MYSQLDUMP OUTPUT
Problem: mysqldump when used with option --routines, dumps
all the routines of the specified database into
output. The statements in this output are written
in such a way that they are version safe using C
style version commenting (of the format
/*!<version num> <sql statement>*/). If a semicolon
is present right before closing of the comment in
dump output, it results in a syntax error while
importing.
Solution: Version comments for dumped routines are
specifically to protect the ones older than 5.0.
When the import is done on 5.0 or later versions,
entire create statement gets executed as all the
check conditions at the beginning of the comments
are cleared. Since the trade off is between the
performance of newer versions which are more in
use and protection of very old versions which are
no longer supported, it is proposed that these
comments be removed altogether to maintain
stability of the versions supported.
client/mysqldump.c:
Bug#14463669 FAILURE TO CORRECTLY PARSE ROUTINES IN
MYSQLDUMP OUTPUT
Output of mysqldump is derived by getting the queries from
show create and appending version comments to them.
query_str is the variable used to store the final string.
Since it is no longer required, its declaration and
manipulations made on it are deleted. At the step where
output is printed, query_str is replaced with the original
query string derived from 'show create'.
TABLE DATA IF DUMPS MYSQL DATABA
Problem: If mysqldump is run without --events (or with --skip-events)
it will not dump the mysql.event table's data. This behaviour is inconsistent
with that of --routines option, which does not affect the dumping of
mysql.proc table. According to the Manual, --events (--skip-events) defines,
if the Event Scheduler events for the dumped databases should be included
in the mysqldump output and this has nothing to do with the mysql.event table
itself.
Solution: A warning has been added when mysqldump is used without --events
(or with --skip-events) and a separate patch with the behavioral change
will be prepared for 5.6/trunk.
TABLE DATA IF DUMPS MYSQL DATABA
Problem: If mysqldump is run without --events (or with --skip-events)
it will not dump the mysql.event table's data. This behaviour is inconsistent
with that of --routines option, which does not affect the dumping of
mysql.proc table. According to the Manual, --events (--skip-events) defines,
if the Event Scheduler events for the dumped databases should be included
in the mysqldump output and this has nothing to do with the mysql.event table
itself.
Solution: A warning has been added when mysqldump is used without --events
(or with --skip-events) and a separate patch with the behavioral change
will be prepared for 5.6/trunk.
WHEN DBNAME CONTAINS MULTIPLE QUOTES
MySQL client's USE command might fail if the
database name contains multiple quotes (backticks).
The reason behind the failure being the method
that client uses to remove/escape the quotes
while parsing the USE command's option (dbname),
where the option parsing might terminate if a
matching quote is found.
Also, C-APIs like mysql_select_db() expect a
normalized dbname. Now, in certain cases, client
might fail to normalize dbname similar to that of
server and hence mysql_select_db() would fail.
Fixed by getting the normalized dbname (indirectly)
from the server by directly sending the "USE dbanme"
as query to the server followed by a "SELECT DATABASE()".
The above steps are only performed if number of quotes
in the dbname is greater than 2. Once the normalized
dbname is received, the original db is restored.
WHEN STDIN IS A PIPE
Problem: Mysqlbinlog does not accept the input from STDIN when
STDIN is a pipe. This prevents the users from passing the input file
through a shell pipe.
Background: The my_seek() function does not check if the file descriptor
passed to it is regular (seekable) file. The check_header() function in
mysqlbinlog calls the my_b_seek() unconditionally and it fails when
the underlying file is a PIPE.
Resolution: We resolve this problem by checking if the underlying file
is a regular file by using my_fstat() before calling my_b_seek().
If the underlying file is not seekable we skip the call to my_b_seek()
in check_header().
client/mysqlbinlog.cc:
Added a check to avoid the my_b_seek() call if the
underlying file is a PIPE.
SHOW 2012 INSTEAD OF 2011
* Added a new macro to hold the current year :
COPYRIGHT_NOTICE_CURRENT_YEAR
* Modified ORACLE_WELCOME_COPYRIGHT_NOTICE macro
to take the initial year as parameter and pick
current year from the above mentioned macro.
Problem description:
Giving "help 'contents'" in the mysql client as a first statement
gives error
Analysis:
In com_server_help() function the "server_cmd" variable was
initialised with buffer->ptr(). And the "server_cmd" variable is not
updated since we are passing "'contents'"(with single quote) so the
buffer->ptr() consists of the previous buffer values and it was sent
to the mysql_real_query() hence we are getting error.
Fix:
We are not initialising the "server_cmd" variable and we are updating
the variable with "server_cmd= cmd_buf" in any of the case i.e with
single quote or without single quote for the contents.
As part of error message improvement, added new error message in case
of "help 'contents'".
client/mysql.cc:
com_server_help(): Properly updated the server_cmd variable and improved
the error message.
Problem:
=======
The return value from my_b_write is ignored by: `my_b_write_quoted',
`my_b_write_bit',`Query_log_event::print_query_header'
Most callers of `my_b_printf' ignore the return value. `log_event.cc'
has many calls to it.
Analysis:
========
`my_b_write' is used to write data into a file. If the write fails it
sets appropriate error number and error message through my_error()
function call and sets the IO_CACHE::error == -1.
`my_b_printf' function is also used to write data into a file, it
internally invokes my_b_write to do the write operation. Upon
success it returns number of characters written to file and on error
it returns -1 and sets the error through my_error() and also sets
IO_CACHE::error == -1. Most of the event specific print functions
for example `Create_file_log_event::print', `Execute_load_log_event::print'
etc are the ones which make several calls to the above two functions and
they do not check for the return value after the 'print' call. All the above
mentioned abuse cases deal with the client side.
Fix:
===
As part of bug fix a check for IO_CACHE::error == -1 has been added at
a very high level after the call to the 'print' function. There are
few more places where the return value of "my_b_write" is ignored
those are mentioned below.
+++ mysys/mf_iocache2.c 2012-06-04 07:03:15 +0000
@@ -430,7 +430,8 @@
memset(buffz, '0', minimum_width - length2);
else
memset(buffz, ' ', minimum_width - length2);
- my_b_write(info, buffz, minimum_width - length2);
+++ sql/log.cc 2012-06-08 09:04:46 +0000
@@ -2388,7 +2388,12 @@
{
end= strxmov(buff, "# administrator command: ", NullS);
buff_len= (ulong) (end - buff);
- my_b_write(&log_file, (uchar*) buff, buff_len);
At these places appropriate return value handlers have been added.
client/mysqlbinlog.cc:
check for IO_CACHE::error == -1 has been added after the call to
the event specific print functions
mysys/mf_iocache2.c:
Added handler to check the written value of `my_b_write'
sql/log.cc:
Added handler to check the written value of `my_b_write'
sql/log_event.cc:
Added error simulation statements in `Create_file_log_event::print`
and `Execute_load_query_log_event::print'
sql/rpl_utility.h:
Removed the extra ';'
1. Clear text password client plugin disabled by default.
2. Added an environment variable LIBMYSQL_ENABLE_CLEARTEXT_PLUGIN, that
when set to something starting with '1', 'Y' or 'y' will enable the clear
text
plugin for all connections.
3. Added a new mysql_options() option : MYSQL_ENABLE_CLEARTEXT_PLUGIN
that takes an my_bool argument. When the value of the argument is non-zero
the clear text plugin is enabled for this connection only.
4. Added an enable-cleartext-plugin config file option that takes a numeric
argument. If the numeric value of the numeric argument is non-zero the
clear
text plugin is enabled for the connection
5. Added a boolean command line option "--enable_cleartext_plugin" to
mysql, mysqlslap and mysqladmin. When specified it will call mysql_options
with the effect of #3
6. Added a new CLEARTEXT option to the connect command in mysqltest.
When specified it will enable the cleartext plugin for usage.
7. Added test cases and updated existing ones that need the clear text
plugin.
executing
The problem is that mysql lacks information about the objects a view
depends on so it can't dump views and tables in the proper order.
Thus it needs to create "stand-in" myisam tables for each view while
dumping the tables that it later drops and replaces with the actual view
view definition.
But since views can have much more columns than an actual table creating
these stand-in tables may be problematic.
There's no way to portably find out how many columns an mysiam table
can have. It's a complicated formula depending on internal server constants.
Thus we can't have a reliable error check without repeating the logic and
the formula inside mysqldump.
1. Changed the type of the columns of the stand-in tables mysqldump
makes to satisfy view dependencies from the original type to smallint
to save on row space.
2. Added a warning on the mysqldump's standard error for a possible
problems replaying the dump file if the columns of a view exceed 1000.
3. Added a test case.
Several fixes :
* sql-common/client.c
Added a validity check of the fields metadata packet sent
by the server.
Now libmysql will check if the length of the data sent by
the server matches what's expected by the protocol before
using the data.
* client/mysqltest.cc
Fixed the error handling code in mysqltest to avoid sending
new commands when the reading the result set failed (and
there are unread data in the pipe).
* sql_common.h + libmysql/libmysql.c + sql-common/client.c
unpack_fields() now generates a proper error when it fails.
Added a new argument to this function to support the error
generation.
* sql/protocol.cc
Added a debug trigger to cause the server to send a NULL
insted of the packet expected by the client for testing
purposes.
Problem: mysqlbinlog exits without any error code in case of
file write error. It is because of the fact that the calls
to Log_event::print() method does not return a value and the
thus any error were being ignored.
Resolution: We resolve this problem by checking for the
IO_CACHE::error == -1 after every call to Log_event:: print()
and terminating the further execution.
client/mysqlbinlog.cc:
- handled error conditions during event->print() calls
- added check for error in end_io_cache()
mysys/my_write.c:
Added debug code to simulate file write error.
error returned will be ENOSPC=> error no space on the disk
sql/log_event.cc:
Added debug code to simulate file write error, by reducing the size of io cache.
CAUSES RESTORE PROBLEM
Merging the fix from mysql-5.1 to mysql-5.5
mysql-test/t/mysqldump.test:
There is a difference in the testcase which is added as
part of this fix, when compared with mysql-5.1. In mysql-5.5
and mysql-5.6, "DROP mysql database" fails by enabling
logging, hence removed those lines.
CAUSES RESTORE PROBLEM
Problem Statement:
------------------
mysqldump is not having the dump stmts for general_log and slow_log
tables. That is because of the fix for Bug#26121. Hence, after
dropping the mysql database, and applying the dump by enabling the
logging, "'general_log' table not found" errors are logged into the
server log file.
Analysis:
---------
As part of the fix for Bug#26121, we skipped the dumping of tables
for general_log and slow_log, because the data dump of those tables
are taking LOCKS, which is not allowed for log tables.
Fix:
----
We came up with an approach that instead of taking both meta data
and data dump information for those tables, take only the meta data
dump which doesn't need LOCKS.
As part of fixing the issue we came up with below algorithm.
Design before fix:
1) mysql database is having tables like db, event,... general_log,
... slow_log...
2) Skip general_log and slow_log while preparing the tables list
3) Take the TL_READ lock on tables which are present in the table
list and do 'show create table'.
4) Release the lock.
Design with the fix:
1) mysql database is having tables like db, event,... general_log,
... slow_log...
2) Skip general_log and slow_log while preparing the tables list
3) Explicitly call the 'show create table' for general_log and
slow_log
3) Take the TL_READ lock on tables which are present in the table
list and do 'show create table'.
4) Release the lock.
While taking the meta data dump for general_log and slow_log the
"CREATE TABLE" is replaced with "CREATE TABLE IF NOT EXISTS".
This is because we skipped "DROP TABLE" for those tables,
"DROP TABLE" fails for these tables if logging is enabled.
Customer is applying the dump by enabling logging so, if the dump
has "DROP TABLE" it will fail. Hence, removed the "DROP TABLE"
stmts for those tables.
After the fix we could observe "Table 'mysql.general_log'
doesn't exist" errors initially that is because in the customer
scenario they are dropping the mysql database by enabling the
logging, Hence, those errors are expected. Once we apply the
dump which is taken before the "drop database mysql", the errors
will not be there.
client/mysqldump.c:
In get_table_structure() added code to skip the DROP TABLE stmts for general_log
and slow_log tables, because when logging is enabled those stmts will fail. And
replaced CREATE TABLE with CREATE IF NOT EXISTS for those tables, just to make
sure CREATE stmt for those tables doesn't fail since we removed DROP stmts for
those tables.
In dump_all_tables_in_db() added code to call get_table_structure() for
general_log and slow_log tables.
mysql-test/r/mysqldump.result:
Added a test as part of fix for Bug #11754178
mysql-test/t/mysqldump.test:
Added a test as part of fix for Bug #11754178
CAUSES RESTORE PROBLEM
Problem Statement:
------------------
mysqldump is not having the dump stmts for general_log and slow_log
tables. That is because of the fix for Bug#26121. Hence, after
dropping the mysql database, and applying the dump by enabling the
logging, "'general_log' table not found" errors are logged into the
server log file.
Analysis:
---------
As part of the fix for Bug#26121, we skipped the dumping of tables
for general_log and slow_log, because the data dump of those tables
are taking LOCKS, which is not allowed for log tables.
Fix:
----
We came up with an approach that instead of taking both meta data
and data dump information for those tables, take only the meta data
dump which doesn't need LOCKS.
As part of fixing the issue we came up with below algorithm.
Design before fix:
1) mysql database is having tables like db, event,... general_log,
... slow_log...
2) Skip general_log and slow_log while preparing the tables list
3) Take the TL_READ lock on tables which are present in the table
list and do 'show create table'.
4) Release the lock.
Design with the fix:
1) mysql database is having tables like db, event,... general_log,
... slow_log...
2) Skip general_log and slow_log while preparing the tables list
3) Explicitly call the 'show create table' for general_log and
slow_log
3) Take the TL_READ lock on tables which are present in the table
list and do 'show create table'.
4) Release the lock.
While taking the meta data dump for general_log and slow_log the
"CREATE TABLE" is replaced with "CREATE TABLE IF NOT EXISTS".
This is because we skipped "DROP TABLE" for those tables,
"DROP TABLE" fails for these tables if logging is enabled.
Customer is applying the dump by enabling logging so, if the dump
has "DROP TABLE" it will fail. Hence, removed the "DROP TABLE"
stmts for those tables.
After the fix we could observe "Table 'mysql.general_log'
doesn't exist" errors initially that is because in the customer
scenario they are dropping the mysql database by enabling the
logging, Hence, those errors are expected. Once we apply the
dump which is taken before the "drop database mysql", the errors
will not be there.
client/mysqldump.c:
In get_table_structure() added code to skip the DROP TABLE stmts for general_log
and slow_log tables, because when logging is enabled those stmts will fail. And
replaced CREATE TABLE with CREATE IF NOT EXISTS for those tables, just to make
sure CREATE stmt for those tables doesn't fail since we removed DROP stmts for
those tables.
In dump_all_tables_in_db() added code to call get_table_structure() for
general_log and slow_log tables.
mysql-test/r/mysqldump.result:
Added a test as part of fix for Bug #11754178
mysql-test/t/mysqldump.test:
Added a test as part of fix for Bug #11754178
This bug is a duplicate of Bug #31173, which was pushed to the
mysql-trunk 5.6 on 4th Aug, 2010. This is just a back-port of
the fix
mysql-test/r/mysqlslap.result:
A test added as part of the fix for Bug #59107
mysql-test/t/mysqlslap.test:
A test added as part of the fix for Bug #59107
This bug is a duplicate of Bug #31173, which was pushed to the
mysql-trunk 5.6 on 4th Aug, 2010. This is just a back-port of
the fix
mysql-test/r/mysqlslap.result:
A test added as part of the fix for Bug #59107
mysql-test/t/mysqlslap.test:
A test added as part of the fix for Bug #59107
This patch changes the mechanism by which the client enables a
plugin. Instead of using INSERT IGNORE to reload a plugin library,
it now uses REPLACE INTO. This allows users to load a library
multiple times replacing the existing values in the mysql.plugin
table. This allows users to replace the symbol reference to a
different dl name in the table. Thus permitting enabling of
multiple versions of the same library without first disabling
the old version.
A regression test was added to ensure this feature works.
routines.
mysqldump in xml mode did not dump routines, events or
triggers.
This patch fixes this issue by fixing the if conditions
that disallowed the dump of above mentioned objects in
xml mode, and added the required code to enable dump
in xml format.
client/mysqldump.c:
BUG#11760384 - 52792: mysqldump in XML mode does not dump
routines.
Fixed some if conditions to allow execution of dump methods
for xml and further added the relevant code at places to produce
the dump in xml format.
mysql-test/r/mysqldump.result:
Added a test case for Bug#11760384.
mysql-test/t/mysqldump.test:
Added a test case for Bug#11760384.
--FLUSH-LOG BREAKS CONSISTENCY
The transaction started by mysqldump gets committed
implicitly when flush-log is specified along with
single-transaction option, and hence can break
consistency.
This is because, COM_REFRESH is executed in order
to flush logs and starting from 5.5 this command
performs an implicit commit.
Fixed by making sure that COM_REFRESH is executed
before the transaction has started and not after it.
Note : This patch triggers following behavioral
changes in mysqldump :
1) After this patch we no longer flush logs before
dumping each database if --single-transaction
option is given like it was done before (in the
absence of --lock-all-tables and --master-data
options).
2) Also, after this patch, we start acquiring
FTWRL before flushing logs in cases when only
--single-transaction and --flush-logs are given.
It becomes safe to use mysqldump with these two
options and without --master-data parameter for
backups.
client/mysqldump.c:
Bug#12809202 61854: MYSQLDUMP --SINGLE-TRANSACTION
--FLUSH-LOG BREAKS CONSISTENCY
Added logic to make sure that, if flush-log option
is specified, mysql_refresh() is never executed after
the transaction has started.
Added verbose messages for all the executions of
mysql_refresh() in order to track its invocation.
mysql-test/r/mysqldump.result:
Added test case for Bug#12809202.
mysql-test/t/mysqldump.test:
Added test case for Bug#12809202.
readline.cc: In function char* batch_readline(LINE_BUFFER*):
readline.cc:60:9: error: out_length may be used uninitialized in this function
log.cc: In function int find_uniq_filename(char*):
log.cc:1857:8: error: number may be used uninitialized in this function
OPTION SKIP-WRITE-BINLOG
System tables were not getting upgraded when
mysql_upgrade was run with --skip-write-binlog
option. (Same for --write-binlog.) Also, with
this option, mysql_upgrade_info file was not
getting created after the upgrade.
mysql_upgrade makes use of mysql client tool in
order to run upgrade scripts, while doing so it
passes some of the command line options (used to
start mysql_upgrade) directly to mysql client.
The reason behind this bug being, some options
like skip-write-binlog and upgrade-system-tables
were being passed to mysql tool along with other
options, and hence mysql execution failed due
presence of these invalid options.
Fixed this issue by filtering out the above mentioned
options from the list of options that will be passed to
mysql and mysqlcheck tools. However, since --write-binlog
is supported by mysqlcheck, this option would be used
explicitly while running mysqlcheck. (not part of patch,
already there)
Checking the contents of general log after the upgrade
is not doable via an mtr test. So performed manual test.
Added a test to verify the creation of mysql_upgrade_info.
client/mysql_upgrade.c:
Bug#11827359 60223: MYSQL_UPGRADE PROBLEM WITH
OPTION SKIP-WRITE-BINLOG
With this patch, --upgrade-system-tables and
--write-binlog options will not be added to the
list of options, used to start mysql and mysqlcheck
tools.
mysql-test/r/mysql_upgrade.result:
Added a testcase for Bug#11827359.
mysql-test/t/mysql_upgrade.test:
Added a testcase for Bug#11827359.
This patch corrects a defect whereby the --mysqld, --my-print-defaults,
and --plugin-ini were required. These options are not required and the
code has been fixed accordingly.
Don't do this for echo, instead:
1) Enable replacements also for assignment from backquoted SQL
2) Allow replace_regex to take a variable for the *entire* argument list
With this, the test can be amended, but only in its version in trunk
Simplified fix avoiding changes to mysys:
Use the MY_HOLD_ORIGINAL_MODES flag when calling my_copy(),
this also stops it from attempting to chown() the file.
Yes this behavior is a bit confusing....
The only case this might change the behavior is if the destination file
exists, but since we also use MY_DONT_OVERWRITE_FILE, it would fail
in those cases anyway.
modified function do_get_error in mysqltest.cc to handle multiple variable passed
added test case to mysqltest.test to verify handling to multiple errors passed
