BUG#51291 Unfortunate effect around variable binlog_direct_non_transactional_updates
BUG#46364 introduced the flag binlog_direct_non_transactional_updates which would make N-changes to be written to the binary log upon committing the statement when "ON". On the other hand, when "OFF" the option was supposed to mimic the behavior in 5.1. However, the implementation was not mimicking the behavior correctly and the following bugs popped up: Case #1: N-changes executed within a transaction would go into the S-cache. When later in the same transaction a T-change occurs, N-changes following it were written to the T-cache instead of the S-cache. In some cases, this raises problems. For example, a Table_map_log_event being written initially into the S-cache, together with the initial N-changes, would be absent from the T-cache. This would log N-changes orphaned from a Table_map_log_event (thence discarded at the slave). (MIXED and ROW) Case #2: When rolling back a transaction, the N-changes that might be in the T-cache were disregarded and truncated along with the T-changes. (MIXED and ROW) Case #3: When a MIXED statement (TN) is ahead of any other T-changes in the transaction and it fails, it is kept in the T-cache until the transaction ends. This is not the case in 5.1 or Betony (5.5.2). In these, the failed TN statement would be written to the binlog at the same instant it had failed and not deferred until transaction end. (SBR) To fix these problems, we have decided to do what follows: For Case #1 and #2, we circumvent them: 1. by not letting binlog_direct_non_transactional_updates affect MIXED and RBR. These modes will keep the behavior provided by WL#2687. Although this will make Celosia to behave differently from 5.1, an execution will be always safe under such modes in the sense that slaves will never go out sync. In 5.1, using either MIXED or ROW while mixing N-statements and T-statements was not safe. For Case #3, we don't actually fix it. We: 1. keep it and make all MIXED statements whether they end up failing or not or whether they are up front in the transaction or after some transactional change to always be stored in the T-cache. This means that it is written to the binary log on transaction commit/rollback only. 2. We make the warning message even more specific about the MIXED statement and SBR. mysql-test/extra/rpl_tests/rpl_mixing_engines.test: Updated the test case to avoid checking inconsistencies between the master and slave when session.binlog_direct_non_transactional_updates is ON and the format is statement. In this scenario, they will diverge because a counter (within a triger) is incremented and associated to the issued statement. However, an n-statement is logged ahead of the transaction and thus is not executed by the same order in the slave and thus gets a different value from the counter. mysql-test/suite/binlog/r/binlog_multi_engine.result: Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT. mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result: Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT. mysql-test/suite/ndb/r/ndb_binlog_format.result: Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT. mysql-test/suite/rpl/r/rpl_concurrency_error.result: Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT. mysql-test/suite/rpl/r/rpl_stm_binlog_max_cache_size.result: Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT. mysql-test/suite/rpl/r/rpl_stm_mixing_engines.result: Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT. mysql-test/suite/rpl/r/rpl_stm_stop_middle_group.result: Updated the test case with the new error ER_BINLOG_UNSAFE_MIXED_STATEMENT. sql/log.cc: Checked if either a trx-cache or a non-trx-cache should be used. If bin_log_direct_non_trans_update is active or the format is either MIXED or ROW, the cache to be used depends on the flag is_transactional. When the format is STMT, the non-trx-cache should be used if the statement is non-transactional and the trx-cache is empty, i.e. if any transactional statement has not committed yet. Otherwise, the trx-cache should be used. sql/share/errmsg-utf8.txt: Added the new unsafe error ER_BINLOG_UNSAFE_MIXED_STATEMENT. sql/sql_class.cc: Started printing ER_BINLOG_UNSAFE_MIXED_STATEMENT, when there is a mixed-statement. Organized the names of the variables and added comments. sql/sql_lex.cc: Added the new unsafe error ER_BINLOG_UNSAFE_MIXED_STATEMENT. sql/sql_lex.h: Added the new unsafe error ER_BINLOG_UNSAFE_MIXED_STATEMENT.
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