org.apache.river.mahalo

Class JoinStateManager

java.lang.Object

org.apache.river.reliableLog.LogHandler

org.apache.river.mahalo.JoinStateManager

class JoinStateManager
extends LogHandler

JoinStateManager provides a utility that manages a service's join state (optionally persisting that state) and manages the join protocol protocol on behalf of the service.

Author:

Sun Microsystems, Inc.

See Also:

ServiceIDListener, LogHandler

Field Summary

Fields

Modifier and Type	Field and Description
private Entry[]	attributes The join state, this data needs to be persisted between restarts
private DiscoveryManagement	dm Object used to find lookups.
private String[]	groups
private boolean	initial Conceptually, true if this is the first time this service has come up, implemented as if there was no previous state then this is the first time.
private static Logger	initlogger Logger for logging initialization related messages
private LookupLocator[]	locators
private ReliableLog	log The object coordinating our persistent state.
private ProxyPreparer	lookupLocatorPreparer ProxyPreparer for LookupLocators
private JoinManager	mgr JoinManager that is handling the details of binding into Jini lookup services.
private static Logger	operationsLogger Logger for logging operations related messages
private static Logger	persistenceLogger Logger for transaction persistence related messages
private Uuid	serviceUuid Service's internal Uuid which needs to be persisted

Constructor Summary

Constructors

Constructor and Description
JoinStateManager(String logPath) Simple constructor.

Method Summary

Modifier and Type	Method and Description
void	addLookupAttributes(Entry[] attrSets) Add attribute sets for the service.
void	addLookupGroups(String[] groups) Add new groups to the set to join.
void	addLookupLocators(LookupLocator[] locators) Add locators for specific new lookup services to join.
void	applyUpdate(Object update) This method always throws UnsupportedOperationException since FileJoinAdminState should never update a log.
void	destroy()
Entry[]	getLookupAttributes() Get the current attribute sets for the service.
String[]	getLookupGroups() Get the list of groups to join.
LookupLocator[]	getLookupLocators() Get the list of locators of specific lookup services to join.
Uuid	getServiceUuid()
void	modifyLookupAttributes(Entry[] attrSetTemplates, Entry[] attrSets) Modify the current attribute sets, using the same semantics as ServiceRegistration.modifyAttributes.
private void	prepareLocators(LookupLocator[] locators) Apply lookupLocatorPreparer to each locator in the array, replacing the original locator with the result of the prepareProxy call.
private static Entry[]	readAttributes(ObjectInput in) Utility method to read in an array of entities from a ObjectInputStream.
(package private) void	recover()
void	recover(InputStream in) Read the snapshot from a stream.
void	removeLookupGroups(String[] groups) Remove groups from the set to join.
void	removeLookupLocators(LookupLocator[] locators) Remove locators for specific lookup services from the set to join.
void	setLookupGroups(String[] groups) Replace the list of groups to join with a new list.
void	setLookupLocators(LookupLocator[] locators) Replace the list of locators of specific lookup services to join with a new list.
void	setServiceUuid(Uuid serviceUuid)
void	snapshot(OutputStream out) Writes the snapshot to a stream.
(package private) void	startManager(Configuration config, Object service, ServiceID serviceID, Entry[] baseAttributes) Start the manager.
void	stop() Make a good faith attempt to terminate discovery, and cancel any lookup registrations.
private void	update()
private static void	writeAttributes(Entry[] attributes, ObjectOutput out) Utility method to write out an array of entities to an ObjectOutputStream.

Methods inherited from class org.apache.river.reliableLog.LogHandler

readUpdate, writeUpdate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

initlogger

private static final Logger initlogger

Logger for logging initialization related messages

operationsLogger

private static final Logger operationsLogger

Logger for logging operations related messages

persistenceLogger

private static final Logger persistenceLogger

Logger for transaction persistence related messages

lookupLocatorPreparer

private volatile ProxyPreparer lookupLocatorPreparer

ProxyPreparer for LookupLocators

dm

private volatile DiscoveryManagement dm

Object used to find lookups. Has to implement DiscoveryManagement and DiscoveryLocatorManagement as well as DiscoveryGroupManagement.

mgr

private volatile JoinManager mgr

JoinManager that is handling the details of binding into Jini lookup services.

log

private volatile ReliableLog log

The object coordinating our persistent state.

attributes

private volatile Entry[] attributes

The join state, this data needs to be persisted between restarts

locators

private volatile LookupLocator[] locators

groups

private volatile String[] groups

serviceUuid

private volatile Uuid serviceUuid

Service's internal Uuid which needs to be persisted

initial

private volatile boolean initial

Conceptually, true if this is the first time this service has come up, implemented as if there was no previous state then this is the first time.

Constructor Detail

JoinStateManager

JoinStateManager(String logPath)
          throws IOException

Simple constructor.

Throws:

IOException

Method Detail

recover

void recover()
      throws IOException

Throws:

IOException

startManager

void startManager(Configuration config,
                  Object service,
                  ServiceID serviceID,
                  Entry[] baseAttributes)
           throws IOException,
                  ConfigurationException

Start the manager. Start looking for lookup and registering with them.

Parameters:

config - object to use to obtain DiscoveryManagement object, and if this is the initial incarnation of this service, the object used to get the initial set of groups, locators, and deployer defined attributes.

service - The proxy object to register with lookups.

baseAttributes - Any attributes the implementation wants attached, only used if this is the initial incarnation.

Throws:

IOException - if the is problem persisting the initial state or in starting discovery.

ConfigurationException - if the configuration is invalid.

setServiceUuid

public void setServiceUuid(Uuid serviceUuid)

getServiceUuid

public Uuid getServiceUuid()

stop

public void stop()

Make a good faith attempt to terminate discovery, and cancel any lookup registrations.

destroy

public void destroy()

getLookupAttributes

public Entry[] getLookupAttributes()

Get the current attribute sets for the service.

Returns:

the current attribute sets for the service

addLookupAttributes

public void addLookupAttributes(Entry[] attrSets)

Add attribute sets for the service. The resulting set will be used for all future joins. The attribute sets are also added to all currently-joined lookup services.

Parameters:

attrSets - the attribute sets to add

Throws:

java.rmi.RuntimeException - if the change can not be persisted.

modifyLookupAttributes

public void modifyLookupAttributes(Entry[] attrSetTemplates,
                                   Entry[] attrSets)

Modify the current attribute sets, using the same semantics as ServiceRegistration.modifyAttributes. The resulting set will be used for all future joins. The same modifications are also made to all currently-joined lookup services.

Parameters:

attrSetTemplates - the templates for matching attribute sets

attrSets - the modifications to make to matching sets

Throws:

java.rmi.RuntimeException - if the change can not be persisted.

See Also:

ServiceRegistration.modifyAttributes(net.jini.core.entry.Entry[], net.jini.core.entry.Entry[])

getLookupGroups

public String[] getLookupGroups()

Get the list of groups to join. An empty array means the service joins no groups (as opposed to "all" groups).

Returns:

an array of groups to join. An empty array means the service joins no groups (as opposed to "all" groups).

See Also:

setLookupGroups(java.lang.String[])

addLookupGroups

public void addLookupGroups(String[] groups)

Add new groups to the set to join. Lookup services in the new groups will be discovered and joined.

Parameters:

groups - groups to join

Throws:

java.rmi.RuntimeException - if the change can not be persisted.

See Also:

removeLookupGroups(java.lang.String[])

removeLookupGroups

public void removeLookupGroups(String[] groups)

Remove groups from the set to join. Leases are cancelled at lookup services that are not members of any of the remaining groups.

Parameters:

groups - groups to leave

Throws:

java.rmi.RuntimeException - if the change can not be persisted.

See Also:

addLookupGroups(java.lang.String[])

setLookupGroups

public void setLookupGroups(String[] groups)

Replace the list of groups to join with a new list. Leases are cancelled at lookup services that are not members of any of the new groups. Lookup services in the new groups will be discovered and joined.

Parameters:

groups - groups to join

Throws:

java.rmi.RuntimeException - if the change can not be persisted.

See Also:

getLookupGroups()

getLookupLocators

public LookupLocator[] getLookupLocators()

Get the list of locators of specific lookup services to join.

Returns:

the list of locators of specific lookup services to join

See Also:

setLookupLocators(net.jini.core.discovery.LookupLocator[])

addLookupLocators

public void addLookupLocators(LookupLocator[] locators)
                       throws RemoteException

Add locators for specific new lookup services to join. The new lookup services will be discovered and joined.

Parameters:

locators - locators of specific lookup services to join

Throws:

java.rmi.RuntimeException - if the change can not be persisted.

RemoteException

See Also:

removeLookupLocators(net.jini.core.discovery.LookupLocator[])

removeLookupLocators

public void removeLookupLocators(LookupLocator[] locators)
                          throws RemoteException

Remove locators for specific lookup services from the set to join. Any leases held at the lookup services are cancelled.

Parameters:

locators - locators of specific lookup services to leave

Throws:

java.rmi.RuntimeException - if the change can not be persisted.

RemoteException

See Also:

addLookupLocators(net.jini.core.discovery.LookupLocator[])

setLookupLocators

public void setLookupLocators(LookupLocator[] locators)
                       throws RemoteException

Replace the list of locators of specific lookup services to join with a new list. Leases are cancelled at lookup services that were in the old list but are not in the new list. Any new lookup services will be discovered and joined.

Parameters:

locators - locators of specific lookup services to join

Throws:

java.rmi.RuntimeException - if the change can not be persisted.

RemoteException

See Also:

getLookupLocators()

prepareLocators

private void prepareLocators(LookupLocator[] locators)
                      throws RemoteException

Apply lookupLocatorPreparer to each locator in the array, replacing the original locator with the result of the prepareProxy call. If call fails with an exception throw that exception.

Parameters:

locators - the LookupLocators to be prepared.

Throws:

RemoteException - if preparation of any of the locators does.

SecurityException - if preparation of any of the locators does.

update

private void update()

writeAttributes

private static void writeAttributes(Entry[] attributes,
                                    ObjectOutput out)
                             throws IOException

Utility method to write out an array of entities to an ObjectOutputStream. Can be recovered by a call to readAttributes()

Packages each attribute in its own MarshalledObject so a bad codebase on an attribute class will not corrupt the whole array.

Throws:

IOException

readAttributes

private static Entry[] readAttributes(ObjectInput in)
                               throws IOException,
                                      ClassNotFoundException

Utility method to read in an array of entities from a ObjectInputStream. Array should have been written by a call to writeAttributes()

Will try and recover as many attributes as possible. Attributes which can't be recovered won't be returned but they will remain in the log.

Throws:

IOException

ClassNotFoundException

snapshot

public void snapshot(OutputStream out)
              throws IOException

Description copied from class: LogHandler

Writes the snapshot to a stream. This callback is invoked when the client calls the snaphot method of ReliableLog.

Specified by:

snapshot in class LogHandler

Parameters:

out - the output stream

Throws:

IOException

recover

public void recover(InputStream in)
             throws Exception

Description copied from class: LogHandler

Read the snapshot from a stream. This callback is invoked when the client calls the recover method of ReliableLog.

Specified by:

recover in class LogHandler

Parameters:

in - the input stream

Throws:

Exception - can raise any exception

applyUpdate

public void applyUpdate(Object update)
                 throws Exception

This method always throws UnsupportedOperationException since FileJoinAdminState should never update a log.

Specified by:

applyUpdate in class LogHandler

Parameters:

update - the update object

Throws:

Exception - can raise any exception