in tests after the last 4.1->5.0 merge, and:
*** The same as ChangeSet@1.1822.1.1, 2004-05-14 23:08:03+02:00, guilhem@mysql.com of MySQL 4.0 ***
Replication testsuite: making the master-slave synchronization less likely to fail,
by adding sleep-and-retries (max 4 times) if MASTER_POS_WAIT() returns NULL
in sync_with_master and sync_slave_with_master.
The problem showed up only today, in MySQL 5.0 in rpl_server_id2.test,
but may affect 4.x as well, so I fixed 4.x too. Note that I am also fixing
5.0, with the same exact patch, because I don't want to leave 5.0 broken
until the next 4.0->4.1->5.0 merge.
Fix remaining cases of Bug #3596: fix possible races caused by an obsolete value of thd->query_length in SHOW PROCESSLIST and SHOW INNODB STATUS; this fix depends on the fact that thd->query is always set to NULL before setting it to point to a new query
(WL#794). This can be of interest in some recovery-from-backup scenarios, and also when you have
two databases in one mysqld, having a certain similarity and you want one db to be updated when the other is
(some sort of trigger).
Plus small fix for BUG#3568 "MySQL server crashes when built --with-debug and CHANGE MASTER +MASTER_POS_WAIT"
In tables_ok(), when there is no table having "updating==TRUE" in the list,
return that we don't replicate this statement (the slave is supposed to
replicate *changes* only).
In practice, the case can only happen for this statement:
DELETE t FROM t,u WHERE ... ;
tables_ok(t,u) will now return 0, which (check all_tables_not_ok())
will give a chance to tables_ok(t) to run.
as we transform the 3.23 Load_log_event into a 4.0 Create_file_log_event which is one
byte longer, we need to increment event_len. The bug was that we did not increment it,
so later in code the end 0 was not seen so there was for example a segfault in
strlen(fname) because fname was not 0-terminated.
Other problems remain in 3.23->4.0 replication of LOAD DATA INFILE but they are less serious:
Exec_master_log_pos and Relay_log_space are incorrect. I'll document them.
They are not fixable without significant code changes (if you fix those problems in 4.0,
you get assertion failures somewhere else etc), * which are already done in 5.0.0 *.
too big by 6 bytes. So I add code to substract 6 bytes if the master is 3.23.
This is not perfect (because it won't work if the slave I/O thread has not
noticed yet that the master is 3.23), but as long as the slave I/O thread
starts Exec_master_log_pos will be ok.
It must be merged to 4.1 but not to 5.0 (or it can be, because of #if MYSQL_VERSION_ID),
because 5.0 already works if the master is 3.23 (and in a more natural way:
in 5.0 we store the end_log_pos in the binlog and relay log).
I had to move functions from slave.h to slave.cc to satisfy gcc.
Fixed bugs in group_concat with ORDER BY and DISTINCT (Bugs #2695, #3381 and #3319)
Fixed crash when doing rollback in slave and the io thread catched up with the sql thread
Set locked_in_memory properly
We introduce a new function mysql_test_parse_for_slave().
If the slave sees that the query got a really bad error on master
(killed e.g.), then it calls this function to know if this query
can be ignored because of replicate-*-table rules (do not worry
about replicate-*-db rules: they are checked so early that they have
no bug). If the answer is yes, it skips the query and continues. If
it's no, then it stops and say "fix your slave data manually" (like it
did before this change).
re-using unused LOCK_active_mi to serialize all administrative
commands related to replication:
START SLAVE, STOP SLAVE, RESET SLAVE, CHANGE MASTER, init_slave()
(replication autostart at server startup), end_slave() (replication
autostop at server shutdown), LOAD DATA FROM MASTER.
This protects us against a handful of deadlocks (like BUG#2921
when two START SLAVE, but when two STOP SLAVE too).
Removing unused variables.
ChangeSet 1.1620.12.1 and ChangeSet 1.1625.2.1
from 4.1. This makes the slave I/O thread flush the relay log
after every event, which provides additional safety in case
of brutal crash (reduces chances to lose a part of the relay log).
- the one about BUG#2921
- the one about relay log flushing
Both will be rewritten in a next changeset
(this one will not be pushed before the next changeset).
BUG#2826 "Seconds behind master weirdness"
(sometimes this column of SHOW SLAVE STATUS shows a very big value,
in fact a small negative number casted to ulonglong).
This problem was reported by only one user, but which uses
synchronized time between his servers.
As suggested by the user, to hide this I display max(0, the value)
so that it will be less confusing. For a user, seeing 0 is probably
better than seeing -1 (both tell you that the slave is very close
to the master).
* A more dynamic binlog format which allows small changes (1064)
* Log session variables in Query_log_event (1063)
It contains a few bugfixes (which I made when running the testsuite).
I carefully updated the results of the testsuite (i.e. I checked for every one,
if the difference between .reject and .result could be explained).
Apparently mysql-test-run --manager is broken in 4.1 and 5.0 currently,
so I could neither run the few tests which require --manager, nor check
that they pass nor modify their .result. But for builds, we don't run
with --manager.
Apart from --manager, the full testsuite passes, with Valgrind too (no errors).
I'm going to push in the next minutes. Remains: update the manual.
Note: by chance I saw that (in 4.1, in 5.0) rpl_get_lock fails when run alone;
this is normal at it makes assumptions on thread ids. I will fix this one day
in 4.1.
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.
