FROM I_S
Issue:
------
There is a difference in the field type created when the
following DDLs are used:
1) CREATE TABLE t0 AS SELECT NULL;
2) CREATE TABLE t0 AS SELECT GREATEST(NULL,NULL);
The first statement creates field of type Field_string and
the second one creates a field of type Field_null.
This creates a problem when the query mentioned in this bug
is used. Since the null_ptr is calculated differently for
Field_null.
Solution:
---------
When there is a function returning null in the select list
as mentioned above, the field should be of type
Field_string.
This was fixed in 5.6+ as part of Bug#14021323. This is a
backport to mysql-5.5.
An incorrect comment in innodb_bug54044.test has been
corrected in all versions.
Permanently removed test case perfschema.aggregate.
The Performance Schema is generally lock-free, allowing for
race conditions that might arise from multi-threaded operation
which occasionally results in temporary and/or minor variances
when aggregating statistics. This test needs to be redesigned
to accommodate such variances.
State column of SHOW PROCESSLIST can have NULL values for being initialized
threads (between new connection was acknowledged and waiting for network data).
Fixed test case to handle such cases by waiting for State to become empty
string.
Analysis: row_drop_table_for_mysql did not allow dropping
referenced table even in case when actual creating of the
referenced table was not successfull if foreign_key_checks=1.
Fix: Allow dropping referenced table even if foreign_key_checks=1
if actual table create returned error.
The combination of --remove_file and --write_file on .expect file creates
a race condition which can be hit by MTR which reads the file in a loop.
Instead, .expect file should be changed with --append_file.
It was fixed in 10.x, but in 5.5 the sporadic failure still affected buildbot.
Fixed 3 test files which use the problematic combination
Use direct persistent index corruption set on InnoDB dictionary
for this test. Do not allow creating new indexes if one of the
existing indexes is already marked as corrupted.
Revert following bug fix:
Bug#20685029: SLAVE IO THREAD SHOULD STOP WHEN DISK IS
FULL
Bug#21753696: MAKE SHOW SLAVE STATUS NON BLOCKING IF IO
THREAD WAITS FOR DISK SPACE
This fix results in a deadlock between slave IO thread
and SQL thread.
INSERTS/UPDATES ON TEMPORARY TABLES
Bug#14294223: CHANGES NOT ALLOWED TO TEMPORARY TABLES ON
READ-ONLY SERVERS
Problem:
========
Running 5.5.14 in read only we can create temporary tables
but can not insert or update records in the table. When we
try we get Error 1290 : The MySQL server is running with the
--read-only option so it cannot execute this statement.
Analysis:
=========
This bug is very specific to binlog being enabled and
binlog-format being stmt/mixed. Standalone server without
binlog enabled or with row based binlog-mode works fine.
How standalone server and row based replication work:
=====================================================
Standalone server and row based replication mark the
transactions as read_write only when they are modifying
non temporary tables as part of their current transaction.
Because of this when code enters commit phase it checks
if a transaction is read_write or not. If the transaction
is read_write and global read only mode is enabled those
transaction will fail with 'server is read only mode'
error.
In the case of statement based mode at the time of writing
to binary log a binlog handler is created and it is always
marked as read_write. In case of temporary tables even
though the engine did not mark the transaction as read_write
but the new transaction that is started by binlog handler is
considered as read_write.
Hence in this case when code enters commit phase it finds
one handler which has a read_write transaction even when
we are modifying temporary table. This causes the server
to throw an error when global read-only mode is enabled.
Fix:
====
At the time of commit in "ha_commit_trans" if a read_write
transaction is found, we should check if this transaction is
coming from a handler other than binlog_handler. This will
ensure that there is a genuine read_write transaction being
sent by the engine apart from binlog_handler and only then
it should be blocked.
FAILURES
Analysis:
=========
Test script is not ensuring that "assert_grep.inc" should be
called only after 'Disk is full' error is written to the
error log.
Test checks for "Queueing master event to the relay log"
state. But this state is set before invoking 'queue_event'.
Actual 'Disk is full' error happens at a very lower level.
It can happen that we might even reset the debug point
before even the actual disk full simulation occurs and the
"Disk is full" message will never appear in the error log.
In order to guarentee that we must have some mechanism where
in after we write "Disk is full" error messge into the error
log we must signal the test to execute SSS and then reset
the debug point. So that test is deterministic.
Fix:
===
Added debug sync point to make script deterministic.
FULL
Bug#21753696: MAKE SHOW SLAVE STATUS NON BLOCKING IF IO
THREAD WAITS FOR DISK SPACE
Problem:
========
Currently SHOW SLAVE STATUS blocks if IO thread waits for
disk space. This makes automation tools verifying
server health block on taking relevant action. Finally this
will create SHOW SLAVE STATUS piles.
Analysis:
=========
SHOW SLAVE STATUS hangs on mi->data_lock if relay log write
is waiting for free disk space while holding mi->data_lock.
mi->data_lock is needed to protect the format description
event (mi->format_description_event) which is accessed by
the clients running FLUSH LOGS and slave IO thread. Note
relay log writes don't need to be protected by
mi->data_lock, LOCK_log is used to protect relay log between
IO and SQL thread (see MYSQL_BIN_LOG::append_event). The
code takes mi->data_lock to protect
mi->format_description_event during relay log rotate which
might get triggered right after relay log write.
Fix:
====
Release the data_lock just for the duration of writing into
relay log.
Made change to ensure the following lock order is maintained
to avoid deadlocks.
data_lock, LOCK_log
data_lock is held during relay log rotations to protect
the description event.
The main.merge test case was failing when tested using row based
binlog format.
While analyzing the issue it was found the following issues:
a) The server is calling binlog related code even when a statement will
not be binlogged;
b) The child table list was not present into table structure by the time
to generate the create table statement;
c) The tables in the child table list will not be opened yet when
generating table create info using row based replication;
d) CREATE TABLE LIKE TEMP_TABLE does not preserve original table storage
engine when using row based replication;
This patch addressed all above issues.
@ sql/sql_class.h
Added a function to determine if the binary log is disabled to
the current session. This is related with issue (a) above.
@ sql/sql_table.cc
Added code to skip binary logging related code if the statement
will not be binlogged. This is related with issue (a) above.
Added code to add the children to the query list of the table that
will have its CREATE TABLE generated. This is related with issue (b)
above.
Added code to force the storage engine to be generated into the
CREATE TABLE. This is related with issue (d) above.
@ storage/myisammrg/ha_myisammrg.cc
Added a test to skip a table getting info about a child table if the
child table is not opened. This is related to issue (c) above.
The test created a file in location relative to the datadir
(a few levels above datadir).
The file was created by MariaDB server (via INTO OUTFILE), and
later removed by mysqltest (via remove_file). The problem is that
when the vardir is a symlink, MariaDB server and mysqltest can
resolve such paths differently. MariaDB server would return back
to where the symlink is located, while mysqltest would go above
the real directory. For example, if the test is run with --mem,
and /bld/5.5/mysql-test/var points at /dev/shm/var_auto_X, then
SELECT INTO OUTFILE created a file in /bld/5.5/mysql-test , but
remove_file would look for it in /dev/shm/.
The test is re-written so that all paths are resolved in perl,
the logic itself hasn't changed.
Problem:
mysql-test/suite/rpl/t/rpl_killed_ddl.test
This test contains code which was disabled because of certain bugs.
BUG#44041 declared to be a duplicate of Bug#45516 which was fixed 2010
BUG#43353 fixed 2012
BUG#44171 fixed 2010
Fix:
Enabled the test code related to the above mentioned bugs.
while according to Storage Engine API column names should be compared
case insensitively. This can cause FRM and InnoDB data dictionary to
go out of sync.
Don't let network errors from mysql_close() leak into THD.
* remove incorrect upstream fix
** table->in_use can be NULL, must use ha_thd()
** clear_error() may remove earlier errors, don't use it
* fix the bug properly in federated and federatedx
fix innodb auto-increment handling
three bugs:
1. innobase_next_autoinc treated the case of current<offset incorrectly
2. ha_innobase::get_auto_increment didn't recalculate current when increment changed
3. ha_innobase::get_auto_increment didn't pass offset down to innobase_next_autoinc
Analysis: debug only assertion I_S function (IS is XtraDB feature) is calling
buf_block_get_frame on any page it reads, which debug-asserts that the page is
buffer-fixed, which is not the case in I_S query.
Fixed by holding the buffer page mutex while the fields are read directly.
Problem:
========
1) Drop table queries are re-generated by server
before writing the events(queries) into binlog
for various reasons. If table name/db name contains
a non regular characters (like latin characters),
the generated query is wrong. Hence it breaks the
replication.
2) In the edge case, when table name/db name contains
64 characters, server is throwing an assert
assert(M_TBLLEN < 128)
3) In the edge case, when db name contains 64 latin
characters, binlog content is interpreted badly
which is leading replication failure.
Analysis & Fix :
================
1) Parser reads the table name from the query and converts
it to standard charset(utf8) and stores it in table_name variable.
When drop table query is regenerated with the same table_name
variable, it should be converted back to the original charset
from standard charset(utf8).
2) Latin character takes two bytes for each character. Limit
of the identifier is 64. SYSTEM_CHARSET_MBMAXLEN is set to '3'.
So there is a possiblity that tablename/dbname contains 3 * 64.
Hence assert is changed to
(M_TBLLEN <= NAME_CHAR_LEN*SYSTEM_CHARSET_MBMAXLEN)
3) db_len in the binlog event header is taking 1 byte.
db_len is ranged from 0 to 192 bytes (3 * 64).
While reading the db_len from the event, server
is casting to uint instead of uchar which is leading
to bad db_len. This problem is fixed by changing the
cast type to uchar.
Problem & Analysis: If DML invokes a trigger or a
stored function that inserts into an AUTO_INCREMENT column,
that DML has to be marked as 'unsafe' statement. If the
tables are locked in the transaction prior to DML statement
(using LOCK TABLES), then the same statement is not marked as
'unsafe' statement. The logic of checking whether unsafeness
is protected with if (!thd->locked_tables_mode). Hence if
we lock the tables prior to DML statement, it is *not* entering
into this if condition. Hence the statement is not marked
as unsafe statement.
Fix: Irrespective of locked_tables_mode value, the unsafeness
check should be done. Now with this patch, the code is moved
out to 'decide_logging_format()' function where all these checks
are happening and also with out 'if(!thd->locked_tables_mode)'.
Along with the specified test case in the bug scenario
(BINLOG_STMT_UNSAFE_AUTOINC_COLUMNS), we also identified that
other cases BINLOG_STMT_UNSAFE_AUTOINC_NOT_FIRST,
BINLOG_STMT_UNSAFE_WRITE_AUTOINC_SELECT, BINLOG_STMT_UNSAFE_INSERT_TWO_KEYS
are also protected with thd->locked_tables_mode which is not right. All
of those checks also moved to 'decide_logging_format()' function.
make it possible to change feedback plugin wait intervals
* only in debug builds
* and force the feedback report to be ignored
update the test to use this feature
