BUG#49481: RBR: MyISAM and bit fields may cause slave to stop on delete:
cant find record
BUG#49482: RBR: Replication may break on deletes when MyISAM tables +
char field are used
When using MyISAM tables, despite the fact that the null bit is
set for some fields, their old value is still in the row. This
can cause the comparison of records to fail when the slave is
doing an index or range scan.
We fix this by avoiding memcmp for MyISAM tables when comparing
records. Additionally, when comparing field by field, we first
check if both fields are not null and if so, then we compare
them. If just one field is null we return failure immediately. If
both fields are null, we move on to the next field.
For tables with metadata sizes ranging from 251 to 255 the size
of the event data (m_data_size) was being improperly calculated
in the Table_map_log_event constructor. This was due to the fact
that when writing the Table_map_log_event body (in
Table_map_log_event::write_data_body) a call to net_store_length
is made for packing the m_field_metadata_size. It happens that
net_store_length uses *one* byte for storing
m_field_metadata_size when it is smaller than 251 but *three*
bytes when it exceeds that value. BUG 42749 had already
pinpointed and fix this fact, but the fix was incomplete, as the
calculation in the Table_map_log_event constructor considers 255
instead of 251 as the threshold to increment m_data_size by
three. Thence, the window for having a mismatch between the
number of bytes written and the number of bytes accounted in the
event length (m_data_size) was left open for
m_field_metadata_size values between 251 and 255.
We fix this by changing the condition in the Table_map_log_event
constructor to match the one in the net_store_length, ie,
increment one byte if m_field_metadata_size < 251 and three if it
exceeds this value.
In statement-based or mixed-mode replication, use DROP TEMPORARY TABLE
to drop multiple tables causes different errors on master and slave,
when one or more of these tables do not exist. Because when executed
on slave, it would automatically add IF EXISTS to the query to ignore
all ER_BAD_TABLE_ERROR errors.
To fix the problem, do not add IF EXISTS when executing DROP TEMPORARY
TABLE on the slave, and clear the ER_BAD_TABLE_ERROR error after
execution if the query does not expect any errors.
'LOAD DATA CONCURRENT [LOCAL] INFILE ...' statment only is binlogged as
'LOAD DATA [LOCAL] INFILE ...' in SBR and MBR. As a result, if replication is on,
queries on slaves will be blocked by the replication SQL thread.
This patch write code to write 'CONCURRENT' into the log event if 'CONCURRENT' option
is in the original statement in SBR and MBR.
Valgrind reports a conditional jump that depends on uninitialized
data while doing a LOAD DATA and for this test case only. This
test case, tests that loading data from a 4.0 or 4.1 instance
into a 5.1 instance is working. As such it handles old binary log
with a different set of events than currently 5.1 codebase uses.
See the following reference for details:
http://forge.mysql.com/wiki/MySQL_Internals_Binary_Log#LOAD_DATA_INFILE_Events
Problem:
The server is handling an Execute_load_log_event, which results
in reading a Load_log_event from the binary log and applying
it. When applying the Load_log_event, some variable setup is
done and then mysql_load is called. Late in mysql_load
execution, if not in row mode logging, the event is
binlogged write_execute_load_query_log_event.
In write_execute_load_query_log_event, thd->lex->local_file is
inspected. The problem is that it has not been set before in the
execution stack. This causes valgrind to report the warning.
Fix:
We fix this by initializing thd->lex->local_file to be the same
as the value of Load_log_event::local_fname, when lex_start is
called inside Load_log_event::do_apply_event.
In function log_event.cc:Query_log_event::write, there was a cast that
was triggering undefined behavior. The offending cast is the
following:
write_str_with_code_and_len((char **)(&start),
catalog, catalog_len, Q_CATALOG_NZ_CODE);
This results in calling write_str_with_code_and_len with first
argument pointing to a (char **) while "start" is itself a pointer to
uchar (uchar *). Inside write_str_with_..., the content of start is
then be updated:
(*dst)+= len;
The instruction above would cause the (*dst) pointer (ie, the "start"
argument, from the caller point of view, and which actually points to
uchar instead of pointing to char) to be updated so that it would
increment catalog_len. However, this seems to break strict-aliasing
rules ultimately causing the increment and assignment to behave
unexpectedly.
We fix this by removing the cast and by making the types match.
Backporting BUG#43789 to mysql-5.1-bugteam
The replication was generating corrupted data, warning messages on Valgrind
and aborting on debug mode while replicating a "null" to "not null" field.
Specifically the unpack_row routine, was considering the slave's table
definition and trying to retrieve a field value, where there was nothing to be
retrieved, ignoring the fact that the value was defined as "null" by the master.
To fix the problem, we proceed as follows:
1 - If it is not STRICT sql_mode, implicit default values are used, regardless
if it is multi-row or single-row statement.
2 - However, if it is STRICT mode, then a we do what follows:
2.1 If it is a transactional engine, we do a rollback on the first NULL that is
to be set into a NOT NULL column and return an error.
2.2 If it is a non-transactional engine and it is the first row to be inserted
with multi-row, we also return the error. Otherwise, we proceed with the
execution, use implicit default values and print out warning messages.
Unfortunately, the current patch cannot mimic the behavior showed by the master
for updates on multi-tables and multi-row inserts. This happens because such
statements are unfolded in different row events. For instance, considering the
following updates and strict mode:
(master)
create table t1 (a int);
create table t2 (a int not null);
insert into t1 values (1);
insert into t2 values (2);
update t1, t2 SET t1.a=10, t2.a=NULL;
t1 would have (10) and t2 would have (0) as this would be handled as a
multi-row update. On the other hand, if we had the following updates:
(master)
create table t1 (a int);
create table t2 (a int);
(slave)
create table t1 (a int);
create table t2 (a int not null);
(master)
insert into t1 values (1);
insert into t2 values (2);
update t1, t2 SET t1.a=10, t2.a=NULL;
On the master t1 would have (10) and t2 would have (NULL). On
the slave, t1 would have (10) but the update on t1 would fail.
Backporting BUG#38173 to mysql-5.1-bugteam
The reason of the bug was incompatibile with the master side behaviour.
INSERT query on the master is allowed to insert into a table without specifying
values of DEFAULT-less fields if sql_mode is not strict.
Fixed with checking sql_mode by the sql thread to decide how to react.
Non-strict sql_mode should allow Write_rows event to complete.
todo: warnings can be shown via show slave status, still this is a
separate rather general issue how to show warnings for the slave threads.
Implemented the server infrastructure for the fix:
1. Added a function LEX_STRING *thd_query_string(THD) to return
a LEX_STRING structure instead of char *.
This is the function that must be called in innodb instead of
thd_query()
2. Did some encapsulation in THD : aggregated thd_query and
thd_query_length into a LEX_STRING and made accessor and mutator
methods for easy code updating.
3. Updated the server code to use the new methods where applicable.
The BINLOG statement was sharing too much code with the slave SQL thread, introduced with
the patch for Bug#32407. This caused statements to be logged with the wrong server_id, the
id stored inside the events of the BINLOG statement rather than the id of the running
server.
Fix by rearranging code a bit so that only relevant parts of the code are executed by
the BINLOG statement, and the server_id of the server executing the statements will
not be overrided by the server_id stored in the 'format description BINLOG statement'.
"load data" statements were written to the binlog as a mix of the original statement
and bits recreated from parse-info. This relied on implementation details and broke
with IGNORE_SPACES and versioned comments.
We now completely resynthesize the query for LOAD DATA for binlog (which among other
things normalizes them somewhat with regard to case, spaces, etc.).
We have already parsed the query properly, so we make use of that rather
than mix-and-match string literals and parsed items.
This should make us safe with regard to versioned comments, even those
spanning multiple tokens. Also no longer affected by IGNORE_SPACES.
HA_ERR_WRONG_INDEX
In RBR, disabling keys on slave table will break replication when
updating or deleting a record. When the slave thread tries to
find the row, by searching in the storage engine, it checks
whether the table has a key or not. If it has one, then the slave
thread uses it to search the record.
Nonetheless, the slave only checks whether the key exists or not,
it does not verify if it is active. Should the key be
disabled (eg, DBA has issued an ALTER TABLE ... DISABLE KEYS)
then it will result in error: HA_ERR_WRONG_INDEX.
This patch addresses this issue by making the slave thread also
check whether the key is active or not before actually using it.
slave leaves slave unstable
Problem: when replicating from non-transactional to
transactional engine with autocommit off, no BEGIN/COMMIT
is written to the binlog. When the slave replicates, it
will start a transaction that never ends.
Fix: Force autocommit=on on slave by always replicating
autocommit=1 from the master.
In RBR, There is an inconsistency between slaves and master.
When INSERT statement which includes an auto_increment field is executed,
Store engine of master will check the value of the auto_increment field.
It will generate a sequence number and then replace the value, if its value is NULL or empty.
if the field's value is 0, the store engine will do like encountering the NULL values
unless NO_AUTO_VALUE_ON_ZERO is set into SQL_MODE.
In contrast, if the field's value is 0, Store engine of slave always generates a new sequence number
whether or not NO_AUTO_VALUE_ON_ZERO is set into SQL_MODE.
SQL MODE of slave sql thread is always consistency with master's.
Another variable is related to this bug.
If generateing a sequence number is decided by the values of
table->auto_increment_field_not_null and SQL_MODE(if includes MODE_NO_AUTO_VALUE_ON_ZERO)
The table->auto_increment_is_not_null is FALSE, which causes this bug to appear. ..
Slave does not correctly handle "expected errors" leading to inconsistencies
between the mater and slave. Specifically, when a statement changes both
transactional and non-transactional tables, the transactional changes are
automatically rolled back on the master but the slave ignores the error and
does not roll them back thus leading to inconsistencies.
To fix the problem, we automatically roll back a statement that fails on
the slave but note that the transaction is not rolled back unless a "rollback"
command is in the relay log file.
In STATEMENT based replication, a statement that failed on the master but that
updated non-transactional tables is written to binary log with the error code
appended to it. On the slave, the statement is executed and the same error is
expected. However, when an "expected error" did not happen on the slave and was
either ignored or was related to a concurrency issue on the master, the slave
did not rollback the effects of the statement and as such inconsistencies might
happen.
To fix the problem, we automatically rollback a statement that should have
failed on a slave but succeded and whose expected failure is either ignored or
stems from a concurrency issue on the master.
Replication SQL thread does not set database default charset to
thd->variables.collation_database properly, when executing LOAD DATA binlog.
This bug can be repeated by using "LOAD DATA" command in STATEMENT mode.
This patch adds code to find the default character set of the current database
then assign it to thd->db_charset when slave server begins to execute a relay log.
The test of this bug is added into rpl_loaddata_charset.test
procedures causes crashes!
The problem of that bugreport was mostly fixed by the
patch for bug 38691.
However, attached test case focused on another crash or
valgrind warning problem: SHOW PROCESSLIST query accesses
freed memory of SP instruction that run in a parallel
connection.
Changes of thd->query/thd->query_length in dangerous
places have been guarded with the per-thread
LOCK_thd_data mutex (the THD::LOCK_delete mutex has been
renamed to THD::LOCK_thd_data).
timeout
In STMT and MIXED modes, a statement that changes both non-transactional and
transactional tables must be written to the binary log whenever there are
changes to non-transactional tables. This means that the statement gets into the
binary log even when the changes to the transactional tables fail. In particular
, in the presence of a failure such statement is annotated with the error number
and wrapped in a begin/rollback. On the slave, while applying the statement, it
is expected the same failure and the rollback prevents the transactional changes
to be persisted.
Unfortunately, statements that fail due to concurrency issues (e.g. deadlocks,
timeouts) are logged in the same way causing the slave to stop as the statements
are applied sequentially by the SQL Thread. To fix this bug, we automatically
ignore concurrency failures on the slave. Specifically, the following failures
are ignored: ER_LOCK_WAIT_TIMEOUT, ER_LOCK_DEADLOCK and ER_XA_RBDEADLOCK.
While reading a binary log that is being used by a master or was not properly
closed, most likely due to a crash, the following warning message is being
printed out: "Warning: this binlog was not closed properly. Most probably mysqld
crashed writing it.". This was scaring our users as the message was not taking
into account the possibility of the file is being just used by the master.
To avoid unnecessarily scaring our users, we replace the original message by the
following one: Warning: "this binlog is either is use or was not closed properly.".
with gcc 4.3.2
Compiling MySQL with gcc 4.3.2 and later produces a number of
warnings, many of which are new with the recent compiler
versions.
This bug will be resolved in more than one patch to limit the
size of changesets. This is the first patch, fixing a number
of the warnings, predominantly "suggest using parentheses
around && in ||", and empty for and while bodies.
with gcc 4.3.2
Compiling MySQL with gcc 4.3.2 and later produces a number of
warnings, many of which are new with the recent compiler
versions.
This bug will be resolved in more than one patch to limit the
size of changesets. This is the first patch, fixing a number
of the warnings, predominantly "suggest using parentheses
around && in ||", and empty for and while bodies.
BEGIN/COMMIT/ROLLBACK was subject to replication db rules, and
caused the boundary of a transaction not recognized correctly
when these queries were ignored by the rules.
Fixed the problem by skipping replication db rules for these
statements.
Make the caller of Query_log_event, Execute_load_log_event
constructors and THD::binlog_query to provide the error code
instead of having the constructors to figure out the error code.
"freeing items"
The calculation of the table map log event in the event constructor
was one byte shorter than what would be actually written. This would
lead to a mismatch between the number of bytes written and the event
end_log_pos, causing bad event alignment in the binlog (corrupted
binlog) or in the transaction cache while fixing positions
(MYSQL_BIN_LOG::write_cache). This could lead to impossible to read
binlog or even infinite loops in MYSQL_BIN_LOG::write_cache.
This patch addresses this issue by correcting the expected event
length in the Table_map_log_event constructor, when the field metadata
size exceeds 255.
In the output from mysqlbinlog, incident log events were
represented as just a comment. Since the incident log event
represents an incident that could cause the contents of the
database to change without being logged to the binary log,
it means that if the SQL is applied to a server, it could
potentially lead to that the databases are out of sync.
In order to handle that, this patch adds the statement "RELOAD
DATABASE" to the SQL output for the incident log event. This will
require a DBA to edit the file and handle the case as apropriate
before applying the output to a server.
165 changesets with 23 conflicts:
Text conflict in mysql-test/r/lock_multi.result
Text conflict in mysql-test/t/lock_multi.test
Text conflict in mysql-test/t/mysqldump.test
Text conflict in sql/item_strfunc.cc
Text conflict in sql/log.cc
Text conflict in sql/log_event.cc
Text conflict in sql/parse_file.cc
Text conflict in sql/slave.cc
Text conflict in sql/sp.cc
Text conflict in sql/sp_head.cc
Text conflict in sql/sql_acl.cc
Text conflict in sql/sql_base.cc
Text conflict in sql/sql_class.cc
Text conflict in sql/sql_crypt.cc
Text conflict in sql/sql_db.cc
Text conflict in sql/sql_lex.cc
Text conflict in sql/sql_parse.cc
Text conflict in sql/sql_select.cc
Text conflict in sql/sql_table.cc
Text conflict in sql/sql_view.cc
Text conflict in storage/innobase/handler/ha_innodb.cc
Text conflict in storage/myisam/mi_packrec.c
Text conflict in tests/mysql_client_test.c
Updates to Innobase, taken from main 5.1:
bzr: ERROR: Some change isn't sane:
File mysql-test/r/innodb-semi-consistent.result is owned by Innobase and should not be updated.
File mysql-test/t/innodb-semi-consistent.test is owned by Innobase and should not be updated.
File storage/innobase/handler/ha_innodb.cc is owned by Innobase and should not be updated.
File storage/innobase/ibuf/ibuf0ibuf.c is owned by Innobase and should not be updated.
File storage/innobase/include/row0mysql.h is owned by Innobase and should not be updated.
File storage/innobase/include/srv0srv.h is owned by Innobase and should not be updated.
File storage/innobase/include/trx0trx.h is owned by Innobase and should not be updated.
File storage/innobase/include/trx0trx.ic is owned by Innobase and should not be updated.
File storage/innobase/lock/lock0lock.c is owned by Innobase and should not be updated.
File storage/innobase/page/page0cur.c is owned by Innobase and should not be updated.
File storage/innobase/row/row0mysql.c is owned by Innobase and should not be updated.
File storage/innobase/row/row0sel.c is owned by Innobase and should not be updated.
File storage/innobase/srv/srv0srv.c is owned by Innobase and should not be updated.
File storage/innobase/trx/trx0trx.c is owned by Innobase and should not be updated.
(Set env var 'ALLOW_UPDATE_INNOBASE_OWNED' to override.)
The rpl_binlog_corruption test case was inject failures, specifically,
incidents with invalid numbers to see if the replication was failing
gracefully. However, this test was causing the following warning message
in Valgrind: "Conditional jump or move depends on uninitialised value(s)"
The patch fixes the problem by correctly initializing the m_inicident
number.
