MySQL Cluster NDB 6.3.27 was pulled shortly after release due to Bug #47844. Users seeking to upgrade from a previous MySQL Cluster NDB 6.3 release should instead use MySQL Cluster NDB 6.3.27a, which contains a fix for this bug, in addition to all bugfixes and improvements made in MySQL Cluster NDB 6.3.27.
This is a bugfix release, fixing recently discovered bugs in the previous MySQL Cluster NDB 6.3 release.
This release incorporates all bugfixes and changes made in previous MySQL Cluster releases, as well as all bugfixes and feature changes which were added in mainline MySQL 5.1 through MySQL 5.1.37 (see Changes in MySQL 5.1.37 (2009-07-13)).
Please refer to our bug database at http://bugs.mysql.com/ for more details about the individual bugs fixed in this version.
Two new columns have been added to the output of
ndb_desc to make it possible to determine how
much of the disk space allocated to a given table or fragment
remains free. (This information is not available from the
FILES table applies only
to Disk Data files.) For more information, see
ndb_desc — Describe NDB Tables.
Important Change; Cluster Replication:
In a MySQL Cluster acting as a replication slave and having
multiple SQL nodes, only the SQL node receiving events directly
from the master recorded DDL statements in its binary logs
unless this SQL node also had binary logging enabled; otherwise,
other SQL nodes in the slave cluster failed to log DDL
statements, regardless of their individual
The fix for this issue aligns binary logging of DDL statements with that of DML statements. In particular, you should take note of the following:
DDL and DML statements on the master cluster are logged with the server ID of the server that actually writes the log.
DDL and DML statements on the master cluster are logged by any attached mysqld that has binary logging enabled.
Affect on upgrades. When upgrading from a previous MySQL CLuster release, you should perform either one of the following:
Upgrade servers that are performing binary logging before those that are not; do not perform any DDL on “old” SQL nodes until all SQL nodes have been upgraded.
Make sure that
enabled on all SQL nodes performing binary logging prior
to the upgrade, so that all DDL is captured.
Logging of DML statements was not affected by this issue.
mysqld allocated an excessively large buffer
BLOB values due to
overestimating their size. (For each row, enough space was
allocated to accommodate every
TEXT column value in the result
set.) This could adversely affect performance when using tables
TEXT columns; in a few extreme
cases, this issue could also cause the host system to run out of
References: See also Bug #47572, Bug #47573.
When an instance of the
handler was recycled (this can happen due to table definition
cache pressure or to operations such as
FLUSH TABLES or
ALTER TABLE), if the last row
read contained blobs of zero length, the buffer was not freed,
even though the reference to it was lost. This resulted in a
For example, consider the table defined and populated as shown here:
CREATE TABLE t (a INT PRIMARY KEY, b LONGTEXT) ENGINE=NDB; INSERT INTO t VALUES (1, REPEAT('F', 20000)); INSERT INTO t VALUES (2, '');
SELECT a, length(b) FROM bl ORDER BY a; FLUSH TABLES;
Prior to the fix, this resulted in a memory leak proportional to
the size of the stored
each time these two statements were executed.
References: See also Bug #47572, Bug #47574.
Large transactions involving joins between tables containing
BLOB columns used excessive
References: See also Bug #47573, Bug #47574.
A variable was left uninitialized while a data node copied data from its peers as part of its startup routine; if the starting node died during this phase, this could lead a crash of the cluster when the node was later restarted. (Bug #47505)
When a data node restarts, it first runs the redo log until
reaching the latest restorable global checkpoint; after this it
scans the remainder of the redo log file, searching for entries
that should be invalidated so they are not used in any
subsequent restarts. (It is possible, for example, if restoring
GCI number 25, that there might be entries belonging to GCI 26
in the redo log.) However, under certain rare conditions, during
the invalidation process, the redo log files themselves were not
always closed while scanning ahead in the redo log. In rare
cases, this could lead to
exceeded, causing a the data node to crash.
For very large values of
overflow when creating large numbers of tables, leading to
NDB error 773 (Out of
string memory, please modify StringMemory config
parameter), even when
StringMemory was set to
100 (100 percent).
The default value for the
configuration parameter, unlike other MySQL Cluster
configuration parameters, was not set in
Signals from a failed API node could be received after an
API_FAILREQ signal (see
Operations and Signals)
has been received from that node, which could result in invalid
states for processing subsequent signals. Now, all pending
signals from a failing API node are processed before any
API_FAILREQ signal is received.
References: See also Bug #44607.
Using triggers on
NDB tables caused
to be treated as having the NDB kernel's internal default
value (32) and the value for this variable as set on the
cluster's SQL nodes to be ignored.
When performing auto-discovery of tables on individual SQL
NDBCLUSTER attempted to overwrite
files and corrupted them.
In the mysql client, create a new table
t2) with same definition as the corrupted
t1). Use your system shell or file
manager to rename the old
.MYD file to
the new file name (for example, mv t1.MYD
t2.MYD). In the mysql client,
repair the new table, drop the old one, and rename the new
table using the old file name (for example,
RENAME TABLE t2
Running ndb_restore with the
could cause it to crash.
(Bug #40428, Bug #33040)
An insert on an
NDB table was not
always flushed properly before performing a scan. One way in
which this issue could manifest was that
LAST_INSERT_ID() sometimes failed
to return correct values when using a trigger on an
When a data node received a
signal from the master before that node had received a
NODE_FAILREP, a race condition could in
References: See also Bug #25364, Bug #28717.
Some joins on large
BLOB columns could cause
mysqld processes to leak memory. The joins
did not need to reference the
BLOB columns directly for this
issue to occur.
On Mac OS X 10.5, commands entered in the management client
failed and sometimes caused the client to hang, although
management client commands invoked using the
-e) option from the system shell worked
For example, the following command failed with an error and hung until killed manually, as shown here:
SHOWWarning, event thread startup failed, degraded printouts as result, errno=36
However, the same management client command, invoked from the system shell as shown here, worked correctly:
ndb_mgm -e "SHOW"
References: See also Bug #34438.
In some cases, a
statement could cause the replication slave to crash. This issue
was specific to MySQL on Windows or Macintosh platforms.
(Bug #45238, Bug #45242, Bug #45243, Bug #46013, Bug #46014, Bug #46030)
References: See also Bug #40796.
Disk Data: Calculation of free space for Disk Data table fragments was sometimes done incorrectly. This could lead to unnecessary allocation of new extents even when sufficient space was available in existing ones for inserted data. In some cases, this might also lead to crashes when restarting data nodes.
This miscalculation was not reflected in the contents of the
as it applied to extents allocated to a fragment, and not to a
In some circumstances, if an API node encountered a data node
failure between the creation of a transaction and the start of a
scan using that transaction, then any subsequent calls to
closeTransaction() could cause the same
transaction to be started and closed repeatedly.
Performing multiple operations using the same primary key within
could lead to a data node crash.
This fix does not make change the fact that performing
multiple operations using the same primary key within the same
not supported; because there is no way to determine the order
of such operations, the result of such combined operations
References: See also Bug #44015.
API: The fix for Bug #24507 could lead in some cases to client application failures due to a race condition. Now the server waits for the “dummy” thread to return before exiting, thus making sure that only one thread can initialize the POSIX threads library. (Bug #42850)