The slave was not able to find the correct row in the innodb
table, because the row fetched from the innodb table would not
match the before image. This happened because the (don't care)
bytes in the NULLed fields would change once the row was stored
in the storage engine (from zero to the default value). This
would make bulk memory comparison (using memcmp) to fail.
We fix this by taking a preventing measure and avoiding memcmp
for tables that contain nullable fields. Therefore, we protect
the slave search routine from engines that return arbitrary
values for don't care bytes (in the nulled fields). Instead, the
slave thread will only check null_bits and those fields that are
not set to NULL when comparing the before image against the
storage engine row.
Currently, rpl_semi_sync is failing in PB due to the warning message:
"Slave SQL: slave SQL thread is being stopped in the middle of "
"applying of a group having updated a non-transaction table; "
"waiting for the group completion ..."
The problem started happening after the fix for BUG#11762407 what was
automatically suppressing some warning messages.
To fix the current issue, we suppress the aforementioned warning message
and exploit the opportunity to make the sentence clearer.
FAILED DROP DATABASE CAN BREAK STATEMENT BASED REPLICATION
The first phase of DROP DATABASE is to delete the tables in the database.
If deletion of one or more of the tables fail (e.g. due to a FOREIGN KEY
constraint), DROP DATABASE will be aborted. However, some tables could
still have been deleted. The problem was that nothing would be written
to the binary log in this case, so any slaves would not delete these tables.
Therefore the master and the slaves would get out of sync.
This patch fixes the problem by making sure that DROP TABLE is written
to the binary log for the tables that were in fact deleted by the failed
DROP DATABASE statement.
Test case added to binlog.binlog_database.test.
In SBR, if a statement does not fail, it is always written to the binary
log, regardless if rows are changed or not. If there is a failure, a
statement is only written to the binary log if a non-transactional (.e.g.
MyIsam) engine is updated.
INSERT ON DUPLICATE KEY UPDATE and INSERT IGNORE were not following the
rule above and were not written to the binary log, if then engine was
Innodb.
The test started failing on the same day patch for BUG 49978 was
pushed. BUG 49978 changed part of the replication testing
infrastructure in mysql-test-run. This caused the test to fail
sporadically with result differences on relay log file
names. When the test fails the relay-log filenames are shifted by
one, eg:
-show relaylog events in 'slave-relay-bin.000002' from <binlog_start>;
+show relaylog events in 'slave-relay-bin.000003' from <binlog_start>;
The problem was caused by a bad cleanup when using the include
files:
- include/setup_fake_relay_log.inc
- include/cleanup_fake_relay_log.inc
Which would leave a spurious relay-log file around (not listed in
slave-relay-bin.index), causing the server to shift the name of
the relay logs by one, even if cleaning up with RESET SLAVE.
We fix this by removing the relay-log file when it is not needed
anymore, ie at setup time and after recreating the fake relay-log
index.
Additionally, to make the affected test more resilient, we
deployed a call to rpl_reset.inc (which resets both master and
slave, including log files) before actually running the test
case.
Finally, appart from the reported bug, we also fix: (a) an
unrelated issue with the failing test itself - in some cases, the
test was not setting the log file name to use when it should;
(b) one typo.
Normally, auto_increment value is generated for the column by
inserting either NULL or 0 into it. NO_AUTO_VALUE_ON_ZERO
suppresses this behavior for 0 so that only NULL generates
the auto_increment value. This behavior is also followed by
a slave, specifically by the SQL Thread, when applying events
in the statement format from a master. However, when applying
events in the row format, the flag was ignored thus causing
an assertion failure:
"Assertion failed: next_insert_id == 0, file .\handler.cc"
In fact, we never need to generate a auto_increment value for
the column when applying events in row format on slave. So we
don't allow it to happen by using 'MODE_NO_AUTO_VALUE_ON_ZERO'.
Refactoring: Get rid of all the sql_mode checks to rows_log_event
when applying it for avoiding problems caused by the inconsistency
of the sql_mode on slave and master as the sql_mode is not set for
Rows_log_event.
Normally, auto_increment value is generated for the column by
inserting either NULL or 0 into it. NO_AUTO_VALUE_ON_ZERO
suppresses this behavior for 0 so that only NULL generates
the auto_increment value. This behavior is also followed by
a slave, specifically by the SQL Thread, when applying events
in the statement format from a master. However, when applying
events in the row format, the flag was ignored thus causing
an assertion failure:
"Assertion failed: next_insert_id == 0, file .\handler.cc"
In fact, we never need to generate a auto_increment value for
the column when applying events in row format on slave. So we
don't allow it to happen by using 'MODE_NO_AUTO_VALUE_ON_ZERO'.
Refactoring: Get rid of all the sql_mode checks to rows_log_event
when applying it for avoiding problems caused by the inconsistency
of the sql_mode on slave and master as the sql_mode is not set for
Rows_log_event.
Major replication test framework cleanup. This does the following:
- Ensure that all tests clean up the replication state when they
finish, by making check-testcase check the output of SHOW SLAVE STATUS.
This implies:
- Slave must not be running after test finished. This is good
because it removes the risk for sporadic errors in subsequent
tests when a test forgets to sync correctly.
- Slave SQL and IO errors must be cleared when test ends. This is
good because we will notice if a test gets an unexpected error in
the slave threads near the end.
- We no longer have to clean up before a test starts.
- Ensure that all tests that wait for an error in one of the slave
threads waits for a specific error. It is no longer possible to
source wait_for_slave_[sql|io]_to_stop.inc when there is an error
in one of the slave threads. This is good because:
- If a test expects an error but there is a bug that causes
another error to happen, or if it stops the slave thread without
an error, then we will notice.
- When developing tests, wait_for_*_to_[start|stop].inc will fail
immediately if there is an error in the relevant slave thread.
Before this patch, we had to wait for the timeout.
- Remove duplicated and repeated code for setting up unusual replication
topologies. Now, there is a single file that is capable of setting
up arbitrary topologies (include/rpl_init.inc, but
include/master-slave.inc is still available for the most common
topology). Tests can now end with include/rpl_end.inc, which will clean
up correctly no matter what topology is used. The topology can be
changed with include/rpl_change_topology.inc.
- Improved debug information when tests fail. This includes:
- debug info is printed on all servers configured by include/rpl_init.inc
- User can set $rpl_debug=1, which makes auxiliary replication files
print relevant debug info.
- Improved documentation for all auxiliary replication files. Now they
describe purpose, usage, parameters, and side effects.
- Many small code cleanups:
- Made have_innodb.inc output a sensible error message.
- Moved contents of rpl000017-slave.sh into rpl000017.test
- Added mysqltest variables that expose the current state of
disable_warnings/enable_warnings and friends.
- Too many to list here: see per-file comments for details.
It is not necessary to support INSERT DELAYED for a single value insert,
while we do not support that for multi-values insert when binlog is
enabled in SBR.
The lock_type is upgrade to TL_WRITE from TL_WRITE_DELAYED for
INSERT DELAYED for single value insert as multi-values insert
did when binlog is enabled. Then it's safe. And binlog it as
INSERT without DELAYED.
When using BINLOG statement to execute rows log events, session variables
foreign_key_checks and unique_checks are changed temporarily. As each rows
log event has their own special session environment and its own
foreign_key_checks and unique_checks can be different from current session
which executing the BINLOG statement. But these variables are not restored
correctly after BINLOG statement. This problem will cause that the following
statements fail or generate unexpected data.
In this patch, code is added to backup and restore these two variables.
So BINLOG statement will not affect current session's variables again.
win x86 debug_max
The windows MTR run exhibited a different test execution
ordering (due to the fact that in these platforms MTR is invoked
with --parallel > 1). This uncovered a bug in the aforementioned
test case, which is triggered by the following conditions:
1. server is not restarted between two different tests;
2. the test before binlog.binlog_row_failure_mixing_engines
issues flush logs;
3. binlog.binlog_row_failure_mixing_engines uses binlog
positions to limit the output of show_binlog_events;
4. binlog.binlog_row_failure_mixing_engines does not state which
binlog file to use, thence it uses a wrong binlog file with
the correct position.
There are two possible fixes: 1. make sure that the test start
from a clean slate - binlog wise; 2. in addition to the position,
also state the binary log file before sourcing
show_binlog_events.inc .
We go for fix#1, ie, deploy a RESET MASTER before the test is
actually started.
After the WL#2687, the binlog_cache_size and max_binlog_cache_size affect both the
stmt-cache and the trx-cache. This means that the resource used is twice the amount
expected/defined by the user.
The binlog_cache_use is incremented when the stmt-cache or the trx-cache is used
and binlog_cache_disk_use is incremented when the disk space from the stmt-cache or the
trx-cache is used. This behavior does not allow to distinguish which cache may be harming
performance due to the extra disk accesses and needs to have its in-memory cache
increased.
To fix the problem, we introduced two new options and status variables related to the
stmt-cache:
Options:
. binlog_stmt_cache_size
. max_binlog_stmt_cache_size
Status Variables:
. binlog_stmt_cache_use
. binlog_stmt_cache_disk_use
So there are
. binlog_cache_size that defines the size of the transactional cache for
updates to transactional engines for the binary log.
. binlog_stmt_cache_size that defines the size of the statement cache for
updates to non-transactional engines for the binary log.
. max_binlog_cache_size that sets the total size of the transactional
cache.
. max_binlog_stmt_cache_size that sets the total size of the statement
cache.
. binlog_cache_use that identifies the number of transactions that used the
temporary transactional binary log cache.
. binlog_cache_disk_use that identifies the number of transactions that used
the temporary transactional binary log cache but that exceeded the value of
binlog_cache_size.
. binlog_stmt_cache_use that identifies the number of statements that used the
temporary non-transactional binary log cache.
. binlog_stmt_cache_disk_use that identifies the number of statements that used
the temporary non-transactional binary log cache but that exceeded the value of
binlog_stmt_cache_size.
The binlog_cache_use is incremented twice when changes to a transactional table
are committed, i.e. TC_LOG_BINLOG::log_xid calls is called. The problem happens
because log_xid calls both binlog_flush_stmt_cache and binlog_flush_trx_cache
without checking if such caches are empty thus unintentionally increasing the
binlog_cache_use value twice.
Although not explicitly mentioned in the bug, the binlog_cache_disk_use presents
the same problem.
The binlog_cache_use and binlog_cache_disk_use are status variables that are
incremented when transactional (i.e. trx-cache) or non-transactional (i.e.
stmt-cache) changes are committed. They are used to compute the ratio between
the use of disk and memory while gathering updates for a transaction.
The problem reported is fixed by avoiding incrementing the binlog_cache_use
and binlog_cache_disk_use if a cache is empty. We also have decided to increment
both variables when a cache is truncated as the cache is used although its
content is discarded and is not written to the binary log.
In this patch, we take the opportunity to re-organize the code around the
function binlog_flush_trx_cache and binlog_flush_stmt_cache.
