Problem: Some system functions that could return different values on
master and slave were not marked unsafe. In particular:
GET_LOCK
IS_FREE_LOCK
IS_USED_LOCK
MASTER_POS_WAIT
RELEASE_LOCK
SLEEP
SYSDATE
VERSION
Fix: Mark these functions unsafe.
One statement that have more than one different tables to update with
autoinc columns just was marked as unsafe in mixed mode, so the unsafe
warning can't be produced in statement mode.
To fix the problem, mark the statement as unsafe in statement mode too.
Mysql server crashes because unsafe statements warning is wrongly elevated to error,
which is set the error status of Diagnostics_area of the thread in THD::binlog_query().
Yet the caller believes that binary logging shouldn't touch the status, so it will
set the status also later by my_ok(), my_error() or my_message() seperately
according to the execution result of the statement or transaction.
But the status of Diagnostics_area of the thread is allowed to set only once.
Fixed to clear the error wrongly set by binary logging, but keep the warning message.
When binlog_format is STATEMENT and the statement is unsafe before,
the unsafe warning/error message was issued without checking
whether the SQL_LOG_BIN was turned on or not.
Fixed with adding a sql_log_bin_toplevel flag in THD to check
whether SQL_LOG_BIN is ON in current session whatever the current is in sp or not.
The problem is that a unfiltered user query was being passed as
the format string parameter of sql_print_warning which later
performs printf-like formatting, leading to crashes if the user
query contains formatting instructions (ie: %s). Also, it was
using THD::query as the source of the user query, but this
variable is not meaningful in some situations -- in a delayed
insert, it points to the table name.
The solution is to pass the user query as a parameter for the
format string and use the function parameter query_arg as the
source of the user query.
binlog_format=mixed
Statement-based replication of DELETE ... LIMIT, UPDATE ... LIMIT,
INSERT ... SELECT ... LIMIT is not safe as order of rows is not
defined.
With this fix, we issue a warning that this statement is not safe to
replicate in statement mode, or go to row-based mode in mixed mode.
Note that we may consider a statement as safe if ORDER BY primary_key
is present. However it may confuse users to see very similiar statements
replicated differently.
Note 2: regular UPDATE statement (w/o LIMIT) is unsafe as well, but
this patch doesn't address this issue. See comment from Kristian
posted 18 Mar 10:55.
Problem: in mixed and statement mode, a query that refers to a
system variable will use the slave's value when replayed on
slave. So if the value of a system variable is inserted into a
table, the slave will differ from the master.
Fix: mark statements that refer to a system variable as "unsafe",
meaning they will be replicated by row in mixed mode and produce a warning
in statement mode. There are some exceptions: some variables are actually
replicated. Those should *not* be marked as unsafe.
BUG#34732: mysqlbinlog does not print default values for auto_increment variables
Problem: mysqlbinlog does not print default values for some variables,
including auto_increment_increment and others. So if a client executing
the output of mysqlbinlog has different default values, replication will
be wrong.
Fix: Always print default values for all variables that are replicated.
I need to fix the two bugs at the same time, because the test cases would
fail if I only fixed one of them.
