Added the ndb_mgmd --nowait-nodes option, which allows a cluster that is configured to use multiple management servers to be started using fewer than the number configured. This is most likely to be useful when a cluster is configured with two management servers and you wish to start the cluster using only one of them.

See Section 17.4.4, “ndb_mgmd — The MySQL Cluster Management Server Daemon”, for more information. (Bug#48669)

This enhanced functionality is supported for upgrades from MySQL Cluster NDB 6.3 when the NDB engine version is 6.3.29 or later. (Bug#48528, Bug#49163)

The output from ndb_config --configinfo --xml now indicates, for each configuration parameter, the following restart type information:

(Bug#47366)

Node takeover during a system restart occurs when the REDO log for one or more data nodes is out of date, so that a node restart is invoked for that node or those nodes. If this happens while a mysqld process is attached to the cluster as an SQL node, the mysqld takes a global schema lock (a row lock), while trying to set up cluster-internal replication.

However, this setup process could fail, causing the global schema lock to be held for an excessive length of time, which made the node restart hang as well. As a result, the mysqld failed to set up cluster-internal replication, which led to tables being read-only, and caused one node to hang during the restart.

(Bug#49560)

Sending SIGHUP to a mysqld running with the --ndbcluster and --log-bin options caused the process to crash instead of refreshing its log files. (Bug#49515)

If the master data node receiving a request from a newly-started API or data node for a node ID died before the request has been handled, the management server waited (and kept a mutex) until all handling of this node failure was complete before responding to any other connections, instead of responding to other connections as soon as it was informed of the node failure (that is, it waited until it had received a NF_COMPLETEREP signal rather than a NODE_FAILREP signal). On visible effect of this misbehavior was that it caused management client commands such as SHOW and ALL STATUS to respond with unnecessary slowness in such circumstances. (Bug#49207)

Attempting to create more than 11435 tables failed with Error 306 (Out of fragment records in DIH). (Bug#49156)

When evaluating the options --include-databases, --include-tables, --exclude-databases, and --exclude-tables, the ndb_restore program overwrote the result of the database-level options with the result of the table-level options rather than merging these results together, sometimes leading to unexpected and unpredictable results.

As part of the fix for this problem, the semantics of these options have been clarified; because of this, the rules governing their evaluation have changed slightly. These changes be summed up as follows:

For more detailed information and examples, see Section 17.4.17, “ndb_restore — Restore a MySQL Cluster Backup”. (Bug#48907)

When performing tasks that generated large amounts of I/O (such as when using ndb_restore), an internal memory buffer could overflow, causing data nodes to fail with signal 6.

Subsequent analysis showed that this buffer was not actually required, so this fix removes it. (Bug#48861)

Exhaustion of send buffer memory or long signal memory caused data nodes to crash. Now an appropriate error message is provided instead when this situation occurs. (Bug#48852)

In some situations, when it was not possible for an SQL node to start a schema transaction (necessary, for instance, as part of an online ALTER TABLE), NDBCLUSTER did not correctly indicate the error to the MySQL server, which led mysqld to crash. (Bug#48841)

Under certain conditions, accounting of the number of free scan records in the local query handler could be incorrect, so that during node recovery or a local checkpoint operations, the LQH could find itself lacking a scan record that is expected to find, causing the node to crash. (Bug#48697)

See also Bug#48564.

The creation of an ordered index on a table undergoing DDL operations could cause a data node crash under certain timing-dependent conditions. (Bug#48604)

During an LCP master takeover, when the newly elected master did not receive a COPY_GCI LCP protocol message but other nodes participating in the local checkpoint had received one, the new master could use an uninitialized variable, which caused it to crash. (Bug#48584)

When running many parallel scans, a local checkpoint (which performs a scan internally) could find itself not getting a scan record, which led to a data node crash. Now an extra scan record is reserved for this purpose, and a problem with obtaining the scan record returns an appropriate error (error code 489, Too many active scans). (Bug#48564)

During a node restart, logging was enabled on a per-fragment basis as the copying of each fragment was completed but local checkpoints were not enabled until all fragments were copied, making it possible to run out of redo log file space (NDB error code 410) before the restart was complete. Now logging is enabled only after all fragments has been copied, just prior to enabling local checkpoints. (Bug#48474)

When using very large transactions containing many inserts, ndbmtd could fail with Signal 11 without an easily detectable reason, due to an internal variable being unitialized in the event that the LongMessageBuffer was overloaded. Now, the variable is initialized in such cases, avoiding the crash, and an appropriate error message is generated. (Bug#48441)

See also Bug#46914.

A data node crashing while restarting, followed by a system restart could lead to incorrect handling of redo log metadata, causing the system restart to fail with Error while reading REDO log. (Bug#48436)

Starting a mysqld process with --ndb-nodeid (either as a command-line option or by assigning it a value in my.cnf) caused the mysqld to get only the corresponding connection from the [mysqld] section in the config.ini file having the matching ID, even when connection pooling was enabled (that is, when the mysqld process was started with --ndb-cluster-connection-pool set greater than 1). (Bug#48405)

See also Bug#27644, Bug#38590, Bug#41592.

The configuration check that each management server runs to verify that all connected ndb_mgmd processes have the same configuration could fail when a configuration change took place while this check was in progress. Now in such cases, the configuration check is rescheduled for a later time, after the change is complete. (Bug#48143)

When employing NDB native backup to back up and restore an empty NDB table that used a non-sequential AUTO_INCREMENT value, the AUTO_INCREMENT value was not restored correctly. (Bug#48005)

ndb_config --xml --configinfo now indicates that parameters belonging in the [SCI], [SCI DEFAULT], [SHM], and [SHM DEFAULT] sections of the config.ini file are deprecated or experimental, as appropriate. (Bug#47365)

NDB stores blob column data in a separate, hidden table that is not accessible from MySQL. If this table was missing for some reason (such as accidental deletion of the file corresponding to the hidden table) when making a MySQL Cluster native backup, ndb_restore crashed when attempting to restore the backup. Now in such cases, ndb_restore fails with the error message Table table_name has blob column (column_name) with missing parts table in backup instead. (Bug#47289)

In MySQL Cluster NDB 7.0, ndb_config and ndb_error_reporter were printing warnings about management and data nodes running on the same host to stdout instead of stderr, as was the case in earlier MySQL Cluster release series. (Bug#44689, Bug#49160)

See also Bug#25941.

DROP DATABASE failed when there were stale temporary NDB tables in the database. This situation could occur if mysqld crashed during execution of a DROP TABLE statement after the table definition had been removed from NDBCLUSTER but before the corresponding .ndb file had been removed from the crashed SQL node's data directory. Now, when mysqld executes DROP DATABASE, it checks for these files and removes them if there are no corresponding table definitions for them found in NDBCLUSTER. (Bug#44529)

Creating an NDB table with an excessive number of large BIT columns caused the cluster to fail. Now, an attempt to create such a table is rejected with error 791 (Too many total bits in bitfields). (Bug#42046)

See also Bug#42047.

When a long-running transaction lasting long enough to cause Error 410 (REDO log files overloaded) was later committed or rolled back, it could happen that NDBCLUSTER was not able to release the space used for the REDO log, so that the error condition persisted indefinitely.

The most likely cause of such transactions is a bug in the application using MySQL Cluster. This fix should handle most cases where this might occur. (Bug#36500)

Deprecation and usage information obtained from ndb_config --configinfo regarding the PortNumber and ServerPort configuration parameters was improved. (Bug#24584)

Disk Data: When running a write-intensive workload with a very large disk page buffer cache, CPU usage approached 100% during a local checkpoint of a cluster containing Disk Data tables. (Bug#49532)

Disk Data: NDBCLUSTER failed to provide a valid error message it failed to commit schema transactions during an initial start if the cluster was configured using the InitialLogFileGroup parameter. (Bug#48517)

Disk Data: In certain limited cases, it was possible when the cluster contained Disk Data tables for ndbmtd to crash during a system restart. (Bug#48498)

See also Bug#47832.

Disk Data: Repeatedly creating and then dropping Disk Data tables could eventually lead to data node failures. (Bug#45794, Bug#48910)

Disk Data: When a crash occurs due to a problem in Disk Data code, the currently active page list is printed to stdout (that is, in one or more ndb_nodeid_out.log files). One of these lists could contain an endless loop; this caused a printout that was effectively never-ending. Now in such cases, a maximum of 512 entries is printed from each list. (Bug#42431)

Disk Data: When the FileSystemPathUndoFiles configuration parameter was set to an non-existent path, the data nodes shut down with the generic error code 2341 (Internal program error). Now in such cases, the error reported is error 2815 (File not found).

Cluster Replication: When expire_logs_days was set, the thread performing the purge of the log files could deadlock, causing all binary log operations to stop. (Bug#49536)

Cluster API: When a DML operation failed due to a uniqueness violation on an NDB table having more than one unique index, it was difficult to determine which constraint caused the failure; it was necessary to obtain an NdbError object, then decode its details property, which in could lead to memory management issues in application code.

To help solve this problem, a new API method Ndb::getNdbErrorDetail() is added, providing a well-formatted string containing more precise information about the index that caused the unque constraint violation. The following additional changes are also made in the NDB API:

For more information, see Ndb::getNdbErrorDetail(), The NdbError Structure, and Dictionary::listObjects(). (Bug#48851)

Cluster API: When using blobs, calling getBlobHandle() requires the full key to have been set using equal(), because getBlobHandle() must access the key for adding blob table operations. However, if getBlobHandle() was called without first setting all parts of the primary key, the application using it crashed. Now, an appropriate error code is returned instead. (Bug#28116, Bug#48973)

The mysql_real_connect() C API function only attempted to connect to the first IP address returned for a hostname. This could be a problem if a hostname mapped to multiple IP address and the server was not bound to the first one returned. Now mysql_real_connect() attempts to connect to all IPv4 or IPv6 addresses that a domain name maps to. (Bug#45017)

See also Bug#47757.