MySQL 5.7 Reference Manual Including MySQL NDB Cluster 7.5 and NDB Cluster 7.6
This section provides information about compatibility between different NDB Cluster 7.6 releases with regard to performing upgrades and downgrades as well as compatibility matrices and notes. Additional information can also be found here regarding downgrades from NDB 7.6 to previous NDB release series. You should already be familiar with installation and configuration of NDB Cluster prior to attempting an upgrade or downgrade. See Section 20.3, “Configuration of NDB Cluster”.
The table shown here provides information on NDB Cluster upgrade and downgrade compatibility among different releases of NDB 7.6. Additional notes about upgrades and downgrades to, from, or within the NDB Cluster 7.6 release series can be found following the table.
Version support. The following versions of NDB Cluster are supported for upgrades to GA releases of NDB Cluster 7.6 (7.6.6 and later):
NDB Cluster 7.5 GA releases (7.5.4 and later)
NDB Cluster 7.4 GA releases (7.4.4 and later)
NDB Cluster 7.3 GA releases (7.3.2 and later)
Known issues. The following issues are known to occur when upgrading to, downgrading from, or between NDB 7.6 releases:
Changes in Disk Data file format. Due to changes in disk format, upgrading to or downgrading from either of the versions listed here requires an initial node restart of each data node:
NDB 7.6.2
NDB 7.6.4
To avoid problems relating to the old format, you should
re-create any existing tablespaces and undo log file groups when
upgrading. You can do this by performing an initial restart of
each data node (that is, using the
--initial
option) as part of the
upgrade process.
If you are using Disk Data tables, a downgrade from
any NDB 7.6 release to any NDB 7.5 or
earlier release requires that you restart all data nodes with
--initial
as part of the downgrade
process. This is because NDB 7.5 and earlier release series are
not able to read the new Disk Data file format.
IndexMemory changes.
If you are downgrading from NDB 7.6 to NDB 7.5 (or earlier),
you must set an explicit value for
IndexMemory
in the
cluster configuration file if none is already present. This is
because NDB 7.6.2 (and later) does not use this parameter and
sets it to 0 by default, whereas it is required in NDB 7.5 and
earlier releases, in which the cluster refuses to start with
Invalid configuration received from Management
Server... if IndexMemory
is not
set to a nonzero value.
Upgrading to NDB 7.6.4 or later from an earlier release, or
downgrading from NDB 7.6.4 or later to an earlier release,
requires purging then re-creating the NDB
data node file system, which means that each data node must be
restarted using the --initial
option as part of the rolling restart or system restart
normally required. (Starting a data node with no file system
is already equivalent to an initial restart; in such cases,
--initial
is implied and not required. This
is unchanged from previous releases of NDB Cluster.)
When such a restart is performed as part of an upgrade to NDB
7.6.4 or later, any existing LCP files are checked for the
presence of the LCP Sysfile
, indicating
that the existing data node file system was written using NDB
7.6.4 or later. If such a node file system exists, but does
not contain the Sysfile
, and if any data
nodes are restarted without the
--initial
option,
NDB
causes the restart to fail with an
appropriate error message.
You should also be aware that no such protection is possible when downgrading from NDB 7.6.4 or later to a release previous to NDB 7.6.4.