This is the main commit for Worklog tasks:
* A more dynamic binlog format which allows small changes (1064)
* Log session variables in Query_log_event (1063)
Below 5.0 means 5.0.0.
MySQL 5.0 is able to replicate FOREIGN_KEY_CHECKS, UNIQUE_KEY_CHECKS (for speed),
SQL_AUTO_IS_NULL, SQL_MODE. Not charsets (WL#1062), not some vars (I can only think
of SQL_SELECT_LIMIT, which deserves a special treatment). Note that this
works for queries, except LOAD DATA INFILE (for this it would have to wait
for Dmitri's push of WL#874, which in turns waits for the present push, so...
the deadlock must be broken!). Note that when Dmitri pushes WL#874 in 5.0.1,
5.0.0 won't be able to replicate a LOAD DATA INFILE from 5.0.1.
Apart from that, the new binlog format is designed so that it can tolerate
a little variation in the events (so that a 5.0.0 slave could replicate a
5.0.1 master, except for LOAD DATA INFILE unfortunately); that is, when I
later add replication of charsets it should break nothing. And when I later
add a UID to every event, it should break nothing.
The main change brought by this patch is a new type of event, Format_description_log_event,
which describes some lengthes in other event types. This event is needed for
the master/slave/mysqlbinlog to understand a 5.0 log. Thanks to this event,
we can later add more bytes to the header of every event without breaking compatibility.
Inside Query_log_event, we have some additional dynamic format, as every Query_log_event
can have a different number of status variables, stored as pairs (code, value); that's
how SQL_MODE and session variables and catalog are stored. Like this, we can later
add count of affected rows, charsets... and we can have options --don't-log-count-affected-rows
if we want.
MySQL 5.0 is able to run on 4.x relay logs, 4.x binlogs.
Upgrading a 4.x master to 5.0 is ok (no need to delete binlogs),
upgrading a 4.x slave to 5.0 is ok (no need to delete relay logs);
so both can be "hot" upgrades.
Upgrading a 3.23 master to 5.0 requires as much as upgrading it to 4.0.
3.23 and 4.x can't be slaves of 5.0.
So downgrading from 5.0 to 4.x may be complicated.
Log_event::log_pos is now the position of the end of the event, which is
more useful than the position of the beginning. We take care about compatibility
with <5.0 (in which log_pos is the beginning).
I added a short test for replication of SQL_MODE and some other variables.
TODO:
- after committing this, merge the latest 5.0 into it
- fix all tests
- update the manual with upgrade notes.
The constructor of Rotate_log_event used when we are rotating our binlog or
relay log, should not assume that there is a nonzero THD available.
For example, when we are reacting to SIGHUP, the THD is 0.
In fact we don't need to use the THD in this constructor;
we can do like for Stop_log_event, and use the minimal Log_event
constructor.
If we were allowed to put Unix-specific commands in the testsuite,
I'd add a test for this (<sigh>).
instead of Log_event::Log_event(THD*, ...) when the event is built in the master
to be written in the binlog.
Rand_log_event already used the good constructor, so there really is no reason
for Intvar_log_event to be an exception.
This fixes a test failure of last night (which appeared after I removed a useless
e.server_id=thd->server_id in log.cc; in fact this line was not useless because
it hid the bad constructor).
Replication tests pass, with Valgrind too.
"If 2 master threads with same-name temp table, slave makes bad binlog"
and (two birds with one stone) for
BUG#1240 "slave of slave breaks when STOP SLAVE was issud on parent slave
and temp tables".
Here is the design change:
in a slave running with --log-slave-updates, events are now logged with the
thread id they had on the master. So no more id conflicts between master threads,
but introduces id conflicts between one master thread and one normal
client thread connected to the slave. This is solved by storing the server id
in the temp table's name.
New test which requires mysql-test-run to be run with --manager,
otherwise it will be skipped.
Undoing a Monty's change (hum, a chill runs down my spine ;) which was
"Cleanup temporary tables when slave ends" in ChangeSet 1.1572.1.1.
"LOAD DATA INFILE is badly filtered by binlog-*-db rules".
There will probably be a second final one to merge Dmitri's changes
to rpl_log.result and mine.
2 new tests:
rpl_loaddata_rule_m : test of logging of LOAD DATA INFILE when the master has binlog-*-db rules,
rpl_loaddata_rule_s : test of logging of LOAD DATA INFILE when the slave has binlog-*-db rules and --log-slave-updates.
as the already-stored timestamp. Now 'created' is used only to know if
this is a first binlog or not. And we may re-use the superfluous bytes
in 5.0 when we need room.
- Comments for future devs.
- Start_log_event::exec_event() : when we hit it, do a rollback.
- We don't need LOG_EVENT_FORCED_ROTATE_F.
- Stop_log_event::exec_event() : when we hit it, we needn't clean anything.
- Removed LOG_EVENT_TIME_F and LOG_EVENT_FORCED_ROTATE_F.
- We don't need Stop events in the relay log.
- Now filtering of server id is done in the I/O thread first.
Fix for bug 254 : the first Start_log_event after server startup will
have created=now(), whereas the next ones (FLUSH LOGS, auto rotation)
will have created=0. Before this, it was always now().
This way, slaves >=4.0.14 will know when they must
drop stale temp tables or not. The next task is now modify 4.0.14 to
implement this.
Class for sending data from server to client (Protocol)
This handles both the old ( <= 4.0 ) protocol and then new binary protocol that is used for prepared statements.
Let MySQL 4.0 read 4.1 .frm files without 4.1 specific extensions
New variables @@rand_seed1 and @@rand_seed2 (used by replication)
DROP TEMPORARY TABLE
