An error occurred fetching the project authors.
- 28 Apr, 2010 1 commit
-
-
Sven Sandberg authored
Clarified error messages related to unsafe statements: - avoid the internal technical term "row injection" - use 'binary log' instead of 'binlog' - avoid the word 'unsafeness'
-
- 31 Mar, 2010 1 commit
-
-
Alfranio Correia authored
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.
-
- 02 Feb, 2010 1 commit
-
-
Alexander Nozdrin authored
Conflicts: - mysql-test/r/mysqld--help-win.result - sql/sys_vars.cc Original revsion (in next-mr-bugfixing): ------------------------------------------------------------ revno: 2971 [merge] revision-id: alfranio.correia@sun.com-20100121210527-rbuheu5rnsmcakh1 committer: Alfranio Correia <alfranio.correia@sun.com> branch nick: mysql-next-mr-bugfixing timestamp: Thu 2010-01-21 21:05:27 +0000 message: BUG#46364 MyISAM transbuffer problems (NTM problem) It is well-known that due to concurrency issues, a slave can become inconsistent when a transaction contains updates to both transaction and non-transactional tables. In a nutshell, the current code-base tries to preserve causality among the statements by writing non-transactional statements to the txn-cache which is flushed upon commit. However, modifications done to non-transactional tables on behalf of a transaction become immediately visible to other connections but may not immediately get into the binary log and therefore consistency may be broken. In general, it is impossible to automatically detect causality/dependency among statements by just analyzing the statements sent to the server. This happen because dependency may be hidden in the application code and it is necessary to know a priori all the statements processed in the context of a transaction such as in a procedure. Moreover, even for the few cases that we could automatically address in the server, the computation effort required could make the approach infeasible. So, in this patch we introduce the option - "--binlog-direct-non-transactional-updates" that can be used to bypass the current behavior in order to write directly to binary log statements that change non-transactional tables. Besides, it is used to enable the WL#2687 which is disabled by default. ------------------------------------------------------------ revno: 2970.1.1 revision-id: alfranio.correia@sun.com-20100121131034-183r4qdyld7an5a0 parent: alik@sun.com-20100121083914-r9rz2myto3tkdya0 committer: Alfranio Correia <alfranio.correia@sun.com> branch nick: mysql-next-mr-bugfixing timestamp: Thu 2010-01-21 13:10:34 +0000 message: BUG#46364 MyISAM transbuffer problems (NTM problem) It is well-known that due to concurrency issues, a slave can become inconsistent when a transaction contains updates to both transaction and non-transactional tables. In a nutshell, the current code-base tries to preserve causality among the statements by writing non-transactional statements to the txn-cache which is flushed upon commit. However, modifications done to non-transactional tables on behalf of a transaction become immediately visible to other connections but may not immediately get into the binary log and therefore consistency may be broken. In general, it is impossible to automatically detect causality/dependency among statements by just analyzing the statements sent to the server. This happen because dependency may be hidden in the application code and it is necessary to know a priori all the statements processed in the context of a transaction such as in a procedure. Moreover, even for the few cases that we could automatically address in the server, the computation effort required could make the approach infeasible. So, in this patch we introduce the option - "--binlog-direct-non-transactional-updates" that can be used to bypass the current behavior in order to write directly to binary log statements that change non-transactional tables. Besides, it is used to enable the WL#2687 which is disabled by default.
-
- 21 Jan, 2010 1 commit
-
-
Alfranio Correia authored
It is well-known that due to concurrency issues, a slave can become inconsistent when a transaction contains updates to both transaction and non-transactional tables. In a nutshell, the current code-base tries to preserve causality among the statements by writing non-transactional statements to the txn-cache which is flushed upon commit. However, modifications done to non-transactional tables on behalf of a transaction become immediately visible to other connections but may not immediately get into the binary log and therefore consistency may be broken. In general, it is impossible to automatically detect causality/dependency among statements by just analyzing the statements sent to the server. This happen because dependency may be hidden in the application code and it is necessary to know a priori all the statements processed in the context of a transaction such as in a procedure. Moreover, even for the few cases that we could automatically address in the server, the computation effort required could make the approach infeasible. So, in this patch we introduce the option - "--binlog-direct-non-transactional-updates" that can be used to bypass the current behavior in order to write directly to binary log statements that change non-transactional tables. Besides, it is used to enable the WL#2687 which is disabled by default.
-
- 11 Nov, 2009 1 commit
-
-
Alfranio Correia authored
-
- 03 Nov, 2009 1 commit
-
-
Alfranio Correia authored
Non-transactional updates that take place inside a transaction present problems for logging because they are visible to other clients before the transaction is committed, and they are not rolled back even if the transaction is rolled back. It is not always possible to log correctly in statement format when both transactional and non-transactional tables are used in the same transaction. In the current patch, we ensure that such scenario is completely safe under the ROW and MIXED modes.
-
- 27 Aug, 2009 1 commit
-
-
Alfranio Correia authored
Slave does not correctly handle "expected errors" leading to inconsistencies between the mater and slave. Specifically, when a statement changes both transactional and non-transactional tables, the transactional changes are automatically rolled back on the master but the slave ignores the error and does not roll them back thus leading to inconsistencies. To fix the problem, we automatically roll back a statement that fails on the slave but note that the transaction is not rolled back unless a "rollback" command is in the relay log file.
-
- 26 Aug, 2009 1 commit
-
-
Alfranio Correia authored
binlog Mixing transactional (T) and non-transactional (N) tables on behalf of a transaction may lead to inconsistencies among masters and slaves in STATEMENT mode. The problem stems from the fact that although modifications done to non-transactional tables on behalf of a transaction become immediately visible to other connections they do not immediately get to the binary log and therefore consistency is broken. Although there may be issues in mixing T and M tables in STATEMENT mode, there are safe combinations that clients find useful. In this bug, we fix the following issue. Mixing N and T tables in multi-level (e.g. a statement that fires a trigger) or multi-table table statements (e.g. update t1, t2...) were not handled correctly. In such cases, it was not possible to distinguish when a T table was updated if the sequence of changes was N and T. In a nutshell, just the flag "modified_non_trans_table" was not enough to reflect that both a N and T tables were changed. To circumvent this issue, we check if an engine is registered in the handler's list and changed something which means that a T table was modified. Check WL 2687 for a full-fledged patch that will make the use of either the MIXED or ROW modes completely safe.
-