skipped):
By moving statement end actions from Rows_log_event::do_apply_event() to
Rows_log_event::do_update_pos() they will always be executed, even if
Rows_log_event::do_apply_event() is skipped because the event originated
at the same server. This because Rows_log_event::do_update_pos() is always
executed (unless Rows_log_event::do_apply_event() failed with an error,
in which case the slave stops with an error anyway).
Adding test case.
Fixing logic to detect if inside a group. If a rotate event occured
when an initial prefix of events for a statement, but for which the
table did contain a key, last_event_start_time is set to zero, causing
rotate to end the group but without unlocking any tables. This left a
lock hanging around, which subsequently triggered an assertion when a
second attempt was made to lock the same sequence of tables.
In order to solve the above problem, a new flag was added to the relay
log info structure that is used to indicate that the replication thread
is currently executing a statement. Using this flag, the replication
thread is in a group if it is either in a statement or inside a trans-
action.
The patch also eliminates some gratuitous header file inclusions that
were not needed (and caused compile errors) and replaced them with
forward definitions.
stopped at pos==4):
Submitting patch on behalf of Andrei, who discovered the problem
and provided the patch.
An update of the group relay log coordinates when rotating forgot to
update the group relay log name and only updated the group relay log
position (and group master log name and position).
This patch adds code to update the group relay log *name* as well as
the position
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.
rows event):
Adding a after image COLS bitmap to Update_rows_log_event (for telling
what columns that are present in the after image of each row update).
Also fixing case where Rows_log_event length was not correctly computed
(happened when the number of columns in a table was more than 251).
- Improve error handling for "out of memory" problems when master is
sending logs to slave. If memory allocation fails the log should
now report error "memory allocation failed reading log event"
when it was printing a Query event, it produced invalid SQL (missing
the BINLOG keyword, so the SQL started with the base64 string, which
is incorrect).
Note: no testcase; I have a .test which shows that the bugfix works,
but it triggers BUG#26361 and so gives Valgrind warnings. I'm sending
this test to the fixer of BUG#26361 for her/him to push when she/he
fixes BUG#26361.
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.
The problem was that some facilities (like CONVERT_TZ() function or
server HELP statement) may require implicit access to some tables in
'mysql' database. This access was done by ordinary means of adding
such tables to the list of tables the query is going to open.
However, if we issued LOCK TABLES before that, we would get "table
was not locked" error trying to open such implicit tables.
The solution is to treat certain tables as MySQL system tables, like
we already do for mysql.proc. Such tables may be opened for reading
at any moment regardless of any locks in effect. The cost of this is
that system table may be locked for writing only together with other
system tables, it is disallowed to lock system tables for writing and
have any other lock on any other table.
After this patch the following tables are treated as MySQL system
tables:
mysql.help_category
mysql.help_keyword
mysql.help_relation
mysql.help_topic
mysql.proc (it already was)
mysql.time_zone
mysql.time_zone_leap_second
mysql.time_zone_name
mysql.time_zone_transition
mysql.time_zone_transition_type
These tables are now opened with open_system_tables_for_read() and
closed with close_system_tables(), or one table may be opened with
open_system_table_for_update() and closed with close_thread_tables()
(the latter is used for mysql.proc table, which is updated as part of
normal MySQL server operation). These functions may be used when
some tables were opened and locked already.
NOTE: online update of time zone tables is not possible during
replication, because there's no time zone cache flush neither on LOCK
TABLES, nor on FLUSH TABLES, so the master may serve stale time zone
data from cache, while on slave updated data will be loaded from the
time zone tables.
fixes).
The legend: on a replication slave, in case a trigger creation
was filtered out because of application of replicate-do-table/
replicate-ignore-table rule, the parsed definition of a trigger was not
cleaned up properly. LEX::sphead member was left around and leaked
memory. Until the actual implementation of support of
replicate-ignore-table rules for triggers by the patch for Bug 24478 it
was never the case that "case SQLCOM_CREATE_TRIGGER"
was not executed once a trigger was parsed,
so the deletion of lex->sphead there worked and the memory did not leak.
The fix:
The real cause of the bug is that there is no 1 or 2 places where
we can clean up the main LEX after parse. And the reason we
can not have just one or two places where we clean up the LEX is
asymmetric behaviour of MYSQLparse in case of success or error.
One of the root causes of this behaviour is the code in Item::Item()
constructor. There, a newly created item adds itself to THD::free_list
- a single-linked list of Items used in a statement. Yuck. This code
is unaware that we may have more than one statement active at a time,
and always assumes that the free_list of the current statement is
located in THD::free_list. One day we need to be able to explicitly
allocate an item in a given Query_arena.
Thus, when parsing a definition of a stored procedure, like
CREATE PROCEDURE p1() BEGIN SELECT a FROM t1; SELECT b FROM t1; END;
we actually need to reset THD::mem_root, THD::free_list and THD::lex
to parse the nested procedure statement (SELECT *).
The actual reset and restore is implemented in semantic actions
attached to sp_proc_stmt grammar rule.
The problem is that in case of a parsing error inside a nested statement
Bison generated parser would abort immediately, without executing the
restore part of the semantic action. This would leave THD in an
in-the-middle-of-parsing state.
This is why we couldn't have had a single place where we clean up the LEX
after MYSQLparse - in case of an error we needed to do a clean up
immediately, in case of success a clean up could have been delayed.
This left the door open for a memory leak.
One of the following possibilities were considered when working on a fix:
- patch the replication logic to do the clean up. Rejected
as breaks module borders, replication code should not need to know the
gory details of clean up procedure after CREATE TRIGGER.
- wrap MYSQLparse with a function that would do a clean up.
Rejected as ideally we should fix the problem when it happens, not
adjust for it outside of the problematic code.
- make sure MYSQLparse cleans up after itself by invoking the clean up
functionality in the appropriate places before return. Implemented in
this patch.
- use %destructor rule for sp_proc_stmt to restore THD - cleaner
than the prevoius approach, but rejected
because needs a careful analysis of the side effects, and this patch is
for 5.0, and long term we need to use the next alternative anyway
- make sure that sp_proc_stmt doesn't juggle with THD - this is a
large work that will affect many modules.
Cleanup: move main_lex and main_mem_root from Statement to its
only two descendants Prepared_statement and THD. This ensures that
when a Statement instance was created for purposes of statement backup,
we do not involve LEX constructor/destructor, which is fairly expensive.
In order to track that the transformation produces equivalent
functionality please check the respective constructors and destructors
of Statement, Prepared_statement and THD - these members were
used only there.
This cleanup is unrelated to the patch.
This patch fixes problem that LOAD DATA could use different
character sets when loading files on master and on slave sides:
- Adding replication of thd->variables.collation_database
- Adding optional character set clause into LOAD DATA
Note, the second way, with explicit CHARACTER SET clause
should be the recommended way to load data using an alternative
character set.
The old way, using "SET @@character_set_database=xxx" should be
gradually depricated.
Submitting patch on Guilhem's behalf (he found the solution).
Correcting a typo that caused very big increases in memory usage when
more memory needed to be allocated for row-based events. Also correcting
a border case check when more memory needed to be allocated.
