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Large transactions and statements may corrupt the binary log if the size of the cache, which is set by the max_binlog_cache_size, is not enough to store the the changes. In a nutshell, to fix the bug, we save the position of the next character in the cache before starting processing a statement. If there is a problem, we simply restore the position thus removing any effect of the statement from the cache. Unfortunately, to avoid corrupting the binary log, we may end up loosing changes on non-transactional tables if they do not fit in the cache. In such cases, we store an Incident_log_event in order to stop the slave and alert users that some changes were not logged. Precisely, for every non-transactional changes that do not fit into the cache, we do the following: a) the statement is *not* logged b) an incident event is logged after committing/rolling back the transaction, if any. Note that if a failure happens before writing the incident event to the binary log, the slave will not stop and the master will not have reported any error. c) its respective statement gives an error For transactional changes that do not fit into the cache, we do the following: a) the statement is *not* logged b) its respective statement gives an error To work properly, this patch requires two additional things. Firstly, callers to MYSQL_BIN_LOG::write and THD::binlog_query must handle any error returned and take the appropriate actions such as undoing the effects of a statement. We already changed some calls in the sql_insert.cc, sql_update.cc and sql_insert.cc modules but the remaining calls spread all over the code should be handled in BUG#37148. Secondly, statements must be either classified as DDL or DML because DDLs that do not get into the cache must generate an incident event since they cannot be rolled back. |
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| std_data | ||
| suite | ||
| t | ||
| Makefile.am | ||
| mysql-stress-test.pl | ||
| mysql-test-run.pl | ||
| purify.supp | ||
| README | ||
| README.gcov | ||
| README.stress | ||
| valgrind.supp | ||
This directory contains a test suite for the MySQL daemon. To run the currently existing test cases, simply execute ./mysql-test-run in this directory. It will fire up the newly built mysqld and test it. Note that you do not have to have to do "make install", and you could actually have a co-existing MySQL installation. The tests will not conflict with it. All tests must pass. If one or more of them fail on your system, please read the following manual section for instructions on how to report the problem: http://dev.mysql.com/doc/mysql/en/mysql-test-suite.html If you want to use an already running MySQL server for specific tests, use the --extern option to mysql-test-run. Please note that in this mode, the test suite expects you to provide the names of the tests to run. For example, here is the command to run the "alias" and "analyze" tests with an external server: mysql-test-run --extern alias analyze To match your setup, you might also need to provide --socket, --user, and other relevant options. With no test cases named on the command line, mysql-test-run falls back to the normal "non-extern" behavior. The reason for this is that some tests cannot run with an external server. You can create your own test cases. To create a test case, create a new file in the t subdirectory using a text editor. The file should have a .test extension. For example: xemacs t/test_case_name.test In the file, put a set of SQL statements that create some tables, load test data, and run some queries to manipulate it. We would appreciate it if you name your test tables t1, t2, t3 ... (to not conflict too much with existing tables). Your test should begin by dropping the tables you are going to create and end by dropping them again. This ensures that you can run the test over and over again. If you are using mysqltest commands (like result file names) in your test case, you should create the result file as follows: mysql-test-run --record test_case_name or mysqltest --record < t/test_case_name.test If you only have a simple test cases consisting of SQL statements and comments, you can create the test case in one of the following ways: mysql-test-run --record test_case_name mysql test < t/test_case_name.test > r/test_case_name.result mysqltest --record --record-file=r/test_case_name.result < t/test_case_name.test When this is done, take a look at r/test_case_name.result - If the result is incorrect, you have found a bug. In this case, you should edit the test result to the correct results so that we can verify that the bug is corrected in future releases. To submit your test case, put your .test file and .result file(s) into a tar.gz archive, add a README that explains the problem, ftp the archive to ftp://support.mysql.com/pub/mysql/secret/ and send a mail to bugs@lists.mysql.com