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BUG#51291 Unfortunate effect around variable binlog_direct_non_transactional_updates

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BUG#46364 introduced the flag binlog_direct_non_transactional_updates which
would make N-changes to be written to the binary log upon committing the
statement when "ON". On the other hand, when "OFF" the option was supposed
to mimic the behavior in 5.1. However, the implementation was not mimicking
the behavior correctly and the following bugs popped up:

  Case #1: N-changes executed within a transaction would go into
           the S-cache. When later in the same transaction a
           T-change occurs, N-changes following it were written
           to the T-cache instead of the S-cache. In some cases,
           this raises problems. For example, a
           Table_map_log_event being written initially into the
           S-cache, together with the initial N-changes, would be
           absent from the T-cache. This would log N-changes
           orphaned from a Table_map_log_event (thence discarded
           at the slave). (MIXED and ROW)

   Case #2: When rolling back a transaction, the N-changes that
            might be in the T-cache were disregarded and
            truncated along with the T-changes. (MIXED and ROW)

   Case #3: When a MIXED statement (TN) is ahead of any other
            T-changes in the transaction and it fails, it is kept
            in the T-cache until the transaction ends. This is
            not the case in 5.1 or Betony (5.5.2). In these, the
            failed TN statement would be written to the binlog at
            the same instant it had failed and not deferred until
            transaction end. (SBR)

To fix these problems, we have decided to do what follows:

   For Case #1 and #2, we circumvent them:

      1. by not letting binlog_direct_non_transactional_updates
         affect MIXED and RBR. These modes will keep the behavior
         provided by WL#2687. Although this will make Celosia to
         behave differently from 5.1, an execution will be always
         safe under such modes in the sense that slaves will never
         go out sync. In 5.1, using either MIXED or ROW while
         mixing N-statements and T-statements was not safe.

   For Case #3, we don't actually fix it. We:

      1. keep it and make all MIXED statements whether they end
         up failing or not or whether they are up front in the
         transaction or after some transactional change to always
         be stored in the T-cache. This means that it is written
         to the binary log on transaction commit/rollback only.

      2. We make the warning message even more specific about the
         MIXED statement and SBR.
This commit is contained in:
Alfranio Correia
2010-03-31 14:22:47 +01:00
parent 6e3646e1ca
commit 7827688f23
13 changed files with 136 additions and 97 deletions
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51
sql/sql_class.cc
View File

@ -3592,10 +3592,28 @@ int THD::decide_logging_format(TABLE_LIST *tables)
handler::Table_flags flags_write_all_set=
HA_BINLOG_ROW_CAPABLE | HA_BINLOG_STMT_CAPABLE;
/*
If different types of engines are about to be updated.
For example: Innodb and Falcon; Innodb and MyIsam.
*/
my_bool multi_write_engine= FALSE;
my_bool multi_engine= FALSE;
my_bool trans_non_trans_multi_engine= FALSE;
my_bool all_trans_engines= TRUE;
/*
If different types of engines are about to be accessed
and any of them is about to be updated. For example:
Innodb and Falcon; Innodb and MyIsam.
*/
my_bool multi_access_engine= FALSE;
/*
If non-transactional and transactional engines are about
to be accessed and any of them is about to be updated.
For example: Innodb and MyIsam.
*/
my_bool trans_non_trans_access_engines= FALSE;
/*
If all engines that are about to be updated are
transactional.
*/
my_bool all_trans_write_engines= TRUE;
TABLE* prev_write_table= NULL;
TABLE* prev_access_table= NULL;
@ -3629,8 +3647,8 @@ int THD::decide_logging_format(TABLE_LIST *tables)
if (prev_write_table && prev_write_table->file->ht !=
table->table->file->ht)
multi_write_engine= TRUE;
all_trans_engines= all_trans_engines &&
table->table->file->has_transactions();
all_trans_write_engines= all_trans_write_engines &&
table->table->file->has_transactions();
prev_write_table= table->table;
flags_write_all_set &= flags;
flags_write_some_set |= flags;
@ -3638,8 +3656,8 @@ int THD::decide_logging_format(TABLE_LIST *tables)
flags_some_set |= flags;
if (prev_access_table && prev_access_table->file->ht != table->table->file->ht)
{
multi_engine= TRUE;
trans_non_trans_multi_engine= trans_non_trans_multi_engine ||
multi_access_engine= TRUE;
trans_non_trans_access_engines= trans_non_trans_access_engines ||
(prev_access_table->file->has_transactions() !=
table->table->file->has_transactions());
}
@ -3650,9 +3668,9 @@ int THD::decide_logging_format(TABLE_LIST *tables)
DBUG_PRINT("info", ("flags_write_some_set: 0x%llx", flags_write_some_set));
DBUG_PRINT("info", ("flags_some_set: 0x%llx", flags_some_set));
DBUG_PRINT("info", ("multi_write_engine: %d", multi_write_engine));
DBUG_PRINT("info", ("multi_engine: %d", multi_engine));
DBUG_PRINT("info", ("trans_non_trans_multi_engine: %d",
trans_non_trans_multi_engine));
DBUG_PRINT("info", ("multi_access_engine: %d", multi_access_engine));
DBUG_PRINT("info", ("trans_non_trans_access_engines: %d",
trans_non_trans_access_engines));
int error= 0;
int unsafe_flags;
@ -3661,8 +3679,10 @@ int THD::decide_logging_format(TABLE_LIST *tables)
Set the statement as unsafe if:
. it is a mixed statement, i.e. access transactional and non-transactional
tables, and updates at least one;
or
tables, and update any of them;
or:
. an early statement updated a transactional table;
. and, the current statement updates a non-transactional table.
@ -3726,8 +3746,9 @@ int THD::decide_logging_format(TABLE_LIST *tables)
isolation level but if we have pure repeatable read or serializable the
lock history on the slave will be different from the master.
*/
if (trans_non_trans_multi_engine ||
(trans_has_updated_trans_table(this) && !all_trans_engines))
if (!trans_non_trans_access_engines)
lex->set_stmt_unsafe(LEX::BINLOG_STMT_UNSAFE_MIXED_STATEMENT);
else if (trans_has_updated_trans_table(this) && !all_trans_write_engines)
lex->set_stmt_unsafe(LEX::BINLOG_STMT_UNSAFE_NONTRANS_AFTER_TRANS);
/*
@ -3740,7 +3761,7 @@ int THD::decide_logging_format(TABLE_LIST *tables)
(flags_write_some_set & HA_HAS_OWN_BINLOGGING))
my_error((error= ER_BINLOG_MULTIPLE_ENGINES_AND_SELF_LOGGING_ENGINE),
MYF(0));
else if (multi_engine && flags_some_set & HA_HAS_OWN_BINLOGGING)
else if (multi_access_engine && flags_some_set & HA_HAS_OWN_BINLOGGING)
lex->set_stmt_unsafe(LEX::BINLOG_STMT_UNSAFE_MULTIPLE_ENGINES_AND_SELF_LOGGING_ENGINE);
/* both statement-only and row-only engines involved */