Database Replication and Clustering
| 5.12.1. Reset a Single Site in a Multisite/Multimaster Topology | ||
|---|---|---|
| Prev | 5.12. Resetting a Tungsten Clustering Dataservice | Next |
Under certain conditions, dataservices in a multimaster configuration may drift and/or become inconsistent with the data in another dataservice. If this occurs, you may need to re-provision the data on one or more of the dataservices after first determining the definitive source of the information.
In the following example the west
service has been determined to be the definitive copy of the data. To fix
the issue, all the datasources in the
east service will be reprovisioned
from one of the datasources in the
west service.
The following is a guide to the steps that should be followed. In the
example procedure it is the
east service
that has failed:
Put the dataservice into
MAINTENANCE mode. This
ensures that Tungsten Clustering will not attempt to automatically recover
the service.
cctrl [east]> set policy maintenancePut the Tungsten Connector for the dataservice offline:
cctrl [east]> router * offline
Stop all services running in
east:
shell east>/opt/continuent/tungsten/cluster-home/bin/stopallshell east>/opt/replicator/tungsten/cluster-home/bin/stopall
Disable cross-site replication and reset the replication position:
shell west>/opt/replicator/tungsten/tungsten-replicator/bin/trepctl -service east offlineshell west>/opt/replicator/tungsten/tungsten-replicator/bin/trepctl -service east reset -all -y
Reprovision the master node in
east:
shell east{master}> /opt/continuent/tungsten/tungsten-replicator/scripts/tungsten_provision_slave --source west{slave}
Restart the services in east:
shell east>/opt/continuent/tungsten/cluster-home/bin/startallshell east>/opt/continuent/tungsten/tungsten-replicator/bin/trepctl onlineshell east>/opt/replicator/tungsten/cluster-home/bin/startall
Ensure that the new service is functioning normally:
shell east>echo ls | /opt/continuent/tungsten/tungsten-manager/bin/cctrlshell east>/opt/replicator/tungsten/tungsten-replicator/bin/trepctl status
Bring the remote replicators back ONLINE
shell west> /opt/replicator/tungsten/tungsten-replicator/bin/trepctl -service east onlineSet the cluster to normal operational state:
cctrl>router * onlinecctrl>set policy automatic
Reprovision the remaining nodes in the
east cluster
shell east{slave1}> /opt/continuent/tungsten/tungsten-replicator/scripts/tungsten_provision_slave \
--source east{master}
shell east{slave1}> /opt/continuent/tungsten/cluster-home/bin/startall
shell east{slave1}> /opt/replicator/tungsten/cluster-home/bin/startall
shell east{slave2}> /opt/continuent/tungsten/tungsten-replicator/scripts/tungsten_provision_slave \
--source east{slave1}
shell east{slave2}> /opt/continuent/tungsten/cluster-home/bin/startall
shell east{slave2}> /opt/replicator/tungsten/cluster-home/bin/startall