Re: bzr commit into mysql-5.1-bugteam branch (Dao-Gang.Qu:2941) Bug#45214

[He Zhenxing]

Hi,

There are some suggestions, you can have a look!

Dao-Gang.Qu@stripped wrote: 
> #At file:///home/daogangq/mysql/bzrwork/bug45214/5.1-bt/ based on
> revid:davi.arnaut@stripped
> 
>  2941 Dao-Gang.Qu@stripped	2009-07-02
>       Bug #45214  get_master_version_and_clock does not report error when queries
> fail
>             
>       The "get_master_version_and_clock(...)" function in sql/slave.cc ignores 
>       error and passes directly when queries fail, or queries succeed 
>       but the result retrieved is empty.
>       
>       The "get_master_version_and_clock(...)" function should try to reconnect
> master
>       if queries fail because of transient network problems, and fail otherwise.
>       The I/O thread should print a warning if the some system variables do not 
>       exist on master (very old master)
>      @ mysql-test/extra/rpl_tests/rpl_get_master_version_and_clock.test
>         Added test file for bug #45214
>      @ mysql-test/suite/rpl/r/rpl_get_master_version_and_clock.result
>         Added test result for bug #45214
>      @ mysql-test/suite/rpl/t/rpl_get_master_version_and_clock.test
>         Added test file for bug #45214
>      @ sql/slave.cc
>         The 'is_network_error()' function is added for checking if the error is
> caused by network.
>         Added a new return value (2) to 'get_master_version_and_clock()' function
> result set 
>         to indicate transient network errors when queries fail, and the caller should
> 
>         try to reconnect in this case.
> 
>     added:
>       mysql-test/extra/rpl_tests/rpl_get_master_version_and_clock.test
>       mysql-test/suite/rpl/r/rpl_get_master_version_and_clock.result
>       mysql-test/suite/rpl/t/rpl_get_master_version_and_clock.test
>     modified:
>       sql/slave.cc
> === added file 'mysql-test/extra/rpl_tests/rpl_get_master_version_and_clock.test'
> --- a/mysql-test/extra/rpl_tests/rpl_get_master_version_and_clock.test	1970-01-01
> 00:00:00 +0000
> +++ b/mysql-test/extra/rpl_tests/rpl_get_master_version_and_clock.test	2009-07-02
> 10:55:59 +0000
> @@ -0,0 +1,63 @@
> +#
> +# BUG#45214
> +# The common part of the "rpl_get_master_version_and_clock" test. 
> +# Restart slave under network disconnection between slave and master
> +# following the steps:
> +#    1 - Got DBUG_SYNC_POINT lock
> +#    2 - Set DBUG_SYNC_POINT before call mysql_real_query(...) function in
> get_master_version_and_clock(...) function and hang here
> +#    3 - shutdown master server for simulating network disconnection
> +#    4 - Release DBUG_SYNC_POINT lock
> +#    5 - Check if the slave I/O thread tries to reconnect to master. 
> +#
> +# Note: Please make sure initialize the $debug_lock when call the test script.
> +#
> +connection slave;
> +if (`SELECT '$debug_lock' = ''`)
> +{
> +    --die Cannot continue. Please set value for $debug_lock.
> +}
> +
> +# Restart slave
> +--disable_warnings
> +stop slave;
> +source include/wait_for_slave_to_stop.inc;
> +start slave;
> +source include/wait_for_slave_to_start.inc;
> +connection master;
> +# Write file to make mysql-test-run.pl expect the "crash", but don't start
> +# it until it's told to
> +--write_file $MYSQLTEST_VARDIR/tmp/mysqld.1.expect
> +wait
> +EOF
> +
> +# Send shutdown to the connected server and give
> +# it 10 seconds to die before zapping it
> +shutdown_server 10;
> +
> +connection slave;
> +eval SELECT RELEASE_LOCK($debug_lock);
> +
> +# Write file to make mysql-test-run.pl start up the server again
> +--append_file $MYSQLTEST_VARDIR/tmp/mysqld.1.expect
> +restart
> +EOF
> +
> +connection master;
> +# Turn on reconnect
> +--enable_reconnect
> +
> +# Call script that will poll the server waiting for it to be back online again
> +--source include/wait_until_connected_again.inc
> +
> +# Turn off reconnect again
> +--disable_reconnect
> +
> +connection slave;
> +source include/wait_for_slave_to_start.inc;
> +
> +# Show slave last IO errno
> +let $last_io_errno= query_get_value("show slave status", Last_IO_Errno, 1);
> +echo Slave_IO_Errno= $last_io_errno;
> +
> +
> +# End of tests
> 
> === added file 'mysql-test/suite/rpl/r/rpl_get_master_version_and_clock.result'
> --- a/mysql-test/suite/rpl/r/rpl_get_master_version_and_clock.result	1970-01-01
> 00:00:00 +0000
> +++ b/mysql-test/suite/rpl/r/rpl_get_master_version_and_clock.result	2009-07-02
> 10:55:59 +0000
> @@ -0,0 +1,40 @@
> +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;
> +SELECT IS_FREE_LOCK("debug_lock.before_get_UNIX_TIMESTAMP");
> +IS_FREE_LOCK("debug_lock.before_get_UNIX_TIMESTAMP")
> +1
> +SELECT GET_LOCK("debug_lock.before_get_UNIX_TIMESTAMP", 1000);
> +GET_LOCK("debug_lock.before_get_UNIX_TIMESTAMP", 1000)
> +1
> +set global debug= 'd,debug_lock.before_get_UNIX_TIMESTAMP';
> +stop slave;
> +start slave;
> +SELECT RELEASE_LOCK("debug_lock.before_get_UNIX_TIMESTAMP");
> +RELEASE_LOCK("debug_lock.before_get_UNIX_TIMESTAMP")
> +1
> +Slave_IO_Errno= 2013
> +SELECT IS_FREE_LOCK("debug_lock.before_get_SERVER_ID");
> +IS_FREE_LOCK("debug_lock.before_get_SERVER_ID")
> +1
> +SELECT GET_LOCK("debug_lock.before_get_SERVER_ID", 1000);
> +GET_LOCK("debug_lock.before_get_SERVER_ID", 1000)
> +1
> +set global debug= 'd,debug_lock.before_get_SERVER_ID';
> +stop slave;
> +start slave;
> +SELECT RELEASE_LOCK("debug_lock.before_get_SERVER_ID");
> +RELEASE_LOCK("debug_lock.before_get_SERVER_ID")
> +1
> +Slave_IO_Errno= 2013
> +set global debug= '';
> +reset master;
> +include/stop_slave.inc
> +change master to master_port=SLAVE_PORT;
> +start slave;
> +*** must be having the replicate-same-server-id IO thread error ***
> +Slave_IO_Errno= 1593
> +Slave_IO_Error= Fatal error: The slave I/O thread stops because master and slave
> have equal MySQL server ids; these ids must be different for replication to work (or the
> --replicate-same-server-id option must be used on slave but this does not always make
> sense; please check the manual before using it).
> 
> === added file 'mysql-test/suite/rpl/t/rpl_get_master_version_and_clock.test'
> --- a/mysql-test/suite/rpl/t/rpl_get_master_version_and_clock.test	1970-01-01
> 00:00:00 +0000
> +++ b/mysql-test/suite/rpl/t/rpl_get_master_version_and_clock.test	2009-07-02
> 10:55:59 +0000
> @@ -0,0 +1,60 @@
> +#
> +# BUG#45214 
> +# This test verifies if the slave I/O tread tries to reconnect to
> +# master when it tries to get the values of the UNIX_TIMESTAMP, SERVER_ID,
> +# COLLATION_SERVER and TIME_ZONE from master under network disconnection.
> +# The COLLATION_SERVER and TIME_ZONE are got only on master server version 4.
> +# So they can't be verified by test case here.
> +# Finish the following tests by calling its common test script:  
> +# extra/rpl_tests/rpl_get_master_version_and_clock.test. 
> +# And meanwhile this test checks that the slave I/O thread refuses to start if
> slave
> +# and master have the same server id (because this is a useless setup,
> +# and otherwise SHOW SLAVE STATUS shows progress but all queries are
> +# ignored, which has caught our customers), unless
> +# --replicate-same-server-id.
> +#
> +
> +source include/master-slave.inc;
> +
> +#Test case 1: Try to get the value of the UNIX_TIMESTAMP from master under network
> disconnection
> +connection slave;
> +let $debug_saved= `select @@global.debug`;
> +
> +let $debug_lock= "debug_lock.before_get_UNIX_TIMESTAMP";
> +eval SELECT IS_FREE_LOCK($debug_lock);
> +eval SELECT GET_LOCK($debug_lock, 1000);
> +
> +set global debug= 'd,debug_lock.before_get_UNIX_TIMESTAMP';
> +source extra/rpl_tests/rpl_get_master_version_and_clock.test; 
> +
> +#Test case 2: Try to get the value of the SERVER_ID from master under network
> disconnection
> +connection slave;
> +let $debug_lock= "debug_lock.before_get_SERVER_ID";
> +eval SELECT IS_FREE_LOCK($debug_lock);
> +eval SELECT GET_LOCK($debug_lock, 1000);
> +
> +set global debug= 'd,debug_lock.before_get_SERVER_ID';
> +source extra/rpl_tests/rpl_get_master_version_and_clock.test;
> +
> +eval set global debug= '$debug_saved';
> +
> +#Test case 3: This test checks that the slave I/O thread refuses to start
> +#if slave and master have the same server id.
> +connection slave;
> +reset master;
> +# replicate ourselves
> +source include/stop_slave.inc;
> +--replace_result $SLAVE_MYPORT SLAVE_PORT
> +eval change master to master_port=$SLAVE_MYPORT;
> +start slave;
> +
> +let $slave_param= Last_IO_Errno;
> +let $slave_param_value= 1593;
> +source include/wait_for_slave_param.inc;
> +--echo *** must be having the replicate-same-server-id IO thread error ***
> +let $last_io_errno= query_get_value("show slave status", Last_IO_Errno, 1);
> +let $last_io_error= query_get_value("show slave status", Last_IO_Error, 1);
> +echo Slave_IO_Errno= $last_io_errno;
> +echo Slave_IO_Error= $last_io_error;
> +
> +# End of tests
> 
> === modified file 'sql/slave.cc'
> --- a/sql/slave.cc	2009-06-09 16:44:26 +0000
> +++ b/sql/slave.cc	2009-07-02 10:55:59 +0000
> @@ -38,6 +38,7 @@
>  #include <my_dir.h>
>  #include <sql_common.h>
>  #include <errmsg.h>
> +#include <mysqld_error.h>
>  #include <mysys_err.h>
>  
>  #ifdef HAVE_REPLICATION
> @@ -842,6 +843,29 @@ int init_intvar_from_file(int* var, IO_C
>    DBUG_RETURN(1);
>  }
>  
> +
> +/*
> +  Check if the error is caused by network.
> +  @param[in]   errorno   Number of the error.
> +  RETURNS:
> +  TRUE         network error
> +  FALSE        not network error
> +*/
> +
> +bool is_network_error(uint errorno)
> +{ 
> +  if (errorno == CR_CONNECTION_ERROR || 
> +      errorno == CR_CONN_HOST_ERROR ||
> +      errorno == CR_SERVER_GONE_ERROR ||
> +      errorno == CR_SERVER_LOST ||
> +      errorno == ER_CON_COUNT_ERROR ||
> +      errorno == ER_SERVER_SHUTDOWN)
> +    return TRUE;
> +
> +  return FALSE;   
> +}
> +
> +
>  /*
>    Note that we rely on the master's version (3.23, 4.0.14 etc) instead of
>    relying on the binlog's version. This is not perfect: imagine an upgrade
> @@ -854,6 +878,7 @@ int init_intvar_from_file(int* var, IO_C
>    RETURNS
>    0       ok
>    1       error
> +  2       transient network problem, the caller should try to reconnect
>  */
>  
>  static int get_master_version_and_clock(MYSQL* mysql, Master_info* mi)
> @@ -864,6 +889,7 @@ static int get_master_version_and_clock(
>    MYSQL_RES *master_res= 0;
>    MYSQL_ROW master_row;
>    DBUG_ENTER("get_master_version_and_clock");
> +  int query_re= 0;
>  
>    /*
>      Free old description_event_for_queue (that is needed if we are in
> @@ -938,21 +964,37 @@ static int get_master_version_and_clock(
>      Compare the master and slave's clock. Do not die if master's clock is
>      unavailable (very old master not supporting UNIX_TIMESTAMP()?).
>    */
> +  DBUG_SYNC_POINT("debug_lock.before_get_UNIX_TIMESTAMP", 10);
> +  query_re= mysql_real_query(mysql, STRING_WITH_LEN("SELECT UNIX_TIMESTAMP()"));
> +  if ((query_re || !(master_res= mysql_store_result(mysql))) && 
> +       is_network_error(mysql_errno(mysql)))
> +  {

master_res= NULL;
if ((!mysql_real_query(...) &&
     (master_res= mysql_store_result(...)) &&
     (master_row= mysql_fetch_row(...)))
{
   // Query is OK
}
else if (is_network_error(...))
{
  // Network error
}
else
{
  // Fatal error
}

This can reduce merge problem and can make it more clear to understand.

> +    mi->report(WARNING_LEVEL, mysql_errno(mysql),
> +               "Get master clock failed with error: %s", mysql_error(mysql));
> +    DBUG_RETURN(2);
> +  }
>  
> -  if (!mysql_real_query(mysql, STRING_WITH_LEN("SELECT UNIX_TIMESTAMP()"))
> &&
> -      (master_res= mysql_store_result(mysql)) &&
> -      (master_row= mysql_fetch_row(master_res)))
> +  if ((master_row= mysql_fetch_row(master_res)))
>    {
>      mi->clock_diff_with_master=
>        (long) (time((time_t*) 0) - strtoul(master_row[0], 0, 10));
>    }
> +  else if (is_network_error(mysql_errno(mysql)))
> +  { 
> +    mi->report(WARNING_LEVEL, mysql_errno(mysql),
> +               "Get master clock failed with error: %s", mysql_error(mysql));
> +    if (master_res)
> +      mysql_free_result(master_res);
> +    DBUG_RETURN(2);
> +  }
>    else if (!check_io_slave_killed(mi->io_thd, mi, NULL))

move this out of the function, check_io_slave_killed() in the caller.

> {
>      mi->clock_diff_with_master= 0; /* The "most sensible" value */
> -    sql_print_warning("\"SELECT UNIX_TIMESTAMP()\" failed on master, "
> -                      "do not trust column Seconds_Behind_Master of SHOW "
> -                      "SLAVE STATUS. Error: %s (%d)",
> -                      mysql_error(mysql), mysql_errno(mysql));
> +    mi->report(ERROR_LEVEL, ER_UNKNOWN_ERROR,
> +               "\"SELECT UNIX_TIMESTAMP()\" failed on master, "
> +               "do not trust column Seconds_Behind_Master of SHOW "
> +               "SLAVE STATUS. Error: %s (%d)",
> +               mysql_error(mysql), mysql_errno(mysql));

This should be a warning.

> }
>    if (master_res)
>      mysql_free_result(master_res);
> @@ -967,26 +1009,54 @@ static int get_master_version_and_clock(
>      Note: we could have put a @@SERVER_ID in the previous SELECT
>      UNIX_TIMESTAMP() instead, but this would not have worked on 3.23 masters.
>    */
> -  if (!mysql_real_query(mysql,
> -                        STRING_WITH_LEN("SHOW VARIABLES LIKE 'SERVER_ID'"))
> &&
> -      (master_res= mysql_store_result(mysql)))
> -  {
> -    if ((master_row= mysql_fetch_row(master_res)) &&
> -        (::server_id == strtoul(master_row[1], 0, 10)) &&
> -        !mi->rli.replicate_same_server_id)
> +  DBUG_SYNC_POINT("debug_lock.before_get_SERVER_ID", 10);
> +  query_re= mysql_real_query(mysql, STRING_WITH_LEN("SHOW VARIABLES LIKE
> 'SERVER_ID'"));
> +  if (query_re || !(master_res= mysql_store_result(mysql)))
> +  { 
> +    if (is_network_error(mysql_errno(mysql)))
>      {
> -      errmsg= "The slave I/O thread stops because master and slave have equal \
> +      mi->report(WARNING_LEVEL, mysql_errno(mysql),
> +                 "Get master SERVER_ID failed with error: %s", mysql_error(mysql));
> +      DBUG_RETURN(2);
> +    }
> +    /* Fatal error */
> +    errmsg= "The slave I/O thread stops because a fatal error is encountered \
> +when it try to get the value of SERVER_ID variable from master.";
> +    err_code= ER_SLAVE_FATAL_ERROR;
> +    sprintf(err_buff, ER(err_code), errmsg);
> +    goto err;
> +  }
> +
> +  master_row= mysql_fetch_row(master_res);
> +  if (master_row && (::server_id == strtoul(master_row[1], 0, 10))
> &&
> +      !mi->rli.replicate_same_server_id)
> +  {
> +    errmsg= "The slave I/O thread stops because master and slave have equal \
>  MySQL server ids; these ids must be different for replication to work (or \
>  the --replicate-same-server-id option must be used on slave but this does \
>  not always make sense; please check the manual before using it).";
> -      err_code= ER_SLAVE_FATAL_ERROR;
> -      sprintf(err_buff, ER(err_code), errmsg);
> +    err_code= ER_SLAVE_FATAL_ERROR;
> +    sprintf(err_buff, ER(err_code), errmsg);
> +  }
> +  else if (!master_row)
> +  {
> +    if (is_network_error(mysql_errno(mysql)))
> +    {
> +      mi->report(WARNING_LEVEL, mysql_errno(mysql),
> +                 "Get master SERVER_ID failed with error: %s", mysql_error(mysql));
> +      mysql_free_result(master_res);
> +      DBUG_RETURN(2);
>      }
> -    mysql_free_result(master_res);
> -    if (errmsg)
> -      goto err;
> +    else
> +      mi->report(WARNING_LEVEL, ER_UNKNOWN_SYSTEM_VARIABLE, 
> +                 "Unknown system variable 'SERVER_ID' on master, \
> +maybe it is a very old master.");
>    }
> +  mysql_free_result(master_res);
>  
> +  if (errmsg)
> +    goto err;

put the goto where errmsg was set.

> + 
>    /*
>      Check that the master's global character_set_server and ours are the same.
>      Not fatal if query fails (old master?).
> @@ -1008,23 +1078,55 @@ not always make sense; please check the 
>    if (*mysql->server_version == '3')
>      goto err;
>  
> -  if ((*mysql->server_version == '4') &&
> -      !mysql_real_query(mysql,
> -                        STRING_WITH_LEN("SELECT @@GLOBAL.COLLATION_SERVER"))
> &&
> -      (master_res= mysql_store_result(mysql)))
> +  if (*mysql->server_version == '4')
>    {
> -    if ((master_row= mysql_fetch_row(master_res)) &&
> -        strcmp(master_row[0], global_system_variables.collation_server->name))
> +    query_re= mysql_real_query(mysql, STRING_WITH_LEN("SELECT
> @@GLOBAL.COLLATION_SERVER"));
> +    if (query_re || !(master_res= mysql_store_result(mysql)))
>      {
> -      errmsg= "The slave I/O thread stops because master and slave have \
> +      if (is_network_error(mysql_errno(mysql)))
> +      {
> +        mi->report(WARNING_LEVEL, mysql_errno(mysql),
> +                   "Get master COLLATION_SERVER failed with error: %s",
> mysql_error(mysql)); 
> +        DBUG_RETURN(2);
> +      }
> +
> +      if (mysql_errno(mysql) != ER_UNKNOWN_SYSTEM_VARIABLE)
> +      {
> +        /* Fatal error */
> +        errmsg= "The slave I/O thread stops because a fatal error is encountered \
> +when it try to get the value of COLLATION_SERVER global variable from master.";
> +        err_code= ER_SLAVE_FATAL_ERROR;
> +        sprintf(err_buff, ER(err_code), errmsg);
> +        goto err;
> +      }
> +      else
> +        mi->report(WARNING_LEVEL, ER_UNKNOWN_SYSTEM_VARIABLE,
> +                   "Unknown system variable 'COLLATION_SERVER' on master, \
> +maybe it is a very old master.");
> +    }
> +    else
> +    {
> +      master_row= mysql_fetch_row(master_res);
> +      if (master_row && strcmp(master_row[0],
> +                               global_system_variables.collation_server->name))
> +      {  
> +        errmsg= "The slave I/O thread stops because master and slave have \
>  different values for the COLLATION_SERVER global variable. The values must \
>  be equal for replication to work";
> -      err_code= ER_SLAVE_FATAL_ERROR;
> -      sprintf(err_buff, ER(err_code), errmsg);
> +        err_code= ER_SLAVE_FATAL_ERROR;
> +        sprintf(err_buff, ER(err_code), errmsg);
> +      }
> +      else if (!master_row && is_network_error(mysql_errno(mysql)))
> +      {
> +        mi->report(WARNING_LEVEL, mysql_errno(mysql),
> +                   "Get master COLLATION_SERVER failed with error: %s",
> mysql_error(mysql));
> +        mysql_free_result(master_res);
> +        DBUG_RETURN(2);
> +      }
> +      mysql_free_result(master_res);
> +      if (errmsg)
> +        goto err;
>      }
> -    mysql_free_result(master_res);
> -    if (errmsg)
> -      goto err;
>    }
>  
>    /*
> @@ -1042,13 +1144,28 @@ be equal for replication to work";
>      This check is only necessary for 4.x masters (and < 5.0.4 masters but
>      those were alpha).
>    */
> -  if ((*mysql->server_version == '4') &&
> -      !mysql_real_query(mysql, STRING_WITH_LEN("SELECT @@GLOBAL.TIME_ZONE"))
> &&
> -      (master_res= mysql_store_result(mysql)))
> -  {
> -    if ((master_row= mysql_fetch_row(master_res)) &&
> -        strcmp(master_row[0],
> -               global_system_variables.time_zone->get_name()->ptr()))
> +  if (*mysql->server_version == '4')
> +  {
> +    query_re= mysql_real_query(mysql, STRING_WITH_LEN("SELECT
> @@GLOBAL.TIME_ZONE"));
> +    if (query_re || !(master_res= mysql_store_result(mysql)))
> +    {
> +      if (is_network_error(mysql_errno(mysql)))
> +      {
> +        mi->report(WARNING_LEVEL, mysql_errno(mysql),
> +                   "Get master TIME_ZONE failed with error: %s",
> mysql_error(mysql));
> +        DBUG_RETURN(2);
> +      }
> +      /* Fatal error */
> +      errmsg= "The slave I/O thread stops because a fatal error is encountered \
> +when it try to get the value of TIME_ZONE global variable from master.";
> +      err_code= ER_SLAVE_FATAL_ERROR;
> +      sprintf(err_buff, ER(err_code), errmsg);
> +      goto err;
> +    }
> +
> +    master_row= mysql_fetch_row(master_res);
> +    if (master_row && strcmp(master_row[0],
> +                            
> global_system_variables.time_zone->get_name()->ptr()))
>      {
>        errmsg= "The slave I/O thread stops because master and slave have \
>  different values for the TIME_ZONE global variable. The values must \
> @@ -1056,6 +1173,13 @@ be equal for replication to work";
>        err_code= ER_SLAVE_FATAL_ERROR;
>        sprintf(err_buff, ER(err_code), errmsg);
>      }
> +    else if (!master_row && is_network_error(mysql_errno(mysql)))
> +    {
> +      mi->report(WARNING_LEVEL, mysql_errno(mysql),
> +                 "Get master TIME_ZONE failed with error: %s", mysql_error(mysql));
> +      mysql_free_result(master_res);
> +      DBUG_RETURN(2);
> +    }    
>      mysql_free_result(master_res);
>  
>      if (errmsg)
> @@ -2372,6 +2496,7 @@ pthread_handler_t handle_slave_io(void *
>    char llbuff[22];
>    uint retry_count;
>    bool suppress_warnings;
> +  int ret;
>  #ifndef DBUG_OFF
>    uint retry_count_reg= 0, retry_count_dump= 0, retry_count_event= 0;
>  #endif
> @@ -2451,8 +2576,20 @@ connected:
>    mi->slave_running= MYSQL_SLAVE_RUN_CONNECT;
>    thd->slave_net = &mysql->net;
>    thd_proc_info(thd, "Checking master version");
> -  if (get_master_version_and_clock(mysql, mi))
> +  ret= get_master_version_and_clock(mysql, mi);
> +  if (ret == 1)
> +    /* Fatal error */
>      goto err;
> +  
> +  if (ret == 2) 
> +  {
> +    suppress_warnings= FALSE;

check_io_slave_killed() here.

> +    /* Try to reconnect because the error was caused by a transient network problem
> */
> +    if (try_to_reconnect(thd, mysql, mi, &retry_count, suppress_warnings,
> +                             reconnect_messages[SLAVE_RECON_ACT_REG]))
> +      goto err;
> +    goto connected;
> +  } 
>  
>    if (mi->rli.relay_log.description_event_for_queue->binlog_version > 1)
>    {