(minus http://bazaar.launchpad.net/~codership/codership-mysql/5.6/revision/4122)

Reason for the problem was that the hash of changed files in the key cache was too small (was 128). Fixed by making the hash size larger and changeable.

- Introduced key-cache-file-hash-size (default 512) for MyISAM and aria_pagecache_file_hash_size (default 512) for Aria.
- Added new status variable "Feature_delay_key_write" which counts number of tables opened that are using delay_key_write


mysql-test/r/features.result:
  Added test of Feature_delay_key_write
mysql-test/r/key_cache.result:
  Updated tests as the number of blocks has changed
mysql-test/r/mysqld--help.result:
  Updated result
mysql-test/suite/maria/maria3.result:
  Updated result
mysql-test/suite/sys_vars/r/key_cache_file_hash_size_basic.result:
  Test new variable
mysql-test/suite/sys_vars/t/aria_pagecache_file_hash_size_basic.test:
  Test new variable
mysql-test/suite/sys_vars/t/key_cache_file_hash_size_basic.test:
  Test new variable
mysql-test/t/features.test:
  Added test of Feature_delay_key_write
mysql-test/t/key_cache.test:
  Updated tests as the number of blocks has changed
mysys/mf_keycache.c:
  Made CHANGED_BLOCKS_HASH dynamic
sql/handler.cc:
  Updated call to init_key_cache()
sql/mysqld.cc:
  Added "Feature_delay_key_write"
  Added support for key-cache-file-hash-size
sql/mysqld.h:
  Added support for key-cache-file-hash-size
sql/sql_class.h:
  Added feature_files_opened_with_delayed_keys
sql/sys_vars.cc:
  Added key_cache_file_hash_size
storage/maria/ha_maria.cc:
  Added pagecache_file_hash_size
  Added counting of files with delay_key_write
storage/maria/ma_checkpoint.c:
  Fixed compiler warning
storage/maria/ma_pagecache.c:
  Made PAGECACHE_CHANGED_BLOCKS_HASH into a variable
storage/maria/ma_pagecache.h:
  Made PAGECACHE_CHANGED_BLOCKS_HASH into a variable
storage/maria/ma_rt_test.c:
  Updated parameters for init_pagecache()
storage/maria/ma_test1.c:
  Updated parameters for init_pagecache()
storage/maria/ma_test2.c:
  Updated parameters for init_pagecache()
storage/maria/ma_test3.c:
  Updated parameters for init_pagecache()
storage/maria/maria_chk.c:
  Updated parameters for init_pagecache()
storage/maria/maria_ftdump.c:
  Updated parameters for init_pagecache()
storage/maria/maria_pack.c:
  Updated parameters for init_pagecache()
storage/maria/maria_read_log.c:
  Updated parameters for init_pagecache()
storage/maria/unittest/ma_pagecache_consist.c:
  Updated parameters for init_pagecache()
storage/maria/unittest/ma_pagecache_rwconsist.c:
  Updated parameters for init_pagecache()
storage/maria/unittest/ma_pagecache_rwconsist2.c:
  Updated parameters for init_pagecache()
storage/maria/unittest/ma_pagecache_single.c:
  Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler-t.c:
  Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_first_lsn-t.c:
  Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_max_lsn-t.c:
  Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_multigroup-t.c:
  Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_multithread-t.c:
  Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_noflush-t.c:
  Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_nologs-t.c:
  Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_pagecache-t.c:
  Updated parameters for init_pagecache()
storage/maria/unittest/ma_test_loghandler_purge-t.c:
  Updated parameters for init_pagecache()
storage/myisam/ha_myisam.cc:
  Added counting of files with delay_key_write
storage/myisam/mi_check.c:
  Updated call to init_key_cache()
storage/myisam/mi_test1.c:
  Updated call to init_key_cache()
storage/myisam/mi_test2.c:
  Updated call to init_key_cache()
storage/myisam/mi_test3.c:
  Updated call to init_key_cache()
storage/myisam/mi_test_all.sh:
  Fixed broken test
storage/myisam/myisam_ftdump.c:
  Updated call to init_key_cache()
storage/myisam/myisamchk.c:
  Updated call to init_key_cache()
storage/myisam/myisamlog.c:
  Updated call to init_key_cache()

Fixed assert in perfschema/pfs.cc::start_idle_wait_v1 when using performance schema and big packets in debug version.

The bug was that my_real_read() called net_before_header_psi() multiple times for long packets.
Fixed by adding a flag when we are reading a header.
Did also some cleanups to interface of my_net_read() to avoid unnecessary calls if performance schema is not used.

- Added my_net_read_packet() as a replacement for my_net_read(). my_net_read() is still in the client library for old clients.
- Removed THD->m_server_idle (not needed anymore as this is now given as argument to my_net_read_packet()
- Added my_net_read_packet(), which is a new version of my_net_read() with a new parameter if we are doing a read for a new command from the server.
- Added tests for compressed protocol and big packets





include/mysql.h.pp:
  Added my_net_read_packet() as a replacement for my_net_read()
include/mysql_com.h:
  Added my_net_read_packet() as a replacement for my_net_read()
mysql-test/r/mysql_client_test_comp.result:
  New test
mysql-test/t/mysql_client_test-master.opt:
  Added max_allowed_packet to be able to test big packets and packet size overflows.
mysql-test/t/mysql_client_test_comp-master.opt:
  New test
mysql-test/t/mysql_client_test_nonblock-master.opt:
  Added max_allowed_packet to be able to test big packets and packet size overflows.
sql-common/client.c:
  Use my_net_read_packet()
sql/mf_iocache.cc:
  Use my_net_read_packet()
sql/mysqld.cc:
  Removed THD->m_server_idle (not needed anymore as this is now given as argument to my_net_read_packet()
sql/net_serv.cc:
  Added argument to my_real_read() to indicte if we are reading the first block of the next statement and should call performance schema.
  Added 'compatibilty function' my_net_read().
  Added my_net_read_packet(), which is a new version of my_net_read() with a new parameter if we are doing a read for a new command from the server.
sql/sql_class.cc:
  Removed m_server_idle (not needed anymore)
sql/sql_class.h:
  Removed m_server_idle (not needed anymore)
sql/sql_parse.cc:
  Removed m_server_idle (not needed anymore)
tests/mysql_client_test.c:
  Added tests for compressed protocol and big packets

MDEV-5262, MDEV-5914, MDEV-5941, MDEV-6020: Deadlocks during parallel replication causing replication to fail.

After-review changes.

For this patch in 10.0, we do not introduce a new public storage engine API,
we just fix the InnoDB/XtraDB issues. In 10.1, we will make a better public
API that can be used for all storage engines (MDEV-6429).

Eliminate the background thread that did deadlock kills asynchroneously.
Instead, we ensure that the InnoDB/XtraDB code can handle doing the kill from
inside the deadlock detection code (when thd_report_wait_for() needs to kill a
later thread to resolve a deadlock).

(We preserve the part of the original patch that introduces dedicated mutex
and condition for the slave init thread, to remove the abuse of
LOCK_thread_count for start/stop synchronisation of the slave init thread).

- Add a Sort_priority_queue_sorts status variable.

replication causing replication to fail.

Remove the temporary fix for MDEV-5914, which used READ COMMITTED for parallel
replication worker threads. Replace it with a better, more selective solution.

The issue is with certain edge cases of InnoDB gap locks, for example between
INSERT and ranged DELETE. It is possible for the gap lock set by the DELETE to
block the INSERT, if the DELETE runs first, while the record lock set by
INSERT does not block the DELETE, if the INSERT runs first. This can cause a
conflict between the two in parallel replication on the slave even though they
ran without conflicts on the master.

With this patch, InnoDB will ask the server layer about the two involved
transactions before blocking on a gap lock. If the server layer tells InnoDB
that the transactions are already fixed wrt. commit order, as they are in
parallel replication, InnoDB will ignore the gap lock and allow the two
transactions to proceed in parallel, avoiding the conflict.

Improve the fix for MDEV-6020. When InnoDB itself detects a deadlock, it now
asks the server layer for any preferences about which transaction to roll
back. In case of parallel replication with two transactions T1 and T2 fixed to
commit T1 before T2, the server layer will ask InnoDB to roll back T2 as the
deadlock victim, not T1. This helps in some cases to avoid excessive deadlock
rollback, as T2 will in any case need to wait for T1 to complete before it can
itself commit.

Also some misc. fixes found during development and testing:

 - Remove thd_rpl_is_parallel(), it is not used or needed.

 - Use KILL_CONNECTION instead of KILL_QUERY when a parallel replication
   worker thread is killed to resolve a deadlock with fixed commit
   ordering. There are some cases, eg. in sql/sql_parse.cc, where a KILL_QUERY
   can be ignored if the query otherwise completed successfully, and this
   could cause the deadlock kill to be lost, so that the deadlock was not
   correctly resolved.

 - Fix random test failure due to missing wait_for_binlog_checkpoint.inc.

 - Make sure that deadlock or other temporary errors during parallel
   replication are not printed to the the error log; there were some places
   around the replication code with extra error logging. These conditions can
   occur occasionally and are handled automatically without breaking
   replication, so they should not pollute the error log.

 - Fix handling of rgi->gtid_sub_id. We need to be able to access this also at
   the end of a transaction, to be able to detect and resolve deadlocks due to
   commit ordering. But this value was also used as a flag to mark whether
   record_gtid() had been called, by being set to zero, losing the value. Now,
   introduce a separate flag rgi->gtid_pending, so rgi->gtid_sub_id remains
   valid for the entire duration of the transaction.

 - Fix one place where the code to handle ignored errors called reset_killed()
   unconditionally, even if no error was caught that should be ignored. This
   could cause loss of a deadlock kill signal, breaking deadlock detection and
   resolution.

 - Fix a couple of missing mysql_reset_thd_for_next_command(). This could
   cause a prior error condition to remain for the next event executed,
   causing assertions about errors already being set and possibly giving
   incorrect error handling for following event executions.

 - Fix code that cleared thd->rgi_slave in the parallel replication worker
   threads after each event execution; this caused the deadlock detection and
   handling code to not be able to correctly process the associated
   transactions as belonging to replication worker threads.

 - Remove useless error code in slave_background_kill_request().

 - Fix bug where wfc->wakeup_error was not cleared at
   wait_for_commit::unregister_wait_for_prior_commit(). This could cause the
   error condition to wrongly propagate to a later wait_for_prior_commit(),
   causing spurious ER_PRIOR_COMMIT_FAILED errors.

 - Do not put the binlog background thread into the processlist. It causes
   too many result differences in mtr, but also it probably is not useful
   for users to pollute the process list with a system thread that does not
   really perform any user-visible tasks...

replication causing replication to fail.

In parallel replication, we run transactions from the master in parallel, but
force them to commit in the same order they did on the master. If we force T1
to commit before T2, but T2 holds eg. a row lock that is needed by T1, we get
a deadlock when T2 waits until T1 has committed.

Usually, we do not run T1 and T2 in parallel if there is a chance that they
can have conflicting locks like this, but there are certain edge cases where
it can occasionally happen (eg. MDEV-5914, MDEV-5941, MDEV-6020). The bug was
that this would cause replication to hang, eventually getting a lock timeout
and causing the slave to stop with error.

With this patch, InnoDB will report back to the upper layer whenever a
transactions T1 is about to do a lock wait on T2. If T1 and T2 are parallel
replication transactions, and T2 needs to commit later than T1, we can thus
detect the deadlock; we then kill T2, setting a flag that causes it to catch
the kill and convert it to a deadlock error; this error will then cause T2 to
roll back and release its locks (so that T1 can commit), and later T2 will be
re-tried and eventually also committed.

The kill happens asynchroneously in a slave background thread; this is
necessary, as the reporting from InnoDB about lock waits happen deep inside
the locking code, at a point where it is not possible to directly call
THD::awake() due to mutexes held.

Deadlock is assumed to be (very) rarely occuring, so this patch tries to
minimise the performance impact on the normal case where no deadlocks occur,
rather than optimise the handling of the occasional deadlock.

Also fix transaction retry due to deadlock when it happens after a transaction
already signalled to later transactions that it started to commit. In this
case we need to undo this signalling (and later redo it when we commit again
during retry), so following transactions will not start too early.

Also add a missing thd->send_kill_message() that got triggered during testing
(this corrects an incorrect fix for MySQL Bug#58933).

The previous patch for this bug was unfortunately completely wrong.

The purpose of cached_charset is to remember which character set we
have installed currently in the THD, so that in the common case where
charset does not change between queries, we do not need to update it
in the THD. Thus, it is important that the cached_charset field is
tightly coupled to the THD for which it handles caching.

Thus the right place to put cached_charset seems to be in the THD.
This patch introduces a field THD:system_thread_info where such info
in general can be placed without further inflating the THD with unused
data for other threads (THD is already far too big as it is). It then
moves the cached_charset into this slot for the SQL driver thread and
for the parallel replication worker threads.

The THD::rpl_filter field is also moved inside system_thread_info, to
keep the size of THD unchanged. Moving further fields in to reduce the
size of THD is a separate task, filed as MDEV-6164.

Added a new system variable:
default_regex_flags='DOTALL,DUPNAMES,EXTENDED,EXTRA,MULTILINE,UNGREEDY'

remove dead code

Reason for the bug was an optimization for higher connect speed where we moved when global status was updated,
but forgot to update states when slave thread dies.
Fixed by adding thd->add_status_to_global() before deleting slave thread's thd.


mysys/my_delete.c:
  Added missing newline
sql/mysqld.cc:
  Use add_status_to_global()
sql/slave.cc:
  Added missing add_status_to_global()
sql/sql_class.cc:
  Use add_status_to_global()
sql/sql_class.h:
  Simplify adding local status to global by adding add_status_to_global()

mysql-test/r/create_or_replace.result:
  Added test of releasing of metadata locks
mysql-test/t/create_or_replace.test:
  Added test of releasing of metadata locks
sql/handler.h:
  Added marker if table was deleted as part of CREATE OR REPLACE
sql/sql_base.cc:
  Added Locked_tables_list::unlock_locked_table()
sql/sql_class.h:
  New prototypes
sql/sql_insert.cc:
  Unlock metadata locks for deleted table in case of error. Also do unlock tables if this was the only locked table.
sql/sql_table.cc:
  Unlock metadata locks for deleted table in case of error. Also do unlock tables if this was the only locked table.

    The fill_schema_table() function used to call get_table_share() for a table name in WHERE
    then clear the error list. That way plugins receive the superfluous error notification if it
    happens in it. Also the problem was that error handler didn't prevent the suppressed
    error message from logging anyway as the logging happens in THD::raise_condition
    before the handler call.
    Trigger_error_handler is remade into Warnings_only_error_handler, so it stores the error
    message in all cases in the thd->stmt_da.
    Then later the stored error is raised.

Clean up and improve the parallel implementation code, mainly related to
scheduling of work to threads and handling of stop and errors.

Fix a lot of bugs in various corner cases that could lead to crashes or
corruption.

Fix that a single replication domain could easily grab all worker threads and
stall all other domains; now a configuration variable
--slave-domain-parallel-threads allows to limit the number of
workers.

Allow next event group to start as soon as previous group begins the commit
phase (as opposed to when it ends it); this allows multiple event groups on
the slave to participate in group commit, even when no other opportunities for
parallelism are available.

Various fixes:

 - Fix some races in the rpl.rpl_parallel test case.

 - Fix an old incorrect assertion in Log_event iocache read.

 - Fix repeated malloc/free of wait_for_commit and rpl_group_info objects.

 - Simplify wait_for_commit wakeup logic.

 - Fix one case in queue_for_group_commit() where killing one thread would
   fail to correctly signal the error to the next, causing loss of the
   transaction after slave restart.

 - Fix leaking of pthreads (and their allocated stack) due to missing
   PTHREAD_CREATE_DETACHED attribute.

 - Fix how one batch of group-committed transactions wait for the previous
   batch before starting to execute themselves. The old code had a very
   complex scheduling where the first transaction was handled differently,
   with subtle bugs in corner cases. Now each event group is always scheduled
   for a new worker (in a round-robin fashion amongst available workers).
   Keep a count of how many transactions have started to commit, and wait for
   that counter to reach the appropriate value.

 - Fix slave stop to wait for all workers to actually complete processing;
   before, the wait was for update of last_committed_sub_id, which happens a
   bit earlier, and could leave worker threads potentially accessing bits of
   the replication state that is no longer valid after slave stop.

 - Fix a couple of places where the test suite would kill a thread waiting
   inside enter_cond() in connection with debug_sync; debug_sync + kill can
   crash in rare cases due to a race with mysys_var_current_mutex in this
   case.

 - Fix some corner cases where we had enter_cond() but no exit_cond().

 - Fix that we could get failure in wait_for_prior_commit() but forget to flag
   the error with my_error().

 - Fix slave stop (both for normal stop and stop due to error). Now, at stop
   we pick a specific safe point (in terms of event groups executed) and make
   sure that all event groups before that point are executed to completion,
   and that no event group after start executing; this ensures a safe place to
   restart replication, even for non-transactional stuff/DDL. In error stop,
   make sure that all prior event groups are allowed to execute to completion,
   and that any later event groups that have started are rolled back, if
   possible. The old code could leave eg. T1 and T3 committed but T2 not, or
   it could even leave half a transaction not rolled back in some random
   worker, which would cause big problems when that worker was later reused
   after slave restart.

 - Fix the accounting of amount of events queued for one worker. Before, the
   amount was reduced immediately as soon as the events were dequeued (which
   happens all at once); this allowed twice the amount of events to be queued
   in memory for each single worker, which is not what users would expect.

 - Fix that an error set during execution of one event was sometimes not
   cleared before executing the next, causing problems with the error
   reporting.

 - Fix incorrect handling of thd->killed in worker threads.

This is port of fix for MySQL BUG#17647863.

revno: 5572
revision-id: jon.hauglid@oracle.com-20131030232243-b0pw98oy72uka2sj
committer: Jon Olav Hauglid <jon.hauglid@oracle.com>
timestamp: Thu 2013-10-31 00:22:43 +0100
message:
  Bug#17647863: MYSQL DOES NOT COMPILE ON OSX 10.9 GM

  Rename test() macro to MY_TEST() to avoid conflict with libc++.

MASTER_GTID_WAIT() is similar to MASTER_POS_WAIT(), but works with a
GTID position rather than an old-style filename/offset.

@@LAST_GTID gives the GTID assigned to the last transaction written
into the binlog.

Together, the two can be used by applications to obtain the GTID of
an update on the master, and then do a MASTER_GTID_WAIT() for that
position on any read slave where it is important to get results that
are caught up with the master at least to the point of the update.

The implementation of MASTER_GTID_WAIT() is implemented in a way
that tries to minimise the performance impact on the SQL threads,
even in the presense of many waiters on single GTID positions (as
from @@LAST_GTID).

- CREATE TABLE is by default executed on the slave as CREATE OR REPLACE
- DROP TABLE is by default executed on the slave as DROP TABLE IF NOT EXISTS

This means that a slave will by default continue even if we try to create
a table that existed on the slave (the table will be deleted and re-created) or
if we try to drop a table that didn't exist on the slave.
This should be safe as instead of having the slave stop because of an inconsistency between
master and slave, it will fix the inconsistency.
Those that would prefer to get a stopped slave instead for the above cases can set slave_ddl_exec_mode to STRICT. 

- Ensure that a CREATE OR REPLACE TABLE which dropped a table is replicated
- DROP TABLE that generated an error on master is handled as an identical DROP TABLE on the slave (IF NOT EXISTS is not added in this case)
- Added slave_ddl_exec_mode variable to decide how DDL's are replicated

New logic for handling BEGIN GTID ... COMMIT from the binary log:

- When we find a BEGIN GTID, we start a transaction and set OPTION_GTID_BEGIN
- When we find COMMIT, we reset OPTION_GTID_BEGIN and execute the normal COMMIT code.
- While OPTION_GTID_BEGIN is set:
  - We don't generate implict commits before or after statements
  - All tables are regarded as transactional tables in the binary log (to ensure things are executed exactly as on the master)
- We reset OPTION_GTID_BEGIN also on rollback

This will help ensuring that we don't get any sporadic commits (and thus new GTID's) on the slave and will help keep the GTID's between master and slave in sync.


mysql-test/extra/rpl_tests/rpl_log.test:
  Added testing of mode slave_ddl_exec_mode=STRICT
mysql-test/r/mysqld--help.result:
  New help messages
mysql-test/suite/rpl/r/create_or_replace_mix.result:
  Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/r/create_or_replace_row.result:
  Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/r/create_or_replace_statement.result:
  Testing replication of create or replace
mysql-test/suite/rpl/r/rpl_gtid_startpos.result:
  Test must be run in slave_ddl_exec_mode=STRICT as part of the test depends on that DROP TABLE should fail on slave.
mysql-test/suite/rpl/r/rpl_row_log.result:
  Updated result
mysql-test/suite/rpl/r/rpl_row_log_innodb.result:
  Updated result
mysql-test/suite/rpl/r/rpl_row_show_relaylog_events.result:
  Updated result
mysql-test/suite/rpl/r/rpl_stm_log.result:
  Updated result
mysql-test/suite/rpl/r/rpl_stm_mix_show_relaylog_events.result:
  Updated result
mysql-test/suite/rpl/r/rpl_temp_table_mix_row.result:
  Updated result
mysql-test/suite/rpl/t/create_or_replace.inc:
  Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/create_or_replace_mix.cnf:
  Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/create_or_replace_mix.test:
  Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/create_or_replace_row.cnf:
  Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/create_or_replace_row.test:
  Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/create_or_replace_statement.cnf:
  Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/create_or_replace_statement.test:
  Testing of CREATE OR REPLACE TABLE with replication
mysql-test/suite/rpl/t/rpl_gtid_startpos.test:
  Test must be run in slave_ddl_exec_mode=STRICT as part of the test depends on that DROP TABLE should fail on slave.
mysql-test/suite/rpl/t/rpl_stm_log.test:
  Removed some lines
mysql-test/suite/sys_vars/r/slave_ddl_exec_mode_basic.result:
  Testing of slave_ddl_exec_mode
mysql-test/suite/sys_vars/t/slave_ddl_exec_mode_basic.test:
  Testing of slave_ddl_exec_mode
sql/handler.cc:
  Regard all tables as transactional in commit if OPTION_GTID_BEGIN is set.
  This is to ensure that statments are not commited too early if non transactional tables are used.
sql/log.cc:
  Regard all tables as transactional in commit if OPTION_GTID_BEGIN is set.
  Also treat 'direct' log events as transactional (to get them logged as they where on the master)
sql/log_event.cc:
  Ensure that the new error from DROP TABLE when trying to drop a view is treated same as the old one.
  Store error code that slave expects in THD.
  Set OPTION_GTID_BEGIN if we find a BEGIN.
  Reset OPTION_GTID_BEGIN if we find a COMMIT.
sql/mysqld.cc:
  Added slave_ddl_exec_mode_options
sql/mysqld.h:
  Added slave_ddl_exec_mode_options
sql/rpl_gtid.cc:
  Reset OPTION_GTID_BEGIN if we record a gtid (safety)
sql/sql_class.cc:
  Regard all tables as transactional in commit if OPTION_GTID_BEGIN is set.
sql/sql_class.h:
  Added to THD: log_current_statement and slave_expected_error
sql/sql_insert.cc:
  Ensure that CREATE OR REPLACE is logged if table was deleted.
  Don't do implicit commit for CREATE if we are under OPTION_GTID_BEGIN
sql/sql_parse.cc:
  Change CREATE TABLE -> CREATE OR REPLACE TABLE for slaves
  Change DROP TABLE -> DROP TABLE IF EXISTS for slaves
  CREATE TABLE doesn't force implicit commit in case of OPTION_GTID_BEGIN
  Don't do commits before or after any statement if OPTION_GTID_BEGIN was set.
sql/sql_priv.h:
  Added OPTION_GTID_BEGIN
sql/sql_show.cc:
  Enhanced store_create_info() to also be able to handle CREATE OR REPLACE
sql/sql_show.h:
  Updated prototype
sql/sql_table.cc:
  Ensure that CREATE OR REPLACE is logged if table was deleted.
sql/sys_vars.cc:
  Added slave_ddl_exec_mode
sql/transaction.cc:
  Added warning if we got a GTID under OPTION_GTID_BEGIN

Using CREATE OR REPLACE TABLE is be identical to

DROP TABLE IF EXISTS table_name;
CREATE TABLE ...;

Except that:

* CREATE OR REPLACE is be atomic (now one can create the same table between drop and create).
* Temporary tables will not shadow the table name for the DROP as the CREATE TABLE tells us already if we are using a temporary table or not.
* If the table was locked with LOCK TABLES, the new table will be locked with the same lock after it's created.

Implementation details:
- We don't anymore open the to-be-created table during CREATE TABLE, which the original code did.
  - There is no need to open a table we are planning to create. It's enough to check if the table exists or not.
- Removed some of duplicated code for CREATE IF NOT EXISTS.
- Give an error when using CREATE OR REPLACE with IF NOT EXISTS (conflicting options).
- As a side effect of the code changes, we don't anymore have to internally re-prepare prepared statements with CREATE TABLE if the table exists.
- Made one code path for all testing if log table are in use.
- Better error message if one tries to create/drop/alter a log table in use
- Added back disabled rpl_row_create_table test as it now seams to work and includes a lot of interesting tests.
- Added HA_LEX_CREATE_REPLACE to mark if we are using CREATE OR REPLACE
- Aligned CREATE OR REPLACE parsing code in sql_yacc.yy for TABLE and VIEW
- Changed interface for drop_temporary_table() to make it more reusable
- Changed Locked_tables_list::init_locked_tables() to work on the table object instead of the table list object. Before this it used a mix of both, which was not good.
- Locked_tables_list::unlock_locked_tables(THD *thd) now requires a valid thd argument. Old usage of calling this with 0 i changed to instead call Locked_tables_list::reset()
- Added functions Locked_tables_list:restore_lock() and Locked_tables_list::add_back_last_deleted_lock() to be able to easily add back a locked table to the lock list.
- Added restart_trans_for_tables() to be able to restart a transaction.
- DROP_ACL is required if one uses CREATE TABLE OR REPLACE.
- Added drop of normal and temporary tables in create_table_imp() if CREATE OR REPLACE was used.
- Added reacquiring of table locks in mysql_create_table() and mysql_create_like_table()




mysql-test/include/commit.inc:
  With new code we get fewer status increments
mysql-test/r/commit_1innodb.result:
  With new code we get fewer status increments
mysql-test/r/create.result:
  Added testing of create or replace with timeout
mysql-test/r/create_or_replace.result:
  Basic testing of CREATE OR REPLACE TABLE
mysql-test/r/partition_exchange.result:
  New error message
mysql-test/r/ps_ddl.result:
  Fewer reprepares with new code
mysql-test/suite/archive/discover.result:
  Don't rediscover archive tables if the .frm file exists
  (Sergei will look at this if there is a better way...)
mysql-test/suite/archive/discover.test:
  Don't rediscover archive tables if the .frm file exists
  (Sergei will look at this if there is a better way...)
mysql-test/suite/funcs_1/r/innodb_views.result:
  New error message
mysql-test/suite/funcs_1/r/memory_views.result:
  New error message
mysql-test/suite/rpl/disabled.def:
  rpl_row_create_table should now be safe to use
mysql-test/suite/rpl/r/rpl_row_create_table.result:
  Updated results after adding back disabled test
mysql-test/suite/rpl/t/rpl_create_if_not_exists.test:
  Added comment
mysql-test/suite/rpl/t/rpl_row_create_table.test:
  Added CREATE OR REPLACE TABLE test
mysql-test/t/create.test:
  Added CREATE OR REPLACE TABLE test
mysql-test/t/create_or_replace-master.opt:
  Create logs
mysql-test/t/create_or_replace.test:
  Basic testing of CREATE OR REPLACE TABLE
mysql-test/t/partition_exchange.test:
  Error number changed as we are now using same code for all log table change issues
mysql-test/t/ps_ddl.test:
  Fewer reprepares with new code
sql/handler.h:
  Moved things around a bit in a structure to get better alignment.
  Added HA_LEX_CREATE_REPLACE to mark if we are using CREATE OR REPLACE
  Added 3 elements to end of HA_CREATE_INFO to be able to store state to add backs locks in case of LOCK TABLES.
sql/log.cc:
  Reimplemented check_if_log_table():
  - Simpler and faster usage
  - Can give error messages
  
  This gives us one code path for allmost all error messages if log tables are in use
sql/log.h:
  New interface for check_if_log_table()
sql/slave.cc:
  More logging
sql/sql_alter.cc:
  New interface for check_if_log_table()
sql/sql_base.cc:
  More documentation
  Changed interface for drop_temporary_table() to make it more reusable
  Changed Locked_tables_list::init_locked_tables() to work on the table object instead of the table list object. Before this it used a mix of both, which was not good.
  Locked_tables_list::unlock_locked_tables(THD *thd) now requires a valid thd argument.  Old usage of calling this with 0 i changed to instead call Locked_tables_list::reset()
  Added functions Locked_tables_list:restore_lock() and Locked_tables_list::add_back_last_deleted_lock() to be able to easily add back a locked table to the lock list.
  Check for command number instead of open_strategy of CREATE TABLE was used.
  Added restart_trans_for_tables() to be able to restart a transaction.  This was needed in "create or replace ... select" between the drop table and the select.
sql/sql_base.h:
  Added and updated function prototypes
sql/sql_class.h:
  Added new prototypes to Locked_tables_list class
  Added extra argument to select_create to avoid double call to eof() or send_error()
  - I needed this in some edge case where the table was not created against expections.
sql/sql_db.cc:
  New interface for check_if_log_table()
sql/sql_insert.cc:
  Remember position to lock information so that we can reaquire table lock for LOCK TABLES + CREATE OR REPLACE TABLE SELECT. Later add back the lock by calling restore_lock().
  Removed one not needed indentation level in create_table_from_items()
  Ensure we don't call send_eof() or abort_result_set() twice.
sql/sql_lex.h:
  Removed variable that I temporarly added in an earlier changeset
sql/sql_parse.cc:
  Removed old test code (marked with QQ)
  Ensure that we have open_strategy set as TABLE_LIST::OPEN_STUB in CREATE TABLE
  Removed some IF NOT EXISTS code as this is now handled in create_table_table_impl().
  Set OPTION_KEEP_LOGS later. This code had to be moved as the test for IF EXISTS has changed place.
  DROP_ACL is required if one uses CREATE TABLE OR REPLACE.
sql/sql_partition_admin.cc:
  New interface for check_if_log_table()
sql/sql_rename.cc:
  New interface for check_if_log_table()
sql/sql_table.cc:
  New interface for check_if_log_table()
  Moved some code in mysql_rm_table() under a common test.
  - Safe as temporary tables doesn't have statistics.
  - !is_temporary_table(table) test was moved out from drop_temporary_table() and merged with upper level code.
  - Added drop of normal and temporary tables in create_table_imp() if CREATE OR REPLACE was used.
  - Added reacquiring of table locks in mysql_create_table() and mysql_create_like_table()
  - In mysql_create_like_table(), restore table->open_strategy() if it was changed.
  - Re-test if table was a view after opening it.
sql/sql_table.h:
  New prototype for mysql_create_table_no_lock()
sql/sql_yacc.yy:
  Added syntax for CREATE OR REPLACE TABLE
  Reuse new code for CREATE OR REPLACE VIEW
sql/table.h:
  Added name for enum type
sql/table_cache.cc:
  More DBUG

Added variable "OLD_MODE" that can be used to turn off the new behavior

mysql-test/r/insert.result:
  Added test case
mysql-test/r/mysqld--help.result:
  Added old_mode
mysql-test/suite/sys_vars/r/old_mode_basic.result:
  Added testing of new variable
mysql-test/suite/sys_vars/t/old_mode_basic.test:
  Added testing of new variable
mysql-test/t/insert.test:
  Added test case
sql/sql_class.h:
  Added bit flags for OLD_MODE
sql/sql_insert.cc:
  Disable duplicate key warnings for INSERT IGNORE of OLD_MODE NO_DUP_KEY_WARNINGS_WITH_IGNORE is used
sql/sql_show.cc:
  Don't show progress reporting on SHOW PROCESSLIST if OLD_MODE NO_PROGRESS_INFO is used
sql/sys_vars.cc:
  Added OLD_MODE

This is a backport of the patch of bug#11765785. Commit message
by Prabakaran Thirumalai from bug#11765785 is reproduced below:
Description:
------------
Global Query ID (global_query_id ) is not incremented for PING and 
statistics command. These two query types are filtered before 
incrementing the global query id. This causes race condition and 
results in duplicate query id for different queries originating from 
different connections.
      
Analysis:
---------
sqlparse.cc::dispath_command() is the only place in code which sets 
thd->query_ id to global_query_id and then increments it based on the 
query type. In all other places it is incremented first and then 
assigned to thd->query_id.
      
This is done such that global_query_id is not incremented for PING 
and statistics commands in dispatch_command() function.
      
Fix:
----
As per suggestion from Serg, "There is no reason to skip query_id for 
the PING and STATISTICS command.", removing the check which filters 
PING and statistics commands.
      
Instead of using get_query_id() and next_query_id() which can still 
cause race condition if context switch happens soon after executing 
get_query_id(), changing the code to use next_query_id() instead of 
get_query_id() as it is done in other parts of code which deals with 
global_query_id.
      
Removed get_query_id() function and forced next_query_id() caller 
to use the return value by specifying warn_unused_result attribute.

Add a test case for killing a waiting query in parallel replication.

Fix several bugs found:

 - We should not wakeup_subsequent_commits() in ha_rollback_trans(), since we
   do not know the right wakeup_error() to give.

 - When a wait_for_prior_commit() is killed, we must unregister from the
   waitee so we do not race and get an extra (non-kill) wakeup.

 - We need to deal with error propagation correctly in queue_for_group_commit
   when one thread is killed.

 - Fix one locking issue in queue_for_group_commit(), we could unlock the
   waitee lock too early and this end up processing wakeup() with insufficient
   locking.

 - Fix Xid_log_event::do_apply_event; if commit fails it must not update the
   in-memory @@gtid_slave_pos state.

 - Fix and cleanup some things in the rpl_parallel.cc error handling.

 - Add a missing check for killed in the slave sql driver thread, to avoid a
   race.

Make wait_for_prior_commit killable, and handle the error if
killed.

This is now otherwise on level wsrep-25.9, but storage/innobase has not been fully merged
wsrep-5.5 is not good source for that, so we probably have to cherry pick innodb changes from wsrep-5.6

This is just before 5.5.34 merge in wsrep-5.5 branch

(and valgrind warnings)

* move thd userstat initialization to the same function
  that was adding thd userstat to global counters.
* initialize thd->start_bytes_received in THD::init
  (when thd->userstat_running is set)

get_cost_calc_buff_size() could return wrong value for the size of imerge_cost_buff.

the current user via the current security_context

- Fix a problem with EXPLAIN multi_table UPDATE: 
  = Do use multi_update object, because multi_update::prepare() does
    various setup, e.g. it disables index-only for the tables to be updated.
  = Protect multi_update::prepare() from being invoked multiple times. 
    If the query has subqueries, they may try to invoke it, for some reason.

Add an error code to the wait_for_commit facility.

Now, when a transaction fails, it can signal the error to
any subsequent transaction that is waiting for it to commit.
The waiting transactions then receive the error code back from
wait_for_prior_commit() and can handle the error appropriately.

Also fix one race that could cause crash if @@slave_parallel_threads
were changed several times quickly in succession.

- Made slaves temporary table multi-thread slave safe by adding mutex around save_temporary_table usage.
  - rli->save_temporary_tables is the active list of all used temporary tables
  - This is copied to THD->temporary_tables when temporary tables are opened and updated when temporary tables are closed
  - Added THD->lock_temporary_tables() and THD->unlock_temporary_tables() to simplify this.
- Relay_log_info->sql_thd renamed to Relay_log_info->sql_driver_thd to avoid wrong usage for merged code.
- Added is_part_of_group() to mark functions that are part of the next function. This replaces setting IN_STMT when events are executed.
- Added is_begin(), is_commit() and is_rollback() functions to Query_log_event to simplify code.
- If slave_skip_counter is set run things in single threaded mode. This simplifies code for skipping events.
- Updating state of relay log (IN_STMT and IN_TRANSACTION) is moved to one single function: update_state_of_relay_log()
  We can't use OPTION_BEGIN to check for the state anymore as the sql_driver and sql execution threads may be different.
  Clear IN_STMT and IN_TRANSACTION in init_relay_log_pos() and Relay_log_info::cleanup_context() to ensure the flags doesn't survive slave restarts
  is_in_group() is now independent of state of executed transaction.
- Reset thd->transaction.all.modified_non_trans_table() if we did set it for single table row events.
  This was mainly for keeping the flag as documented.
- Changed slave_open_temp_tables to uint32 to be able to use atomic operators on it.
- Relay_log_info::sleep_lock -> rpl_group_info::sleep_lock
- Relay_log_info::sleep_cond -> rpl_group_info::sleep_cond
- Changed some functions to take rpl_group_info instead of Relay_log_info to make them multi-slave safe and to simplify usage
  - do_shall_skip()
  - continue_group()
  - sql_slave_killed()
  - next_event()
- Simplifed arguments to io_salve_killed(), check_io_slave_killed() and sql_slave_killed(); No reason to supply THD as this is part of the given structure.
- set_thd_in_use_temporary_tables() removed as in_use is set on usage
- Added information to thd_proc_info() which thread is waiting for slave mutex to exit.
- In open_table() reuse code from find_temporary_table()

Other things:
- More DBUG statements
- Fixed the rpl_incident.test can be run with --debug
- More comments
- Disabled not used function rpl_connect_master()

mysql-test/suite/perfschema/r/all_instances.result:
  Moved sleep_lock and sleep_cond to rpl_group_info
mysql-test/suite/rpl/r/rpl_incident.result:
  Updated result
mysql-test/suite/rpl/t/rpl_incident-master.opt:
  Not needed anymore
mysql-test/suite/rpl/t/rpl_incident.test:
  Fixed that test can be run with --debug
sql/handler.cc:
  More DBUG_PRINT
sql/log.cc:
  More comments
sql/log_event.cc:
  Added DBUG statements
  do_shall_skip(), continue_group() now takes rpl_group_info param
  Use is_begin(), is_commit() and is_rollback() functions instead of inspecting query string
  We don't have set slaves temporary tables 'in_use' as this is now done when tables are opened.
  Removed IN_STMT flag setting. This is now done in update_state_of_relay_log()
  Use IN_TRANSACTION flag to test state of relay log.
  In rows_event_stmt_cleanup() reset thd->transaction.all.modified_non_trans_table if we had set this before.
sql/log_event.h:
  do_shall_skip(), continue_group() now takes rpl_group_info param
  Added is_part_of_group() to mark events that are part of the next event. This replaces setting IN_STMT when events are executed.
  Added is_begin(), is_commit() and is_rollback() functions to Query_log_event to simplify code.
sql/log_event_old.cc:
  Removed IN_STMT flag setting. This is now done in update_state_of_relay_log()
  do_shall_skip(), continue_group() now takes rpl_group_info param
sql/log_event_old.h:
  Added is_part_of_group() to mark events that are part of the next event.
  do_shall_skip(), continue_group() now takes rpl_group_info param
sql/mysqld.cc:
  Changed slave_open_temp_tables to uint32 to be able to use atomic operators on it.
  Relay_log_info::sleep_lock -> Rpl_group_info::sleep_lock
  Relay_log_info::sleep_cond -> Rpl_group_info::sleep_cond
sql/mysqld.h:
  Updated types and names
sql/rpl_gtid.cc:
  More DBUG
sql/rpl_parallel.cc:
  Updated TODO section
  Set thd for event that is execution
  Use new  is_begin(), is_commit() and is_rollback() functions.
  More comments
sql/rpl_rli.cc:
  sql_thd -> sql_driver_thd
  Relay_log_info::sleep_lock -> rpl_group_info::sleep_lock
  Relay_log_info::sleep_cond -> rpl_group_info::sleep_cond
  Clear IN_STMT and IN_TRANSACTION in init_relay_log_pos() and Relay_log_info::cleanup_context() to ensure the flags doesn't survive slave restarts.
  Reset table->in_use for temporary tables as the table may have been used by another THD.
  Use IN_TRANSACTION instead of OPTION_BEGIN to check state of relay log.
  Removed IN_STMT flag setting. This is now done in update_state_of_relay_log()
sql/rpl_rli.h:
  Changed relay log state flags to bit masks instead of bit positions (most other code we have uses bit masks)
  Added IN_TRANSACTION to mark if we are in a BEGIN ... COMMIT section.
  save_temporary_tables is now thread safe
  Relay_log_info::sleep_lock -> rpl_group_info::sleep_lock
  Relay_log_info::sleep_cond -> rpl_group_info::sleep_cond
  Relay_log_info->sql_thd renamed to Relay_log_info->sql_driver_thd to avoid wrong usage for merged code
  is_in_group() is now independent of state of executed transaction.
sql/slave.cc:
  Simplifed arguments to io_salve_killed(), sql_slave_killed() and check_io_slave_killed(); No reason to supply THD as this is part of the given structure.
  set_thd_in_use_temporary_tables() removed as in_use is set on usage in sql_base.cc
  sql_thd -> sql_driver_thd
  More DBUG
  Added update_state_of_relay_log() which will calculate the IN_STMT and IN_TRANSACTION state of the relay log after the current element is executed.
  If slave_skip_counter is set run things in single threaded mode.
  Simplifed arguments to io_salve_killed(), check_io_slave_killed() and sql_slave_killed(); No reason to supply THD as this is part of the given structure.
  Added information to thd_proc_info() which thread is waiting for slave mutex to exit.
  Disabled not used function rpl_connect_master()
  Updated argument to next_event()
sql/sql_base.cc:
  Added mutex around usage of slave's temporary tables. The active list is always kept up to date in sql->rgi_slave->save_temporary_tables.
  Clear thd->temporary_tables after query (safety)
  More DBUG
  When using temporary table, set table->in_use to current thd as the THD may be different for slave threads.
  Some code is ifdef:ed with REMOVE_AFTER_MERGE_WITH_10 as the given code in 10.0 is not yet in this tree.
  In open_table() reuse code from find_temporary_table()
sql/sql_binlog.cc:
  rli->sql_thd -> rli->sql_driver_thd
  Remove duplicate setting of rgi->rli
sql/sql_class.cc:
  Added helper functions rgi_lock_temporary_tables() and rgi_unlock_temporary_tables()
  Would have been nicer to have these inline, but there was no easy way to do that
sql/sql_class.h:
  Added functions to protect slaves temporary tables
sql/sql_parse.cc:
  Added DBUG_PRINT
sql/transaction.cc:
  Added comment

Merging the following MySQL-5.6 changes:
- WL#5624: Collation customization improvements
  http://dev.mysql.com/worklog/task/?id=5624

- WL#4013: Unicode german2 collation
  http://dev.mysql.com/worklog/task/?id=4013

- Bug#62429 XML: ExtractValue, UpdateXML max arg length 127 chars
  http://bugs.mysql.com/bug.php?id=62429
  (required by WL#5624)

- Initial implementation. 

It is now possible to kill query by query id. KILL syntax was extended to:
KILL [HARD | SOFT] [CONNECTION | QUERY [ID query_id]] [thread_id | USER user_name]

Added QUERY_ID column to INFORMATION_SCHEMA.PROCESSLIST.

Fixed tests affected by this change:
- added PROCESSLIST.QUERY_ID column
- ID is now keyword and is quoted in SHOW CREATE TABLE output
- PFS statement digest is calculated basing on token id
  (not token text). Token id has shifted for keywords residing
  after ID in keywords array.

Some after-review fixes.