DROP USER
RENAME USER CURRENT_USER() ...
GRANT ... TO CURRENT_USER()
REVOKE ... FROM CURRENT_USER()
ALTER DEFINER = CURRENT_USER() EVENTbut, When these statements are binlogged, CURRENT_USER() just is binlogged
as 'CURRENT_USER()', it is not expanded to the real user name. When slave
executes the log event, 'CURRENT_USER()' is expand to the user of slave
SQL thread, but SQL thread's user name always NULL. This breaks the replication.
After this patch, session's user will be written into query log events
if these statements call CURREN_USER() or 'ALTER EVENT' does not assign a definer.
DROP USER
RENAME USER CURRENT_USER() ...
GRANT ... TO CURRENT_USER()
REVOKE ... FROM CURRENT_USER()
ALTER DEFINER = CURRENT_USER() EVENTbut, When these statements are binlogged, CURRENT_USER() just is binlogged
as 'CURRENT_USER()', it is not expanded to the real user name. When slave
executes the log event, 'CURRENT_USER()' is expand to the user of slave
SQL thread, but SQL thread's user name always NULL. This breaks the replication.
After this patch, session's user will be written into query log events
if these statements call CURREN_USER() or 'ALTER EVENT' does not assign a definer.
The default storage engine is changed from MyISAM to
InnoDB, in all builds except for the embedded server.
In addition, the following system variables are
changed:
* innodb_file_per_table is enabled
* innodb_strict_mode is enabled
* innodb_file_format_name_update is changed
to 'Barracuda'
The test suite is changed so that tests that do not
explicitly include the have_innodb.inc are run with
--default-storage-engine=MyISAM. This is to ease the
transition, so that most regression tests are run
with the same engine as before.
Some tests are disabled for the embedded server
regression test, as the output of certain statements
will be different that for the regular server
(i.e SELECT @@default_storage_engine). This is to
ease transition.
locks for DML statements and changes the way MDL locks
are acquired/granted in contended case.
Instead of backing-off when a lock conflict is encountered
and waiting for it to go away before restarting open_tables()
process we now wait for lock to be released without releasing
any previously acquired locks. If conflicting lock goes away
we resume opening tables. If waiting leads to a deadlock we
try to resolve it by backing-off and restarting open_tables()
immediately.
As result both waiting for possibility to acquire and
acquiring of a metadata lock now always happen within the
same MDL API call. This has allowed to make release of a lock
and granting it to the most appropriate pending request an
atomic operation.
Thanks to this it became possible to wake up during release
of lock only those waiters which requests can be satisfied
at the moment as well as wake up only one waiter in case
when granting its request would prevent all other requests
from being satisfied. This solves thundering herd problem
which occured in cases when we were releasing some lock and
woke up many waiters for SNRW or X locks (this was the issue
in bug#52289 "performance regression for MyISAM in sysbench
OLTP_RW test".
This also allowed to implement more fair (FIFO) scheduling
among waiters with the same priority.
It also opens the door for introducing new types of requests
for metadata locks such as low-prio SNRW lock which is
necessary in order to support LOCK TABLES LOW_PRIORITY WRITE.
Notice that after this sometimes can report ER_LOCK_DEADLOCK
error in cases in which it has not happened before.
Particularly we will always report this error if waiting for
conflicting lock has happened in the middle of transaction
and resulted in a deadlock. Before this patch the error was
not reported if deadlock could have been resolved by backing
off all metadata locks acquired by the current statement.
When using Unique Keys with nullable parts in RBR, the slave can
choose the wrong row to update. This happens because a table with
an unique key containing nullable parts cannot strictly guarantee
uniqueness. As stated in the manual, for all engines, a UNIQUE
index allows multiple NULL values for columns that can contain
NULL.
We fix this at the slave by extending the checks before assuming
that the row found through an unique index is is the correct
one. This means that when a record (R) is fetched from the storage
engine and a key that is not primary (K) is used, the server does
the following:
- If K is unique and has no nullable parts, it returns R;
- Otherwise, if any field in the before image that is part of K
is null do an index scan;
- If there is no NULL field in the BI part of K, then return R.
A side change: renamed the existing test case file and added a
test case covering the changes in this patch.
errors
In the fix of BUG#39934 in 5.1-rep+3, errors are generated when
binlog_format=row and a statement modifies a table restricted to
statement-logging (ER_BINLOG_ROW_MODE_AND_STMT_ENGINE); or if
binlog_format=statement and a statement modifies a table restricted to
row-logging (ER_BINLOG_STMT_MODE_AND_ROW_ENGINE).
However, some DDL statements that lock tables (e.g. ALTER TABLE,
CREATE INDEX and CREATE TRIGGER) were causing spurious errors,
although no row might be inserted into the binary log.
To fix the problem, we tagged statements that may generate
rows into the binary log and thence the warning messages are
only printed out when the appropriate conditions hold and rows
might be changed.
breaks
When a "CREATE TEMPORARY TABLE SELECT * FROM" was executed the OPTION_KEEP_LOG was
not set into the thd->variables.option_bits. For that reason, if the transaction
had updated only transactional engines and was rolled back at the end (.e.g due to
a deadlock) the changes were not written to the binary log, including the creation
of the temporary table.
To fix the problem, we have set the OPTION_KEEP_LOG into the
thd->variables.option_bits when a "CREATE TEMPORARY TABLE
SELECT * FROM" is executed.
Add code to waiting for a set of errors.
Add code to waiting for an error instead of waiting for io thread to stop, as
after 'START SLAVE', the status of io thread is still not running.
But it doesn't mean slave io thread encounters an error.
The thd->variables.option_bits & OPTION_BIN_LOG is currently abused:
it's both a system variable and an implementation switch. The current
approach to this option bit breaks the session variable encapsulation.
Besides it is allowed to change @@session.sql_bin_log within a
transaction what may lead to not correctly logging a transaction.
To fix the problems, we created a thd->variables variable to represent
the "sql_log_bin" and prohibited its update inside a transaction or
sub-statement.
Some of the test cases reference to binlog position and
these position numbers are written into result explicitly.
It is difficult to maintain if log event format changes.
There are a couple of cases explicit position number appears,
we handle them in different ways
A. 'CHANGE MASTER ...' with MASTER_LOG_POS or/and RELAY_LOG_POS options
Use --replace_result to mask them.
B. 'SHOW BINLOG EVENT ...'
Replaced by show_binlog_events.inc or wait_for_binlog_event.inc.
show_binlog_events.inc file's function is enhanced by given
$binlog_file and $binlog_limit.
C. 'SHOW SLAVE STATUS', 'show_slave_status.inc' and 'show_slave_status2.inc'
For the test cases just care a few items in the result of 'SHOW SLAVE STATUS',
only the items related to each test case are showed.
'show_slave_status.inc' is rebuild, only the given items in $status_items
will be showed.
'check_slave_is_running.inc' and 'check_slave_no_error.inc'
and 'check_slave_param.inc' are auxiliary files helping
to show running status and error information easily.
This patch fixes two problems described as follows:
1 - If there is an on-going transaction and a temporary table is created or
dropped, any failed statement that follows the "create" or "drop commands"
triggers a rollback and by consequence the slave will go out sync because
the binary log will have a wrong sequence of events.
To fix the problem, we changed the expression that evaluates when the
cache should be flushed after either the rollback of a statment or
transaction.
2 - When a "CREATE TEMPORARY TABLE SELECT * FROM" was executed the
OPTION_KEEP_LOG was not set into the thd->options. For that reason, if
the transaction had updated only transactional engines and was rolled
back at the end (.e.g due to a deadlock) the changes were not written
to the binary log, including the creation of the temporary table.
To fix the problem, we have set the OPTION_KEEP_LOG into the thd->options
when a "CREATE TEMPORARY TABLE SELECT * FROM" is executed.
MTR sporadically reported that rpl_do_grant does not
clean up after itself.
We fix this by backporting BUG 50984 fix. This deploys
missing synchronization between master and slave.
Additionally, it also fixes the check_testcase for
rpl_tmp_table_and_DDL.
When using a non-transactional table (t1) on the master
and with autocommit disabled, no COMMIT is recorded
in the binary log ending the statement. Therefore, if
the slave has t1 in a transactional engine, then it will
be as if a transaction is started but never ends. This is
actually BUG#29288 all over again.
We fix this by cherrypicking the cset for BUG#29288 which
was pushed to a later mysql version. The revision picked
was: mats@sun.com-20090923094343-bnheplq8n95opjay .
Additionally, a test case for covering the scenario depicted
in the bug report is included in this cset.
Conflicts:
Text conflict in configure.in
Text conflict in dbug/dbug.c
Text conflict in mysql-test/r/ps.result
Text conflict in mysql-test/t/ps.test
Text conflict in sql/CMakeLists.txt
Text conflict in sql/ha_ndbcluster.cc
Text conflict in sql/mysqld.cc
Text conflict in sql/sql_plugin.cc
Text conflict in sql/sql_table.cc
Clarified error messages related to unsafe statements:
- avoid the internal technical term "row injection"
- use 'binary log' instead of 'binlog'
- avoid the word 'unsafeness'
Stored routine DDL statements use statement-based replication
regardless of the current binlog format. The problem here was
that if a DDL statement failed during metadata lock acquisition
or opening of mysql.proc, the binlog format would not be reset
before returning. So the following DDL or DML statements are
binlogged with a wrong binlog format, which causes the slave
to stop.
The problem can be resolved by grabbing an exclusive MDL lock firstly
instead of clearing the current binlog format. So that the binlog
format will not be affected when the lock grab returns directly with
an error. The same way is taken to open a proc table for update.
Statements with CONNECTION_ID were forced to be kept in the transactional
cache and by consequence non-transactional changes that were supposed to
be flushed ahead of the transaction were kept in the transactional cache.
This happened because after BUG#51894 any statement whose thd's
thread_specific_used was set was kept in the transactional cache. The idea
was to keep changes on temporary tables in the transactional cache. However,
the thread_specific_used was set not only for statements that accessed
temporary tables but also when the CONNECTION_ID was used.
To fix the problem, we created a new variable to keep track of updates
to temporary tables.
of sync
In RBR, sometimes the table->s->last_null_bit_pos can be zero. This
has impact at the slave when it compares records fetched from the
storage engine against records in the binary log event. If
last_null_bit_pos is zero the slave, while comparing in
log_event.cc:record_compare function, would set all bits in the last
null_byte to 1 (assumed all 8 were unused) . Thence it would loose the
ability to distinguish records that were similar in contents except
for the fact that some field was null in one record, but not in the
other. Ultimately this would cause wrong matches, and in the specific
case depicted in the bug report the same record would be updated
twice, resulting in a lost update.
Additionally, in the record_compare function the slave was setting the
X bit unconditionally. There are cases that the X bit does not exist
in the record header. This could also lead to wrong matches between
records.
We fix both by conditionally resetting the bits: (i) unused null_bits
are set if last_null_bit_pos > 0; (ii) X bit is set if
HA_OPTION_PACK_RECORD is in use.
transaction
BUG#52616 Temp table prevents switch binlog format from STATEMENT to ROW
Before the WL#2687 and BUG#46364, every non-transactional change that happened
after a transactional change was written to trx-cache and flushed upon
committing the transaction. WL#2687 and BUG#46364 changed this behavior and
non-transactional changes are now written to the binary log upon committing
the statement.
A binary log event is identified as transactional or non-transactional through
a flag in the Log_event which is set taking into account the underlie storage
engine on what it is stems from. In the current bug, this flag was not being
set properly when the DROP TEMPORARY TABLE was executed.
However, while fixing this bug we figured out that changes to temporary tables
should be always written to the trx-cache if there is an on-going transaction.
Otherwise, binlog events in the reversed order would be produced.
Regarding concurrency, keeping changes to temporary tables in the trx-cache is
also safe as temporary tables are only visible to the owner connection.
In this patch, we classify the following statements as unsafe:
1 - INSERT INTO t_myisam SELECT * FROM t_myisam_temp
2 - INSERT INTO t_myisam_temp SELECT * FROM t_myisam
3 - CREATE TEMPORARY TABLE t_myisam_temp SELECT * FROM t_myisam
On the other hand, the following statements are classified as safe:
1 - INSERT INTO t_innodb SELECT * FROM t_myisam_temp
2 - INSERT INTO t_myisam_temp SELECT * FROM t_innodb
The patch also guarantees that transactions that have a DROP TEMPORARY are
always written to the binary log regardless of the mode and the outcome:
commit or rollback. In particular, the DROP TEMPORARY is extended with the
IF EXISTS clause when the current statement logging format is set to row.
Finally, the patch allows to switch from STATEMENT to MIXED/ROW when there
are temporary tables but the contrary is not possible.
