Problem:
========
The test now fails with the following trace:
CURRENT_TEST: rpl.rpl_parallel_temptable
--- /mariadb/10.4/mysql-test/suite/rpl/r/rpl_parallel_temptable.result
+++ /mariadb/10.4/mysql-test/suite/rpl/r/rpl_parallel_temptable.reject
@@ -194,7 +194,6 @@
30 conservative
31 conservative
32 optimistic
-33 optimistic
Analysis:
=========
The part of test which fails with result content mismatch is given below.
CREATE TEMPORARY TABLE t4 (a INT PRIMARY KEY) ENGINE=InnoDB;
INSERT INTO t4 VALUES (32);
INSERT INTO t4 VALUES (33);
INSERT INTO t1 SELECT a, "optimistic" FROM t4;
slave_parallel_mode=optimistic
The expectation of the above test script is, INSERT FROM SELECT should read both
32, 33 and populate table 't1'. But this expectation fails occasionally.
All three INSERT statements are handed over to three different slave parallel
workers. Temporary tables are not safe for parallel replication. They were
designed to be visible to one thread only, so have no table locking. Thus there
is no protection against two conflicting transactions committing in parallel and
things like that.
So anything that uses temporary tables will be serialized with anything before
it, when using parallel replication by using a "wait_for_prior_commit" function
call. This will ensure that the each transaction is executed sequentially.
But there exists a code path in which the above wait doesn't happen. Because of
this at times INSERT from SELECT doesn't wait for the INSERT (33) to complete
and it completes its executes and enters commit stage. Hence only row 32 is
found in those cases resulting in test failure.
The wait needs to be added within "open_temporary_table" call. The code looks
like this within "open_temporary_table".
Each thread tries to open temporary table in 3 different ways:
case 1: Find a temporary table which is already in use by using
find_temporary_table(tl) && wait_for_prior_commit()
case 2: If above failed then try to look for temporary table which is marked for
free for reuse. This internally calls "wait_for_prior_commit()" if table
is found.
find_and_use_tmp_table(tl, &table)
case 3: If none of the above open a new table handle from table share.
if (!table && (share= find_tmp_table_share(tl)))
{ table= open_temporary_table(share, tl->get_table_name(), true); }
At present the "wait_for_prior_commit" happens only in case 1 & 2.
Fix:
====
On slave add a call for "wait_for_prior_commit" for case 3.
The above wait on slave will solve the issue. A more detailed fix would be to
mark temporary tables as not safe for parallel execution on the master side.
In order to do that, on the master side, mark the Gtid_log_event specific flag
FL_TRANSACTIONAL to be false all the time. So that they are not scheduled
parallely.
The bug was that when using mysql_list_fields, then
table_list->schema_table_name was not filled in.
Fixed by using table_list->schema_table instead, which is always
filled in.
we had the statistics tables in the FROM list of the select.
The statistics for tables are not read in such cases, so we need
to check this case separately.
truncating a temporary table
TRUNCATE expects only one TABLE instance (which is used by TRUNCATE
itself) to be open. However this requirement wasn't enforced after
"MDEV-5535: Cannot reopen temporary table".
Fixed by closing unused table instances before performing TRUNCATE.
Problem:
========
We have a Master/Master Setup on two servers, but are only writing to one of
those servers (so it is essentially Master/Slave) We upgraded from 10.1.* to
10.2.22 last week and starting with the upgrade, we are getting duplicate key
errors on the slave. BINLOG=mixed.
Analysis:
=========
This issue happens with LOCK TABLES and binlog_format=MIXED combination. When an
UNSAFE statement is encountered in 'MIXED' mode, it is logged in the form of
'ROW' format. For all the tables that are part of LOCK TABLES list their table maps
are written into the binary log. For each table in the list a check is
done to see if 'check_table_binlog_row_based_done' flag is set or not. If it is not set
a check process is initiated to see if table qualifies for row based binary
logging or not and 'check_table_binlog_row_based_done' is set. This flag will be
cleared at the time of closing thread tables.
But there can be special cases where the LOCK TABLES contains more number of
tables but the unsafe query is actually using subset of tables from LOCK TABLES
list.
For example: LOCK TABLES locks t1,t2,t3 but the unsafe statement makes use of
only two tables t1,t3. In this case the 'check_table_binlog_row_based_done' flag
is enabled for table 't2' while writing table map, but 'close_thread_tables'
function call will not reset this flag. Since the flag is not cleared for table
't2' even a safe statement which used t2 will be logged in the form of row based
format.
This leads to an assert on debug builds and causes duplicate entries in release
builds. In release builds a statement is logged in the form of both ROW and
STATEMENT format. This causes the slave to fail with duplicate key error.
Fix:
===
During 'close_thread_tables' when LOCK TABLE modes are active "ha_reset" is done
for all the tables which were part of current statement. As mentioned in the
example 'ha_reset' is called for tables 't1' and 't3'. This will clear the
'check_table_binlog_row_based_done' flag. At this point add a check for the rest
of the tables to see if 'check_table_binlog_row_based_done' is enabled or not.
If enabled clear the flag.
Some places didn't match the previous rules, making the Floor
address wrong.
Additional sed rules:
sed -i -e 's/Place.*Suite .*, Boston/Street, Fifth Floor, Boston/g'
sed -i -e 's/Suite .*, Boston/Fifth Floor, Boston/g'
This commit is based on the work of Michal Schorm, rebased on the
earliest MariaDB version.
Th command line used to generate this diff was:
find ./ -type f \
-exec sed -i -e 's/Foundation, Inc., 59 Temple Place, Suite 330, Boston, /Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, /g' {} \; \
-exec sed -i -e 's/Foundation, Inc. 59 Temple Place.* Suite 330, Boston, /Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, /g' {} \; \
-exec sed -i -e 's/MA.*.....-1307.*USA/MA 02110-1335 USA/g' {} \; \
-exec sed -i -e 's/Foundation, Inc., 59 Temple/Foundation, Inc., 51 Franklin/g' {} \; \
-exec sed -i -e 's/Place, Suite 330, Boston, MA.*02111-1307.*USA/Street, Fifth Floor, Boston, MA 02110-1335 USA/g' {} \; \
-exec sed -i -e 's/MA.*.....-1307/MA 02110-1335/g' {} \;
No functional change.
Call my_timer_init() only once and then reuse it from InnoDB and
perfschema storage engines.
This patch speeds up empty test for me like this:
./mtr -mem innodb.kevg,xtradb 1.21s user 0.84s system 34% cpu 5.999 total
./mtr -mem innodb.kevg,xtradb 1.12s user 0.60s system 31% cpu 5.385 total
The crash happens when writing into log file.
The reason is likely that the call to WriteFile() was missing a valid
parameter for lpNumberOfBytesWritten. This seems only to happen on ancient
version of Windows.
Since the fix to MDEV-16430 in 141bc58ac9, null pointer was passed
instead of valid pointer.
The fix is to provide a valid lpNumberOfBytesWritten parameter.
A sequel to 9180e86 and 149b754.
ALTER TABLE ... ADD FOREIGN KEY may crash if parent table is updated
concurrently.
Block FK parent table updates even earlier, before intermediate child
table is created.
Use proper charset info for my_casedn_str() and don't update original
identifiers so that lower_cast_table_names == 2 is honoured.
The bug occurs because Item_func_set_user var is allowed to be pushed
into materialized derived table/view.
To fix it excl_dep_on_table() as added to Item_func_set_user_var class
to prevent pushdown.
Need to call split_sum_func if an aggregate function is part of order by
or partition by clause so that we have the required fields inside the temporary
table, as all the fields inside the partition by and order by clause of the
window function needs to be there in the temp table used for window function
computation.
The issue here is that for a window function in the ORDER BY clause, we were not
creating an extra field in the temporary table for the window function
(which is contained in an expression).
So a call to split_sum_func is added to handle this case
Also we need to update all items that contain a window function
in the temp table during window function computation as filesort would need
these values to be updated to calculate the ORDER BY clause of the select.
For degenerate joins we may have JOIN::table_list as NULL, so instead
of using JOIN::top_join_tab_count use the function JOIN::exec_join_tab_cnt
to get the number of tables joined at the top level.
To read histograms for a table, we should check if the allocation of statistics was done or not,
if not done we should not try to read histograms for such a table.
The working directory, resource limits and core pattern will
aid the user finding a core file in the case of failure.
While the core file size is most relevant however other resource
limits may give a clue as the the cause of the fatal signal so
include them also.
As signal handler functions are limited, proc filesystem reads/
readlink calls are used instead of the more obvious getcwd/getrlimits
functions which aren't listed as signal safe.
Results in output of the form:
Writing a core file: working directory at /tmp/datadir
Resource Limits:
Limit Soft Limit Hard Limit Units
Max cpu time unlimited unlimited seconds
Max file size unlimited unlimited bytes
Max data size unlimited unlimited bytes
Max stack size 8388608 unlimited bytes
Max core file size unlimited unlimited bytes
Max resident set unlimited unlimited bytes
Max processes 47194 47194 processes
Max open files 1024 4096 files
Max locked memory 65536 65536 bytes
Max address space unlimited unlimited bytes
Max file locks unlimited unlimited locks
Max pending signals 47194 47194 signals
Max msgqueue size 819200 819200 bytes
Max nice priority 0 0
Max realtime priority 0 0
Max realtime timeout unlimited unlimited us
Core pattern: |/usr/libexec/abrt-hook-ccpp %s %c %p %u %g %t %P %I
Segmentation fault (core dumped)
Closes#537
use s->fields instead of s->stored_fields. extra_null_bitmap is allocated in Table_triggers_list::prepare_record_accessors with respect to virtual fields, so it will not overflow
Closes#1292
Restore EXPAIN flag in SELECT_LEX before execution multi-update by flag in LEX
(the same but in other way made before INSERT/DELETE/SELECT)
Without it, mysql_update() didn't know that there will be EXPLAIN result set and was sending OK at the end of the update, which conflicted with the EOF sent later by EXPLAIN.
copy_if_not_alloced() did not handle situations when
"from" is a constant string pointing to a substring of "to",
so this code part freed "to" but then tried to copy its old (already freed)
content to a new buffer:
if (to->realloc(from_length))
return from;
if ((to->str_length=MY_MIN(from->str_length,from_length)))
memcpy(to->Ptr,from->Ptr,to->str_length);
Adding a new code piece that catches such constant substrings
and propery reallocs "to" to preserve its important part referenced
by "from".
depends on uninitialised value
Initialized THD::force_read_stats introduced in the patch for MDEV-17605.
Leaving this field uninitialized in the constructor of the THD class may
trigger reading statistical data that is not needed.
Item_func_min_max::fix_length_and_dec() erroneously set max_length
to UINT32_MAX.
Merge notes:
In 10.3 this problem had been fixed earlier.
During merge to 10.3, do a "null merge" in item_func.cc
