::
+    update_tracking_activeness_from_session_variable(const THD *thd) {
+  m_curr_session_track_gtids = thd->variables.session_track_gtids;
+}
+
 bool Session_consistency_gtids_ctx::notify_after_response_packet(
     const THD *thd) {
   int res = false;
@@ -144,7 +149,7 @@ bool Session_consistency_gtids_ctx::notify_after_response_packet(
    this value. It may have changed (the previous command may have been
    a SET SESSION session_track_gtids=...;).
    */
-  m_curr_session_track_gtids = thd->variables.session_track_gtids;
+  update_tracking_activeness_from_session_variable(thd);
   return res;
 }
 
@@ -162,7 +167,7 @@ void Session_consistency_gtids_ctx::register_ctx_change_listener(
      if the session_track_gtids value is set at startup time to anything
      different than OFF.
      */
-    m_curr_session_track_gtids = thd->variables.session_track_gtids;
+    update_tracking_activeness_from_session_variable(thd);
   }
 }
 

sql/rpl_context.h

@@ -201,6 +201,11 @@ class Session_consistency_gtids_ctx {
     return notify_after_transaction_commit(thd);
   }
 
+  /**
+    Update session tracker (m_curr_session_track_gtids) from thd.
+  */
+  void update_tracking_activeness_from_session_variable(const THD *thd);
+
  private:
   // not implemented
   Session_consistency_gtids_ctx(const Session_consistency_gtids_ctx &rsc);

sql/rpl_slave.cc

@@ -3815,6 +3815,11 @@ void set_slave_thread_options(THD *thd) {
   thd->variables.option_bits = options;
   thd->variables.completion_type = 0;
 
+  /* Do not track GTIDs for slave threads to avoid performance issues. */
+  thd->variables.session_track_gtids = OFF;
+  thd->rpl_thd_ctx.session_gtids_ctx()
+      .update_tracking_activeness_from_session_variable(thd);
+
   /*
     Set autocommit= 1 when info tables are used and autocommit == 0 to
     avoid trigger asserts on mysql_execute_command(THD *thd) caused by