This is the non-ndb part of the patch.
The return value of mysql_bin_log.write was ignored by most callers,
which may lead to inconsistent on master and slave if the transaction
was committed while the binlog was not correctly written. If
my_error() is call in mysql_bin_log.write, this could also lead to
assertion issue if my_ok() or my_error() is called after.
This fixed the problem by let the caller to check and handle the
return value of mysql_bin_log.write. This patch only adresses the
simple cases.
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 problem: described in the bug report.
The fix:
--increase buffers where it's necessary
(buffers which are used in stxnmov)
--decrease buffer lengths which are used
Problem: executing queries like "ALTER TABLE view1;" we don't
check new view's name (which is not specified),
that leads to server crash.
Fix: do nothing (to be consistent with the behaviour for tables)
in such cases.
mysql_rename_view can not rename view if database is not the same.
The fix is to add new argument 'new_db' to mysql_rename_view() and
allow rename with different databases
(only for ALTER DATABASE ... UPGRADE DATA DIRECTORY NAME).
This bug is actually two bugs in one, one of which is CREATE TRIGGER under
LOCK TABLES and the other is CREATE TRIGGER under LOCK TABLES simultaneous
to a FLUSH TABLES WITH READ LOCK (global read lock). Both situations could
lead to a server crash or deadlock.
The first problem arises from the fact that when under LOCK TABLES, if the
table is in the set of locked tables, the table is already open and it doesn't
need to be reopened (not a placeholder). Also in this case, if the table is
not write locked, a exclusive lock can't be acquired because of a possible
deadlock with another thread also holding a (read) lock on the table. The
second issue arises from the fact that one should never wait for a global
read lock if it's holding any locked tables, because the global read lock
is waiting for these tables and this leads to a circular wait deadlock.
The solution for the first case is to check if the table is write locked
and upgraded the write lock to a exclusive lock and fail otherwise for non
write locked tables. Grabbin the exclusive lock in this case also means
to ensure that the table is opened only by the calling thread. The second
issue is partly fixed by not waiting for the global read lock if the thread
is holding any locked tables.
The second issue is only partly addressed in this patch because it turned
out to be much wider and also affects other DDL statements. Reported as
Bug#32395
The problem is that DROP TABLE and other DDL statements failed to
automatically close handlers associated with tables that were marked
for reopen (FLUSH TABLES).
The current implementation fails to properly discard handlers of
dropped tables (that were marked for reopen) because it searches
on the open handler tables list and using the current alias of the
table being dropped. The problem is that it must not use the open
handler tables list to search because the table might have been
closed (marked for reopen) by a flush tables command and also it
must not use the current table alias at all since multiple different
aliases may be associated with a single table. This is specially
visible when a user has two open handlers (using alias) of a same
table and a flush tables command is issued before the table is
dropped (see test case). Scanning the handler table list is also
useless for dropping handlers associated with temporary tables,
because temporary tables are not kept in the THD::handler_tables
list.
The solution is to simple scan the handlers hash table searching
for, and deleting all handlers with matching table names if the
reopen flag is not passed to the flush function, indicating that
the handlers should be deleted. All matching handlers are deleted
even if the associated the table is not open.
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.
asserts.
The patch for Bug#21074 replaces acquisition of the global LOCK_open lock
with exclusive locks on table names in such operations ad DROP TABLE
and RENAME TABLE.
Unfortunately, NDB internally assumes that LOCK_open is acquired and
tries to release it.
This dependency should be fixed by a separate (and significant in size)
patch. For now we just satisfy it - after all, the original
goal of the patch for Bug#21074 was to move query_cache_invalidate
outside of the scope of LOCK_open, and we still can do that.
This fixes some failing NDB tests in the runtime tree.
Invaldating a subset of a sufficiently large query cache can take a long time.
During this time the server is efficiently frozen and no other operation can
be executed. This patch addresses this problem by moving the locks which cause
the freezing and also by temporarily disable the query cache while the
invalidation takes place.
CREATE/DROP TEMPORARY TABLE + ROLLBACK on master
The transaction ability of the storage engines of
the tables on the replication master and the replication
slave must generally be the same.
When the storage engine type of the slave is
non-transactional then transactions on the master that
mix update of transactional and non-transactional tables
should be avoided because they will cause inconsistency of
the data between the master's transactional table and the
slave's non-transactional table.
The effect described by this bug is actually expected.
A detailed test case is added (to be merged later to
the updated rpl_ddl.test), as there was no coverage
by the existing tests.
Some code cleanup is also added by this change.
Corrected spelling in copyright text
Makefile.am:
Don't update the files from BitKeeper
Many files:
Removed "MySQL Finland AB & TCX DataKonsult AB" from copyright header
Adjusted year(s) in copyright header
Many files:
Added GPL copyright text
Removed files:
Docs/Support/colspec-fix.pl
Docs/Support/docbook-fixup.pl
Docs/Support/docbook-prefix.pl
Docs/Support/docbook-split
Docs/Support/make-docbook
Docs/Support/make-makefile
Docs/Support/test-make-manual
Docs/Support/test-make-manual-de
Docs/Support/xwf
Fixed compiler warnings (detected by VC++):
- Removed not used variables
- Added casts
- Fixed wrong assignments to bool
- Fixed wrong calls with bool arguments
- Added missing argument to store(longlong), which caused wrong store method to be called.
- Removed not used variables
- Changed some ulong parameters/variables to ulonglong (possible serious bug)
- Added casts to get rid of safe assignment from longlong to long (and similar)
- Added casts to function parameters
- Fixed signed/unsigned compares
- Added some constructores to structures
- Removed some not portable constructs
Better fix for bug Bug #21428 "skipped 9 bytes from file: socket (3)" on "mysqladmin shutdown"
(Added new parameter to net_clear() to define when we want the communication buffer to be emptied)
The mysql_alter_table() was able to rename only a table.
The view/table renaming code is moved from the function rename_tables
to the new function called do_rename().
The mysql_alter_table() function calls it when it needs to rename a view.
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).
Continued implementation of WL#1324 (table name to filename encoding)
The intermediate (not temporary) files of the new table
during ALTER TABLE was visible for SHOW TABLES. These
intermediate files are copies of the original table with
the changes done by ALTER TABLE. After all the data is
copied over from the original table, these files are renamed
to the original tables file names. So they are not temporary
files. They persist after ALTER TABLE, but just with another
name.
In 5.0 the intermediate files are invisible for SHOW TABLES
because all file names beginning with "#sql" were suppressed.
This failed since 5.1.6 because even temporary table names were
converted when making file names from them. The prefix became
converted to "@0023sql". Converting the prefix during SHOW TABLES
would suppress the listing of user tables that start with "#sql".
The solution of the problem is to continue the implementation of
the table name to file name conversion feature. One requirement
is to suppress the conversion for temporary table names.
This change is straightforward for real temporary tables as there
is a function that creates temporary file names.
But the generated path names are located in TMPDIR and have no
relation to the internal table name. This cannot be used for
ALTER TABLE. Its intermediate files need to be in the same
directory as the old table files. And it is necessary to be
able to deduce the same path from the same table name repeatedly.
Consequently the intermediate table files must be handled like normal
tables. Their internal names shall start with tmp_file_prefix
(#sql) and they shall not be converted like normal table names.
I added a flags parameter to all relevant functions that are
called from ALTER TABLE. It is used to suppress the conversion
for the intermediate table files.
The outcome is that the suppression of #sql in SHOW TABLES
works again. It does not suppress user tables as these are
converted to @0023sql on file level.
This patch does also fix ALTER TABLE ... RENAME, which could not
rename a table with non-ASCII characters in its name.
It does also fix the problem that a user could create a table like
`#sql-xxxx-yyyy`, where xxxx is mysqld's pid and yyyy is the thread
ID of some other thread, which prevented this thread from running
ALTER TABLE.
Some of the above problems are mentioned in Bug 1405, which can
be closed with this patch.
This patch does also contain some minor fixes for other forgotten
conversions. Still known problems are reported as bugs 21370,
21373, and 21387.
Let us transfer triggers associated with table when we rename it (but only if
we are not changing database to which table belongs, in the latter case we will
emit error).
- Encoding itself, implemented as a charset
"filename". Originally planned to use '.'
as an escape character, but now changed to '@'
for two reasons: "ls" does not return
file names starting with '.' considering them
as a kind of hidden files; some platforms
do not allow several dots in a file name.
- replacing many calls of my_snprintf() and
strnxmov() to the new build_table_filename().
- Adding MY_APPEND_EXT mysys flag, to append
an extention rather that replace it.
- Replacing all numeric constants in fn_format
flag arguments to their mysys definitions, e.g.
MY_UNPACK_FILENAME,
- Predictability in several function/methods:
when a table name can appear with or withot .frm
extension. Some functions/methods were changed
so accept names strictly with .frm, other - strictly
without .frm extensions. Several DBUG_ASSERTs were
added to check whether an extension is passed.
Many files:
table name to file name encoding
mysql_priv.h:
Prototypes for new table name encoding tools.
ctype-utf8.c:
Implementing "filename" charset for
table name to file name encoding.
row0mysql.c:
Fixing table name prefix.
mf_format.c:
Adding MY_APPEND_EXT processing.
Many files:
Fixing tests.
my_sys.h:
Adding new flag to append rather than replace an extension.
m_ctype.h:
Adding "filename" charset definition.
Split TABLE to TABLE and TABLE_SHARE (TABLE_SHARE is still allocated as part of table, will be fixed soon)
Created Field::make_field() and made Field_num::make_field() to call this
Added 'TABLE_SHARE->db' that points to database name; Changed all usage of table_cache_key as database name to use this instead
Changed field->table_name to point to pointer to alias. This allows us to change alias for a table by just updating one pointer.
Renamed TABLE_SHARE->real_name to table_name
Renamed TABLE->table_name to alias
Renamed TABLE_LIST->real_name to table_name
CREATE DATABASE statement used the current database instead of the
database created when checking conditions for replication.
CREATE/DROP/ALTER DATABASE statements are now replicated based on
the manipulated database.
