BUG#24860 (Incorrect SLAVE_TRANSACTION_RETRIES code can result in slave stuck):

If a temporary error occured inside a group on an event that was not the first
event of the group, the slave could get stuck because the retry counter is reset
whenever an event was executed successfully.

This patch only reset the retry counter when an entire group has been successfully
executed, or failed with a non-transient error.


sql/slave.cc:
  Adding debug printouts to every place where Relay_log_info::trans_retries
  is changed and to has_temporary_error() to print the error when returning.
  
  Adding debug variable all_errors_are_temporary_errors to make all errors
  for slave thread temporary errors.
  
  Adding code so that the Relay_log_info::trans_retries is only reset when
  an entire group was sucessfully executed, or a non-temporary error occured.
mysql-test/suite/rpl/r/rpl_temporary_errors.result:
  New BitKeeper file ``mysql-test/suite/rpl/r/rpl_temporary_errors.result''
mysql-test/suite/rpl/t/rpl_temporary_errors-slave.opt:
  New BitKeeper file ``mysql-test/suite/rpl/t/rpl_temporary_errors-slave.opt''
mysql-test/suite/rpl/t/rpl_temporary_errors.test:
  New BitKeeper file ``mysql-test/suite/rpl/t/rpl_temporary_errors.test''

mysql-test/suite/rpl/r/rpl_temporary_errors.result

+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+**** On Master ****
+SET SESSION BINLOG_FORMAT=ROW;
+CREATE TABLE t1 (a INT PRIMARY KEY, b INT);
+INSERT INTO t1 VALUES (1,1), (2,2), (3,3), (4,4);
+**** On Slave ****
+SHOW STATUS LIKE 'Slave_retried_transactions';
+Variable_name	Value
+Slave_retried_transactions	0
+UPDATE t1 SET a = 5, b = 47 WHERE a = 1;
+SELECT * FROM t1;
+a	b
+5	47
+2	2
+3	3
+4	4
+**** On Master ****
+UPDATE t1 SET a = 5, b = 5 WHERE a = 1;
+SELECT * FROM t1;
+a	b
+5	5
+2	2
+3	3
+4	4
+**** On Slave ****
+SHOW STATUS LIKE 'Slave_retried_transactions';
+Variable_name	Value
+Slave_retried_transactions	2
+SELECT * FROM t1;
+a	b
+5	47
+2	2
+3	3
+4	4
+SHOW SLAVE STATUS;
+Slave_IO_State	#
+Master_Host	127.0.0.1
+Master_User	root
+Master_Port	MASTER_PORT
+Connect_Retry	1
+Master_Log_File	master-bin.000001
+Read_Master_Log_Pos	408
+Relay_Log_File	#
+Relay_Log_Pos	#
+Relay_Master_Log_File	master-bin.000001
+Slave_IO_Running	Yes
+Slave_SQL_Running	No
+Replicate_Do_DB	
+Replicate_Ignore_DB	
+Replicate_Do_Table	
+Replicate_Ignore_Table	#
+Replicate_Wild_Do_Table	
+Replicate_Wild_Ignore_Table	
+Last_Errno	1032
+Last_Error	Error in Update_rows event: error during transaction execution on table test.t1. Can't find record in 't1'
+Skip_Counter	0
+Exec_Master_Log_Pos	318
+Relay_Log_Space	#
+Until_Condition	None
+Until_Log_File	
+Until_Log_Pos	0
+Master_SSL_Allowed	No
+Master_SSL_CA_File	
+Master_SSL_CA_Path	
+Master_SSL_Cert	
+Master_SSL_Cipher	
+Master_SSL_Key	
+Seconds_Behind_Master	#
+Master_SSL_Verify_Server_Cert	No
+Last_IO_Errno	#
+Last_IO_Error	#
+Last_SQL_Errno	1032
+Last_SQL_Error	Error in Update_rows event: error during transaction execution on table test.t1. Can't find record in 't1'
+DROP TABLE t1;
+**** On Master ****
+DROP TABLE t1;

mysql-test/suite/rpl/t/rpl_temporary_errors-slave.opt

+--loose-debug="+d,all_errors_are_temporary_errors" --slave-transaction-retries=2
+
+

mysql-test/suite/rpl/t/rpl_temporary_errors.test

+source include/master-slave.inc;
+
+--echo **** On Master ****
+connection master;
+SET SESSION BINLOG_FORMAT=ROW;
+CREATE TABLE t1 (a INT PRIMARY KEY, b INT);
+INSERT INTO t1 VALUES (1,1), (2,2), (3,3), (4,4);
+--echo **** On Slave ****
+sync_slave_with_master;
+SHOW STATUS LIKE 'Slave_retried_transactions';
+UPDATE t1 SET a = 5, b = 47 WHERE a = 1;
+SELECT * FROM t1;
+--echo **** On Master ****
+connection master;
+UPDATE t1 SET a = 5, b = 5 WHERE a = 1;
+save_master_pos;
+SELECT * FROM t1;
+#SHOW BINLOG EVENTS;
+--echo **** On Slave ****
+connection slave;
+source include/wait_for_slave_sql_to_stop.inc;
+SHOW STATUS LIKE 'Slave_retried_transactions';
+SELECT * FROM t1;
+source include/show_slave_status.inc;
+DROP TABLE t1;
+
+--echo **** On Master ****
+connection master;
+DROP TABLE t1;

sql/slave.cc

@@ -1714,7 +1714,14 @@ static int has_temporary_error(THD *thd)
   DBUG_ENTER("has_temporary_error");
 
   if (thd->is_fatal_error)
+  {
+    DBUG_PRINT("info", ("thd->net.last_errno: %s", ER(thd->net.last_errno)));
     DBUG_RETURN(0);
+  }
+
+  DBUG_EXECUTE_IF("all_errors_are_temporary_errors",
+                  if (thd->net.last_errno)
+                    thd->net.last_errno= ER_LOCK_DEADLOCK;);
 
   /*
     Temporary error codes:
@@ -1723,7 +1730,10 @@ static int has_temporary_error(THD *thd)
   */
   if (thd->net.last_errno == ER_LOCK_DEADLOCK ||
       thd->net.last_errno == ER_LOCK_WAIT_TIMEOUT)
+  {
+    DBUG_PRINT("info", ("thd->net.last_errno: %s", ER(thd->net.last_errno)));
     DBUG_RETURN(1);
+  }
 
 #ifdef HAVE_NDB_BINLOG
   /*
@@ -1905,7 +1915,8 @@ static int exec_relay_log_event(THD* thd, Relay_log_info* rli)
     }
     if (slave_trans_retries)
     {
-      if (exec_res && has_temporary_error(thd))
+      int temp_err;
+      if (exec_res && (temp_err= has_temporary_error(thd)))
       {
         const char *errmsg;
         /*
@@ -1953,15 +1964,19 @@ static int exec_relay_log_event(THD* thd, Relay_log_info* rli)
                           "the slave_transaction_retries variable.",
                           slave_trans_retries);
       }
-      else if (!((thd->options & OPTION_BEGIN) && opt_using_transactions))
+      else if (exec_res && !temp_err ||
+               (opt_using_transactions &&
+                rli->group_relay_log_pos == rli->event_relay_log_pos))
       {
         /*
-          Only reset the retry counter if the event succeeded or
-          failed with a non-transient error.  On a successful event,
-          the execution will proceed as usual; in the case of a
+          Only reset the retry counter if the entire group succeeded
+          or failed with a non-transient error.  On a successful
+          event, the execution will proceed as usual; in the case of a
           non-transient error, the slave will stop with an error.
          */
         rli->trans_retries= 0; // restart from fresh
+        DBUG_PRINT("info", ("Resetting retry counter, rli->trans_retries: %d",
+                            rli->trans_retries));
       }
     }
     DBUG_RETURN(exec_res);
@@ -2450,6 +2465,7 @@ pthread_handler_t handle_slave_sql(void *arg)
   rli->ignore_log_space_limit= 0;
   pthread_mutex_unlock(&rli->log_space_lock);
   rli->trans_retries= 0; // start from "no error"
+  DBUG_PRINT("info", ("rli->trans_retries: %d", rli->trans_retries));
 
   if (init_relay_log_pos(rli,
                          rli->group_relay_log_name,