MDEV-4506: Parallel replication: Intermediate commit.

Fix some part of update of old-style coordinates in parallel replication:

 - Ignore XtraDB request for old-style coordinates, not meaningful for
   parallel replication (must use GTID to get crash-safe parallel slave).

 - Only update relay log coordinates forward, not backwards, to ensure
   that parallel threads do not conflict with each other.

 - Move future_event_relay_log_pos to rgi.

7 files changed, 69 insertions, 42 deletions

diff --git a/sql/log_event.cc b/sql/log_event.cc
index 55166b65df4..cd6da8baa22 100644
--- a/sql/log_event.cc
+++ b/sql/log_event.cc
@@ -3881,7 +3881,7 @@ int Query_log_event::do_apply_event(rpl_group_info *rgi,
       future-change-proof addon, e.g if COMMIT handling will start checking
       invariants like IN_STMT flag must be off at committing the transaction.
     */
-    const_cast<Relay_log_info*>(rli)->inc_event_relay_log_pos();
+    rgi->inc_event_relay_log_pos();
     const_cast<Relay_log_info*>(rli)->clear_flag(Relay_log_info::IN_STMT);
   }
   else
@@ -4249,7 +4249,6 @@ end:
 
 int Query_log_event::do_update_pos(rpl_group_info *rgi)
 {
-  Relay_log_info *rli= rgi->rli;
   /*
     Note that we will not increment group* positions if we are just
     after a SET ONE_SHOT, because SET ONE_SHOT should not be separated
@@ -4257,7 +4256,7 @@ int Query_log_event::do_update_pos(rpl_group_info *rgi)
   */
   if (thd->one_shot_set)
   {
-    rli->inc_event_relay_log_pos();
+    rgi->inc_event_relay_log_pos();
     return 0;
   }
   else
@@ -4864,7 +4863,6 @@ int Format_description_log_event::do_apply_event(rpl_group_info *rgi)
 
 int Format_description_log_event::do_update_pos(rpl_group_info *rgi)
 {
-  Relay_log_info *rli= rgi->rli;
   if (server_id == (uint32) global_system_variables.server_id)
   {
     /*
@@ -4880,7 +4878,7 @@ int Format_description_log_event::do_update_pos(rpl_group_info *rgi)
       Intvar_log_event instead of starting at a Table_map_log_event or
       the Intvar_log_event respectively.
      */
-    rli->inc_event_relay_log_pos();
+    rgi->inc_event_relay_log_pos();
     return 0;
   }
   else
@@ -5955,7 +5953,7 @@ int Rotate_log_event::do_update_pos(rpl_group_info *rgi)
                         (ulong) rli->group_master_log_pos));
     memcpy(rli->group_master_log_name, new_log_ident, ident_len+1);
     rli->notify_group_master_log_name_update();
-    rli->inc_group_relay_log_pos(pos, TRUE /* skip_lock */);
+    rli->inc_group_relay_log_pos(pos, rgi, TRUE /* skip_lock */);
     DBUG_PRINT("info", ("new group_master_log_name: '%s'  "
                         "new group_master_log_pos: %lu",
                         rli->group_master_log_name,
@@ -5978,7 +5976,7 @@ int Rotate_log_event::do_update_pos(rpl_group_info *rgi)
       thd->variables.auto_increment_offset= 1;
   }
   else
-    rli->inc_event_relay_log_pos();
+    rgi->inc_event_relay_log_pos();
 
 
   DBUG_RETURN(0);
@@ -6290,8 +6288,7 @@ Gtid_log_event::do_apply_event(rpl_group_info *rgi)
 int
 Gtid_log_event::do_update_pos(rpl_group_info *rgi)
 {
-  Relay_log_info *rli= rgi->rli;
-  rli->inc_event_relay_log_pos();
+  rgi->inc_event_relay_log_pos();
   return 0;
 }
 
@@ -6723,8 +6720,7 @@ int Intvar_log_event::do_apply_event(rpl_group_info *rgi)
 
 int Intvar_log_event::do_update_pos(rpl_group_info *rgi)
 {
-  Relay_log_info *rli= rgi->rli;
-  rli->inc_event_relay_log_pos();
+  rgi->inc_event_relay_log_pos();
   return 0;
 }
 
@@ -6820,8 +6816,7 @@ int Rand_log_event::do_apply_event(rpl_group_info *rgi)
 
 int Rand_log_event::do_update_pos(rpl_group_info *rgi)
 {
-  Relay_log_info *rli= rgi->rli;
-  rli->inc_event_relay_log_pos();
+  rgi->inc_event_relay_log_pos();
   return 0;
 }
 
@@ -7485,8 +7480,7 @@ int User_var_log_event::do_apply_event(rpl_group_info *rgi)
 
 int User_var_log_event::do_update_pos(rpl_group_info *rgi)
 {
-  Relay_log_info *rli= rgi->rli;
-  rli->inc_event_relay_log_pos();
+  rgi->inc_event_relay_log_pos();
   return 0;
 }
 
@@ -7717,11 +7711,11 @@ int Stop_log_event::do_update_pos(rpl_group_info *rgi)
     the target position when in fact we have not.
   */
   if (rli->get_flag(Relay_log_info::IN_TRANSACTION))
-    rli->inc_event_relay_log_pos();
+    rgi->inc_event_relay_log_pos();
   else
   {
     rpl_global_gtid_slave_state.record_and_update_gtid(thd, rgi);
-    rli->inc_group_relay_log_pos(0);
+    rli->inc_group_relay_log_pos(0, rgi);
     flush_relay_log_info(rli);
   }
   DBUG_RETURN(0);
@@ -9543,7 +9537,7 @@ Rows_log_event::do_update_pos(rpl_group_info *rgi)
   }
   else
   {
-    rli->inc_event_relay_log_pos();
+    rgi->inc_event_relay_log_pos();
   }
 
   DBUG_RETURN(error);
@@ -9767,8 +9761,7 @@ int Annotate_rows_log_event::do_apply_event(rpl_group_info *rgi)
 #if !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION)
 int Annotate_rows_log_event::do_update_pos(rpl_group_info *rgi)
 {
-  Relay_log_info *rli= rgi->rli;
-  rli->inc_event_relay_log_pos();
+  rgi->inc_event_relay_log_pos();
   return 0;
 }
 #endif
@@ -10395,8 +10388,7 @@ Table_map_log_event::do_shall_skip(rpl_group_info *rgi)
 
 int Table_map_log_event::do_update_pos(rpl_group_info *rgi)
 {
-  Relay_log_info *rli= rgi->rli;
-  rli->inc_event_relay_log_pos();
+  rgi->inc_event_relay_log_pos();
   return 0;
 }
 
@@ -11930,11 +11922,21 @@ bool rpl_get_position_info(const char **log_file_name, ulonglong *log_pos,
   return FALSE;
 #else
   const Relay_log_info *rli= &(active_mi->rli);
-  *log_file_name= rli->group_master_log_name;
-  *log_pos= rli->group_master_log_pos +
-    (rli->future_event_relay_log_pos - rli->group_relay_log_pos);
-  *group_relay_log_name= rli->group_relay_log_name;
-  *relay_log_pos= rli->future_event_relay_log_pos;
+  if (opt_slave_parallel_threads == 0)
+  {
+    *log_file_name= rli->group_master_log_name;
+    *log_pos= rli->group_master_log_pos +
+      (rli->future_event_relay_log_pos - rli->group_relay_log_pos);
+    *group_relay_log_name= rli->group_relay_log_name;
+    *relay_log_pos= rli->future_event_relay_log_pos;
+  }
+  else
+  {
+    *log_file_name= "";
+    *log_pos= 0;
+    *group_relay_log_name= "";
+    *relay_log_pos= 0;
+  }
   return TRUE;
 #endif
 }
diff --git a/sql/log_event_old.cc b/sql/log_event_old.cc
index 174219a8e72..cc212d6051b 100644
--- a/sql/log_event_old.cc
+++ b/sql/log_event_old.cc
@@ -1839,7 +1839,7 @@ Old_rows_log_event::do_update_pos(rpl_group_info *rgi)
   }
   else
   {
-    rli->inc_event_relay_log_pos();
+    rgi->inc_event_relay_log_pos();
   }
 
   DBUG_RETURN(error);
diff --git a/sql/rpl_parallel.cc b/sql/rpl_parallel.cc
index 19ae2a35339..fbf135c0bb6 100644
--- a/sql/rpl_parallel.cc
+++ b/sql/rpl_parallel.cc
@@ -64,6 +64,7 @@ rpt_handle_event(rpl_parallel_thread::queued_event *qev,
   /* ToDo: Access to thd, and what about rli, split out a parallel part? */
   mysql_mutex_lock(&rli->data_lock);
   qev->ev->thd= thd;
+  rgi->future_event_relay_log_pos= qev->future_event_relay_log_pos;
   err= apply_event_and_update_pos(qev->ev, thd, rgi, rpt);
   thd->rgi_slave= NULL;
 
@@ -659,6 +660,7 @@ rpl_parallel::do_event(rpl_group_info *serial_rgi, Log_event *ev)
   }
   qev->ev= ev;
   qev->next= NULL;
+  qev->future_event_relay_log_pos= rli->future_event_relay_log_pos;
 
   if (typ == GTID_EVENT)
   {
diff --git a/sql/rpl_parallel.h b/sql/rpl_parallel.h
index b9106392faf..7830470a929 100644
--- a/sql/rpl_parallel.h
+++ b/sql/rpl_parallel.h
@@ -23,6 +23,7 @@ struct rpl_parallel_thread {
     queued_event *next;
     Log_event *ev;
     rpl_group_info *rgi;
+    ulonglong future_event_relay_log_pos;
   } *event_queue, *last_in_queue;
 };
 
diff --git a/sql/rpl_rli.cc b/sql/rpl_rli.cc
index 53481d2efaf..0ea6b1e5d13 100644
--- a/sql/rpl_rli.cc
+++ b/sql/rpl_rli.cc
@@ -869,17 +869,33 @@ improper_arguments: %d  timed_out: %d",
 
 
 void Relay_log_info::inc_group_relay_log_pos(ulonglong log_pos,
-                                                bool skip_lock)
+                                             rpl_group_info *rgi,
+                                             bool skip_lock)
 {
   DBUG_ENTER("Relay_log_info::inc_group_relay_log_pos");
 
   if (!skip_lock)
     mysql_mutex_lock(&data_lock);
-  inc_event_relay_log_pos();
-  group_relay_log_pos= event_relay_log_pos;
-  strmake_buf(group_relay_log_name,event_relay_log_name);
-
-  notify_group_relay_log_name_update();
+  rgi->inc_event_relay_log_pos();
+  if (opt_slave_parallel_threads > 0)
+  {
+    /* In case of parallel replication, do not update the position backwards. */
+    int cmp= strcmp(group_relay_log_name, event_relay_log_name);
+    if (cmp < 0)
+    {
+      group_relay_log_pos= event_relay_log_pos;
+      strmake_buf(group_relay_log_name, event_relay_log_name);
+      notify_group_relay_log_name_update();
+    } else if (cmp == 0 && group_relay_log_pos < event_relay_log_pos)
+      group_relay_log_pos= event_relay_log_pos;
+  }
+  else
+  {
+    /* Non-parallel case. */
+    group_relay_log_pos= event_relay_log_pos;
+    strmake_buf(group_relay_log_name, event_relay_log_name);
+    notify_group_relay_log_name_update();
+  }
 
   /*
     If the slave does not support transactions and replicates a transaction,
@@ -1226,10 +1242,10 @@ void Relay_log_info::stmt_done(my_off_t event_master_log_pos,
   */
   if ((rgi->thd->variables.option_bits & OPTION_BEGIN) &&
       opt_using_transactions)
-    inc_event_relay_log_pos();
+    rgi->inc_event_relay_log_pos();
   else
   {
-    inc_group_relay_log_pos(event_master_log_pos);
+    inc_group_relay_log_pos(event_master_log_pos, rgi);
     if (rpl_global_gtid_slave_state.record_and_update_gtid(thd, rgi))
     {
       report(WARNING_LEVEL, ER_CANNOT_UPDATE_GTID_STATE,
diff --git a/sql/rpl_rli.h b/sql/rpl_rli.h
index 68cd051be2a..92f65a1397d 100644
--- a/sql/rpl_rli.h
+++ b/sql/rpl_rli.h
@@ -351,13 +351,9 @@ public:
     if (until_condition==UNTIL_MASTER_POS)
       until_log_names_cmp_result= UNTIL_LOG_NAMES_CMP_UNKNOWN;
   }
-  
-  inline void inc_event_relay_log_pos()
-  {
-    event_relay_log_pos= future_event_relay_log_pos;
-  }
 
   void inc_group_relay_log_pos(ulonglong log_pos,
+			       rpl_group_info *rgi,
 			       bool skip_lock=0);
 
   int wait_for_pos(THD* thd, String* log_name, longlong log_pos, 
@@ -561,6 +557,8 @@ struct rpl_group_info
   */
   time_t last_event_start_time;
 
+  ulonglong future_event_relay_log_pos;
+
 private:
   /*
     Runtime state for printing a note when slave is taking
@@ -684,6 +682,13 @@ public:
   {
     return long_find_row_note_printed;
   }
+
+  inline void inc_event_relay_log_pos()
+  {
+    if (opt_slave_parallel_threads == 0 ||
+        rli->event_relay_log_pos < future_event_relay_log_pos)
+      rli->event_relay_log_pos= future_event_relay_log_pos;
+  }
 };
 
 
diff --git a/sql/slave.cc b/sql/slave.cc
index 61c63cd2862..50960991faf 100644
--- a/sql/slave.cc
+++ b/sql/slave.cc
@@ -3331,7 +3331,7 @@ static int exec_relay_log_event(THD* thd, Relay_log_info* rli,
                         rli->abort_slave= 1;
                         mysql_mutex_unlock(&rli->data_lock);
                         delete ev;
-                        rli->inc_event_relay_log_pos();
+                        serial_rgi->inc_event_relay_log_pos();
                         DBUG_RETURN(0);
                       };);
     }
@@ -3360,6 +3360,7 @@ static int exec_relay_log_event(THD* thd, Relay_log_info* rli,
       DBUG_RETURN(1);
     }
 
+    serial_rgi->future_event_relay_log_pos= rli->future_event_relay_log_pos;
     exec_res= apply_event_and_update_pos(ev, thd, serial_rgi, NULL);
 
     delete_or_keep_event_post_apply(serial_rgi, typ, ev);