REPLICATION FILTERS ARE USED.
Problem:
When Filtered-slave applies Int_var_log_event and when it
tries to write the event to its own binlog, LAST_INSERT_ID
value is written wrongly.
Analysis:
THD::stmt_depends_on_first_successful_insert_id_in_prev_stmt
is a variable which is set when LAST_INSERT_ID() is used by
a statement. If it is set, first_successful_insert_id_in_
prev_stmt_for_binlog will be stored in the statement-based
binlog. This variable is CUMULATIVE along the execution of
a stored function or trigger: if one substatement sets it
to 1 it will stay 1 until the function/trigger ends,
thus making sure that first_successful_insert_id_in_
prev_stmt_for_binlog does not change anymore and is
propagated to the caller for binlogging. This is achieved
using the following code
if(!stmt_depends_on_first_successful_insert_id_in_prev_stmt)
{
/* It's the first time we read it */
first_successful_insert_id_in_prev_stmt_for_binlog=
first_successful_insert_id_in_prev_stmt;
stmt_depends_on_first_successful_insert_id_in_prev_stmt= 1;
}
Slave server, after receiving Int_var_log_event event from
master, it is setting
stmt_depends_on_first_successful_insert_id_in_prev_stmt
to true(*which is wrong*) and not setting
first_successful_insert_id_in_prev_stmt_for_binlog. Because
of this problem, when the actual DML statement with
LAST_INSERT_ID() is parsed by slave SQL thread,
first_successful_insert_id_in_prev_stmt_for_binlog is not
set. Hence the value zero (default value) is written to
slave's binlog.
Why only *Filtered slave* is effected when the code is
in common place:
-------------------------------------------------------
In Query_log_event::do_apply_event,
THD::stmt_depends_on_first_successful_insert_id_in_prev_stmt
is reset to zero at the end of the function. In case of
normal slave (No Filters), this variable will be reset.
In Filtered slave, Slave SQL thread defers all IRU events's
execution until IRU's Query_log event is received. Once it
receives Query_log_event it executes all pending IRU events
and then it executes Query_log_event. Hence the variable is
not getting reset to 0, causing this bug.
Fix: As described above, the root cause was setting
THD::stmt_depends_on_first_successful_insert_id_in_prev_stmt
when Int_var_log_event was executed by a SQL thread. Hence
removing the problematic line from the code.
Description: Fix for bug CVE-2012-5611 (bug 67685) is
incomplete. The ACL_KEY_LENGTH-sized buffers in acl_get() and
check_grant_db() can be overflown by up to two bytes. That's
probably not enough to do anything more serious than crashing
mysqld.
Analysis: In acl_get() when "copy_length" is calculated it
just adding the variable lengths. But when we are using them
with strmov() we are adding +1 to each. This will lead to a
three byte buffer overflow (i.e two +1's at strmov() and one
byte for the null added by strmov() function). Similarly it
happens for check_grant_db() function as well.
Fix: We need to add "+2" to "copy_length" in acl_get()
and "+1" to "copy_length" in check_grant_db().
REPEATED TWICE IN BINLOG
Problem:
=======
If LOAD DATA ... SET ... is used the last argument of SET is
repeated twice in replication binlog.
Analysis:
========
LOAD DATA statements are reconstructed once again before
they are written to the binary log. When SET clauses are
specified as part of LOAD DATA statement, these SET clause
user command strings need to be stored in order to rebuild
the original user command. During parsing each column and
the value in the SET command are stored in two differenet
lists. All the values are stored in a string list.
When SET expression has more than one value as shown in the
following example:
SET a = @a, b = CONCAT(@b, '| 123456789');
Parser extracts values in the following manner i.e Item name
, value string, actual length of the value of the item with
in the string.
Item a:
Value for a:"= @a, b = CONCAT(@b, '| 123456789')
str_length = 4
Item b:
Value for b:"= CONCAT(@b, '| 123456789')
str_length = 27
During reconstructing the LOAD DATA command the above
strings are retrived as it is and appended to the LOAD DATA
statement. Hence it becomes as shown below.
SET `a`= @a, b = CONCAT(@b, '| 123456789'),
`b`= CONCAT(@b, '| 123456789')
Fix:
===
During reconstruction of SET command, retrieve exact item
value string rather than reading the entire string.
sql/sql_load.cc:
Added code to extract the exact Item value.
This worklog aims at testing the two following scenarios:
1) Whenever the mysql_binlog_send method (dump thread)
reaches the end of file when reading events from the binlog, before
checking if it should wait for more events, there was a test to
check if the file being read was still active, i.e, it was the last
known binlog. However, it was possible that something was written to
the binary log and then a rotation would happen, after EOF was
detected and before the check for active was performed. In this
case, the end of the binary log would not be read by the dump
thread, and this would cause the slave to lose updates.
This test verifies that the problem has been fixed. It waits during
this window while forcing a rotation in the binlog.
2) Verify dump thread can send events in active file, correctly after
encountering an IO error.
AND 'KILL SESSION' LEAD TO CRASH
Analysis:
--------
This situation occurs when the connection executes query
"show engine innodb status" and this connection is killed by
executing statement "kill <con>" by another connection.
In function "innodb_show_status", function "stat_print"
is called to print the status but return value of function
is not checked. After killing connection, if write to
connection fails then error is returned and same is set
in Diagnostic area. Since FALSE is returned from
"innodb_show_status" now, assert to check no error
is set in function "set_eof_status" (called from
my_eof) is failing.
Fix:
----
Changed code to check return value of function "stat_print"
in "innodb_show_status".
ha_innobase::records_in_range() should return HA_POS_ERROR for the table during discarded without requesting pages.
The later other handler method should treat the error correctly.
Approved by Sunny in rb#3433
Description:
------------
There are 2 issues reported in the bug report,
1. One session running a "long" select, then, from the other
session, you kill that first one, while select is
running, and it receives that message "Server shutdown in
progress".
Reported Date: 02-Apr-2006
=> Looks like this isuse is already fixed in 2009 by the patch
pushed for bug28141.
2. Killing query which goes to filesort, logs error entries like:
120416 9:17:28 [ERROR] mysqld: Sort aborted: Server shutdown in
progress
120416 9:18:48 [ERROR] mysqld: Sort aborted: Server shutdown in
progress
120416 9:19:39 [ERROR] mysqld: Sort aborted: Server shutdown in
progress
Reported Date: 16-Apr-2012
=> This issue is introduced in 5.5+ versions. Fixing this issue
in this patch.
Analysis:
---------
In function "filesort()", on error we are logging error message.
To the error message, the message related THD::killed_errno is
also appeneded, if it is set.(THD::kill_errno value is obtained
by calling member function THD::killed_errno)
In the scenario mentioned in this bug report, when we kill the
connection, THD::kill_errno is set to the THD::KILL_CONNECTION.
Enum type THD::KILL_CONNECTION corressponds to value
ER_SERVER_SHUTDOWN. Because of this, "Server shutdown in ...." is
appended to the message logged.
Fix:
----
Modified code of "filesort()" function to append "KILL_QUERY"
status to error message when thread is killed and server
shutdown is not in progress.
INDEX_READ_MAP HAD NO MATCH
If index_read_map is called for exact search and no matching records
exists it will position the cursor on the next record, but still having the
relative position to BTR_PCUR_ON.
This will make a call for index_next to read yet another next record,
instead of returning the record the cursor points to.
Fixed by setting pcur->rel_pos = BTR_PCUR_BEFORE if an exact
[prefix] search is done, but failed.
Also avoids optimistic restoration if rel_pos != BTR_PCUR_ON,
since btr_cur may be different than old_rec.
rb#3324, approved by Marko and Jimmy
Registry redirection was improper and hence not able to pick the value for the OLDERVERSION property. as a result in the install upgrade dialog null value wa being passed.
The testcase for this bug fails randomly due to two reasons.
1. Due to ibuf merge happening background
2. Due to dict stats update which brings the evicted page back into
buffer pool.
Fix ibuf_contract_ext() to not do any merges with ibuf_debug enabled and
also changed dict_stats_update() to return fake statistics without
bringing the secondary index pages into buffer pool.
Approved by Marko. rb#3419
DURING INNODB RECOVERY
Problem:
=======
The connection 'master' is dropped by mysqltest after
rpl_end.inc. At this point, dropping temporary tables
at the connection 'master' are not synced at slave.
So, the temporary tables replicated from master remain
on slave leading to an inconsistent close of the test.
The following test thus complains about the presence of
temporary table(s) left over from the previous test.
Fix:
===
- Put explicit drop commands in replication tests so
that the temporary tables are dropped at slave as well.
- Added the check for Slave_open_temp_tables in
mtr_check.sql to warn about the remaining temporary
table, if any, at the close of a test.
RPL_SEMI_SYNC_MASTER_ENABLED OFF.
Problem:
=======
If master is waiting for a reply from slave, at this time
set global rpl_semi_sync_master_enabled=OFF, the master
server will crash.
Analysis:
========
When master is waiting for a reply from slave, at this time
if semi sync is switched off on master, during switch off if
active transactions are present the transactions will be
cleared and "active_tranxs_" variable will be set to NULL.
When the waiting master connection finds that semi sync is
switched of it tries to access "active_tranxs_" without
checking if the transaction list exists or not. Accessing
NULL transaction list causes the crash.
Fix:
===
A check has been added to see a valid list exists before
accessing the "active_tranxs_".
plugin/semisync/semisync_master.cc:
Added check for the existence of valid 'active_transx_'.
IT IS DONE IN-PLACE
With change buffer enabled, InnoDB doesn't write a transaction log
record when it merges a record from the insert buffer to an secondary
index page if the insertion is performed as an update-in-place.
Fixed by logging the 'update-in-place' operation on secondary index
pages.
Approved by Marko. rb#2429
WITH MY_B_VPRINTF()
Issue : In LP 64 machine max long value can be 20 digit
decimal value. But in my_b_vprintf() the intermediate
buffer storage used is 17 bytes length. This will lead to
buffer overflow.
Solution : Increased the buffer storage from 17 to 32 bytes.
code is backported from 5.6
mysys/mf_iocache2.c:
In function my_b_vprintf increased the size of local buff from 17 to
32 bytes.
For queries like
update t1 set ... where <unique key> order by ... limit ...
we need to handle the fact that unique keys allow NULL
values, and hence can return more than one row.
sql/opt_range.cc:
When the unique key has multiple key parts,
check each key_part for nullability, rather than the first key part.
(s/key->part ==/key_tree->part ==/)
Also: revert the if() test, for better readability.
