Problem: in mixed and statement mode, a query that refers to a
system variable will use the slave's value when replayed on
slave. So if the value of a system variable is inserted into a
table, the slave will differ from the master.
Fix: mark statements that refer to a system variable as "unsafe",
meaning they will be replicated by row in mixed mode and produce a warning
in statement mode. There are some exceptions: some variables are actually
replicated. Those should *not* be marked as unsafe.
BUG#34732: mysqlbinlog does not print default values for auto_increment variables
Problem: mysqlbinlog does not print default values for some variables,
including auto_increment_increment and others. So if a client executing
the output of mysqlbinlog has different default values, replication will
be wrong.
Fix: Always print default values for all variables that are replicated.
I need to fix the two bugs at the same time, because the test cases would
fail if I only fixed one of them.
Problem: it is unsafe to read base64-printed events without first
reading the Format_description_log_event (FD). Currently, mysqlbinlog
cannot print the FD.
As a side effect, another bug has also been fixed: When mysqlbinlog
--start-position=X was specified, no ROLLBACK was printed. I changed
this, so that ROLLBACK is always printed.
This patch does several things:
- Format_description_log_event (FD) now print themselves in base64
format.
- mysqlbinlog is now able to print FD events. It has three modes:
--base64-output=auto Print row events in base64 output, and print
FD event. The FD event is printed even if
it is outside the range specified with
--start-position, because it would not be
safe to read row events otherwise. This is
the default.
--base64-output=always Like --base64-output=auto, but also print
base64 output for query events. This is
like the old --base64-output flag, which
is also a shorthand for
--base64-output=always
--base64-output=never Never print base64 output, generate error if
row events occur in binlog. This is
useful to suppress the FD event in binlogs
known not to contain row events (e.g.,
because BINLOG statement is unsafe,
requires root privileges, is not SQL, etc)
- the BINLOG statement now handles FD events correctly, by setting
the thread's rli's relay log's description_event_for_exec to the
loaded event.
In fact, executing a BINLOG statement is almost the same as reading
an event from a relay log. Before my patch, the code for this was
separated (exec_relay_log_event in slave.cc executes events from
the relay log, mysql_client_binlog_statement in sql_binlog.cc
executes BINLOG statements). I needed to augment
mysql_client_binlog_statement to do parts of what
exec_relay_log_event does. Hence, I did a small refactoring and
moved parts of exec_relay_log_event to a new function, which I
named apply_event_and_update_pos. apply_event_and_update_pos is
called both from exec_relay_log_event and from
mysql_client_binlog_statement.
- When a non-FD event is executed in a BINLOG statement, without
previously executing a FD event in a BINLOG statement, it generates
an error, because that's unsafe. I took a new error code for that:
ER_NO_FORMAT_DESCRIPTION_EVENT_BEFORE_BINLOG_STATEMENTS.
In order to get a decent error message containing the name of the
event, I added the class method char*
Log_event::get_type_str(Log_event_type type), which returns a
string name for the given Log_event_type. This is just like the
existing char* Log_event::get_type_str(), except it is a class
method that takes the log event type as parameter.
I also added PRE_GA_*_ROWS_LOG_EVENT to Log_event::get_type_str(),
so that names of old rows event are properly printed.
- When reading an event, I added a check that the event type is known
by the current Format_description_log_event. Without this, it may
crash on bad input (and I was struck by this several times).
- I patched the following test cases, which all contain BINLOG
statements for row events which must be preceded by BINLOG
statements for FD events:
- rpl_bug31076
While I was here, I fixed some small things in log_event.cc:
- replaced hard-coded 4 by EVENT_TYPE_OFFSET in 3 places
- replaced return by DBUG_VOID_RETURN in one place
- The name of the logfile can be '-' to indicate stdin. Before my
patch, the code just checked if the first character is '-'; now it
does a full strcmp(). Probably, all arguments that begin with a -
are already handled somewhere else as flags, but I still think it
is better that the code reflects what it is supposed to do, with as
little dependencies as possible on other parts of the code. If we
one day implement that all command line arguments after -- are
files (as most unix tools do), then we need this.
I also fixed the following in slave.cc:
- next_event() was declared twice, and queue_event was not static but
should be static (not used outside the file).
Bug#27894: mysqlbinlog formats timestamp wrong in comment
Date stamps lack zero padding, and so are meaningless.
Implement minimum-width zero padding for the percent-escape sequences
used in the logging code.
Adding an event that can be used to denote that an incident occured
on the master. The event can be used to denote a gap in the replication
stream, but can also be used to denote other incidents.
In addition, the injector interface is extended with functions to
generate an incident event. The function will also rotate the binary
log after generating an incident event to get a fresh binary log.
Server starts any binlog dump from Format_description_log_event,
this shifted all offset calculations in mysqlbinlog and made it
to stop the dump earlier than --stop-position. Now mysqlbinlog
takes Format_description_log_event into account
field does not work
Fix to prevent MyISAM from reading data from NULL BLOB.
Fix to make record comparison independent of values of unused bits in
record.
Updating binlog positions in tests.
Problem: mysqlbinlog_base64 failed sporadically.
Reason: Missing "flush logs" before running $MYSQL_BINLOG,
which could start dumping the log file before server
has finished writting into it.
Fix:
- implementing --force-if-open option to "mysqlbinlog"
- adding --disable-force-if-open to make $MYSQL_BINLOG
fail on non-closed log files, to garantee that nobody
will forget "flush logs" in the future.
- adding "flush logs" into all affected tests.
The following is an excerption from the WL.
1. Change so that MIXED is default format
1.1 to change the default for command line --binlog-format
1.2 to alter global_system_variables.binlog_format calculation
basing on command line --binlog-format parameter and
its default.
2. Change test suite so that more testing is done by MIXED format.
2.1 to check if there are test cases requiring --binlog-foramt=statement via
`source include/have_binlog_format_statement.inc' and affected by
altering the latter to be "mixed".
2.2 to check the content of such vulnerable cases to find if
extending to the mixed does not modify results. In that case simply
substitute source arguments as explained.
2.3 if a test in mixed mode deals with features triggering
row-binlogging then if necessary we can switch explicitly
to statement mode or create another test to run with
non-recommended STATEMENT mode
Particullarily, extracting INSERT DELAYED
binlogging subtest for statement mode is performed, and
the snippet is moved into a separate test file.
Note that since now all three modes verify this use case
through 3 different tests.
No changes in item 3 of HLD appeared to be needed.
This saves one byte per Query_log_event on disk compared to 5.0.[0..3]. Compatibility problems with 5.0.x where x<4
are explained in the comments in log_event.cc. Putting back s/my_open(O_TRUNC)/(my_delete+my_create) change which had
been wiped away by somebody doing a wrong 4.1->5.0 merge (which happened just
before 5.0.3 :( ). Applying it to new events for LOAD DATA INFILE.
If slave fails in Execute_load_query_log_event::exec_event(),
don't delete the file (so that it's re-usable at next START SLAVE).
And (youpi!) fix for BUG#3247 "a partially completed LOAD DATA INFILE is not
executed at all on the slave" (storing an Execute_load_query_log_event
to binlog, with its error code, instead of Delete_file_log_event).
Now one can use user variables as target for data loaded from file
(besides table's columns). Also LOAD DATA got new SET-clause in which
one can specify values for table columns as expressions.
For example the following is possible:
LOAD DATA INFILE 'words.dat' INTO TABLE t1 (a, @b) SET c = @b + 1;
This patch also implements new way of replicating LOAD DATA.
Now we do it similarly to other queries.
We store LOAD DATA query in new Execute_load_query event
(which is last in the sequence of events representing LOAD DATA).
When we are executing this event we simply rewrite part of query which
holds name of file (we use name of temporary file) and then execute it
as usual query. In the beggining of this sequence we use Begin_load_query
event which is almost identical to Append_file event
Fixed (together with Guilhem) bugs in mysqlbinlog regarding --offset
Prefix addresses with 0x for easier comparisons of debug logs
Fixed problem where MySQL choosed index-read even if there would be a much better range on the same index
This fix changed some 'index' queries to 'range' queries in the test suite
Don't create 'dummy' WHERE clause for trivial WHERE clauses where we can remove the WHERE clause.
This fix removed of a lot of 'Using where' notes in the test suite.
Give NOTE instead of WARNING if table/function doesn't exists when using DROP IF EXISTS
Give NOTE instead of WARNING for safe field-type conversions
options for mysqlbinlog, with a test file.
This enables user to say "recover my database to how it was this morning at 10:30"
(mysqlbinlog "--stop-datetime=2003-07-29 10:30:00").
Using time functions into client/ made me move them out of sql/ into sql-common/.
+ (small) fix for BUG#4507 "mysqlbinlog --read-from-remote-server sometimes
cannot accept 2 binlogs" (that is, on command line).