mirror of
https://github.com/MariaDB/server.git
synced 2025-01-20 22:12:30 +01:00
c7bbd8917c
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.
177 lines
5.8 KiB
Text
177 lines
5.8 KiB
Text
set global general_log= OFF;
|
|
truncate table mysql.general_log;
|
|
truncate table mysql.slow_log;
|
|
show global variables
|
|
where Variable_name = 'log' or Variable_name = 'log_slow_queries' or
|
|
Variable_name = 'general_log' or Variable_name = 'slow_query_log';
|
|
Variable_name Value
|
|
general_log OFF
|
|
log OFF
|
|
log_slow_queries OFF
|
|
slow_query_log OFF
|
|
flush logs;
|
|
set global general_log= ON;
|
|
create table t1(f1 int);
|
|
select * from mysql.general_log;
|
|
event_time user_host thread_id server_id command_type argument
|
|
TIMESTAMP USER_HOST # 1 Query create table t1(f1 int)
|
|
TIMESTAMP USER_HOST # 1 Query select * from mysql.general_log
|
|
set global general_log= OFF;
|
|
drop table t1;
|
|
select * from mysql.general_log;
|
|
event_time user_host thread_id server_id command_type argument
|
|
TIMESTAMP USER_HOST # 1 Query create table t1(f1 int)
|
|
TIMESTAMP USER_HOST # 1 Query select * from mysql.general_log
|
|
TIMESTAMP USER_HOST # 1 Query set global general_log= OFF
|
|
set global general_log= ON;
|
|
flush logs;
|
|
show global variables
|
|
where Variable_name = 'log' or Variable_name = 'log_slow_queries' or
|
|
Variable_name = 'general_log' or Variable_name = 'slow_query_log';
|
|
Variable_name Value
|
|
general_log ON
|
|
log ON
|
|
log_slow_queries OFF
|
|
slow_query_log OFF
|
|
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
|
|
set global slow_query_log= ON;
|
|
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
|
|
TIMESTAMP USER_HOST QUERY_TIME 00:00:00 1 0 test 0 0 1 select sleep(2)
|
|
show global variables
|
|
where Variable_name = 'log' or Variable_name = 'log_slow_queries' or
|
|
Variable_name = 'general_log' or Variable_name = 'slow_query_log';
|
|
Variable_name Value
|
|
general_log ON
|
|
log ON
|
|
log_slow_queries ON
|
|
slow_query_log ON
|
|
set global general_log= ON;
|
|
set global general_log= OFF;
|
|
set global general_log= OFF;
|
|
set global slow_query_log= ON;
|
|
set global slow_query_log= OFF;
|
|
set global slow_query_log= OFF;
|
|
set global general_log= ON;
|
|
truncate table mysql.general_log;
|
|
create table t1(f1 int);
|
|
drop table t1;
|
|
select * from mysql.general_log;
|
|
event_time user_host thread_id server_id command_type argument
|
|
TIMESTAMP USER_HOST # 1 Query create table t1(f1 int)
|
|
TIMESTAMP USER_HOST # 1 Query drop table t1
|
|
TIMESTAMP USER_HOST # 1 Query select * from mysql.general_log
|
|
set global general_log= OFF;
|
|
truncate table mysql.general_log;
|
|
select * from mysql.general_log;
|
|
event_time user_host thread_id server_id command_type argument
|
|
set global general_log= ON;
|
|
show global variables
|
|
where Variable_name = 'log' or Variable_name = 'log_slow_queries' or
|
|
Variable_name = 'general_log' or Variable_name = 'slow_query_log';
|
|
Variable_name Value
|
|
general_log ON
|
|
log ON
|
|
log_slow_queries OFF
|
|
slow_query_log OFF
|
|
show variables like 'general_log_file';
|
|
Variable_name Value
|
|
general_log_file #
|
|
show variables like 'slow_query_log_file';
|
|
Variable_name Value
|
|
slow_query_log_file #
|
|
show variables like 'log_output';
|
|
Variable_name Value
|
|
log_output FILE,TABLE
|
|
set global general_log_file='/not exiting path/log.master';
|
|
ERROR 42000: Variable 'general_log_file' can't be set to the value of '/not exiting path/log.master'
|
|
set global general_log_file='MYSQLTEST_VARDIR';
|
|
ERROR 42000: Variable 'general_log_file' can't be set to the value of 'MYSQLTEST_VARDIR'
|
|
set global general_log_file='';
|
|
ERROR 42000: Variable 'general_log_file' can't be set to the value of ''
|
|
show variables like 'general_log_file';
|
|
Variable_name Value
|
|
general_log_file #
|
|
set global general_log= OFF;
|
|
set global general_log_file='MYSQLTEST_VARDIR/tmp/log.master';
|
|
set global general_log= ON;
|
|
create table t1(f1 int);
|
|
drop table t1;
|
|
set global general_log= OFF;
|
|
set global general_log_file=default;
|
|
set global general_log= ON;
|
|
create table t1(f1 int);
|
|
drop table t1;
|
|
show variables like 'general_log_file';
|
|
Variable_name Value
|
|
general_log_file #
|
|
show variables like 'slow_query_log_file';
|
|
Variable_name Value
|
|
slow_query_log_file #
|
|
set global general_log= default;
|
|
set global slow_query_log= default;
|
|
set global general_log_file= default;
|
|
set global slow_query_log_file= default;
|
|
show variables like 'general_log';
|
|
Variable_name Value
|
|
general_log OFF
|
|
show variables like 'slow_query_log';
|
|
Variable_name Value
|
|
slow_query_log OFF
|
|
set global general_log=ON;
|
|
set global log_output=default;
|
|
show variables like 'log_output';
|
|
Variable_name Value
|
|
log_output FILE
|
|
set global general_log=OFF;
|
|
set global log_output=FILE;
|
|
truncate table mysql.general_log;
|
|
show variables like 'log_output';
|
|
Variable_name Value
|
|
log_output FILE
|
|
set global general_log=ON;
|
|
create table t1(f1 int);
|
|
select * from mysql.general_log;
|
|
event_time user_host thread_id server_id command_type argument
|
|
set global general_log=OFF;
|
|
set global log_output="FILE,TABLE";
|
|
show variables like 'log_output';
|
|
Variable_name Value
|
|
log_output FILE,TABLE
|
|
set global general_log=ON;
|
|
drop table t1;
|
|
select * from mysql.general_log;
|
|
event_time user_host thread_id server_id command_type argument
|
|
TIMESTAMP USER_HOST # 1 Query drop table t1
|
|
TIMESTAMP USER_HOST # 1 Query select * from mysql.general_log
|
|
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;
|
|
FLUSH TABLES WITH READ LOCK;
|
|
SET GLOBAL general_log = OFF;
|
|
SET GLOBAL slow_query_log = OFF;
|
|
UNLOCK TABLES;
|
|
FLUSH TABLES WITH READ LOCK;
|
|
SET GLOBAL general_log = ON;
|
|
SET GLOBAL slow_query_log = ON;
|
|
UNLOCK TABLES;
|
|
SET GLOBAL READ_ONLY = ON;
|
|
SET GLOBAL general_log = OFF;
|
|
SET GLOBAL slow_query_log = OFF;
|
|
SET GLOBAL READ_ONLY = OFF;
|
|
SET GLOBAL READ_ONLY = ON;
|
|
SET GLOBAL general_log = ON;
|
|
SET GLOBAL slow_query_log = ON;
|
|
SET GLOBAL READ_ONLY = OFF;
|
|
SET GLOBAL general_log = @old_general_log_state;
|
|
SET GLOBAL slow_query_log = @old_slow_log_state;
|