auto-ROLLBACK if binlog was not closed properly

auto-commit on Xid_log_event


client/mysqlbinlog.cc:
  auto-ROLLBACK if binlog was not closed properly.
mysql-test/r/ctype_ucs.result:
  results updated
mysql-test/r/mix_innodb_myisam_binlog.result:
  results updated
mysql-test/r/mysqlbinlog2.result:
  results updated
mysql-test/r/rpl_relayrotate.result:
  results updated
mysql-test/r/user_var.result:
  results updated
mysql-test/t/ctype_ucs.test:
  finalize binlog before calling mysqlbinlog
mysql-test/t/user_var.test:
  finalize binlog before calling mysqlbinlog
sql/log_event.cc:
  commit at Xid_log_event
  comments edited
sql/mysqld.cc:
  free(0) fixed
sql/slave.cc:
  rollback at fake Rotate_log_event
sql/sql_class.h:
  no commit_or_rollback argument for binlog->write(THD *thd, IO_CACHE *cache)
sql/log.cc:
  don't write "COMMIT" query, Xid_log_event is enough
sql/log_event.h:
  more comments for LOG_EVENT_BINLOG_IN_USE_F
  LOG_EVENT_FORCE_ROLLBACK_F added
sql/sql_repl.cc:
  rollback at Rotate_log_event.
  don't consider binlog corrupted if it was open when we read Formar_description but closed when we got to the end
sql/sql_repl.h:
  style fix

1 files changed, 49 insertions, 24 deletions

diff --git a/sql/log_event.h b/sql/log_event.h
index bc950441ab0..3e9f89bef39 100644
--- a/sql/log_event.h
+++ b/sql/log_event.h
@@ -303,15 +303,38 @@ struct sql_ex_info
 #endif
 
 /*
-   This flag only makes sense for Format_description_log_event.
-   It is set not when the event is written, but when a binlog file
-   is closed. It serves as a reliable indicator that binlog was
-   closed correctly. (Stop_log_event is not enough, there's always
-   a small chance that mysqld crashes in the middle of insert
-   and end of the binlog would look like a Stop_log_event)
+   This flag only makes sense for Format_description_log_event. It is set
+   when the event is written, and *reset* when a binlog file is
+   closed (yes, it's the only case when MySQL modifies already written
+   part of binlog).  Thus it is a reliable indicator that binlog was
+   closed correctly.  (Stop_log_event is not enough, there's always a
+   small chance that mysqld crashes in the middle of insert and end of
+   the binlog would look like a Stop_log_event).
+
+   This flag is used to detect a restart after a crash,
+   and to provide "unbreakable" binlog. The problem is that on a crash
+   storage engines rollback automatically, while binlog does not.
+   To solve this we use this flag and automatically append ROLLBACK
+   to every non-closed binlog (append virtually, on reading, file itself
+   is not changed). If this flag is found, mysqlbinlog simply prints "ROLLBACK"
+   Replication master does not abort on binlog corruption, but takes it as EOF,
+   and replication slave forces a rollback in this case (see below).
+
+   Note, that old binlogs does not have this flag set, so we get a
+   a backward-compatible behaviour.
 */
 
-#define LOG_EVENT_BINLOG_CLOSED_F   0x1
+#define LOG_EVENT_BINLOG_IN_USE_F       0x1
+
+/*
+  This flag is only used for fake Rotate_log_event. When a master, doing
+  binlog dump, reaches the end of the binlog and fakes a rotate to make
+  the slave to go to a new file, this flag is used if there was no
+  "natural" Rotate_log_event.
+  If this flag is set, slave will execute ROLLBACK before going further
+*/
+
+#define LOG_EVENT_FORCE_ROLLBACK_F      0x1
 
 /*
    If the query depends on the thread (for example: TEMPORARY TABLE).
@@ -335,21 +358,22 @@ struct sql_ex_info
 #define LOG_EVENT_SUPPRESS_USE_F    0x8
 
 /*
-   OPTIONS_WRITTEN_TO_BIN_LOG are the bits of thd->options which must be written
-   to the binlog. OPTIONS_WRITTEN_TO_BINLOG could be written into the
-   Format_description_log_event, so that if later we don't want to replicate a
-   variable we did replicate, or the contrary, it's doable. But it should not be
-   too hard to decide once for all of what we replicate and what we don't, among
-   the fixed 32 bits of thd->options.
+   OPTIONS_WRITTEN_TO_BIN_LOG are the bits of thd->options which must be
+   written to the binlog. OPTIONS_WRITTEN_TO_BINLOG could be written
+   into the Format_description_log_event, so that if later we don't want
+   to replicate a variable we did replicate, or the contrary, it's
+   doable. But it should not be too hard to decide once for all of what
+   we replicate and what we don't, among the fixed 32 bits of
+   thd->options.
    I (Guilhem) have read through every option's usage, and it looks like
-   OPTION_AUTO_IS_NULL and OPTION_NO_FOREIGN_KEYS are the only ones which alter
-   how the query modifies the table. It's good to replicate
-   OPTION_RELAXED_UNIQUE_CHECKS too because otherwise, the slave may insert data
-   slower than the master, in InnoDB.
+   OPTION_AUTO_IS_NULL and OPTION_NO_FOREIGN_KEYS are the only ones
+   which alter how the query modifies the table. It's good to replicate
+   OPTION_RELAXED_UNIQUE_CHECKS too because otherwise, the slave may
+   insert data slower than the master, in InnoDB.
    OPTION_BIG_SELECTS is not needed (the slave thread runs with
-   max_join_size=HA_POS_ERROR) and OPTION_BIG_TABLES is not needed either, as
-   the manual says (because a too big in-memory temp table is automatically
-   written to disk).
+   max_join_size=HA_POS_ERROR) and OPTION_BIG_TABLES is not needed
+   either, as the manual says (because a too big in-memory temp table is
+   automatically written to disk).
 */
 #define OPTIONS_WRITTEN_TO_BIN_LOG (OPTION_AUTO_IS_NULL | \
 OPTION_NO_FOREIGN_KEY_CHECKS | OPTION_RELAXED_UNIQUE_CHECKS)
@@ -470,14 +494,15 @@ public:
   ulong data_written;
 
   /*
-    The master's server id (is preserved in the relay log; used to prevent from
-    infinite loops in circular replication).
+    The master's server id (is preserved in the relay log; used to
+    prevent from infinite loops in circular replication).
   */
   uint32 server_id;
 
   /*
-    Some 16 flags. Look above for LOG_EVENT_TIME_F, LOG_EVENT_FORCED_ROTATE_F,
-    LOG_EVENT_THREAD_SPECIFIC_F, and LOG_EVENT_SUPPRESS_USE_F for notes.
+    Some 16 flags. Look above for LOG_EVENT_TIME_F,
+    LOG_EVENT_FORCED_ROTATE_F, LOG_EVENT_THREAD_SPECIFIC_F, and
+    LOG_EVENT_SUPPRESS_USE_F for notes.
   */
   uint16 flags;