MySQL 8.4 Reference Manual Including MySQL NDB Cluster 8.4
The following table shows all Performance Schema tables relating
to the NDBCLUSTER storage engine.
Table 29.3 Performance Schema NDB Tables
| Table Name | Description |
|---|---|
ndb_sync_excluded_objects |
NDB objects which cannot be synchronized |
ndb_sync_pending_objects |
NDB objects waiting for synchronization |
Automatic synchronization in NDB
attempts to detect and synchronize automatically all mismatches
in metadata between the NDB Cluster's internal dictionary
and the MySQL Server's datadictionary. This is done by
default in the background at regular intervals as determined by
the ndb_metadata_check_interval
system variable, unless disabled using
ndb_metadata_check or
overridden by setting
ndb_metadata_sync.
Information about the current state of automatic synchronization is exposed by a MySQL server acting as an SQL node in an NDB Cluster in these two Performance Schema tables:
ndb_sync_pending_objects:
Displays information about NDB
database objects for which mismatches have been detected
between the NDB dictionary and the MySQL
data dictionary. When attempting to synchronize such
objects, NDB removes the object
from the queue awaiting synchronization, and from this
table, and tries to reconcile the mismatch. If
synchronization of the object fails due to a temporary
error, it is picked up and added back to the queue (and to
this table) the next time NDB performs
mismatch detection; if the attempts fails due a permanent
error, the object is added to the
ndb_sync_excluded_objects
table.
ndb_sync_excluded_objects:
Shows information about NDB
database objects for which automatic synchronization has
failed due to permanent errors resulting from mismatches
which cannot be reconciled without manual intervention;
these objects are blocklisted and not considered again for
mismatch detection until this has been done.
The ndb_sync_pending_objects and
ndb_sync_excluded_objects tables
are present only if MySQL has support enabled for the
NDBCLUSTER storage engine.
These tables are described in more detail in the following two sections.