INSERT/DELETE/UPDATE followed by ALTER TABLE within LOCK TABLES
may cause table corruption on Windows.
That happens because ALTER TABLE writes outdated shared state
info into index file.
Fixed by removing obsolete workaround.
Affects MyISAM tables on Windows only.
Bug#25422 (Hang with log tables)
Bug 17876 (Truncating mysql.slow_log in a SP after using cursor locks the
thread)
Bug 23044 (Warnings on flush of a log table)
Bug 29129 (Resetting general_log while the GLOBAL READ LOCK is set causes
a deadlock)
Prior to this fix, the server would hang when performing concurrent
ALTER TABLE or TRUNCATE TABLE statements against the LOG TABLES,
which are mysql.general_log and mysql.slow_log.
The root cause traces to the following code:
in sql_base.cc, open_table()
if (table->in_use != thd)
{
/* wait_for_condition will unlock LOCK_open for us */
wait_for_condition(thd, &LOCK_open, &COND_refresh);
}
The problem with this code is that the current implementation of the
LOGGER creates 'fake' THD objects, like
- Log_to_csv_event_handler::general_log_thd
- Log_to_csv_event_handler::slow_log_thd
which are not associated to a real thread running in the server,
so that waiting for these non-existing threads to release table locks
cause the dead lock.
In general, the design of Log_to_csv_event_handler does not fit into the
general architecture of the server, so that the concept of general_log_thd
and slow_log_thd has to be abandoned:
- this implementation does not work with table locking
- it will not work with commands like SHOW PROCESSLIST
- having the log tables always opened does not integrate well with DDL
operations / FLUSH TABLES / SET GLOBAL READ_ONLY
With this patch, the fundamental design of the LOGGER has been changed to:
- always open and close a log table when writing a log
- remove totally the usage of fake THD objects
- clarify how locking of log tables is implemented in general.
See WL#3984 for details related to the new locking design.
Additional changes (misc bugs exposed and fixed):
1)
mysqldump which would ignore some tables in dump_all_tables_in_db(),
but forget to ignore the same in dump_all_views_in_db().
2)
mysqldump would also issue an empty "LOCK TABLE" command when all the tables
to lock are to be ignored (numrows == 0), instead of not issuing the query.
3)
Internal errors handlers could intercept errors but not warnings
(see sql_error.cc).
4)
Implementing a nested call to open tables, for the performance schema tables,
exposed an existing bug in remove_table_from_cache(), which would perform:
in_use->some_tables_deleted=1;
against another thread, without any consideration about thread locking.
This call inside remove_table_from_cache() was not required anyway,
since calling mysql_lock_abort() takes care of aborting -- cleanly -- threads
that might hold a lock on a table.
This line (in_use->some_tables_deleted=1) has been removed.
Added libCsup as a mysql library dependency on hpux11.
This means any projects statically linking to our libraries using the HPUX11 compiler will need to add the -lCSup option to their build link options. If they use the mysql_config tool this will happen automatically.
Projects that dynamically link to libmysqlclient will continue to work without any modifications.
Library libCsup is a C++ runtime library needed for yassl support when built with the hpux11 C/C++ compiler. The first attempts to fix this bug were to remove the yassl dependencies on libCsup. We tried removing all pure virtual functions and other hacks, but the dependency remained. The only other options left involve extensive restructuring of the yassl library.
- make ha_berkeley::cmp_ref() take into account that auto-generated PKs
are stored in LSB-first order.
- Remove the temporary code that made the bugfix work for innodb only
5.1.20 -> 5.1.21 upgrades.
We generate mysql_fix_privilege.sql file, which contains SQL
statements required to upgrade the system database. This script
is generated by concatenation of mysql_system_tables.sql and
mysql_system_tables_fix.sql.
The problem was that
- in order to create general_log and slow_log tables we use
stored programs in mysql_system_tables.sql;
- we upgrade mysql.proc table in mysql_system_tables_fix.sql;
So, if mysql.proc table needs to be upgraded, stored procedures
can not be used in mysql_system_tables.sql.
In other words, in mysql_system_tables.sql stored programs must
not be used because they may be unavailable at this point.
The fix is to use dynamic SQL instead of stored programs.
There is no test case for this bug because our test suite
is not suitable for such test cases. system_mysql_db_fix* test
cases play with the database "test". Here we need to modify
the system database and we can not do that in the test suite.
available and reduce the chance of failure. This should fix bug#28585
which is caused by the script being quite random in how it finds files it
requires and not giving very good feedback to the user about what went
wrong.
Also update make_binary_distribution so that it provides the correct path
to the required SQL scripts when generating mysql_install_db. The script
only previously worked because of the permissive behaviour which looked
around the current working directory before the "correct" location. This
could lead to severe problems if the user happened to run the script from
a location which contained older or even broken copies of the SQL scripts.
We now require either a complete binary release (and the mysql_install_db
script ran from inside the extracted archive), or an installed compiled
tree, as this is the only way we can be sure everything that we need is
available and ready to run.
While working on this fix, also clean up the mysql_install_db script a lot
to make it simpler, easier to read, and hopefully less prone to bugs in
the future.
to 150 or 107 characters for those messages which are generated
by the embedded server during release builds.
This fixes bug#16635:
Error messages wrong: absolute path names, "%s" format code
See the bug report or the changelog for "sql/share/english/errmsg.txt"
for instructions how to do that with other languages,
even at the customer site, and for the restrictions to keep.
the master but on the slave
MySQL can decide to "downgrade" a INSERT DELAYED statement
to normal insert in certain situations.
One such situation is when the slave is replaying a
replication feed.
However INSERT DELAYED is logged even if there're no updates
whereas the NORMAL INSERT is not logged in such cases.
Fixed by always logging a "downgraded" INSERT DELAYED: even
if there were no updates.
Problem: trying to repair an old (e.g. with "old" varstring fields) corrupted
table with use_frm option we don't actually repair the table, just altering it
which may couse data loss.
Fix: if use_frm repair option is set, do repair instead of altering even
if the table needs upgrade.
"log.cc:1448: failed assertion `mysql_bin_log.is_open() && rex_data->empty()'"
When Federated's transaction support was disabled by bug29875,
this assertion became unreproducable.
"Federated Denial of Service"
Federated storage engine used to attempt to open connections within
the ::create() and ::open() methods which are invoked while LOCK_open
mutex is being held by mysqld. As a result, no other client sessions
can open tables while Federated is attempting to open a connection.
Long DNS lookup times would stall mysqld's operation and a rogue
connection string which connects to a remote server which simply
stalls during handshake can stall mysqld for a much longer period of
time.
This patch moves the opening of the connection much later, when the
federated actually issues queries, by which time the LOCK_open mutex is
no longer being held.