From: alfranio correia
Date: November 7 2008 11:24am
Subject: Re: bzr commit into mysql-5.0-bugteam branch (alfranio.correia:2704)
 Bug#31665 Bug#35542 Bug#40337
List-Archive: http://lists.mysql.com/commits/58166
Message-Id: <4914256A.7020204@sun.com>
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Hi Mats,

See in-line comments.

Mats Kindahl wrote:
> Hi Alfranio,
>
> Comments on the patch below. The main issue is the question about the use of
> sync_relayloginfo_period.
>   
The idea of this patch is to improve resilience. Taking this into
account that and the fact the the relay-log is flushed per transaction,
it does not make sense to have the count in such case.

> Best wishes,
> Mats Kindahl
>
> Alfranio Correia wrote:
>   
>> #At file:///home/acorreia/workspace.sun/playground.mysql/mysql-5.0.68-custom_build/
>>
>>  2704 Alfranio Correia	2008-10-29
>>       Added option to sync master.info (--sync-master-info, integer) and relay log (--sync-relay-log, integer) to disk after every event and the relay info (--sync-relay-log-info, boolean) per transaction. This supersedes the patch proposed by Sinisa and modified by He Zhenxing 
>>       to fix bugs: BUG#35542 and BUG#31665. This is an update to BUG#40337.
>> modified:
>>   sql/log.cc
>>   sql/mysql_priv.h
>>   sql/mysqld.cc
>>   sql/set_var.cc
>>   sql/set_var.h
>>   sql/slave.cc
>>   sql/sql_class.h
>>
>> === modified file 'sql/log.cc'
>> --- a/sql/log.cc	2008-07-24 12:28:21 +0000
>> +++ b/sql/log.cc	2008-10-29 17:52:28 +0000
>> @@ -32,8 +32,7 @@
>>  #include "message.h"
>>  #endif
>>  
>> -MYSQL_LOG mysql_log, mysql_slow_log, mysql_bin_log;
>> -ulong sync_binlog_counter= 0;
>> +MYSQL_LOG mysql_log, mysql_slow_log, mysql_bin_log(&sync_binlog_period);
>>  
>>  static Muted_query_log_event invisible_commit;
>>  
>> @@ -402,10 +401,11 @@ static int find_uniq_filename(char *name
>>  }
>>  
>>  
>> -MYSQL_LOG::MYSQL_LOG()
>> +MYSQL_LOG::MYSQL_LOG(uint *sync_period)
>>    :bytes_written(0), last_time(0), query_start(0), name(0),
>>     prepared_xids(0), log_type(LOG_CLOSED), file_id(1), open_count(1),
>>     write_error(FALSE), inited(FALSE), need_start_event(TRUE),
>> +   sync_period_ptr(sync_period),
>>     description_event_for_exec(0), description_event_for_queue(0)
>>  {
>>    /*
>> @@ -1622,6 +1622,8 @@ bool MYSQL_LOG::append(Log_event* ev)
>>    }
>>    bytes_written+= ev->data_written;
>>    DBUG_PRINT("info",("max_size: %lu",max_size));
>> +  if (flush_and_sync())
>> +    goto err;
>>    if ((uint) my_b_append_tell(&log_file) > max_size)
>>      new_file(0);
>>  
>> @@ -1652,6 +1654,8 @@ bool MYSQL_LOG::appendv(const char* buf,
>>      bytes_written += len;
>>    } while ((buf=va_arg(args,const char*)) && (len=va_arg(args,uint)));
>>    DBUG_PRINT("info",("max_size: %lu",max_size));
>> +  if (flush_and_sync())
>> +    goto err;
>>    if ((uint) my_b_append_tell(&log_file) > max_size)
>>      new_file(0);
>>  
>> @@ -1758,9 +1762,10 @@ bool MYSQL_LOG::flush_and_sync()
>>    safe_mutex_assert_owner(&LOCK_log);
>>    if (flush_io_cache(&log_file))
>>      return 1;
>> -  if (++sync_binlog_counter >= sync_binlog_period && sync_binlog_period)
>> +  uint sync_period= get_sync_period();
>> +  if (sync_period && ++sync_counter >= sync_period)
>>    {
>> -    sync_binlog_counter= 0;
>> +    sync_counter= 0;
>>      err=my_sync(fd, MYF(MY_WME));
>>    }
>>    return err;
>>
>> === modified file 'sql/mysql_priv.h'
>> --- a/sql/mysql_priv.h	2008-10-02 11:57:52 +0000
>> +++ b/sql/mysql_priv.h	2008-10-29 17:52:28 +0000
>> @@ -1310,7 +1310,8 @@ extern ulong max_binlog_size, max_relay_
>>  extern ulong rpl_recovery_rank, thread_cache_size;
>>  extern ulong back_log;
>>  extern ulong specialflag, current_pid;
>> -extern ulong expire_logs_days, sync_binlog_period, sync_binlog_counter;
>> +extern ulong expire_logs_days;
>> +extern uint sync_binlog_period, sync_relaylog_period, sync_relayloginfo_period, sync_masterinfo_period;
>>  extern ulong opt_tc_log_size, tc_log_max_pages_used, tc_log_page_size;
>>  extern ulong tc_log_page_waits;
>>  extern my_bool relay_log_purge, opt_innodb_safe_binlog, opt_innodb;
>>
>> === modified file 'sql/mysqld.cc'
>> --- a/sql/mysqld.cc	2008-08-26 08:32:43 +0000
>> +++ b/sql/mysqld.cc	2008-10-29 17:52:28 +0000
>> @@ -466,7 +466,9 @@ ulong max_prepared_stmt_count;
>>  */
>>  ulong prepared_stmt_count=0;
>>  ulong thread_id=1L,current_pid;
>> -ulong slow_launch_threads = 0, sync_binlog_period;
>> +ulong slow_launch_threads = 0;
>> +uint sync_binlog_period= 0, sync_relaylog_period= 0, 
>>     
>
> Why did you change the sync_binlog_period to uint? Is there any reason to make
> this change?
>   
This is the original patch written by Sinisa and Jasonh. I will
investigate the reason.
>   
>> +  sync_relayloginfo_period= 0, sync_masterinfo_period= 0;
>>  ulong expire_logs_days = 0;
>>  ulong rpl_recovery_rank=0;
>>  
>> @@ -4995,7 +4997,10 @@ enum options_mysqld
>>    OPT_SECURE_FILE_PRIV,
>>    OPT_KEEP_FILES_ON_CREATE,
>>    OPT_INNODB_ADAPTIVE_HASH_INDEX,
>> -  OPT_FEDERATED
>> +  OPT_FEDERATED,
>> +  OPT_SYNC_RELAY_LOG,
>> +  OPT_SYNC_RELAY_LOG_INFO,
>> +  OPT_SYNC_MASTER_INFO
>>  };
>>  
>>  
>> @@ -6342,8 +6347,23 @@ The minimum value for this variable is 4
>>    {"sync-binlog", OPT_SYNC_BINLOG,
>>     "Synchronously flush binary log to disk after every #th event. "
>>     "Use 0 (default) to disable synchronous flushing.",
>> -   (gptr*) &sync_binlog_period, (gptr*) &sync_binlog_period, 0, GET_ULONG,
>> -   REQUIRED_ARG, 0, 0, ULONG_MAX, 0, 1, 0},
>> +   (gptr*) &sync_binlog_period, (gptr*) &sync_binlog_period, 0, GET_UINT,
>> +   REQUIRED_ARG, 0, 0, UINT_MAX, 0, 1, 0},
>> +  {"sync-relay-log", OPT_SYNC_RELAY_LOG,
>> +   "Synchronously flush relay log to disk after every #th event. "
>> +   "Use 0 (default) to disable synchronous flushing.",
>> +   (gptr *) &sync_relaylog_period, (gptr *) &sync_relaylog_period, 0, GET_UINT,
>> +   REQUIRED_ARG, 0, 0, UINT_MAX, 0, 1, 0},
>> +  {"sync-relay-log-info", OPT_SYNC_RELAY_LOG_INFO,
>> +   "Synchronously flush relay log info to disk after every commit/rollback. "
>> +   "Use 0 (default) to disable synchronous flushing.",
>> +   (gptr *) &sync_relayloginfo_period, (gptr *) &sync_relayloginfo_period, 0, GET_BOOL,
>> +   NO_ARG, 0, 0, 1, 0, 1, 0},
>> +  {"sync-master-info", OPT_SYNC_MASTER_INFO,
>> +   "Synchronously flush master info to disk after every #th event. "
>> +   "Use 0 (default) to disable synchronous flushing.",
>> +   (gptr *) &sync_masterinfo_period, (gptr *) &sync_masterinfo_period, 0, GET_UINT,
>> +   REQUIRED_ARG, 0, 0, UINT_MAX, 0, 1, 0},
>>    {"sync-frm", OPT_SYNC_FRM, "Sync .frm to disk on create. Enabled by default.",
>>     (gptr*) &opt_sync_frm, (gptr*) &opt_sync_frm, 0, GET_BOOL, NO_ARG, 1, 0,
>>     0, 0, 0, 0},
>>
>> === modified file 'sql/set_var.cc'
>> --- a/sql/set_var.cc	2008-08-25 12:11:59 +0000
>> +++ b/sql/set_var.cc	2008-10-29 17:52:28 +0000
>> @@ -402,7 +402,10 @@ sys_var_thd_table_type  sys_table_type("
>>  sys_var_thd_storage_engine sys_storage_engine("storage_engine",
>>  				       &SV::table_type);
>>  #ifdef HAVE_REPLICATION
>> -sys_var_sync_binlog_period sys_sync_binlog_period("sync_binlog", &sync_binlog_period);
>> +sys_var_int_ptr sys_sync_binlog_period("sync_binlog", &sync_binlog_period);
>> +sys_var_int_ptr sys_sync_relaylog_period("sync_relay_log", &sync_relaylog_period);
>> +sys_var_int_ptr sys_sync_relayloginfo_period("sync_relay_log_info", &sync_relayloginfo_period);
>> +sys_var_int_ptr sys_sync_masterinfo_period("sync_master_info", &sync_masterinfo_period);
>>     
>
> OK. Good that you generalized the code.
>
>   
>>  #endif
>>  sys_var_bool_ptr	sys_sync_frm("sync_frm", &opt_sync_frm);
>>  sys_var_const_str	sys_system_time_zone("system_time_zone",
>> @@ -762,6 +765,9 @@ sys_var *sys_variables[]=
>>    &sys_storage_engine,
>>  #ifdef HAVE_REPLICATION
>>    &sys_sync_binlog_period,
>> +  &sys_sync_relaylog_period,
>> +  &sys_sync_relayloginfo_period,
>> +  &sys_sync_masterinfo_period,
>>  #endif
>>    &sys_sync_frm,
>>    &sys_system_time_zone,
>> @@ -1090,6 +1096,9 @@ struct show_var_st init_vars[]= {
>>    {sys_storage_engine.name,   (char*) &sys_storage_engine,          SHOW_SYS},
>>  #ifdef HAVE_REPLICATION
>>    {sys_sync_binlog_period.name,(char*) &sys_sync_binlog_period,     SHOW_SYS},
>> +  {sys_sync_relaylog_period.name,(char*) &sys_sync_relaylog_period,     SHOW_SYS},
>> +  {sys_sync_relayloginfo_period.name,(char*) &sys_sync_relayloginfo_period,     SHOW_SYS},
>> +  {sys_sync_masterinfo_period.name,(char*) &sys_sync_masterinfo_period,     SHOW_SYS},
>>  #endif
>>    {sys_sync_frm.name,         (char*) &sys_sync_frm,               SHOW_SYS},
>>  #ifdef HAVE_TZNAME
>> @@ -1486,6 +1495,23 @@ static bool get_unsigned(THD *thd, set_v
>>  }
>>  
>>  
>> +bool sys_var_int_ptr::check(THD *thd, set_var *var)
>> +{
>> +  var->save_result.ulong_value= (ulong) var->value->val_int();
>> +  return 0;
>> +}
>> +
>> +bool sys_var_int_ptr::update(THD *thd, set_var *var)
>> +{
>> +  *value= (uint) var->save_result.ulong_value;
>> +  return 0;
>> +}
>> +
>> +void sys_var_int_ptr::set_default(THD *thd, enum_var_type type)
>> +{
>> +  *value= (uint) option_limits->def_value;
>> +}
>> +
>>  sys_var_long_ptr::
>>  sys_var_long_ptr(const char *name_arg, ulong *value_ptr_arg,
>>                   sys_after_update_func after_update_arg)
>> @@ -2759,13 +2785,6 @@ bool sys_var_slave_skip_counter::update(
>>    pthread_mutex_unlock(&LOCK_active_mi);
>>    return 0;
>>  }
>> -
>> -
>> -bool sys_var_sync_binlog_period::update(THD *thd, set_var *var)
>> -{
>> -  sync_binlog_period= (ulong) var->save_result.ulonglong_value;
>> -  return 0;
>> -}
>>  #endif /* HAVE_REPLICATION */
>>  
>>  bool sys_var_rand_seed1::update(THD *thd, set_var *var)
>>
>> === modified file 'sql/set_var.h'
>> --- a/sql/set_var.h	2008-01-23 15:03:58 +0000
>> +++ b/sql/set_var.h	2008-10-29 17:52:28 +0000
>> @@ -110,6 +110,26 @@ public:
>>    { return (byte*) value; }
>>  };
>>  
>> +/**
>> +   Unsigned int system variable class
>> + */
>> +class sys_var_int_ptr :public sys_var
>> +{
>> +public:
>> +  sys_var_int_ptr(const char *name_arg, uint *value_ptr_arg,
>> +                  sys_after_update_func after_update_arg= NULL)
>> +    :sys_var(name_arg, after_update_arg),
>> +     value(value_ptr_arg)
>> +  {}
>> +  bool check(THD *thd, set_var *var);
>> +  bool update(THD *thd, set_var *var);
>> +  void set_default(THD *thd, enum_var_type type);
>> +  SHOW_TYPE show_type() { return SHOW_INT; }
>> +  byte *value_ptr(THD *thd, enum_var_type type, LEX_STRING *base)
>> +  { return (byte*) value; }
>> +private:
>> +  uint *value;
>> +};
>>  
>>  /*
>>    A global ulong variable that is protected by LOCK_global_system_variables
>> @@ -550,11 +570,11 @@ public:
>>    */
>>  };
>>  
>> -class sys_var_sync_binlog_period :public sys_var_long_ptr
>> +class sys_var_sync_binlog_period :public sys_var_int_ptr
>>  {
>>  public:
>> -  sys_var_sync_binlog_period(const char *name_arg, ulong *value_ptr_arg)
>> -    :sys_var_long_ptr(name_arg,value_ptr_arg) {}
>> +  sys_var_sync_binlog_period(const char *name_arg, uint *value_ptr_arg)
>> +    :sys_var_int_ptr(name_arg,value_ptr_arg) {}
>>    bool update(THD *thd, set_var *var);
>>  };
>>  #endif
>>
>> === modified file 'sql/slave.cc'
>> --- a/sql/slave.cc	2008-03-28 20:01:05 +0000
>> +++ b/sql/slave.cc	2008-10-29 17:52:28 +0000
>> @@ -2582,6 +2582,7 @@ int flush_master_info(MASTER_INFO* mi, b
>>  {
>>    IO_CACHE* file = &mi->file;
>>    char lbuf[22];
>> +  int err= 0;
>>    DBUG_ENTER("flush_master_info");
>>    DBUG_PRINT("enter",("master_pos: %ld", (long) mi->master_log_pos));
>>  
>> @@ -2597,9 +2598,12 @@ int flush_master_info(MASTER_INFO* mi, b
>>      When we come to this place in code, relay log may or not be initialized;
>>      the caller is responsible for setting 'flush_relay_log_cache' accordingly.
>>    */
>> -  if (flush_relay_log_cache &&
>> -      flush_io_cache(mi->rli.relay_log.get_log_file()))
>> -    DBUG_RETURN(2);
>> +  if (flush_relay_log_cache)
>> +  {
>> +    IO_CACHE *log_file= mi->rli.relay_log.get_log_file();
>> +    if (flush_io_cache(log_file))
>> +      DBUG_RETURN(2);
>> +  }
>>     
>
> Although I personally prefer the refactored code, any code change potentially
> can lead to merge problems, so it is usually better to avoid it even if you
> don't like the code.
>
>   
This is the original patch. I will remove this.

>>  
>>    /*
>>      We flushed the relay log BEFORE the master.info file, because if we crash
>> @@ -2626,12 +2630,21 @@ int flush_master_info(MASTER_INFO* mi, b
>>  	      mi->password, mi->port, mi->connect_retry,
>>                (int)(mi->ssl), mi->ssl_ca, mi->ssl_capath, mi->ssl_cert,
>>                mi->ssl_cipher, mi->ssl_key);
>> -  DBUG_RETURN(-flush_io_cache(file));
>> +  err= flush_io_cache(file);
>> +  static unsigned int count=1;
>> +  if (sync_masterinfo_period && !err && count > sync_masterinfo_period)
>> +  {
>> +    err= my_sync(mi->fd, MYF(MY_WME));
>> +    count= 1;
>> +  }
>> +  count++;
>> +  DBUG_RETURN(-err);
>>  }
>>  
>>  
>>  st_relay_log_info::st_relay_log_info()
>> -  :info_fd(-1), cur_log_fd(-1), save_temporary_tables(0),
>> +  :info_fd(-1), cur_log_fd(-1), relay_log(&sync_relaylog_period),
>> +   save_temporary_tables(0),
>>     cur_log_old_open_count(0), group_master_log_pos(0), log_space_total(0),
>>     ignore_log_space_limit(0), last_master_timestamp(0), slave_skip_counter(0),
>>     abort_pos_wait(0), slave_run_id(0), sql_thd(0), last_slave_errno(0),
>> @@ -4872,6 +4885,12 @@ bool flush_relay_log_info(RELAY_LOG_INFO
>>      error=1;
>>    if (flush_io_cache(file))
>>      error=1;
>> +  if (sync_relayloginfo_period &&
>> +      !error)
>>     
>
> There is nothing similar to "count > sync_relayloginfo_period" here, and AFAICT,
>  this function is called each time the relay log info should be flushed.
>
>   
Comments above.
>> +  {
>> +    if (my_sync(rli->info_fd, MYF(MY_WME)))
>> +      error=1;
>> +  }
>>    /* Flushing the relay log is done by the slave I/O thread */
>>    return error;
>>  }
>>
>> === modified file 'sql/sql_class.h'
>> --- a/sql/sql_class.h	2008-09-17 06:34:00 +0000
>> +++ b/sql/sql_class.h	2008-10-29 17:52:28 +0000
>> @@ -238,6 +238,18 @@ class MYSQL_LOG: public TC_LOG
>>    bool no_auto_events;
>>    friend class Log_event;
>>  
>> +  /* pointer to the sync period variable, for binlog this will be
>> +     sync_binlog_period, for relay log this will be
>> +     sync_relay_log_period
>> +  */
>> +  uint *sync_period_ptr;
>> +  uint sync_counter;
>> +
>> +  inline uint get_sync_period()
>> +  {
>> +    return *sync_period_ptr;
>> +  }
>> +
>>  public:
>>    /*
>>      These describe the log's format. This is used only for relay logs.
>> @@ -250,7 +262,7 @@ public:
>>    Format_description_log_event *description_event_for_exec,
>>      *description_event_for_queue;
>>  
>> -  MYSQL_LOG();
>> +  MYSQL_LOG(uint *sync_period=0);
>>    /*
>>      note that there's no destructor ~MYSQL_LOG() !
>>      The reason is that we don't want it to be automatically called
>>
>>
>>     
>
>   

Cheers.