This release incorporates new features in the
NDB storage engine and fixes
recently discovered bugs in previous MySQL Cluster NDB 7.0
Obtaining MySQL Cluster NDB 7.0. The latest MySQL Cluster NDB 7.0 binaries for supported platforms can be obtained from http://dev.mysql.com/downloads/cluster/. Source code for the latest MySQL Cluster NDB 7.0 release can be obtained from the same location. You can also access the MySQL Cluster NDB 7.0 development source tree at https://code.launchpad.net/~mysql/mysql-server/mysql-cluster-7.0.
This release also 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 5.1.63 (see Changes in MySQL 5.1.63 (2012-05-07)).
Please refer to our bug database at http://bugs.mysql.com/ for more details about the individual bugs fixed in this version.
Important Change: When
FILEwas used for the value of the
LogDestinationparameter without also specifying the
filename, the log file name defaulted to
logger.log. Now in such cases, the name defaults to
ndb_. (Bug #11764570, Bug #57417)
If the Transaction Coordinator aborted a transaction in the “prepared” state, this could cause a resource leak. (Bug #14208924)
When attempting to connect using a socket with a timeout, it was possible (if the timeout was exceeded) for the socket not to be set back to blocking. (Bug #14107173)
An error handling routine in the local query handler (
DBLQH) used the wrong code path, which could corrupt the transaction ID hash, causing the data node process to fail. This could in some cases possibly lead to failures of other data nodes in the same node group when the failed node attempted to restart. (Bug #14083116)
When a fragment scan occurring as part of a local checkpoint (LCP) stopped progressing, this kept the entire LCP from completing, which could result it redo log exhaustion, write service outage, inability to recover nodes, and longer system recovery times. To help keep this from occurring, MySQL Cluster now implements an LCP watchdog mechanism, which monitors the fragment scans making up the LCP and takes action if the LCP is observed to be delinquent.
This is intended to guard against any scan related system-level I/O errors or other issues causing problems with LCP and thus having a negative impact on write service and recovery times. Each node independently monitors the progress of local fragment scans occurring as part of an LCP. If no progress is made for 20 seconds, warning logs are generated every 10 seconds thereafter for up to 1 minute. At this point, if no progress has been made, the fragment scan is considered to have hung, and the node is restarted to enable the LCP to continue.
In addition, a new ndbd exit code NDBD_EXIT_LCP_SCAN_WATCHDOG_FAIL is added to identify when this occurs. See LQH Errors, for more information. (Bug #14075825)
In some circumstances, transactions could be lost during an online upgrade. (Bug #13834481)
Attempting to add both a column and an index on that column in the same online
ALTER TABLEstatement caused mysqld to fail. Although this issue affected only the mysqld shipped with MySQL Cluster, the table named in the
ALTER TABLEcould use any storage engine for which online operations are supported. (Bug #12755722)
Cluster API: When an NDB API application called
NdbScanOperation::nextResult()again after the previous call had returned end-of-file (return code 1), a transaction object was leaked. Now when this happens, NDB returns error code 4210 (Ndb sent more info than length specified); previouslyu in such cases, -1 was returned. In addition, the extra transaction object associated with the scan is freed, by returning it to the transaction coordinator's idle list. (Bug #11748194)