database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2026-01-06 05:22:24 +03:00
Code Activity

Bug#12809202 61854: MYSQLDUMP --SINGLE-TRANSACTION

Browse Source 
--FLUSH-LOG BREAKS CONSISTENCY

The transaction started by mysqldump gets committed
implicitly when flush-log is specified along with
single-transaction option, and hence can break
consistency.

This is because, COM_REFRESH is executed in order
to flush logs and starting from 5.5 this command
performs an implicit commit.

Fixed by making sure that COM_REFRESH is executed
before the transaction has started and not after it.

Note : This patch triggers following behavioral
       changes in mysqldump :

1) After this patch we no longer flush logs before
   dumping each database if --single-transaction
   option is given like it was done before (in the
   absence of --lock-all-tables and --master-data
   options).

2) Also, after this patch, we start acquiring
   FTWRL before flushing logs in cases when only
   --single-transaction and --flush-logs are given.
   It becomes safe to use mysqldump with these two
   options and without --master-data parameter for
   backups.
This commit is contained in:
Nirbhay Choubey
2011-12-23 23:05:00 +05:30
parent 74a8331c08
commit a4343d56ed
3 changed files with 164 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
mysql-test/t/mysqldump.test
View File

@@ -2215,5 +2215,37 @@ CREATE TABLE t1 (a INT);
--exec $MYSQL_DUMP --compatible=no_t,no_f --skip-comments test
DROP TABLE t1;
--echo #
--echo # Bug#12809202 61854: MYSQLDUMP --SINGLE-TRANSACTION --FLUSH-LOG BREAKS
--echo # CONSISTENCY
--echo #
--disable_warnings
DROP DATABASE IF EXISTS b12809202_db;
--enable_warnings
CREATE DATABASE b12809202_db;
CREATE TABLE b12809202_db.t1 (c1 INT);
CREATE TABLE b12809202_db.t2 (c1 INT);
INSERT INTO b12809202_db.t1 VALUES (1), (2), (3);
INSERT INTO b12809202_db.t2 VALUES (1), (2), (3);
--echo # Starting mysqldump with --single-transaction & --flush-log options..
--echo # Note : In the following dump the transaction
--echo # should start only after the logs are
--echo # flushed, as 'flush logs' causes implicit
--echo # commit starting 5.5.
--echo
--echo #### Dump starts here ####
--replace_regex /-- Server version.*// /-- MySQL dump .*// /-- Dump completed on .*/-- Dump completed/
--exec $MYSQL_DUMP --verbose --single-transaction --flush-log b12809202_db 2>&1
--echo
--echo #### Dump ends here ####
DROP TABLE b12809202_db.t1;
DROP TABLE b12809202_db.t2;
DROP DATABASE b12809202_db;
# Wait till we reached the initial number of concurrent sessions
--source include/wait_until_count_sessions.inc