when generating new name.
If find_uniq_filename returns an error, then this error is not
being propagated upwards, and execution does not report error to
the user (although a entry in the error log is generated).
Additionally, some more errors were ignored in new_file_impl:
- when writing the rotate event
- when reopening the index and binary log file
This patch addresses this by propagating the error up in the
execution stack. Furthermore, when rotation of the binary log
fails, an incident event is written, because there may be a
chance that some changes for a given statement, were not properly
logged. For example, in SBR, LOAD DATA INFILE statement requires
more than one event to be logged, should rotation fail while
logging part of the LOAD DATA events, then the logged data would
become inconsistent with the data in the storage engine.
A CREATE...SELECT that fails is written to the binary log if a non-transactional
statement is updated. If the logging format is ROW, the CREATE statement and the
changes are written to the binary log as distinct events and by consequence the
created table is not rolled back in the slave.
In this patch, we opted to let the slave goes out of sync by not writting to the
binary log the CREATE statement. We do this by simply reseting the binary log's
cache.
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.
MYSQL_BIN_LOG m_table_map_version member and it's associated
functions were not used in the logic of binlogging and replication,
this patch removed all related code.
This patch fixes three bugs as follows. First, aborting the server while purging
binary logs might generate orphan files due to how the purge operation was
implemented:
(purge routine - sql/log.cc - MYSQL_BIN_LOG::purge_logs)
1 - register the files to be removed in a temporary buffer.
2 - update the log-bin.index.
3 - flush the log-bin.index.
4 - erase the files whose names where register in the temporary buffer
in step 1.
Thus a failure while executing step 4 would generate an orphan file. Second,
a similar issue might happen while creating a new binary as follows:
(create routine - sql/log.cc - MYSQL_BIN_LOG::open)
1 - open the new log-bin.
2 - update the log-bin.index.
Thus a failure while executing step 1 would generate an orphan file.
To fix these issues, we record the files to be purged or created before really
removing or adding them. So if a failure happens such records can be used to
automatically remove dangling files. The new steps might be outlined as follows:
(purge routine - sql/log.cc - MYSQL_BIN_LOG::purge_logs)
1 - register the files to be removed in the log-bin.~rec~ placed in
the data directory.
2 - update the log-bin.index.
3 - flush the log-bin.index.
4 - delete the log-bin.~rec~.
(create routine - sql/log.cc - MYSQL_BIN_LOG::open)
1 - register the file to be created in the log-bin.~rec~
placed in the data directory.
2 - open the new log-bin.
3 - update the log-bin.index.
4 - delete the log-bin.~rec~.
(recovery routine - sql/log.cc - MYSQL_BIN_LOG::open_index_file)
1 - open the log-bin.index.
2 - open the log-bin.~rec~.
3 - for each file in log-bin.~rec~.
3.1 Check if the file is in the log-bin.index and if so ignore it.
3.2 Otherwise, delete it.
The third issue can be described as follows. The purge operation was allowing
to remove a file in use thus leading to the loss of data and possible
inconsistencies between the master and slave. Roughly, the routine was only
taking into account the dump threads and so if a slave was not connect the
file might be delete even though it was in use.
Large transactions and statements may corrupt the binary log if the size of the
cache, which is set by the max_binlog_cache_size, is not enough to store the
the changes.
In a nutshell, to fix the bug, we save the position of the next character in the
cache before starting processing a statement. If there is a problem, we simply
restore the position thus removing any effect of the statement from the cache.
Unfortunately, to avoid corrupting the binary log, we may end up loosing changes
on non-transactional tables if they do not fit in the cache. In such cases, we
store an Incident_log_event in order to stop the slave and alert users that some
changes were not logged.
Precisely, for every non-transactional changes that do not fit into the cache,
we do the following:
a) the statement is *not* logged
b) an incident event is logged after committing/rolling back the transaction,
if any. Note that if a failure happens before writing the incident event to
the binary log, the slave will not stop and the master will not have reported
any error.
c) its respective statement gives an error
For transactional changes that do not fit into the cache, we do the following:
a) the statement is *not* logged
b) its respective statement gives an error
To work properly, this patch requires two additional things. Firstly, callers to
MYSQL_BIN_LOG::write and THD::binlog_query must handle any error returned and
take the appropriate actions such as undoing the effects of a statement. We
already changed some calls in the sql_insert.cc, sql_update.cc and sql_insert.cc
modules but the remaining calls spread all over the code should be handled in
BUG#37148. Secondly, statements must be either classified as DDL or DML because
DDLs that do not get into the cache must generate an incident event since they
cannot be rolled back.
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.
conflicts:
Text conflict in client/mysqltest.cc
Text conflict in mysql-test/include/wait_until_connected_again.inc
Text conflict in mysql-test/lib/mtr_report.pm
Text conflict in mysql-test/mysql-test-run.pl
Text conflict in mysql-test/r/events_bugs.result
Text conflict in mysql-test/r/log_state.result
Text conflict in mysql-test/r/myisam_data_pointer_size_func.result
Text conflict in mysql-test/r/mysqlcheck.result
Text conflict in mysql-test/r/query_cache.result
Text conflict in mysql-test/r/status.result
Text conflict in mysql-test/suite/binlog/r/binlog_index.result
Text conflict in mysql-test/suite/binlog/r/binlog_innodb.result
Text conflict in mysql-test/suite/rpl/r/rpl_packet.result
Text conflict in mysql-test/suite/rpl/t/rpl_packet.test
Text conflict in mysql-test/t/disabled.def
Text conflict in mysql-test/t/events_bugs.test
Text conflict in mysql-test/t/log_state.test
Text conflict in mysql-test/t/myisam_data_pointer_size_func.test
Text conflict in mysql-test/t/mysqlcheck.test
Text conflict in mysql-test/t/query_cache.test
Text conflict in mysql-test/t/rpl_init_slave_func.test
Text conflict in mysql-test/t/status.test
BUG#39325 Server crash inside MYSQL_LOG::purge_first_log halts replicaiton
The patch reverses the order of the purging and updating events for log and
relay-log.info/index files respectively.
This solves the problem of having holes caused by crashes happening between updating
info/index files and purging logs.
This patch also contains an aditional test case for testing the crashing before purge logs.
NOTE1: This is a combined patch for BUG#38826 and BUG#39325. This patch is based on
bugteam tree and takes into account reviewers suggestions.
NOTE2: Merge from 5.0-bugteam
Rotate event is automatically generated and written when rotating binary
log or relay log. Rotate events for relay logs are usually ignored by slave
SQL thread becuase they have the same server id as that of the slave.
However, if --replicate-same-server-id is enabled, rotate event
for relay log would be treated as if it's a rotate event from master, and
would be executed by slave to update the rli->group_master_log_name and
rli->group_master_log_pos to a wrong value and cause the MASTER_POS_WAIT
function to fail and return NULL.
This patch fixed this problem by setting a flag bit (LOG_EVENT_RELAY_LOG_F)
in the event to tell the SQL thread to ignore these Rotate events generated
for relay logs.
This patch also added another binlog event flag bit (LOG_EVENT_ARTIFICIAL_F)
to distinquish faked events, the method used before this was by checking if
log_pos was zero.
The assertion indicates that some data was left in the transaction
cache when the server was shut down, which means that a previous
statement did not commit or rollback correctly.
What happened was that a bug in the rollback of a transactional
table caused the transaction cache to be emptied, but not reset.
The error can be triggered by having a failing UPDATE or INSERT,
on a transactional table, causing an implicit rollback.
Fixed by always flushing the pending event to reset the state
properly.
The general log write function (general_log_print) uses printf style
arguments which need to be pre-processed, meaning that the all arguments
are copied to a single buffer and the problem is that the buffer size is
constant (1022 characters) but queries can be much larger then this.
The solution is to introduce a new log write function that accepts a
buffer and it's length as arguments. The function is to be used when
a formatted output is not required, which is the case for almost all
query write-to-log calls.
This is a incompatible change with respect to the log format of prepared
statements.
--long-query-time is now given in seconds with microseconds as decimals
--min_examined_row_limit added for slow query log
long_query_time user variable is now double with 6 decimals
Added functions to get time in microseconds
Added faster time() functions for system that has gethrtime() (Solaris)
We now do less time() calls.
Added field->in_read_set() and field->in_write_set() for easier field manipulation by handlers
set_var.cc and my_getopt() can now handle DOUBLE variables.
All time() calls changed to my_time()
my_time() now does retry's if time() call fails.
Added debug function for stopping in mysql_admin_table() when tables are locked
Some trivial function and struct variable renames to avoid merge errors.
Fixed compiler warnings
Initialization of some time variables on windows moved to my_init()
Bug#25422 (Hang with log tables)
Bug 17876 (Truncating mysql.slow_log in a SP after using cursor locks the
thread)
Bug 23044 (Warnings on flush of a log table)
Bug 29129 (Resetting general_log while the GLOBAL READ LOCK is set causes
a deadlock)
Prior to this fix, the server would hang when performing concurrent
ALTER TABLE or TRUNCATE TABLE statements against the LOG TABLES,
which are mysql.general_log and mysql.slow_log.
The root cause traces to the following code:
in sql_base.cc, open_table()
if (table->in_use != thd)
{
/* wait_for_condition will unlock LOCK_open for us */
wait_for_condition(thd, &LOCK_open, &COND_refresh);
}
The problem with this code is that the current implementation of the
LOGGER creates 'fake' THD objects, like
- Log_to_csv_event_handler::general_log_thd
- Log_to_csv_event_handler::slow_log_thd
which are not associated to a real thread running in the server,
so that waiting for these non-existing threads to release table locks
cause the dead lock.
In general, the design of Log_to_csv_event_handler does not fit into the
general architecture of the server, so that the concept of general_log_thd
and slow_log_thd has to be abandoned:
- this implementation does not work with table locking
- it will not work with commands like SHOW PROCESSLIST
- having the log tables always opened does not integrate well with DDL
operations / FLUSH TABLES / SET GLOBAL READ_ONLY
With this patch, the fundamental design of the LOGGER has been changed to:
- always open and close a log table when writing a log
- remove totally the usage of fake THD objects
- clarify how locking of log tables is implemented in general.
See WL#3984 for details related to the new locking design.
Additional changes (misc bugs exposed and fixed):
1)
mysqldump which would ignore some tables in dump_all_tables_in_db(),
but forget to ignore the same in dump_all_views_in_db().
2)
mysqldump would also issue an empty "LOCK TABLE" command when all the tables
to lock are to be ignored (numrows == 0), instead of not issuing the query.
3)
Internal errors handlers could intercept errors but not warnings
(see sql_error.cc).
4)
Implementing a nested call to open tables, for the performance schema tables,
exposed an existing bug in remove_table_from_cache(), which would perform:
in_use->some_tables_deleted=1;
against another thread, without any consideration about thread locking.
This call inside remove_table_from_cache() was not required anyway,
since calling mysql_lock_abort() takes care of aborting -- cleanly -- threads
that might hold a lock on a table.
This line (in_use->some_tables_deleted=1) has been removed.
The log tables are by nature PERFORMANCE_SCHEMA tables,
which should not be affected by SET GLOBAL READ_ONLY or FLUSH TABLES
WITH READ LOCK.
The implementation of FLUSH TABLES WITH READ LOCK already ignored log tables.
Now with this patch, the implementation of LOCK TABLE also ignore a
global read lock for log tables, which was the missing symmetry.
provide the writable datadir for mysqld --help (for lower_case test)
sql/log.h, sql/mysqld.cc
make default binlog_format value to be 0 (for a hack of using
GET_STR for enum to continue to work)
There was hanging at binlog_commit by a thread executing autocommit query.
The hang appeared to be due to an overly condtion for early return
from binlog_commit introduced by bug#20265 fix.
Fixed with reverting the logic back to 5.0 version.
SF/Triggers in SBR mode."
BUG#14914 "SP: Uses of session variables in routines are not always replicated"
BUG#25167 "Dupl. usage of user-variables in trigger/function is not replicated
correctly"
User-defined variables used inside of stored functions/triggers in
statements which did not update tables directly were not replicated.
We also had problems with replication of user-defined variables which
were used in triggers (or stored functions called from table-updating
statements) more than once.
This patch addresses the first issue by enabling logging of all
references to user-defined variables in triggers/stored functions
and not only references from table-updating statements.
The second issue stemmed from the fact that for user-defined
variables used from triggers or stored functions called from
table-updating statements we were writing binlog events for each
reference instead of only one event for the first reference.
This problem is already solved for stored functions called from
non-updating statements with help of "event unioning" mechanism.
So the patch simply extends this mechanism to the case affected.
It also fixes small problem in this mechanism which caused wrong
logging of references to user-variables in cases when non-updating
statement called several stored functions which used the same
variable and some of these function calls were omitted from binlog
as they were not updating any tables.
Removed a lot of compiler warnings
Removed not used variables, functions and labels
Initialize some variables that could be used unitialized (fatal bugs)
%ll -> %l
from log):
When row-based logging is used, the CREATE-SELECT is written as two
parts: as a CREATE TABLE statement and as the rows for the table. For
both transactional and non-transactional tables, the CREATE TABLE
statement was written to the transaction cache, as were the rows, and
on statement end, the entire transaction cache was written to the binary
log if the table was non-transactional. For transactional tables, the
events were kept in the transaction cache until end of transaction (or
statement that were not part of a transaction).
For the case when AUTOCOMMIT=0 and we are creating a transactional table
using a create select, we would then keep the CREATE TABLE statement and
the rows for the CREATE-SELECT, while executing the following statements.
On a rollback, the transaction cache would then be cleared, which would
also remove the CREATE TABLE statement. Hence no table would be created
on the slave, while there is an empty table on the master.
This relates to BUG#22865 where the table being created exists on the
master, but not on the slave during insertion of rows into the newly
created table. This occurs since the CREATE TABLE statement were still
in the transaction cache until the statement finished executing, and
possibly longer if the table was transactional.
This patch changes the behaviour of the CREATE-SELECT statement by
adding an implicit commit at the end of the statement when creating
non-temporary tables. Hence, non-temporary tables will be written to the
binary log on completion, and in the even of AUTOCOMMIT=0, a new
transaction will be started. Temporary tables do not commit an ongoing
transaction: neither as a pre- not a post-commit.
The events for both transactional and non-transactional tables are
saved in the transaction cache, and written to the binary log at end
of the statement.
Bug #21785 "Server crashes after rename of the log table" and
Bug #21966 "Strange warnings on create like/repair of the log
tables"
According to the patch, from now on, one should use RENAME to
perform a log table rotation (this should also be reflected in
the manual).
Here is a sample:
use mysql;
CREATE TABLE IF NOT EXISTS general_log2 LIKE general_log;
RENAME TABLE general_log TO general_log_backup, general_log2 TO general_log;
The rules for Rename of the log tables are following:
IF 1. Log tables are enabled
AND 2. Rename operates on the log table and nothing is being
renamed to the log table.
DO 3. Throw an error message.
ELSE 4. Perform rename.
The very RENAME query will go the the old (backup) table. This is
consistent with the behavoiur we have with binlog ROTATE LOGS
statement.
Other problems, which are solved by the patch are:
1) Now REPAIR of the log table is exclusive operation (as it should be), this
also eliminates lock-related warnings. and
2) CREATE LIKE TABLE now usese usual read lock on the source table rather
then name lock, which is too restrictive. This way we get rid of another
log table-related warning, which occured because of the above fact
(as a side-effect, name lock resulted in a warning).
gets deadlocked when dropping w/ log on"
Log tables rely on concurrent insert machinery to add data.
This means that log tables are always opened and locked by
special (artificial) logger threads. Because of this, the thread
which tries to drop a log table starts to wait for the table
to be unlocked. Which will happen only if the log table is disabled.
Alike situation happens if one tries to alter a log table.
However in addition to the problem above, alter table calls
check_if_locking_is_allowed() routine for the engine. The
routine does not allow alter for the log tables. So, alter
doesn't start waiting forever for logs to be disabled, but
returns with an error.
Another problem is that not all engines could be used for
the log tables. That's because they need concurrent insert.
In this patch we:
(1) Explicitly disallow to drop/alter a log table if it
is currently used by the logger.
(2) Update MyISAM to support log tables
(3) Allow to drop log tables/alter log tables if log is
disabled
At the same time we (4) Disallow to alter log tables to
unsupported engine (after this patch CSV and MyISAM are
alowed)
Recommit with review fixes.
Added missing DBUG_xxx_RETURN statements
Fixed some usage of not initialized variables (as found by valgrind)
Ensure that we don't remove locked tables used as name locks from open table cache until unlock_table_names() are called.
This was fixed by having drop_locked_name() returning any table used as a name lock so that we can free it in unlock_table_names()
This will allow Tomas to continue with his work to use namelocks to syncronize things.
Note: valgrind still produces a lot of warnings about using not initialized code and shows memory loss errors when running the ndb tests
and new binlog format called "mixed" (which is statement-based except if only row-based is correct,
in this cset it means if UDF or UUID is used; more cases could be added in later 5.1 release):
SET GLOBAL|SESSION BINLOG_FORMAT=row|statement|mixed|default;
the global default is statement unless cluster is enabled (then it's row) as in 5.1-alpha.
It's not possible to use SET on this variable if a session is currently in row-based mode and has open temporary tables (because CREATE
TEMPORARY TABLE was not binlogged so temp table is not known on slave), or if NDB is enabled (because
NDB does not support such change on-the-fly, though it will later), of if in a stored function (see below).
The added tests test the possibility or impossibility to SET, their effects, and the mixed mode,
including in prepared statements and in stored procedures and functions.
Caveats:
a) The mixed mode will not work for stored functions: in mixed mode, a stored function will
always be binlogged as one call and in a statement-based way (e.g. INSERT VALUES(myfunc()) or SELECT myfunc()).
b) for the same reason, changing the thread's binlog format inside a stored function is
refused with an error message.
c) the same problems apply to triggers; implementing b) for triggers will be done later (will ask
Dmitri).
Additionally, as the binlog format is now changeable by each user for his session, I remove the implication
which was done at startup, where row-based automatically set log-bin-trust-routine-creators to 1
(not possible anymore as a user can now switch to stmt-based and do nasty things again), and automatically
set --innodb-locks-unsafe-for-binlog to 1 (was anyway theoretically incorrect as it disabled
phantom protection).
Plus fixes for compiler warnings.
