The bug occurs when a transaction does a retry after all transactions have
done mark_start_commit() in a batch of group commit from the master. In this
case, the retrying transaction can unmark_start_commit() after the following
batch has already started running and de-allocated the GCO. Then after retry,
the transaction will re-do mark_start_commit() on a de-allocated GCO, and also
wakeup of later GCOs can be lost.
This was seen "in the wild" by a user, even though it is not known exactly
what circumstances can lead to retry of one transaction after all transactions
in a group have reached the commit phase.
The lifetime around GCO was somewhat clunky anyway. With this patch, a GCO
lives until rpl_parallel_entry::last_committed_sub_id has reached the last
transaction in the GCO. This guarantees that the GCO will still be alive when
a transaction does mark_start_commit(). Also, we now loop over the list of
active GCOs for wakeup, to ensure we do not lose a wakeup even in the
problematic case.
The test case tried to trigger a DEBUG_SYNC point at the end of a SELECT
SLEEP(5) statement. It did this by using EXECUTE 2, intending to trigger first
at the end of SET DEBUG_SYNC, and second at the end of the SELECT SLEEP(5).
However, in --ps-protocol mode, this does not work, because the SELECT is
executed in two steps (Prepare followed by Execute). Thus, the DEBUG_SYNC got
triggered too early, during the Prepare stage rather than Execute, and the
test case could race and information_schema.processlist see the thread in the
wrong state.
This patch fixes by changing the way the DEBUG_SYNC point is triggered. Now we
add a DBUG injection inside the code for SLEEP(5). This ensures that the
DEBUG_SYNC point is not activated until the SLEEP(5) is running, ensuring
that the following wait for completion will be effective.
Analysis: For some reason actual thread handle is not
returned on Windows instead lpThreadId was returned and
thread handle was closed after thread create. Later
CloseHandle was called for recv_writer_thread_handle
and psort_info->thread_hdl.
Fix: Return thread handle from os_thread_create()
also on Windows and store these thread handles also
in srv0start.cc so that they can be later closed.
tables. This should fix bug MDEV-7343.
modified:
storage/connect/ha_connect.cc
storage/connect/myconn.cpp
storage/connect/myconn.h
storage/connect/reldef.cpp
storage/connect/reldef.h
storage/connect/table.cpp
storage/connect/tabmysql.cpp
storage/connect/xtable.h
- Prevent double column evaluation when CONNECT does filtering
modified:
storage/connect/connect.cc
- Export CreateFileMap and CloseMemMap (for OEM tables)
modified:
storage/connect/maputil.h
- Add the compute function to be used on VALUE types.
Preserve precision for DOUBLE values.
modified:
storage/connect/value.cpp
storage/connect/value.h
- Typo (in preparation to the future JSON table type)
modified:
storage/connect/ha_connect.cc
storage/connect/mycat.cc
storage/connect/plgdbsem.h
Use include/sync_with_master_gtid.inc instead of --sync_with_master to avoid a
race in the test case.
In parallel replication, the old-style slave position (which is used by
--sync_with_master) is updated out-of-order between parallel threads. This
makes it possible for the position to be updated past DROP TEMPORARY TABLE t2
just before the commit of INSERT INTO t1 SELECT * FROM t2 becomes visible.
In this case, there is a small window where a SELECT just after
--sync_with_master may not see the changes from the INSERT.
Fix:
===
Backport Bug#11756194 to mysql-5.5. slave breaks if
'drop database' fails on master and mismatched tables on
slave.
'DROP TABLE <deleted tables>' was binlogged when
'DROP DATABASE' failed and at least one table was deleted
from the database. The log event would lead slave SQL thread
stop if some of the tables did not exist on slave.
After this patch, It is always binlogged with 'IF EXISTS'
option.
CRASHES ON EVERY START ATTEMPT
Description:
------------
push_warning_printf function is used to print the warning message
to the client. So this function should not invoke while recovering
the server. Moreover current_thd is NULL while starting the server.
Solution:
---------
- Avoiding the warning to be printed while recovery.
This patch already pushed in mysql-5.6.
generate_derived_keys_for_table() did not work correctly in the case where
- it had a potential index on derived table
- however, TABLE::check_tmp_key() would disallow creation of this index
after looking at its future key parts (because of the key parts exceeding
max. index length)
- the code would leave a KEYUSE structure that refers to a non-existant index.
Depending on further optimizer calculations, this could cause a crash.
