2006-01-19 05:56:06 +03:00
use mysql;
truncate table general_log;
select * from general_log;
event_time user_host thread_id server_id command_type argument
2006-05-23 09:49:04 -07:00
TIMESTAMP USER_HOST THREAD_ID 1 Query select * from general_log
2006-01-19 05:56:06 +03:00
truncate table slow_log;
select * from slow_log;
start_time user_host query_time lock_time rows_sent rows_examined db last_insert_id insert_id server_id sql_text
truncate table general_log;
select * from general_log where argument like '%general_log%';
event_time user_host thread_id server_id command_type argument
2006-05-23 09:49:04 -07:00
TIMESTAMP USER_HOST THREAD_ID 1 Query select * from general_log where argument like '%general_log%'
2006-01-19 05:56:06 +03:00
create table join_test (verbose_comment varchar (80), command_type varchar(64));
insert into join_test values ("User performed a usual SQL query", "Query");
insert into join_test values ("New DB connection was registered", "Connect");
insert into join_test values ("Get the table info", "Field List");
select verbose_comment, user_host, argument
from mysql.general_log join join_test
on (mysql.general_log.command_type = join_test.command_type);
verbose_comment user_host argument
2006-05-22 11:34:41 -07:00
User performed a usual SQL query USER_HOST select * from general_log where argument like '%general_log%'
User performed a usual SQL query USER_HOST create table join_test (verbose_comment varchar (80), command_type varchar(64))
User performed a usual SQL query USER_HOST insert into join_test values ("User performed a usual SQL query", "Query")
User performed a usual SQL query USER_HOST insert into join_test values ("New DB connection was registered", "Connect")
User performed a usual SQL query USER_HOST insert into join_test values ("Get the table info", "Field List")
User performed a usual SQL query USER_HOST select verbose_comment, user_host, argument
2006-01-19 05:56:06 +03:00
from mysql.general_log join join_test
on (mysql.general_log.command_type = join_test.command_type)
drop table join_test;
flush logs;
lock tables mysql.general_log WRITE;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
ERROR HY000: You can't use locks with log tables.
2006-01-19 05:56:06 +03:00
lock tables mysql.slow_log WRITE;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
ERROR HY000: You can't use locks with log tables.
2006-01-19 05:56:06 +03:00
lock tables mysql.general_log READ;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
ERROR HY000: You can't use locks with log tables.
2006-01-19 05:56:06 +03:00
lock tables mysql.slow_log READ;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
ERROR HY000: You can't use locks with log tables.
2006-01-19 05:56:06 +03:00
lock tables mysql.slow_log READ LOCAL, mysql.general_log READ LOCAL;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
ERROR HY000: You can't use locks with log tables.
show create table mysql.general_log;
Table Create Table
general_log CREATE TABLE `general_log` (
`event_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`user_host` mediumtext,
`thread_id` int(11) DEFAULT NULL,
`server_id` int(11) DEFAULT NULL,
`command_type` varchar(64) DEFAULT NULL,
`argument` mediumtext
) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='General log'
show fields from mysql.general_log;
Field Type Null Key Default Extra
event_time timestamp NO CURRENT_TIMESTAMP
user_host mediumtext YES NULL
thread_id int(11) YES NULL
server_id int(11) YES NULL
command_type varchar(64) YES NULL
argument mediumtext YES NULL
show create table mysql.slow_log;
Table Create Table
slow_log CREATE TABLE `slow_log` (
`start_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`user_host` mediumtext NOT NULL,
`query_time` time NOT NULL,
`lock_time` time NOT NULL,
`rows_sent` int(11) NOT NULL,
`rows_examined` int(11) NOT NULL,
`db` varchar(512) DEFAULT NULL,
`last_insert_id` int(11) DEFAULT NULL,
`insert_id` int(11) DEFAULT NULL,
`server_id` int(11) DEFAULT NULL,
`sql_text` mediumtext NOT NULL
) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='Slow log'
show fields from mysql.slow_log;
Field Type Null Key Default Extra
start_time timestamp NO CURRENT_TIMESTAMP
user_host mediumtext NO
query_time time NO
lock_time time NO
rows_sent int(11) NO
rows_examined int(11) NO
db varchar(512) YES NULL
last_insert_id int(11) YES NULL
insert_id int(11) YES NULL
server_id int(11) YES NULL
sql_text mediumtext NO
2006-10-04 23:48:24 +02:00
flush logs;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
flush tables;
SET GLOBAL GENERAL_LOG=ON;
SET GLOBAL SLOW_QUERY_LOG=ON;
show open tables;
Database Table In_use Name_locked
mysql general_log 0 0
flush logs;
show open tables;
Database Table In_use Name_locked
mysql general_log 0 0
flush tables;
show open tables;
Database Table In_use Name_locked
mysql general_log 0 0
SET GLOBAL GENERAL_LOG=OFF;
SET GLOBAL SLOW_QUERY_LOG=OFF;
flush tables;
show open tables;
Database Table In_use Name_locked
SET GLOBAL GENERAL_LOG=ON;
SET GLOBAL SLOW_QUERY_LOG=ON;
2006-02-03 13:05:14 +03:00
truncate table mysql.general_log;
set names utf8;
create table bug16905 (s char(15) character set utf8 default 'пусто');
insert into bug16905 values ('новое');
select * from mysql.general_log;
event_time user_host thread_id server_id command_type argument
2006-05-23 09:49:04 -07:00
TIMESTAMP USER_HOST THREAD_ID 1 Query set names utf8
TIMESTAMP USER_HOST THREAD_ID 1 Query create table bug16905 (s char(15) character set utf8 default 'пусто')
TIMESTAMP USER_HOST THREAD_ID 1 Query insert into bug16905 values ('новое')
TIMESTAMP USER_HOST THREAD_ID 1 Query select * from mysql.general_log
2006-02-03 13:05:14 +03:00
drop table bug16905;
2006-03-06 21:03:17 +03:00
truncate table mysql.slow_log;
set session long_query_time=1;
select sleep(2);
sleep(2)
0
select * from mysql.slow_log;
start_time user_host query_time lock_time rows_sent rows_examined db last_insert_id insert_id server_id sql_text
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
TIMESTAMP USER_HOST QUERY_TIME 00:00:00 1 0 mysql 0 0 1 select sleep(2)
2006-08-03 21:28:15 +04:00
alter table mysql.general_log engine=myisam;
2006-09-27 17:48:00 +04:00
ERROR HY000: You cannot 'ALTER' a log table if logging is enabled
2006-08-03 21:28:15 +04:00
alter table mysql.slow_log engine=myisam;
2006-09-27 17:48:00 +04:00
ERROR HY000: You cannot 'ALTER' a log table if logging is enabled
2006-08-03 21:28:15 +04:00
drop table mysql.general_log;
2006-09-27 17:48:00 +04:00
ERROR HY000: You cannot 'DROP' a log table if logging is enabled
2006-08-03 21:28:15 +04:00
drop table mysql.slow_log;
2006-09-27 17:48:00 +04:00
ERROR HY000: You cannot 'DROP' a log table if logging is enabled
2006-08-03 21:28:15 +04:00
set global general_log='OFF';
alter table mysql.slow_log engine=myisam;
2006-09-27 17:48:00 +04:00
ERROR HY000: You cannot 'ALTER' a log table if logging is enabled
2006-08-03 21:28:15 +04:00
set global slow_query_log='OFF';
show create table mysql.general_log;
Table Create Table
general_log CREATE TABLE `general_log` (
`event_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`user_host` mediumtext,
`thread_id` int(11) DEFAULT NULL,
`server_id` int(11) DEFAULT NULL,
`command_type` varchar(64) DEFAULT NULL,
`argument` mediumtext
) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='General log'
show create table mysql.slow_log;
Table Create Table
slow_log CREATE TABLE `slow_log` (
`start_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`user_host` mediumtext NOT NULL,
`query_time` time NOT NULL,
`lock_time` time NOT NULL,
`rows_sent` int(11) NOT NULL,
`rows_examined` int(11) NOT NULL,
`db` varchar(512) DEFAULT NULL,
`last_insert_id` int(11) DEFAULT NULL,
`insert_id` int(11) DEFAULT NULL,
`server_id` int(11) DEFAULT NULL,
`sql_text` mediumtext NOT NULL
) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='Slow log'
alter table mysql.general_log engine=myisam;
alter table mysql.slow_log engine=myisam;
show create table mysql.general_log;
Table Create Table
general_log CREATE TABLE `general_log` (
`event_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`user_host` mediumtext,
`thread_id` int(11) DEFAULT NULL,
`server_id` int(11) DEFAULT NULL,
`command_type` varchar(64) DEFAULT NULL,
`argument` mediumtext
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COMMENT='General log'
show create table mysql.slow_log;
Table Create Table
slow_log CREATE TABLE `slow_log` (
`start_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`user_host` mediumtext NOT NULL,
`query_time` time NOT NULL,
`lock_time` time NOT NULL,
`rows_sent` int(11) NOT NULL,
`rows_examined` int(11) NOT NULL,
`db` varchar(512) DEFAULT NULL,
`last_insert_id` int(11) DEFAULT NULL,
`insert_id` int(11) DEFAULT NULL,
`server_id` int(11) DEFAULT NULL,
`sql_text` mediumtext NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COMMENT='Slow log'
set global general_log='ON';
set global slow_query_log='ON';
select * from mysql.general_log;
event_time user_host thread_id server_id command_type argument
TIMESTAMP USER_HOST THREAD_ID 1 Query set names utf8
TIMESTAMP USER_HOST THREAD_ID 1 Query create table bug16905 (s char(15) character set utf8 default 'пусто')
TIMESTAMP USER_HOST THREAD_ID 1 Query insert into bug16905 values ('новое')
TIMESTAMP USER_HOST THREAD_ID 1 Query select * from mysql.general_log
TIMESTAMP USER_HOST THREAD_ID 1 Query drop table bug16905
TIMESTAMP USER_HOST THREAD_ID 1 Query truncate table mysql.slow_log
TIMESTAMP USER_HOST THREAD_ID 1 Query set session long_query_time=1
TIMESTAMP USER_HOST THREAD_ID 1 Query select sleep(2)
TIMESTAMP USER_HOST THREAD_ID 1 Query select * from mysql.slow_log
TIMESTAMP USER_HOST THREAD_ID 1 Query alter table mysql.general_log engine=myisam
TIMESTAMP USER_HOST THREAD_ID 1 Query alter table mysql.slow_log engine=myisam
TIMESTAMP USER_HOST THREAD_ID 1 Query drop table mysql.general_log
TIMESTAMP USER_HOST THREAD_ID 1 Query drop table mysql.slow_log
TIMESTAMP USER_HOST THREAD_ID 1 Query set global general_log='OFF'
TIMESTAMP USER_HOST THREAD_ID 1 Query set global slow_query_log='ON'
TIMESTAMP USER_HOST THREAD_ID 1 Query select * from mysql.general_log
flush logs;
lock tables mysql.general_log WRITE;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
ERROR HY000: You can't use locks with log tables.
2006-08-03 21:28:15 +04:00
lock tables mysql.slow_log WRITE;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
ERROR HY000: You can't use locks with log tables.
2006-08-03 21:28:15 +04:00
lock tables mysql.general_log READ;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
ERROR HY000: You can't use locks with log tables.
2006-08-03 21:28:15 +04:00
lock tables mysql.slow_log READ;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
ERROR HY000: You can't use locks with log tables.
2006-08-03 21:28:15 +04:00
set global general_log='OFF';
set global slow_query_log='OFF';
2007-03-02 08:43:45 -08:00
set @save_storage_engine= @@session.storage_engine;
set storage_engine= MEMORY;
2006-08-03 21:28:15 +04:00
alter table mysql.slow_log engine=ndb;
2006-09-15 13:07:23 +04:00
ERROR HY000: This storage engine cannot be used for log tables"
2006-08-03 21:28:15 +04:00
alter table mysql.slow_log engine=innodb;
2006-09-15 13:07:23 +04:00
ERROR HY000: This storage engine cannot be used for log tables"
2006-08-03 21:28:15 +04:00
alter table mysql.slow_log engine=archive;
2006-09-15 13:07:23 +04:00
ERROR HY000: This storage engine cannot be used for log tables"
2006-08-03 21:28:15 +04:00
alter table mysql.slow_log engine=blackhole;
2006-09-15 13:07:23 +04:00
ERROR HY000: This storage engine cannot be used for log tables"
2007-03-02 08:43:45 -08:00
set storage_engine= @save_storage_engine;
2006-08-03 21:28:15 +04:00
drop table mysql.slow_log;
drop table mysql.general_log;
drop table mysql.general_log;
ERROR 42S02: Unknown table 'general_log'
drop table mysql.slow_log;
ERROR 42S02: Unknown table 'slow_log'
use mysql;
CREATE TABLE `general_log` (
`event_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP
ON UPDATE CURRENT_TIMESTAMP,
`user_host` mediumtext,
`thread_id` int(11) DEFAULT NULL,
`server_id` int(11) DEFAULT NULL,
`command_type` varchar(64) DEFAULT NULL,
`argument` mediumtext
) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='General log';
CREATE TABLE `slow_log` (
`start_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP
ON UPDATE CURRENT_TIMESTAMP,
`user_host` mediumtext NOT NULL,
`query_time` time NOT NULL,
`lock_time` time NOT NULL,
`rows_sent` int(11) NOT NULL,
`rows_examined` int(11) NOT NULL,
`db` varchar(512) DEFAULT NULL,
`last_insert_id` int(11) DEFAULT NULL,
`insert_id` int(11) DEFAULT NULL,
`server_id` int(11) DEFAULT NULL,
`sql_text` mediumtext NOT NULL
) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='Slow log';
set global general_log='ON';
set global slow_query_log='ON';
use test;
2006-08-03 17:23:37 +04:00
flush tables with read lock;
unlock tables;
use mysql;
lock tables general_log read local, help_category read local;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
ERROR HY000: You can't use locks with log tables.
2006-08-03 17:23:37 +04:00
unlock tables;
2006-10-13 17:26:46 +04:00
use mysql;
RENAME TABLE general_log TO renamed_general_log;
ERROR HY000: Cannot rename 'general_log'. When logging enabled, rename to/from log table must rename two tables: the log table to an archive table and another table back to 'general_log'
RENAME TABLE slow_log TO renamed_slow_log;
ERROR HY000: Cannot rename 'slow_log'. When logging enabled, rename to/from log table must rename two tables: the log table to an archive table and another table back to 'slow_log'
truncate table general_log;
select * from general_log;
event_time user_host thread_id server_id command_type argument
TIMESTAMP USER_HOST THREAD_ID 1 Query select * from general_log
truncate table slow_log;
select * from slow_log;
start_time user_host query_time lock_time rows_sent rows_examined db last_insert_id insert_id server_id sql_text
create table general_log_new like general_log;
rename table general_log TO renamed_general_log, general_log_new TO general_log;
create table slow_log_new like slow_log;
rename table slow_log TO renamed_slow_log, slow_log_new TO slow_log;
rename table general_log TO general_log_new, renamed_general_log TO general_log, slow_log to renamed_slow_log;
ERROR HY000: Cannot rename 'slow_log'. When logging enabled, rename to/from log table must rename two tables: the log table to an archive table and another table back to 'slow_log'
select * from general_log;
event_time user_host thread_id server_id command_type argument
TIMESTAMP USER_HOST THREAD_ID 1 Query create table slow_log_new like slow_log
TIMESTAMP USER_HOST THREAD_ID 1 Query rename table slow_log TO renamed_slow_log, slow_log_new TO slow_log
TIMESTAMP USER_HOST THREAD_ID 1 Query rename table general_log TO general_log_new, renamed_general_log TO general_log, slow_log to renamed_slow_log
TIMESTAMP USER_HOST THREAD_ID 1 Query select * from general_log
select * from renamed_general_log;
event_time user_host thread_id server_id command_type argument
TIMESTAMP USER_HOST THREAD_ID 1 Query select * from general_log
TIMESTAMP USER_HOST THREAD_ID 1 Query truncate table slow_log
TIMESTAMP USER_HOST THREAD_ID 1 Query select * from slow_log
TIMESTAMP USER_HOST THREAD_ID 1 Query create table general_log_new like general_log
TIMESTAMP USER_HOST THREAD_ID 1 Query rename table general_log TO renamed_general_log, general_log_new TO general_log
select * from slow_log;
start_time user_host query_time lock_time rows_sent rows_examined db last_insert_id insert_id server_id sql_text
select * from renamed_slow_log;
start_time user_host query_time lock_time rows_sent rows_examined db last_insert_id insert_id server_id sql_text
set global general_log='OFF';
RENAME TABLE general_log TO general_log2;
set global slow_query_log='OFF';
RENAME TABLE slow_log TO slow_log2;
set global general_log='ON';
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
ERROR 42S02: Table 'mysql.general_log' doesn't exist
2006-10-13 17:26:46 +04:00
set global slow_query_log='ON';
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
ERROR 42S02: Table 'mysql.slow_log' doesn't exist
2006-10-13 17:26:46 +04:00
RENAME TABLE general_log2 TO general_log;
RENAME TABLE slow_log2 TO slow_log;
set global general_log='ON';
set global slow_query_log='ON';
flush logs;
flush logs;
drop table renamed_general_log, renamed_slow_log;
use test;
use mysql;
repair table general_log;
Table Op Msg_type Msg_text
mysql.general_log repair status OK
repair table slow_log;
Table Op Msg_type Msg_text
mysql.slow_log repair status OK
create table general_log_new like general_log;
create table slow_log_new like slow_log;
show tables like "%log%";
Tables_in_mysql (%log%)
general_log
general_log_new
2006-12-01 15:49:07 +01:00
ndb_binlog_index
2006-10-13 17:26:46 +04:00
slow_log
slow_log_new
drop table slow_log_new, general_log_new;
use test;
Bug#27857 (Log tables supplies the wrong value for generating AUTO_INCREMENT
numbers)
Before this patch, the code in the class Log_to_csv_event_handler, which is
used by the global LOGGER object to write to the tables mysql.slow_log and
mysql_general_log, was supporting only records of the format defined for
these tables in the database creation scripts.
Also before this patch, the server would allow, with certain limitations,
to perform ALTER TABLE on the LOG TABLES.
As implemented, the behavior of the server, with regards to LOG TABLES,
is inconsistent:
- either ALTER TABLES on LOG TABLES should be prohibited,
and the code writing to these tables can make assumptions on the record
format,
- or ALTER TABLE on LOG TABLES is permitted, in which case the code
writing a record to these tables should be more flexible and honor
new fields.
In particular, adding an AUTO_INCREMENT column to the logs,
does not work as expected (per the bug report).
Given that the ALTER TABLE on log tables statement has been explicitly
implemented to check that the log should be off to perform the operation,
and that current test cases already cover this, the user expectation is
already set that this is a "feature" and should be supported.
With this patch, the server will:
- populate AUTO INCREMENT columns if present,
- populate any additional column with it's default value
when writing a record to the LOG TABLES.
Tests are provided, that detail the precise sequence of statements
a SUPER user might want to perform to add more columns to the log tables.
2007-06-13 22:05:22 -06:00
SET GLOBAL LOG_OUTPUT = 'TABLE';
SET GLOBAL general_log = 0;
FLUSH LOGS;
TRUNCATE TABLE mysql.general_log;
ALTER TABLE mysql.general_log ENGINE = MyISAM;
ALTER TABLE mysql.general_log
ADD COLUMN seq BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY;
SET GLOBAL general_log = 1;
FLUSH LOGS;
SELECT * FROM mysql.general_log;
event_time user_host thread_id server_id command_type argument seq
EVENT_TIME USER_HOST THREAD_ID SERVER_ID Query FLUSH LOGS 1
EVENT_TIME USER_HOST THREAD_ID SERVER_ID Query SELECT * FROM mysql.general_log 2
SELECT * FROM mysql.general_log;
event_time user_host thread_id server_id command_type argument seq
EVENT_TIME USER_HOST THREAD_ID SERVER_ID Query FLUSH LOGS 1
EVENT_TIME USER_HOST THREAD_ID SERVER_ID Query SELECT * FROM mysql.general_log 2
EVENT_TIME USER_HOST THREAD_ID SERVER_ID Query SELECT * FROM mysql.general_log 3
SELECT "My own query 1";
My own query 1
My own query 1
SELECT "My own query 2";
My own query 2
My own query 2
SELECT * FROM mysql.general_log;
event_time user_host thread_id server_id command_type argument seq
EVENT_TIME USER_HOST THREAD_ID SERVER_ID Query FLUSH LOGS 1
EVENT_TIME USER_HOST THREAD_ID SERVER_ID Query SELECT * FROM mysql.general_log 2
EVENT_TIME USER_HOST THREAD_ID SERVER_ID Query SELECT * FROM mysql.general_log 3
EVENT_TIME USER_HOST THREAD_ID SERVER_ID Query SELECT "My own query 1" 4
EVENT_TIME USER_HOST THREAD_ID SERVER_ID Query SELECT "My own query 2" 5
EVENT_TIME USER_HOST THREAD_ID SERVER_ID Query SELECT * FROM mysql.general_log 6
SET GLOBAL general_log = 0;
FLUSH LOGS;
ALTER TABLE mysql.general_log DROP COLUMN seq;
ALTER TABLE mysql.general_log ENGINE = CSV;
SET @old_long_query_time:=@@long_query_time;
SET GLOBAL slow_query_log = 0;
FLUSH LOGS;
TRUNCATE TABLE mysql.slow_log;
ALTER TABLE mysql.slow_log ENGINE = MyISAM;
ALTER TABLE mysql.slow_log
ADD COLUMN seq BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY;
SET SESSION long_query_time = 1;
SET GLOBAL slow_query_log = 1;
FLUSH LOGS;
SELECT "My own slow query", sleep(2);
My own slow query sleep(2)
My own slow query 0
SELECT "My own slow query", sleep(2);
My own slow query sleep(2)
My own slow query 0
SELECT "My own slow query", sleep(2);
My own slow query sleep(2)
My own slow query 0
SELECT "My own slow query", sleep(2);
My own slow query sleep(2)
My own slow query 0
SELECT * FROM mysql.slow_log WHERE seq >= 2 LIMIT 3;
start_time user_host query_time lock_time rows_sent rows_examined db last_insert_id insert_id server_id sql_text seq
START_TIME USER_HOST QUERY_TIME 00:00:00 1 0 test NULL NULL 1 SELECT "My own slow query", sleep(2) 2
START_TIME USER_HOST QUERY_TIME 00:00:00 1 0 test NULL NULL 1 SELECT "My own slow query", sleep(2) 3
START_TIME USER_HOST QUERY_TIME 00:00:00 1 0 test NULL NULL 1 SELECT "My own slow query", sleep(2) 4
SET GLOBAL slow_query_log = 0;
SET SESSION long_query_time =@old_long_query_time;
FLUSH LOGS;
ALTER TABLE mysql.slow_log DROP COLUMN seq;
ALTER TABLE mysql.slow_log ENGINE = CSV;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
drop procedure if exists proc25422_truncate_slow;
drop procedure if exists proc25422_truncate_general;
drop procedure if exists proc25422_alter_slow;
drop procedure if exists proc25422_alter_general;
use test//
create procedure proc25422_truncate_slow (loops int)
begin
declare v1 int default 0;
2007-08-01 16:48:14 +04:00
declare continue handler for sqlexception /* errors from truncate */
begin end;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
while v1 < loops do
truncate mysql.slow_log;
set v1 = v1 + 1;
end while;
end//
create procedure proc25422_truncate_general (loops int)
begin
declare v1 int default 0;
2007-08-01 16:48:14 +04:00
declare continue handler for sqlexception /* errors from truncate */
begin end;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
while v1 < loops do
truncate mysql.general_log;
set v1 = v1 + 1;
end while;
end//
create procedure proc25422_alter_slow (loops int)
begin
declare v1 int default 0;
declare ER_BAD_LOG_STATEMENT condition for 1575;
declare continue handler for ER_BAD_LOG_STATEMENT begin end;
while v1 < loops do
set @old_log_state = @@global.slow_query_log;
set global slow_query_log = 'OFF';
alter table mysql.slow_log engine = CSV;
set global slow_query_log = @old_log_state;
set v1 = v1 + 1;
end while;
end//
create procedure proc25422_alter_general (loops int)
begin
declare v1 int default 0;
declare ER_BAD_LOG_STATEMENT condition for 1575;
declare continue handler for ER_BAD_LOG_STATEMENT begin end;
while v1 < loops do
set @old_log_state = @@global.general_log;
set global general_log = 'OFF';
alter table mysql.general_log engine = CSV;
set global general_log = @old_log_state;
set v1 = v1 + 1;
end while;
end//
2007-08-01 16:48:14 +04:00
set @iterations=100;
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
"Serial test (proc25422_truncate_slow)"
2007-08-01 16:48:14 +04:00
call proc25422_truncate_slow(@iterations);
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
"Serial test (proc25422_truncate_general)"
2007-08-01 16:48:14 +04:00
call proc25422_truncate_general(@iterations);
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
"Serial test (proc25422_alter_slow)"
2007-08-01 16:48:14 +04:00
call proc25422_alter_slow(@iterations);
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
"Serial test (proc25422_alter_general)"
2007-08-01 16:48:14 +04:00
call proc25422_alter_general(@iterations);
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
"Parallel test"
2007-08-01 16:48:14 +04:00
call proc25422_truncate_slow(@iterations);
call proc25422_truncate_slow(@iterations);
call proc25422_truncate_general(@iterations);
call proc25422_truncate_general(@iterations);
call proc25422_alter_slow(@iterations);
call proc25422_alter_slow(@iterations);
call proc25422_alter_general(@iterations);
call proc25422_alter_general(@iterations);
WL#3984 (Revise locking of mysql.general_log and mysql.slow_log)
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.
2007-07-27 00:31:06 -06:00
drop procedure proc25422_truncate_slow;
drop procedure proc25422_truncate_general;
drop procedure proc25422_alter_slow;
drop procedure proc25422_alter_general;
FLUSH TABLE mysql.general_log;
show warnings;
Level Code Message
FLUSH TABLE mysql.slow_log;
show warnings;
Level Code Message
DROP TABLE IF EXISTS `db_17876.slow_log_data`;
DROP TABLE IF EXISTS `db_17876.general_log_data`;
DROP PROCEDURE IF EXISTS `db_17876.archiveSlowLog`;
DROP PROCEDURE IF EXISTS `db_17876.archiveGeneralLog`;
DROP DATABASE IF EXISTS `db_17876`;
CREATE DATABASE db_17876;
CREATE TABLE `db_17876.slow_log_data` (
`start_time` timestamp default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP,
`user_host` mediumtext ,
`query_time` time ,
`lock_time` time ,
`rows_sent` int(11) ,
`rows_examined` int(11) ,
`db` varchar(512) default NULL,
`last_insert_id` int(11) default NULL,
`insert_id` int(11) default NULL,
`server_id` int(11) default NULL,
`sql_text` mediumtext
);
CREATE TABLE `db_17876.general_log_data` (
`event_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`user_host` mediumtext,
`thread_id` int(11) DEFAULT NULL,
`server_id` int(11) DEFAULT NULL,
`command_type` varchar(64) DEFAULT NULL,
`argument` mediumtext
);
CREATE procedure `db_17876.archiveSlowLog`()
BEGIN
DECLARE start_time, query_time, lock_time CHAR(20);
DECLARE user_host MEDIUMTEXT;
DECLARE rows_set, rows_examined, last_insert_id, insert_id, server_id INT;
DECLARE dbname MEDIUMTEXT;
DECLARE sql_text BLOB;
DECLARE done INT DEFAULT 0;
DECLARE ER_SP_FETCH_NO_DATA CONDITION for 1329;
DECLARE cur1 CURSOR FOR SELECT * FROM mysql.slow_log;
OPEN cur1;
REPEAT
BEGIN
BEGIN
DECLARE CONTINUE HANDLER FOR ER_SP_FETCH_NO_DATA SET done = 1;
FETCH cur1 INTO
start_time, user_host, query_time, lock_time,
rows_set, rows_examined, dbname, last_insert_id,
insert_id, server_id, sql_text;
END;
IF NOT done THEN
BEGIN
INSERT INTO
`db_17876.slow_log_data`
VALUES(start_time, user_host, query_time, lock_time, rows_set, rows_examined,
dbname, last_insert_id, insert_id, server_id, sql_text);
END;
END IF;
END;
UNTIL done END REPEAT;
CLOSE cur1;
TRUNCATE mysql.slow_log;
END //
CREATE procedure `db_17876.archiveGeneralLog`()
BEGIN
DECLARE event_time CHAR(20);
DECLARE user_host, argument MEDIUMTEXT;
DECLARE thread_id, server_id INT;
DECLARE sql_text BLOB;
DECLARE done INT DEFAULT 0;
DECLARE command_type VARCHAR(64);
DECLARE ER_SP_FETCH_NO_DATA CONDITION for 1329;
DECLARE cur1 CURSOR FOR SELECT * FROM mysql.general_log;
OPEN cur1;
REPEAT
BEGIN
BEGIN
DECLARE CONTINUE HANDLER FOR ER_SP_FETCH_NO_DATA SET done = 1;
FETCH cur1 INTO
event_time, user_host, thread_id, server_id,
command_type, argument;
END;
IF NOT done THEN
BEGIN
INSERT INTO
`db_17876.general_log_data`
VALUES(event_time, user_host, thread_id, server_id,
command_type, argument);
END;
END IF;
END;
UNTIL done END REPEAT;
CLOSE cur1;
TRUNCATE mysql.general_log;
END //
SET @old_general_log_state = @@global.general_log;
SET @old_slow_log_state = @@global.slow_query_log;
SET GLOBAL general_log = ON;
SET GLOBAL slow_query_log = ON;
select "put something into general_log";
put something into general_log
put something into general_log
select "... and something more ...";
... and something more ...
... and something more ...
call `db_17876.archiveSlowLog`();
call `db_17876.archiveGeneralLog`();
SET GLOBAL general_log = OFF;
SET GLOBAL slow_query_log = OFF;
call `db_17876.archiveSlowLog`();
call `db_17876.archiveGeneralLog`();
DROP TABLE `db_17876.slow_log_data`;
DROP TABLE `db_17876.general_log_data`;
DROP PROCEDURE IF EXISTS `db_17876.archiveSlowLog`;
DROP PROCEDURE IF EXISTS `db_17876.archiveGeneralLog`;
DROP DATABASE IF EXISTS `db_17876`;
SET GLOBAL general_log = @old_general_log_state;
SET GLOBAL slow_query_log = @old_slow_log_state;