MDL_lock::find_deadlock".
On some platforms deadlock detector in metadata locking
subsystem under certain conditions might have exhausted
stack space causing server crashes.
Particularly this caused failures of rqg_mdl_stability
test on Solaris in PushBuild.
During search for deadlock MDL deadlock detector could
sometimes encounter loop in the waiters graph in which
MDL_context which has started search for a deadlock
does not participate. In such case our algorithm will
continue looping assuming that either this deadlock will
be resolved by MDL_context which has created it (i.e.
by one of loop participants) or maximum search depth
will be reached.
Since max search depth was set to 1000 in the latter case
on platforms where each iteration of deadlock search
algorithm needs more than DEFAULT_STACK_SIZE/1000 bytes
of stack (around 192 bytes for 32-bit and around 256 bytes
for 64-bit platforms) we might have exhausted stack space.
This patch solves this problem by reducing maximum search
depth for MDL deadlock detector to 32. This should be safe
at the moment as it is unlikely that each iteration of the
current deadlock detector algorithm will consume more than
1K of stack (thus total amount of stack required can't be
more than 32K) and we require at least 80K of stack in order
to open any table. Also this value should be (hopefully) big
enough to not cause too much false deadlock errors (there
is an anecdotal evidence that real-life deadlocks are
typically shorter than that).
Additional reasearch should be conducted in future in order
to determine the more optimal value of maximum search depth.
This patch does not include test case as existing
rqg_mdl_stability test can serve as one.
TEMPORARY + HANDLER + LOCK + SP".
Server crashed when one:
1) Opened HANDLER or acquired global read lock
2) Then locked one or several temporary tables with
LOCK TABLES statement (but no base tables).
3) Then issued any statement causing commit (explicit
or implicit).
4) Issued statement which should have closed HANDLER
or released global read lock.
The problem was that when entering LOCK TABLES mode in the
scenario described above we incorrectly set transactional
MDL sentinel to zero. As result during commit all metadata
locks were released (including lock for open HANDLER or
global metadata shared lock). Indeed, attempt to release
metadata lock for the second time which happened during
HANLDER CLOSE or during release of GLR caused crash.
This patch fixes problem by changing MDL_context's
set_trans_sentinel() method to set sentinel to correct
value (it should point to the most recent ticket).
DDL workload".
When a RENAME TABLE or LOCK TABLE ... WRITE statement which
mentioned the same table several times were aborted during
the process of acquring metadata locks (due to deadlock
which was discovered or because of KILL statement) server
might have crashed.
When attempt to acquire all locks requested had failed we
went through the list of requests and released locks which
we have managed to acquire by that moment one by one. Since
in the scenario described above list of requests contained
duplicates this led to releasing the same ticket twice and
a crash as result.
This patch solves the problem by employing different approach
to releasing locks in case of failure to acquire all locks
requested.
Now we take a MDL savepoint before starting acquiring locks
and simply rollback to it if things go bad.
In POSIX systems, the file descriptor set used in the select(2)
system call is represented by a bit vector of size FD_SETSIZE.
When select(2) is used on file/socket descriptors with a value
that is beyond this size, unpredictable errors may occur.
In this case, the error happens when there are a large number
of tables that need repair. These tables are opened before
the sockets for incoming connections are acquired, resulting
in these sockets getting descriptor id which is higher than
FD_SETSIZE.
Replacing the call to select(2) with poll(2) fixes the problem,
as poll takes an array of the wanted descriptors, instead of
a bit vector.
MS Windows has a different implementation of 'select', and is not
affected by this bug.
function with distinct.
Loose index scan is used to find MIN/MAX values using appropriate index and
thus allow to avoid grouping. For each found row it updates non-aggregated
fields with values from row with found MIN/MAX value.
Without loose index scan non-aggregated fields are copied by end_send_group
function. With loose index scan there is no need in end_send_group and
end_send is used instead. Non-aggregated fields still need to be copied and
this was wrongly implemented in QUICK_GROUP_MIN_MAX_SELECT::get_next.
WL#3220 added a case when loose index scan can be used with end_send_group to
optimize calculation of aggregate functions with distinct. In this case
the row found by QUICK_GROUP_MIN_MAX_SELECT::get_next might belong to a next
group and copying it will produce wrong result.
Update of non-aggregated fields is moved to the end_send function from
QUICK_GROUP_MIN_MAX_SELECT::get_next.
failed in enter_locked_tables_mode".
Server was aborted due to assertion failure when one tried to
execute statement requiring prelocking (i.e. firing triggers
or using stored functions) while having open HANDLERs.
The problem was that THD::enter_locked_tables_mode() method
which was called at the beginning of execution of prelocked
statement assumed there are no open HANDLERs. It had to do
so because corresponding THD::leave_locked_tables_mode()
method was unable to properly restore MDL sentinel when
leaving LOCK TABLES/prelocked mode in the presence of open
HANDLERs.
This patch solves this problem by changing the latter method
to properly restore MDL sentinel and thus removing need for
this assumption. As a side-effect, it lifts unjustified
limitation by allowing to keep HANDLERs open when entering
LOCK TABLES mode.
--slave-load-tm
The MDL_SHARED lock was introduced for an object in 5.4, but the 'TABLE_LIST'
object was not initialized with the MDL_SHARED lock when applying event with
LOAD DATA INFILE into table. So the failure is caused when checking the
MDL_SHARED lock for the object.
To fix the problem, the 'TABLE_LIST' object was initialized with the MDL_SHARED
lock when applying event with LOAD DATA INFILE into table.
--slave-load-tm
The MDL_SHARED lock was introduced for an object in 5.4, but the 'TABLE_LIST'
object was not initialized with the MDL_SHARED lock when applying event with
LOAD DATA INFILE into table. So the failure is caused when checking the
MDL_SHARED lock for the object.
To fix the problem, the 'TABLE_LIST' object was initialized with the MDL_SHARED
lock when applying event with LOAD DATA INFILE into table.
this includes a major whitespace (formatting) alignment
and sequence changes to better agree with other spec files.
Further changes:
- All features are controlled by "%define" set from call
options or builtin.
- "bundled zlib" is on by default.
- "with libgcc" is controlled by runtime detection of gcc.
- Handling of "CFLAGS" and "CXXFLAGS" is more concentrated.
- Several missing man pages were added.
causing crashes!
Adding a SPATIAL INDEX on a non-geometrical column caused a
segmentation fault when the table was subsequently
inserted into.
A test was added in mysql_prepare_create_table to explicitly
check whether non-geometrical columns are used in a
spatial index, and throw an error if so.
corruption and crash results
An index creation statement where the index key
is larger/wider than the column it references
should throw an error.
A statement like:
CREATE TABLE t1 (a CHAR(1), PRIMARY KEY (A(255)))
did not error, but a segmentation fault followed when
an insertion was attempted on the table
The partial key validiation clause has been
restructured to (hopefully) better document which
uses of partial keys are valid.
Fixing problems discovered by "mtr --embedded" and "mtr --ps"
@ libmysqld/lib_sql.cc
"mtr --embedded --do-test=ps" failed.
Applying a similar change to the one previously done in protocol.cc,
to make embedded version work the same with client/server version.
(a bug in the WL#2649 patch)
@ mysql-test/include/ctype_numconv.inc
@ mysql-test/r/ctype_binary.result
@ mysql-test/r/ctype_cp1251.result
@ mysql-test/r/ctype_latin1.result
@ mysql-test/r/ctype_ucs.result
- Changing tinyint(30) to tinyint(4)
due to problems with "mtr --ps"
Possibly a bug in libmysql.cc, in function fetch_long_with_conversion().
Zerofill buffer is to short.
- Commenting tests with get_lock/release_lock
"mtr --ps" failed for some reasons in ctype_cp1251.
