Problem
-------
For one-statement contains multiple row events, Flashback didn't reverse the
sequence of row events inside one-statement.
Solution
--------
Using a new array 'events_in_stmt' to store the row events of one-statement,
when parsed the last one event, then print from the last one to the first one.
In the same time, fixed another bug, without -vv will not insert the table_map
into print_event_info->m_table_map, then change_to_flashback_event() will not
execute because of Table_map_log_event is empty.
==== Description ====
Flashback can rollback the instances/databases/tables to an old snapshot.
It's implement on Server-Level by full image format binary logs (--binlog-row-image=FULL), so it supports all engines.
Currently, it’s a feature inside mysqlbinlog tool (with --flashback arguments).
Because the flashback binlog events will store in the memory, you should check if there is enough memory in your machine.
==== New Arguments to mysqlbinlog ====
--flashback (-B)
It will let mysqlbinlog to work on FLASHBACK mode.
==== New Arguments to mysqld ====
--flashback
Setup the server to use flashback. This enables binary log in row mode
and will enable extra logging for DDL's needed by flashback feature
==== Example ====
I have a table "t" in database "test", we can compare the output with "--flashback" and without.
#client/mysqlbinlog /data/mysqldata_10.0/binlog/mysql-bin.000001 -vv -d test -T t --start-datetime="2013-03-27 14:54:00" > /tmp/1.sql
#client/mysqlbinlog /data/mysqldata_10.0/binlog/mysql-bin.000001 -vv -d test -T t --start-datetime="2013-03-27 14:54:00" -B > /tmp/2.sql
Then, importing the output flashback file (/tmp/2.log), it can flashback your database/table to the special time (--start-datetime).
And if you know the exact postion, "--start-postion" is also works, mysqlbinlog will output the flashback logs that can flashback to "--start-postion" position.
==== Implement ====
1. As we know, if binlog_format is ROW (binlog-row-image=FULL in 10.1 and later), all columns value are store in the row event, so we can get the data before mis-operation.
2. Just do following things:
2.1 Change Event Type, INSERT->DELETE, DELETE->INSERT.
For example:
INSERT INTO t VALUES (...) ---> DELETE FROM t WHERE ...
DELETE FROM t ... ---> INSERT INTO t VALUES (...)
2.2 For Update_Event, swapping the SET part and WHERE part.
For example:
UPDATE t SET cols1 = vals1 WHERE cols2 = vals2
--->
UPDATE t SET cols2 = vals2 WHERE cols1 = vals1
2.3 For Multi-Rows Event, reverse the rows sequence, from the last row to the first row.
For example:
DELETE FROM t WHERE id=1; DELETE FROM t WHERE id=2; ...; DELETE FROM t WHERE id=n;
--->
DELETE FROM t WHERE id=n; ...; DELETE FROM t WHERE id=2; DELETE FROM t WHERE id=1;
2.4 Output those events from the last one to the first one which mis-operation happened.
For example:
Add some event types for the compressed event, there are:
QUERY_COMPRESSED_EVENT,
WRITE_ROWS_COMPRESSED_EVENT_V1,
UPDATE_ROWS_COMPRESSED_EVENT_V1,
DELETE_POWS_COMPRESSED_EVENT_V1,
WRITE_ROWS_COMPRESSED_EVENT,
UPDATE_ROWS_COMPRESSED_EVENT,
DELETE_POWS_COMPRESSED_EVENT.
These events inheritance the uncompressed editor events. One of their constructor functions and write
function have been overridden for uncompressing and compressing. Anything but this is totally the same.
On slave, The IO thread will uncompress and convert them When it receiving the events from the master.
So the SQL and worker threads can be stay unchanged.
Now we use zlib as compress algorithm. It maybe support other algorithm in the future.
This includes fixing all utilities to not have any memory leaks,
as safemalloc warnings stopped tests from passing on MacOSX.
- Ensure that all clients takes character-set-dir, as the
libmysqlclient library will use it.
- mysql-test-run now passes character-set-dir to all external clients.
- Changed dynstr_free() so that it can be called twice (made freeing code easier)
- Changed rpl_global_gtid_slave_state to be allocated dynamicly as it
includes a mutex that needs to be initizlied/destroyed before my_end() is called.
- Removed rpl_slave_state::init() and rpl_slave_stage::deinit() as
their job are better handling by constructor and delete.
- Print alias instead of table_name in check_duplicate_key as
table_name may have been converted to lower case.
Other things:
- Fixed a case in time_to_datetime_with_warn() where we where
using && instead of & in tests
The following left in semi-improved state to keep patch size reasonable:
- Field operator new: left thd_alloc(current_thd)
- Sql_alloc operator new: left thd_alloc(thd_get_current_thd())
- Item_args constructors: left thd_alloc(thd)
- Item_func_interval::fix_length_and_dec(): no THD arg, have to call current_thd
- Item_func_dyncol_exists::val_int(): same
- Item_dyncol_get::val_str(): same
- Item_dyncol_get::val_int(): same
- Item_dyncol_get::val_real(): same
- Item_dyncol_get::val_decimal(): same
- Item_singlerow_subselect::fix_length_and_dec(): same
There are three Log_event::read_log_event() methods:
1. read the event image from IO_CACHE into String
2. create Log_event from the in-memory event image
3. read the event image from IO_CACHE and create Log_event
The 3rd was reading event image into memory and invoking the 2nd to
create Log_event. Now the 3rd also uses the 1st to read the event image
from IO_CACHE into memory, instead of duplicating its functionality.
partially cherry-pick from mysql/5.6.
No test case (mysql/5.6 test case is useless, the correct
test case uses too much memory)
commit e061985813db54948f99892d89f7e076242473a5
Author: <Dao-Gang.Qu@sun.com>
Date: Tue Jun 1 15:02:22 2010 +0800
Bug #49931 Incorrect type in read_log_event error
Bug #49932 mysqlbinlog max_allowed_packet hard coded to 1GB
Problem: For every event read, mysqlbinlog calls localtime() which in turn
calls stat(/etc/localtime) which is causing kernel mutex contention.
Analysis and Fix:
localtime() calls stat(/etc/localtime) for every instance of the call
where as localtime_r() the reentrant version was optimized to store
the read only tz internal structure. Hence it will not call
stat(/etc/localtime). It will call only once at the beginning.
The mysql server is calling localtime_r() and mysqlbinlog tool is
one place where we are still using localtime().
Once the process (mysqlbinlog) is started if timezone is changed
it will be not picked up the the process and it will continue
with the same values as the beginning of the process. This
behavior is in-lined with mysql server.
Also adding localtime_r() and gmtime_r() support for windows.
mysql_upgrade --help now also prints out --default options and variable values.
mysql_upgrade now prints permission errors.
mysql_upgrade doesn't print some non essential info if --silent is used.
Added handler error message about incompatible versions
Fixed that mysqlbug and mysql_install_db have the executable flag set.
Removed executable flag for some non executable files.
Changed in mysql_install_db askmonty.org to mariadb.com.
Ensured that all client executables prints --default options the same way.
Allow REPAIR ... USE_FRM for old .frm files if the are still compatible.
Extended shown error for storage engine messages.
client/mysql.cc:
print_defaults() should be first (as in all other programs)
client/mysql_upgrade.c:
--help now also prints out --default options and variable values
Print out error if wrong permissions
Don't print info if --silent
client/mysqladmin.cc:
print_defaults() should be first (as in all other programs)
client/mysqlbinlog.cc:
Added print_defaults() to --help
client/mysqlcheck.c:
Added empty line in --help
client/mysqlimport.c:
Added empty line in --help
client/mysqlshow.c:
Made --help compatible
client/mysqlslap.c:
Made --help compatible
client/mysqltest.cc:
Added print_defaults() to --help
include/handler_ername.h:
Added handler error message
include/my_base.h:
Added handler error message
mysql-test/r/mysql_upgrade.result:
Updated results
mysql-test/r/repair.result:
Added test case for better error messages
mysql-test/std_data/host_old.MYD:
Added test case for better error messages
mysql-test/std_data/host_old.MYI:
Added test case for better error messages
mysql-test/std_data/host_old.frm:
Added test case for better error messages
mysql-test/t/repair.test:
Added test case for better error messages
mysys/my_handler_errors.h:
Added handler error message
scripts/CMakeLists.txt:
Fixed that mysqlbug and mysql_install_db have the executable flag set
scripts/mysql_install_db.sh:
askmonty.org -> mariadb.com
sql/ha_partition.cc:
Sometimes table_type() can be called for errors even if partition didn't manage to open any files
sql/handler.cc:
Write clear text for not handled, but defined error messages.
sql/share/errmsg-utf8.txt:
Extended shown error for storage engine messages
sql/sql_admin.cc:
Allow REPAIR ... USE_FRM for old .frm files if the are still compatible
storage/myisam/ha_myisam.cc:
Use new error message
includes:
* remove some remnants of "Bug#14521864: MYSQL 5.1 TO 5.5 BUGS PARTITIONING"
* introduce LOCK_share, now LOCK_ha_data is strictly for engines
* rea_create_table() always creates .par file (even in "frm-only" mode)
* fix a 5.6 bug, temp file leak on dummy ALTER TABLE
