Rechercher dans le manuel MySQL
22.5.3.5 Taking an NDB with Parallel Data Nodes
Beginning with NDB 8.0.16, it is possible to take a backup with
multiple local data managers (LDMs) acting in parallel on the
data nodes. For this to work, all data nodes in the cluster must
use multiple LDMs, and each data node must use the same number
of LDMs. This means that all data nodes must run
ndbmtd (ndbd is
single-threaded and thus always has only one LDM) and they must
be configured to use multiple LDMs before taking the backup;
ndbmtd by default runs in single-threaded mode. You can cause
them to use multiple LDMs this by choosing an appropriate
setting for one of the multi-threaded data node configuration
parameters
MaxNoOfExecutionThreads
or ThreadConfig
. Keep
in mind that changing these parameters requires a restart of the
cluster; this can be a rolling restart.
Depending on the number of LDMs and other factors, you may also
need to increase
NoOfFragmentLogParts
.
If you are using large Disk Data tables, you may also need to
increase
DiskPageBufferMemory
. As
with single-threaded backups, you also want or need to make
adjustments to settings for
BackupDataBufferSize
,
BackupMemory
, and other
configuration parameters relating to backups (see
Backup parameters).
Once all data nodes are using multiple LDMs, you can take the
parallel backup using the START
BACKUP
command in the NDB management client just as
you would if the data nodes were running ndbd
(or ndbmtd in single-threaded mode); no
additional or special syntax is required, and you can specify a
backup ID, wait option, or snapshot option in any combination as
needed or desired.
Backups using multiple LDMs create subdirectories, one per LDM,
under the directory
BACKUP/BACKUP-
(which in turn resides under the
backup_id
/BackupDataDir
) on each
data node; these subdirectories are named
BACKUP-
,
backup_id
-PART-1-OF-N
/BACKUP-
,
and so on, up to
backup_id
-PART-2-OF-N
/BACKUP-
,
where backup_id
-PART-N
-OF-N
/backup_id
is the backup ID used
for this backup and N
is the number
of LDMs per data node. Each of these subdirectories contains the
usual backup files
BACKUP-
,
backup_id
-0.node_id
.DataBACKUP-
,
and backup_id
.node_id
.ctlBACKUP-backup_id.node_id.log
, where
node_id
is the node ID of this data
node.
In NDB 8.0.16 and later, ndb_restore automatically checks for the presence of the subdirectories just described; if it finds them, it attempts to restore the backup in parallel. For information about restoring backups taken with multiple LDMs, see Section 22.4.23.2, “Restoring from a backup taken in parallel”.
Traduction non disponible
Le manuel MySQL n'est pas encore traduit en français sur l'infobrol. Seule la version anglaise est disponible pour l'instant.
Document créé le 26/06/2006, dernière modification le 26/10/2018
Source du document imprimé : https://www.gaudry.be/mysql-rf-mysql-cluster-backup-parallel-data-nodes.html
L'infobrol est un site personnel dont le contenu n'engage que moi. Le texte est mis à disposition sous licence CreativeCommons(BY-NC-SA). Plus d'info sur les conditions d'utilisation et sur l'auteur.
Références
Ces références et liens indiquent des documents consultés lors de la rédaction de cette page, ou qui peuvent apporter un complément d'information, mais les auteurs de ces sources ne peuvent être tenus responsables du contenu de cette page.
L'auteur de ce site est seul responsable de la manière dont sont présentés ici les différents concepts, et des libertés qui sont prises avec les ouvrages de référence. N'oubliez pas que vous devez croiser les informations de sources multiples afin de diminuer les risques d'erreurs.