MDEV-36563 Assertion `!mysql_bin_log.is_open()' failed in
THD::mark_tmp_table_as_free_for_reuse
The purpose of this commit is to ensure that creation and changes of
temporary tables are properly and predicable logged to the binary
log. It also fixes some bugs where ROW logging was used in MIXED mode,
when STATEMENT would be a better (and expected) choice.
In this comment STATEMENT stands for logging to binary log in
STATEMENT format, MIXED stands for MIXED binlog format and ROW for ROW
binlog format.
New rules for logging of temporary tables
- CREATE of temporary tables are now by default binlogged only if
STATEMENT binlog format is used. If it is binlogged, 1 is stored in
TABLE_SHARE->table_creation_was_logged. The user can change this
behavior by setting create_temporary_table_binlog_formats to
MIXED,STATEMENT in which case the create is logged in statement
format also in MIXED mode (as before).
- Changes to temporary tables are only binlogged if and only if
the CREATE was logged. The logging happens under STATEMENT or MIXED.
If binlog_format=ROW, temporary table changes are not binlogged. A
temporary table that are changed under ROW are marked as 'not up to
date in binlog' and no future row changes are logged. Any usage of
this temporary table will force row logging of other tables in any
future statements using the temporary table to be row logged.
- DROP TEMPORARY is binlogged only of the CREATE was binlogged.
Changes done:
- Row logging is forced for any statement using temporary tables that
are not up to date in the binary log.
(Before the row logging was forced if the user has a temporary table)
- If there is any changes to the temporary table that is not binlogged,
the table is marked as not up to date.
- TABLE_SHARE->table_creation_was_logged has a new definition for
temporary tables:
0 Table creating was not logged to binary log
1 Table creating was logged to binary log and table is up to date.
2 Table creating was logged to binary log but some changes where
not logged to binary log.
Table is not up to date in binary log is defined as value 0 or 2.
- If a multi-table-update or multi-table-delete fails then
all updated temporary tables are marked as not up to date.
- Enforce row logging if the query is using temporary tables
that are not up to date.
Before row logging was enforced if the user had any
temporary tables.
- When dropping temporary tables use IF EXISTS. This ensures
that slave will not stop if it had crashed and lost the
temporary tables.
- Remove comment and version from DROP /*!4000 TEMPORARY.. generated when
a connection closes that has open temporary tables. Added 'generated by
server' at the end of the DROP.
Bugs fixed:
- When using temporary tables with commands that forced row based,
like INSERT INTO temporary_table VALUES (UUID()), this was never
logged which causes the temporary table to be inconsistent on
master and slave.
- Used binlog format is now clearly defined. It is now only depending
on the current binlog_format and the tables used.
Before it was depending on the user had ANY temporary tables and
the state of 'current_stmt_binlog_format' set by previous queries.
This also caused temporary tables to be logged to binary log in
some cases.
- CREATE TABLE t1 LIKE not_logged_temporary_table caused replication
to stop.
- Rename of not binlogged temporary tables where binlogged to binary log
which caused replication to stop.
Changes in behavior:
- By default create_temporary_table_binlog_formats=STATEMENT, which
means that CREATE TEMPORARY is not logged to binary log under MIXED
binary logging. This can be changed by setting
create_temporary_table_binlog_formats to MIXED,STATEMENT.
- Using temporary tables that was not logged to the binary log will
cause any query using them for updating other tables to be logged in
ROW format. Before all queries was logged in ROW format if the user had
any temporary tables, even if they were not used by the query.
- Generated DROP TEMPORARY TABLE is now always using IF EXISTS and
has a "generated by server" comment in the binary log.
The consequences of the above is that manipulations of a lot of rows
through temporary tables will by default be be slower in mixed mode.
For example:
BEGIN;
CREATE TEMPORARY TABLE tmp AS SELECT a, b, c FROM
large_table1 JOIN large_table2 ON ...;
INSERT INTO other_table SELECT b, c FROM tmp WHERE a <100;
DROP TEMPORARY TABLE tmp;
COMMIT;
By default this will create a huge entry in the binary log, compared
to just a few hundred bytes in statement mode. However the change in
this commit will make usage of temporary tables more reliable and
predicable and is thus worth it. Using statement mode or
create_temporary_table_binlog_formats can be used to avoid this issue.
This patch augments Gtid_log_event with the user thread-id.
In particular that compensates for the loss of this info in
Rows_log_events.
Gtid_log_event::thread_id gets visible in mysqlbinlog output like
#231025 16:21:45 server id 1 end_log_pos 537 CRC32 0x1cf1d963 GTID 0-1-2 ddl thread_id=10
as a 32 bit unsigned integer. Note this is a 32-bit value, as
the connection id can only be 32 bits (see MDEV-15089 for
details).
While the size of Gtid event has grown by 4 bytes
replication from OLD <-> NEW is not affected by it. This patch
also slightly changes the logic to convert Gtid events to Query
events for older replicas which don't support Gtid. Instead of
hard-coding the padding of the sys var section of the generated
Query event, the length to pad is dynamically calculated based
on the length of the Gtid event.
This work was started by the late Sujatha Sivakumar.
Brandon Nesterenko took it over, reviewed initial patches and
extended the work.
Also thanks to Andrei for his help in finalizing the fixes for
MDEV-33924, which were squashed into this patch.
Reviewed-by:
=============
Andrei Elkin <andrei.elkin@mariadb.com>
Kristian Nielsen <knielsen@knielsen-hq.org>
This reverts commit c37b2087b4abe576f1b0391c8d379dba6299dcb5.
In c37b20887, when re-binlogging a GTID event on a replica,
it will overwrite the thread_id from the primary to be the
value of the slave applier (SQL thread or parallel worker).
This should be the value of the original thread_id on the
master connection though, to both help track temporary
tables, and be consistent with Query_log_event.
Reverting the commit to re-target 11.5, so we can re-test
with the corrected thread_id.
This patch augments Gtid_log_event with the user thread-id.
In particular that compensates for the loss of this info in
Rows_log_events.
Gtid_log_event::thread_id gets visible in mysqlbinlog output like
#231025 16:21:45 server id 1 end_log_pos 537 CRC32 0x1cf1d963 GTID 0-1-2 ddl thread_id=10
as 64 bit unsigned integer.
While the size of Gtid event has grown by 8-9 bytes
replication from OLD <-> NEW is not affected by it.
This work was started by the late Sujatha Sivakumar.
Brandon Nesterenko took it over, reviewed initial patches and extended
the work.
Reviewed-by: <andrei.elkin@mariadb.com>
Problem:
========
During point in time recovery of binary log syntax error is reported for
BEGIN statement and recovery fails.
Analysis:
=========
In MariaDB 10.3 and later, setting the sql_mode system variable to Oracle
allows the server to understand a subset of Oracle's PL/SQL language. When
sql_mode=ORACLE is set, it switches the parser from the MariaDB parser to
Oracle compatible parser. With this change 'BEGIN' is not considered as
'START TRANSACTION'. Hence the syntax error is reported.
Fix:
===
At preset 'BEGIN' query is generated from 'Gtid_log_event::print'. The current
session specific 'sql_mode' information is not present as part of
'Gtid_log_event'. If it was available then, mysqlbinlog tool can make use of
'sql_mode == ORACLE' and can output "START TRANSACTION" in this particular
mode and for other sql_modes it will write "BEGIN" as part of output. Since it
is not available 'mysqlbinlog' tool will output all 'BEGIN' statements as
'START TRANSACTION' irrespective of 'sql_mode'.
Problem:
=======
Test "binlog.binlog_parallel_replication_marks_row" fails sporadically due to
result length mismatch.
Analysis:
=========
Test generates a binary log and it looks for certain words within the binary
log file and prints them. For example word like "GTID,BEGIN,COMMIT ...".
Binary log output contains base64 encoded characters. Occasionally the encoded
characters match with the above words and results in test failure.
+XwoFWxMBAAAALgAAAGEDAAAAAB8AAAAAAAEABHRlc3QAAnQxAAIDAwACFGTIDQ==
+AAAAAAAAAAAEEwQADQgICAoKCgGTIDw9
Fix:
===
Improve the regular expression to match exact words.
MDEV-5589 commit set up a policy to skip DROP TEMPORARY TABLE binary logging
in case the target table has not been "CREATEed" in binlog (no CREATE
Query-log-event was logged into the binary log).
It turns out that
1. the rule did not cover non-existing table DROPped with IF-EXISTS clause.
The logged-create knowledge for the non-existing one does not even need
MDEV-5589 patch, and
2. connection close disobeys it to trigger automatic DROP-IF-EXISTS
binlogging.
Either 1 or 2 or even both is/are also responsible for unexpected binlog
records observed in MDEV-17863, actually rendering a referred
@@global.read_only irrelevant as far as the described stored procedure
definition *and* the ROW binlog-format are concerned.
The test did not handle correctly possible difference in system
timezone. The fix is to remove non-functional setting of local
time_zone and instead allow timestamp replacement to work with
any date/time
CREATE/DROP TEMPORARY TABLE are not safe to optimistically replicate in
parallel with other transactions, so they need to be marked as "ddl" in the
binlog.
This was already done for stand-alone CREATE/DROP TEMPORARY. But temporary
tables can also be created and dropped inside a BEGIN...END transaction, and
such transactions were not marked as ddl. Nor was the DROP TEMPORARY TABLE
statement emitted implicitly when a client connection is closed.
So this patch adds such ddl mark for the missing cases.
The difference to Kristian's original patch is mainly a fix in
mysql_trans_commit_alter_copy_data() to remember the unsafe_rollback_flags
over the temporary commit.
