The default replication behaviour of a service is defined by the service in its deployment descriptor, but may be overridden by an administrator after the service has been installed into the SLEE.
Default replication behaviour
Default replication behaviour is specified by a service in its oc-service.xml extension service deployment descriptor.
The service can specify the conditions under which the application state of the service will be replicated by using the following replication selectors:
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Savanna — Service replication will occur if the namespace the service is installed in replicates application state over the traditional Savanna framework.
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KeyValueStore — Service replication will occur if the namespace the service is installed in utilises a key/value store to persist application state.
-
Always — The service will always be replicated regardless of any underlying replication mechanism.
Zero or more replication selectors can be specified by the service. If any condition for replication is matched at deployment time then the service application state will be replicated. If not, no replication will take place for that service.
Configuring replication behaviour
The default replication selectors specified by a service can be changed by an administrator after the service is installed, but before it is deployed, using the following rhino-console commands or related MBean operations.
Console commands
getservicereplicationselectors
Command |
getservicereplicationselectors <service-id>
Description
Get the replication selectors for a service
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|---|---|
Example |
To check the current replication selectors for a service: $ ./rhino-console getservicereplicationselectors name=service1,vendor=OpenCloud,version=1.0 Service ServiceID[name=service1,vendor=OpenCloud,version=1.0] current replication selectors are: [KEYVALUESTORE] |
setservicereplicationselectors
Command |
setservicereplicationselectors <service-id> -none|selector*
Description
Set the replication selectors for a service, valid selectors are: [ALWAYS,
SAVANNA, KEYVALUESTORE]
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|---|---|
Example |
The change the replication selectors for a service: $ ./rhino-console setservicereplicationselectors name=service1,vendor=OpenCloud,version=1.0 SAVANNA KEYVALUESTORE Service ServiceID[name=service1,vendor=OpenCloud,version=1.0] replication selectors set to [SAVANNA, KEYVALUESTORE] |
MBean operations: getReplicationSelectors and setReplicationSelectors
MBean |
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|---|---|
Rhino extension |
Get the current replication selectors for a service.
public ReplicationSelector[] getReplicationSelectors(ServiceID id)
throws NullPointerException, UnrecognizedServiceException, ManagementException;
Set the replication selectors for a service.
public void setReplicationSelectors(ServiceID id, ReplicationSelector[] selectors)
throws NullPointerException, UnrecognizedServiceException, InvalidStateException, ManagementException;
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