(Attempt #2)
- Don't attempt to use BKA for materialized derived tables. The
table is neither filled nor fully opened yet, so attempt to
call handler->multi_range_read_info() causes crash.
some of the tables are created in InnoDB and some tables are created in MyISAM.
We need to create all tables on InnoDB. Fix is to add engine=innodb to the
CREATE TABLE statements.
approved in IM by Marko and Vasil.
some of the tables are created in InnoDB and some tables are created in MyISAM.
We need to create all tables on InnoDB. Fix is to add engine=innodb to the
CREATE TABLE statements.
approved in IM by Marko and Vasil.
The test case waits for other threads to complete, but the wait is only 2
seconds. This is likely to sometimes be too little on our heavily loaded
buildbot VMs, that can easily stall for more than 2 seconds from time to time.
So let's try to increase the timeout (to about 40 seconds) and see if it
helps.
The test case runs SHOW SLAVE HOSTS. The output of this is only stable after
all slaves have had time to register with the master; this happens
asynchroneously.
The test was waiting for the slave with server_id=3 to appear in the output,
but it was missing a similar wait for server_id=2. Thus, if server_id=2 was
much slower to connect for some reason, it could be missing from the output,
causing the test to fail.
I think I finally found the problem, managed to reproduce locally using a
sleep in the test case to simulate the particular race condition that causes
the test to fail often in Buildbot.
The test starts an ALTER TABLE that does repair by sort in one thread, then
another thread waits for the sort to be visible in SHOW PROCESSLIST and runs a
SHOW statement in parallel.
The problem happens when the sort manages to run to completion before the
other thread has the time to look at SHOW PROCESSLIST. In this case, the wait
times out because the state looked for has already passed.
Earlier I added some DEBUG_SYNC to prevent this race, but it turns out that
DEBUG_SYNC itself changes the state in the processlist. So when the debug sync
point was hit, the processlist was showing the wrong state, so the wait would
still time out.
Fixed now by looking for the processlist to contain either the "Repair by
sorting" state or the debug sync wait stage.
Also clean up previous attempts to fix it. Set the wait timeout back to
reasonable 60 seconds, and simplify the DEBUG_SYNC operations to work closer
to how the original test case was intended.
1. Do not use NULL `info' field in processlist to select the thread of
interest. This can fail if the read of processlist ends up happening after
REAP succeeds, but before the `info' field is reset. Instead, select on the
CONNECTION_ID(), making sure we still scan the whole list to trigger the same
code as in the original test case.
2. Wait for the query to really complete before reading it in the
processlist. When REAP returns, it only means that ack has been sent to
client, the reset of query stage happens a bit later in the code.
Add missing REAP to the test.
A later test failed with strange incorrect values for COM_SELECT
in information_schema.global_status. Since global_status is updated
at the end of session activity, it seems appropriate to ensure that
all background connections have completed before accessing it.
(I checked that the original bug still triggers the test case after
the modification with REAP).
- Don't attempt to use BKA for materialized derived tables. The
table is neither filled nor fully opened yet, so attempt to
call handler->multi_range_read_info() causes crash.
innodb_buffer_pool_pages_total depends on page size. On Power8 it is 65k
compared to 4k on Intel. As we round allocations on page size we may get
slightly more memory for buffer pool.
- test_if_skip_sort_order()/create_ref_for_key() may change table
access from EQ_REF(index1) to REF(index2).
- Doing so doesn't make much sense from optimization POV, but since
they are doing it, they should update tab->read_record.unlock_row
accordingly.
Don't double-check privileges for a column in the GROUP BY that refers to
the same column in SELECT clause. Privileges were already checked for SELECT clause.
- Fix the crash by making get_column_range_cardinality()
to handle the special case where Column_stats objects
is an all-zeros object (the question of what is the point
of having Field::read_stats point to such object remains a
mystery)
- Added a few comments. Learning the code still.
merge from MySQL-5.6, revision:
revno: 3677.2.1
committer: Alfranio Correia <alfranio.correia@oracle.com>
timestamp: Tue 2012-02-28 16:26:37 +0000
message:
BUG#13627921 - MISSING FLAGS IN SQL_COMMAND_FLAGS MAY LEAD TO REPLICATION PROBLEMS
Flags in sql_command_flags[command] are not correctly set for the following
commands:
. SQLCOM_SET_OPTION is missing CF_CAN_GENERATE_ROW_EVENTS;
. SQLCOM_BINLOG_BASE64_EVENT is missing CF_CAN_GENERATE_ROW_EVENTS;
. SQLCOM_REVOKE_ALL is missing CF_CHANGES_DATA;
. SQLCOM_CREATE_FUNCTION is missing CF_AUTO_COMMIT_TRANS;
This may lead to a wrong sequence of events in the binary log. To fix
the problem, we correctly set the flags in sql_command_flags[command].
Normally, SET SESSION SQL_LOG_BIN is used by DBAs to run a
non-conflicting command locally only, ensuring it does not
get replicated.
Setting GLOBAL SQL_LOG_BIN would not require all sessions to
disconnect. When SQL_LOG_BIN is changed globally, it does not
immediately take effect for any sessions. It takes effect by
becoming the session-level default inherited at the start of
each new session, and this setting is kept and cached for the
duration of that session. Setting it intentionally is unlikely
to have a useful effect under any circumstance; setting it
unintentionally, such as while intending to use SET [SESSION]
is potentially disastrous. Accidentally using SET GLOBAL
SQL_LOG_BIN will not show an immediate effect to the user,
instead not having the desired session-level effect, and thus
causing other potential problems with local-only maintenance
being binlogged and executed on slaves; And transactions from
new sessions (after SQL_LOG_BIN is changed globally) are not
binlogged and replicated, which would result in irrecoverable
or difficult data loss.
This is the regular GLOBAL variables way to work, but in
replication context it does not look right on a working server
(with connected sessions) 'set global sql_log_bin' and none of
that connections is affected. Unexperienced DBA after noticing
that the command did "nothing" will change the session var and
most probably won't unset the global var, causing new sessions
to not be binlog.
Setting GLOBAL SQL_LOG_BIN allows DBA to stop binlogging on all
new sessions, which can be used to make a server "replication
read-only" without restarting the server. But this has such big
requirements, stop all existing connections, that it is more
likely to make a mess, it is too risky to allow the GLOBAL variable.
The statement 'SET GLOBAL SQL_LOG_BIN=N' will produce an error
in 5.5, 5.6 and 5.7. Reading the GLOBAL SQL_LOG_BIN will produce
a deprecation warning in 5.7.
Normally, SET SESSION SQL_LOG_BIN is used by DBAs to run a
non-conflicting command locally only, ensuring it does not
get replicated.
Setting GLOBAL SQL_LOG_BIN would not require all sessions to
disconnect. When SQL_LOG_BIN is changed globally, it does not
immediately take effect for any sessions. It takes effect by
becoming the session-level default inherited at the start of
each new session, and this setting is kept and cached for the
duration of that session. Setting it intentionally is unlikely
to have a useful effect under any circumstance; setting it
unintentionally, such as while intending to use SET [SESSION]
is potentially disastrous. Accidentally using SET GLOBAL
SQL_LOG_BIN will not show an immediate effect to the user,
instead not having the desired session-level effect, and thus
causing other potential problems with local-only maintenance
being binlogged and executed on slaves; And transactions from
new sessions (after SQL_LOG_BIN is changed globally) are not
binlogged and replicated, which would result in irrecoverable
or difficult data loss.
This is the regular GLOBAL variables way to work, but in
replication context it does not look right on a working server
(with connected sessions) 'set global sql_log_bin' and none of
that connections is affected. Unexperienced DBA after noticing
that the command did "nothing" will change the session var and
most probably won't unset the global var, causing new sessions
to not be binlog.
Setting GLOBAL SQL_LOG_BIN allows DBA to stop binlogging on all
new sessions, which can be used to make a server "replication
read-only" without restarting the server. But this has such big
requirements, stop all existing connections, that it is more
likely to make a mess, it is too risky to allow the GLOBAL variable.
The statement 'SET GLOBAL SQL_LOG_BIN=N' will produce an error
in 5.5, 5.6 and 5.7. Reading the GLOBAL SQL_LOG_BIN will produce
a deprecation warning in 5.7.
Added comments
Ensure that tokudb test works even if jemalloc is not installed
Removed not referenced function Item::remove_fixed()
mysql-test/suite/rpl/t/rpl_gtid_reconnect.test:
Fixed race condition
sql/item.cc:
Indentation fix
sql/item.h:
Removed not used function
Added comment
sql/sql_select.cc:
Fixed indentation
storage/tokudb/mysql-test/rpl/include/have_tokudb.opt:
Ensure that tokudb test works even if jemalloc is not installed
storage/tokudb/mysql-test/tokudb/suite.opt:
Ensure that tokudb test works even if jemalloc is not installed
storage/tokudb/mysql-test/tokudb_add_index/suite.opt:
Ensure that tokudb test works even if jemalloc is not installed
storage/tokudb/mysql-test/tokudb_alter_table/suite.opt:
Ensure that tokudb test works even if jemalloc is not installed
storage/tokudb/mysql-test/tokudb_bugs/suite.opt:
Ensure that tokudb test works even if jemalloc is not installed
storage/tokudb/mysql-test/tokudb_mariadb/suite.opt:
Ensure that tokudb test works even if jemalloc is not installed
FROM A FUNCTION
Scenario:
In a stored procedure, CREATE TABLE statement is not allowed. But an
exception is provided for CREATE TEMPORARY TABLE. We can create a temporary
table in a stored procedure.
Let there be two stored functions f1 and f2 and two stored procedures p1 and
p2. Their properties are as follows:
. stored function f1() calls stored procedure p1().
. stored function f2() calls stored procedure p2().
. stored procedure p1() creates temporary table t1.
. stored procedure p2() does DML on t1.
Consider the following situation:
1. Autocommit mode is on.
2. select f1()
3. select f2()
Step 2: In this step, t1 would be created via p1(). A table level transaction
lock would have been taken. The ::external_lock() would not have been called
on this table. At the end of step 2, because of autocommit mode on, this table
level lock will be released.
Step 3: When we execute DML on table t1 via p2() we have two problems:
Problem 1:
The function ha_innobase::external_lock() would have been called but since
it is a select query no table level locks would have been taken. Hence the
following assert will fail:
ut_ad(lock_table_has(thr_get_trx(thr), index->table, LOCK_IX));
Solution:
The solution would be to identify this situation and take a table level lock
and use the proper lock type prebuilt->select_lock_type = LOCK_X for DML
operations.
Problem 2:
Another problem is that in step 3, ha_innobase::open() is never called on
the table t1.
Solution:
The solution would be to identify this situation and call re-init the handler
of table t1.
rb#6429 approved by Krunal.
FROM A FUNCTION
Scenario:
In a stored procedure, CREATE TABLE statement is not allowed. But an
exception is provided for CREATE TEMPORARY TABLE. We can create a temporary
table in a stored procedure.
Let there be two stored functions f1 and f2 and two stored procedures p1 and
p2. Their properties are as follows:
. stored function f1() calls stored procedure p1().
. stored function f2() calls stored procedure p2().
. stored procedure p1() creates temporary table t1.
. stored procedure p2() does DML on t1.
Consider the following situation:
1. Autocommit mode is on.
2. select f1()
3. select f2()
Step 2: In this step, t1 would be created via p1(). A table level transaction
lock would have been taken. The ::external_lock() would not have been called
on this table. At the end of step 2, because of autocommit mode on, this table
level lock will be released.
Step 3: When we execute DML on table t1 via p2() we have two problems:
Problem 1:
The function ha_innobase::external_lock() would have been called but since
it is a select query no table level locks would have been taken. Hence the
following assert will fail:
ut_ad(lock_table_has(thr_get_trx(thr), index->table, LOCK_IX));
Solution:
The solution would be to identify this situation and take a table level lock
and use the proper lock type prebuilt->select_lock_type = LOCK_X for DML
operations.
Problem 2:
Another problem is that in step 3, ha_innobase::open() is never called on
the table t1.
Solution:
The solution would be to identify this situation and call re-init the handler
of table t1.
rb#6429 approved by Krunal.
