restores from mysqlbinlog out
Problem: using "mysqlbinlog | mysql" for recoveries the connection_id()
result may differ from what was used when issuing the statement.
Fix: if there is a connection_id() in a statement, write to binlog
SET pseudo_thread_id= XXX; before it and use the value later on.
Bug #27417 thd->no_trans_update.stmt lost value inside of SF-exec-stack
Once had been set the flag might later got reset inside of a stored routine
execution stack.
The reason was in that there was no check if a new statement started at time
of resetting.
The artifact affects most of binlogable DML queries. Notice, that multi-update
is wrapped up within
bug@27716 fix, multi-delete bug@29136.
Fixed with saving parent's statement flag of whether the statement modified
non-transactional table, and unioning (merging) the value with that was gained
in mysql_execute_command.
Resettling thd->no_trans_update members into thd->transaction.`member`;
Asserting code;
Effectively the following properties are held.
1. At the end of a substatement thd->transaction.stmt.modified_non_trans_table
reflects the fact if such a table got modified by the substatement.
That also respects THD::really_abort_on_warnin() requirements.
2. Eventually thd->transaction.stmt.modified_non_trans_table will be computed as
the union of the values of all invoked sub-statements.
That fixes this bug#27417;
Computing of thd->transaction.all.modified_non_trans_table is refined to base to
the stmt's value for all the case including insert .. select statement which
before the patch had an extra issue bug@28960.
Minor issues are covered with mysql_load, mysql_delete, and binloggin of insert in
to temp_table select.
The supplied test verifies limitely, mostly asserts. The ultimate testing is defered
for bug@13270, bug@23333.
When innodb detects a deadlock it calls ha_rollback_trans() to rollback the
main transaction. But such action isn't allowed from inside of triggers and
functions. When it happen the 'Explicit or implicit commit' error is thrown
even if there is no commit/rollback statements in the trigger/function. This
leads to the user confusion.
Now the convert_error_code_to_mysql() function doesn't call the
ha_rollback_trans() function directly but rather calls the
mark_transaction_to_rollback function and returns an error.
The sp_rcontext::find_handler() now doesn't allow errors to be caught by the
trigger/function error handlers when the thd->is_fatal_sub_stmt_error flag
is set. Procedures are still allowed to catch such errors.
The sp_rcontext::find_handler function now accepts a THD handle as a parameter.
The transaction_rollback_request and the is_fatal_sub_stmt_error flags are
added to the THD class. The are initialized by the THD class constructor.
Now the ha_autocommit_or_rollback function rolls back main transaction
when not in a sub statement and the thd->transaction_rollback_request
is set.
The THD::restore_sub_statement_state function now resets the
thd->is_fatal_sub_stmt_error flag on exit from a sub-statement.
between perm and temp tables. Review fixes.
The original bug report complains that if we locked a temporary table
with LOCK TABLES statement, we would not leave LOCK TABLES mode
when this temporary table is dropped.
Additionally, the bug was escalated when it was discovered than
when a temporary transactional table that was previously
locked with LOCK TABLES statement was dropped, futher actions with
this table, such as UNLOCK TABLES, would lead to a crash.
The problem originates from incomplete support of transactional temporary
tables. When we added calls to handler::store_lock()/handler::external_lock()
to operations that work with such tables, we only covered the normal
server code flow and did not cover LOCK TABLES mode.
In LOCK TABLES mode, ::external_lock(LOCK) would sometimes be called without
matching ::external_lock(UNLOCK), e.g. when a transactional temporary table
was dropped. Additionally, this table would be left in the list of LOCKed
TABLES.
The patch aims to address this inadequacy. Now, whenever an instance
of 'handler' is destroyed, we assert that it was priorly
external_lock(UNLOCK)-ed. All the places that violate this assert
were fixed.
This patch introduces no changes in behavior -- the discrepancy in
behavior will be fixed when we start calling ::store_lock()/::external_lock()
for all tables, regardless whether they are transactional or not,
temporary or not.
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.
we now have exclusive name lock on the table name in mysql_rm_table_part2,
we still should keep LOCK_open - some storage engines are not
ready for locking scope change and assume that LOCK_open is kept.
Still, the binary logging and query cache invalidation calls
moved out of LOCK_open scope.
Fixes some of the broken 5.1-runtime tests (tests break on asserts).
gettimeofday() can fail and presumably, so can time().
Keep an eye on it.
Since we have no data on this at all so far, we just
retry on failure (and log the event), assuming that
this is just an intermittant failure. This might of
course hang the threat until we succeed. Once we know
more about these failures, an appropriate more clever
scheme may be picked (only try so many times per thread,
etc., if that fails, return last "good" time() we got or
some such). Using sql_print_information() to log as this
probably only occurs in high load scenarios where the debug-
trace likely is disabled (or might interfere with testing
the effect). No test-case as this is a non-deterministic
issue.
By default MyISAM overwrites .MYD and .MYI files no
DATA DIRECTORY option is used. This can lead to two tables
using the same .MYD and .MYI files (that can't be dropped).
To prevent CREATE TABLE from overwriting a file a new option
is introduced : keep_files_on_create
When this is on the CREATE TABLE throws an error if either
the .MYD or .MYI exists for a MyISAM table.
The option is off by default (resulting in compatible behavior).
The SELECT INTO OUTFILE FIELDS ENCLOSED BY digit or minus sign,
followed by the same LOAD DATA INFILE statement, used wrond encoding
of non-string fields contained the enclosed character in their text
representation.
Example:
SELECT 15, 9 INTO OUTFILE 'text' FIELDS ENCLOSED BY '5';
Old encoded result in the text file:
5155 595
^ was decoded as the 1st enclosing character of the 2nd field;
^ was skipped as garbage;
^ ^ was decoded as a pair of englosing characters of the 1st field;
^ was decoded as traling space of the first field;
^^ was decoded as a doubled enclosed character.
New encoded result in the text file:
51\55 595
^ ^ pair of enclosing characters of the 1st field;
^^ escaped enclosed character.
Add more accessors to MySQL internals in mysql/plugin.h, for storage
engine plugins.
Add some accessors specific to the InnoDB storage engine, to allow
InnoDB to be compiled as a plugin (without MYSQL_SERVER). InnoDB
has additional requirements, due to its foreign key support, etc.
The `SELECT 'r' INTO OUTFILE ... FIELDS ENCLOSED BY 'r' ' statement
encoded the 'r' string to a 4 byte string of value x'725c7272'
(sequence of 4 characters: r\rr).
The LOAD DATA statement decoded this string to a 1 byte string of
value x'0d' (ASCII Carriage Return character) instead of the original
'r' character.
The same error also happened with the FIELDS ENCLOSED BY clause
followed by special characters: 'n', 't', 'r', 'b', '0', 'Z' and 'N'.
NOTE 1: This is a result of the undocumented feature: the LOAD DATA INFILE
recognises 2-byte input sequences like \n, \t, \r and \Z in addition
to documented 2-byte sequences: \0 and \N. This feature should be
documented (here backspace character is a default ESCAPED BY character,
in the real-life example it may be any ESCAPED BY character).
NOTE 2, changed behaviour:
Now the `SELECT INTO OUTFILE' statement with the `FIELDS ENCLOSED BY'
clause followed by one of: 'n', 't', 'r', 'b', '0', 'Z' or 'N' characters
encodes this special character itself by doubling it ('r' --> 'rr'),
not by prepending it with an escape character.
leads to the table corruption
New Field::store() method implemented to explicitly set thd->count_cuted_fields
before value storing, instead of (incorrectly) setting it in the CSV storage engine.
Thread row counter now properly incremented during check and repair in the CSV engine.
