Hi Chuck
I am working on BUG#34447 recently, and it turns out to be a dup of this
bug. I think you patch is correct, but I have some consideratins about
its performance impact. Correct me if I am wrong :)
With your patch, we now get the binlog lock at the start of a statement,
when we write the Table_map event into binlog, and will be release when
we flush the row log event, but this could take long, one statement can
insert many records into a table, and user may use a set
binlog_row_event_max_size to a very big value. So this would block other
threads for a long time.
My suggestion is postpone writing the Table_map event until right before
we flush the row log events. By this way, we will not block other
threads writing their binlog events.
On 2007-08-21 Tue 21:56 +0200，cbell@stripped wrote：
> Below is the list of changes that have just been committed into a local
> 5.1 repository of cbell. When cbell does a push these changes will
> be propagated to the main repository and, within 24 hours after the
> push, to the public repository.
> For information on how to access the public repository
> see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html
>
> ChangeSet@stripped, 2007-08-21 15:56:03-04:00, cbell@mysql_cab_desk. +4 -0
> BUG#29020 : Test: Event results not replicated to slave in RBR
>
> Patch adds new methods to initiate locks on the binlog. These locks are
> used to ensure a table map / row event pair are written as a pair and
> prevent interleaving of the events.
>
> sql/log.cc@stripped, 2007-08-21 15:55:53-04:00, cbell@mysql_cab_desk. +28 -0
> BUG#29020 : Test: Event results not replicated to slave in RBR
>
> Patch adds new methods to initiate locks on the binlog. These locks are
> used to ensure a table map / row event pair are written as a pair and
> prevent interleaving of the events.
>
> sql/log.h@stripped, 2007-08-21 15:55:53-04:00, cbell@mysql_cab_desk. +2 -0
> BUG#29020 : Test: Event results not replicated to slave in RBR
>
> Patch adds new method declarations to initiate locks on the binlog.
>
> sql/sql_class.cc@stripped, 2007-08-21 15:55:54-04:00, cbell@mysql_cab_desk. +5 -1
> BUG#29020 : Test: Event results not replicated to slave in RBR
>
> Patch initializes thread variables for detecting when the new binlog lock
> methods are called.
>
> Adds a call to unlock the new binlog lock.
>
> sql/sql_class.h@stripped, 2007-08-21 15:55:55-04:00, cbell@mysql_cab_desk. +2 -0
> BUG#29020 : Test: Event results not replicated to slave in RBR
>
> Patch initializes thread variables for detecting when the new binlog lock
> methods are called.
>
> diff -Nrup a/sql/log.cc b/sql/log.cc
> --- a/sql/log.cc 2007-08-01 20:39:57 -04:00
> +++ b/sql/log.cc 2007-08-21 15:55:53 -04:00
> @@ -3399,10 +3399,13 @@ int THD::binlog_write_table_map(TABLE *t
>
> Table_map_log_event
> the_event(this, table, table->s->table_map_id, is_trans, flags);
> + binlog_in_trans= is_trans;
>
> if (is_trans && binlog_table_maps == 0)
> binlog_start_trans_and_stmt();
>
> + mysql_bin_log.binlog_begin_stmt();
> +
> if ((error= mysql_bin_log.write(&the_event)))
> DBUG_RETURN(error);
>
> @@ -3526,6 +3529,31 @@ MYSQL_BIN_LOG::flush_and_set_pending_row
>
> DBUG_RETURN(error);
> }
> +
> +bool MYSQL_BIN_LOG::binlog_begin_stmt()
> +{
> + bool error= 0;
> + DBUG_ENTER("MYSQL_BIN_LOG::binlog_begin_stmt()");
> + if (!current_thd->binlog_lock_taken &&
> !current_thd->binlog_in_trans)
> + {
> + current_thd->binlog_lock_taken= TRUE;
> + pthread_mutex_lock(&LOCK_log);
> + }
> + DBUG_RETURN(error);
> +}
> +
> +bool MYSQL_BIN_LOG::binlog_end_stmt()
> +{
> + bool error= 0;
> + DBUG_ENTER("MYSQL_BIN_LOG::binlog_end_stmt()");
> + if (current_thd->binlog_lock_taken)
> + {
> + pthread_mutex_unlock(&LOCK_log);
> + current_thd->binlog_lock_taken= FALSE;
> + }
> + DBUG_RETURN(error);
> +}
> +
>
> /*
> Write an event to the binary log
> diff -Nrup a/sql/log.h b/sql/log.h
> --- a/sql/log.h 2007-07-27 14:19:33 -04:00
> +++ b/sql/log.h 2007-08-21 15:55:53 -04:00
> @@ -337,6 +337,8 @@ public:
> /* Use this to start writing a new log file */
> void new_file();
>
> + bool binlog_begin_stmt();
> + bool binlog_end_stmt();
> bool write(Log_event* event_info); // binary log write
> bool write(THD *thd, IO_CACHE *cache, Log_event *commit_event);
>
> diff -Nrup a/sql/sql_class.cc b/sql/sql_class.cc
> --- a/sql/sql_class.cc 2007-08-02 04:22:29 -04:00
> +++ b/sql/sql_class.cc 2007-08-21 15:55:54 -04:00
> @@ -375,7 +375,9 @@ THD::THD()
> bootstrap(0),
> derived_tables_processing(FALSE),
> spcont(NULL),
> - m_lip(NULL)
> + m_lip(NULL),
> + binlog_lock_taken(FALSE),
> + binlog_in_trans(FALSE)
> {
> ulong tmp;
>
> @@ -3241,6 +3243,8 @@ int THD::binlog_flush_pending_rows_event
> }
>
> error= mysql_bin_log.flush_and_set_pending_rows_event(this, 0);
> + if (stmt_end)
> + mysql_bin_log.binlog_end_stmt();
> }
>
> DBUG_RETURN(error);
> diff -Nrup a/sql/sql_class.h b/sql/sql_class.h
> --- a/sql/sql_class.h 2007-08-01 20:59:39 -04:00
> +++ b/sql/sql_class.h 2007-08-21 15:55:55 -04:00
> @@ -1119,6 +1119,8 @@ public:
> Rows_log_event* binlog_get_pending_rows_event() const;
> void binlog_set_pending_rows_event(Rows_log_event* ev);
> int binlog_flush_pending_rows_event(bool stmt_end);
> + my_bool binlog_lock_taken;
> + my_bool binlog_in_trans;
>
> private:
> uint binlog_table_maps; // Number of table maps currently in the binlog
>
