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.
SHOW CREATE TABLE fails
Underlying table names, that merge engine fails to open were not
reported.
With this fix CHECK TABLE issued against merge table reports all
underlying table names that it fails to open. Other statements
are unaffected, that is underlying table names are not included
into error message.
This fix doesn't solve SHOW CREATE TABLE issue.
There is an existing macros for initializing LEX_STRINGs
with constant strings -> C_STRING_WITH_LEN. Change existing code to use it.
(char *) STRING_WITH_LEN -> C_STRING_WITH_LEN
Before this fix,
- a runtime error in a statement in a stored procedure with no error handlers
was properly detected (as expected)
- a runtime error in a statement with an error handler inherited from a non
local runtime context (i.e., proc a with a handler, calling proc b) was
properly detected (as expected)
- a runtime error in a statement with a *local* error handler was executed
as follows :
a) the statement would succeed, regardless of the error condition, (bug)
b) the error handler would be called (as expected).
The root cause is that functions like my_messqge_sql would "forget" to set
the thread flag thd->net.report_error to 1, because of the check involving
sp_rcontext::found_handler_here().
Failure to set this flag would cause, later in the call stack,
in Item_func::fix_fields() at line 190, the code to return FALSE and consider
that executing the statement was successful.
With this fix :
- error handling code, that was duplicated in different places in the code,
is now implemented in sp_rcontext::handle_error(),
- handle_error() correctly sets thd->net.report_error when a handler is
present, regardless of the handler location (local, or in the call stack).
A test case, bug8153_subselect, has been written to demonstrate the change
of behavior before and after the fix.
Another test case, bug8153_function_a, as also been writen.
This test has the same behavior before and after the fix.
This test has been written to demonstrate that the previous expected
result of procedure bug18787, was incorrect, since select no_such_function()
should fail and therefore not produce a result.
The incorrect result for bug18787 has the same root cause as Bug#8153,
and the expected result has been adjusted.
error for LIMIT placeholder".
The patch adds grammar support for LIMIT ?, ? and changes the
type of ST_SELECT_LEX::select_limit,offset_limit from ha_rows to Item*,
so that it can point to Item_param.
Now thd->mem_root is a pointer to thd->main_mem_root and THR_MALLOC is a pointer to thd->mem_root.
This gives us the following benefits:
- Allow us to easily detect if arena has already been swapped before (this fixes a bug in setup_conds() where arena was swaped twice in some cases)
- Faster swaps of arenas (as we don't have to copy the whole MEM_ROOT)
- We don't anymore have to call my_pthread_setspecific_ptr(THR_MALLOC,...) to change where memory is alloced. Now it's enough to set thd->mem_root
New mysqltest that can run mysqltest with PS
Added support for ZEROFILL in PS
Fixed crash when one called mysql_stmt_store_result() without a preceding mysql_stmt_bind_result()
Updated test cases to support --ps-protocol
(Some tests are still run using old protocol)
Fixed crash in PS when using SELECT * FROM t1 NATURAL JOIN t2...
Fixed crash in PS when using sub queries
Create table didn't signal when table was created. This could cause a "DROP TABLE created_table" in another thread to wait "forever"
Fixed wrong permissions check in PS and multi-table updates (one could get permission denied for legal quries)
Fix for PS and SELECT ... PROCEDURE
Reset all warnings when executing a new PS query
group_concat(...ORDER BY) didn't work with PS
Fixed problem with test suite when not using innodb
Fixed compiler warnings (a lot of hidden variables detected by the Forte compiler)
Added a lot of 'version_xxx' strings to 'show variables'
Prevent copying of TMP_TABLE_PARAM (This caused core dump bug on Solaris)
Fixed problem with printing sub selects to debug log
Fix LOAD DATA INFILE warnings to have a better meanigful messages
Fix to make the mysql command line to automatically show the warnings count for all basic commands
Changed timestamp to return string in YYYY-MM-DD HH:MM:SS format.
DATE_ADD() and related functions now returns correct DATE/DATETIME type depending on argument types.
Now all tests passes, still some work left to remove warnings in log files from mysql-test-run
Class for sending data from server to client (Protocol)
This handles both the old ( <= 4.0 ) protocol and then new binary protocol that is used for prepared statements.
Warning handling and initial prepared statement handling (last not complete yet)
Changed a lot of functions that returned 0/1 to my_bool type.
GRANT handling now uses read/write locks instead of mutex
Change basic net functions to use THD instead of NET
(needed for 4.1 protocol)
Use my_sprintf instead of sprintf() + strlen()
Added alloc_query() to be able to chare query initialization code with
prepared statements.
Cleanup handling of SHOW COUNT(*) WARNINGS and SELECT LAST_INSERT_ID()
Note that the following test fails (will be fixed ASAP):
sub_select, union, rpl_rotate_logs and rpl_mystery22
new file
Client-server protocol 4.1 changes - Server side:
* Enhanced metadata information:
- SHOW [COUNT(*)] ERRORS [LIMIT [offset,] rows]
- SHOW [COUNT(*)] WARNING [LIMIT [offset,] rows]
- SHOW TABLE TYPES
- SHOW PRIVILEGES
- SHOW COLUMN TYPES (Not fully implemented)
* Prepared execution
* Long data handling in pieces
* And other misc changes
