jgroup.relacs.daemon
Class Daemon

java.lang.Object
  jgroup.relacs.daemon.Daemon

All Implemented Interfaces:

java.rmi.Remote, DaemonService, EventTags, MssConstants, MssUser

public final class Daemon
extends java.lang.Object
implements DaemonService, MssUser, EventTags, MssConstants

The Daemon is the access interface for the group membership service and reliable multicast service.

Since:

Jgroup 0.1

Author:

Alberto Montresor, Hein Meling, Marcin Solarski

Field Summary

static byte	R_ACK
static byte	R_ESTIM
static java.lang.String[]	R_ExTAGS
static byte	R_FORWARD
static byte	R_INTEREST
static byte	R_JOIN
static byte	R_JOINACK
static byte	R_LEAVE
static byte	R_MCAST
static byte	R_NOGID
static byte	R_NOINTEREST
static byte	R_PROP
static byte	R_RESULT
static byte	R_SYMM
static byte	R_SYNCH
static java.lang.String[]	R_TAGS
static byte	R_VIEW
static int	S_ESTIMATE
static int	S_IDLE
static int	S_SYNCH

Fields inherited from interface jgroup.relacs.daemon.DaemonService

DAEMON_NAME

Fields inherited from interface jgroup.relacs.events.EventTags

DAEMON_FAILURE_EVENT, DELIVERY_ACK, DELIVERY_EVENT, INSTALL_ACK, INSTALL_EVENT, JOIN_REQUEST, LEAVE_REQUEST, MEMBER_LEFT_EVENT, MULTICAST_REQUEST, PREPARE_ACK, PREPARE_EVENT

Fields inherited from interface jgroup.relacs.mss.MssConstants

ALL, EHANDLER_PRIORITY, HEADER_SIZE, MINIMUM_ALIVE_VALUE, MSS_HEADER_SIZE, MSSUSER_PRIORITY, NACKSUPPRESSION, NI_PRIORITY, OVERHEAD_SIZE, ROUTING_ENABLED, TRAILER_SIZE, UNDEF, UNREACHABLE

Method Summary

void	addEvent(Event event) Adds an event generated by a member to the local queue of events.
static void	bindLocalDaemon(DaemonService daemonService)
static Daemon	createDaemon(TransportConfig conf) Create a daemon object on the local host.
MemberId	getMemberId(EndPoint localEndPoint) Returns a new member id for a new member.
void	localReceive(Event event) Handles a message received by a local member.
void	localSuspect(MemberId memberId) Invoked to notify the objects implementing this interface that a remote object is not responding to remote method invocations, and thus should be crashed.
static DaemonService	lookupLocalDaemon() Obtain a remote reference for a local daemon.
int	members() Returns the number of members associated with this Jgroup daemon.
static DaemonService	quickLookupLocalDaemon() Lookup a local daemon without retrying.
void	remoteReceive(byte tag, InMessage stream, EndPoint src) Handles a message received from a remote host.
void	remoteSuspect(EndPoint[] trset, EndPoint[] nrset, EndPoint[] nuset, EndPoint[] newinc) Handles variations in the mss-reachability

Methods inherited from class java.lang.Object

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

Field Detail

S_IDLE

public static final int S_IDLE

See Also:

Constant Field Values

S_SYNCH

public static final int S_SYNCH

See Also:

Constant Field Values

S_ESTIMATE

public static final int S_ESTIMATE

See Also:

Constant Field Values

R_MCAST

public static final byte R_MCAST

See Also:

Constant Field Values

R_ACK

public static final byte R_ACK

See Also:

Constant Field Values

R_ESTIM

public static final byte R_ESTIM

See Also:

Constant Field Values

R_FORWARD

public static final byte R_FORWARD

See Also:

Constant Field Values

R_SYNCH

public static final byte R_SYNCH

See Also:

Constant Field Values

R_SYMM

public static final byte R_SYMM

See Also:

Constant Field Values

R_PROP

public static final byte R_PROP

See Also:

Constant Field Values

R_VIEW

public static final byte R_VIEW

See Also:

Constant Field Values

R_RESULT

public static final byte R_RESULT

See Also:

Constant Field Values

R_NOGID

public static final byte R_NOGID

See Also:

Constant Field Values

R_INTEREST

public static final byte R_INTEREST

See Also:

Constant Field Values

R_NOINTEREST

public static final byte R_NOINTEREST

See Also:

Constant Field Values

R_LEAVE

public static final byte R_LEAVE

See Also:

Constant Field Values

R_JOIN

public static final byte R_JOIN

See Also:

Constant Field Values

R_JOINACK

public static final byte R_JOINACK

See Also:

Constant Field Values

R_TAGS

public static final java.lang.String[] R_TAGS

R_ExTAGS

public static final java.lang.String[] R_ExTAGS

Method Detail

createDaemon

public static Daemon createDaemon(TransportConfig conf)
                           throws ConfigurationException,
                                  java.io.IOException

Create a daemon object on the local host.

Parameters:

conf - Transport configuration parameters

Returns:

A daemon instance.

Throws:

java.io.IOException - Raised if a daemon could not be created due to a problem with port initialization. Another application (or daemon) may be using our socket port.

ConfigurationException - Raised if a daemon could not be created due to a misconfiguration.

bindLocalDaemon

public static void bindLocalDaemon(DaemonService daemonService)
                            throws JgroupException

Throws:

JgroupException

lookupLocalDaemon

public static DaemonService lookupLocalDaemon()
                                       throws JgroupException

Obtain a remote reference for a local daemon.

This method can be invoked if we are unable to bind a daemon instance to the port specifed in the distributed system configuration. This may occur on two occasions; (i) there is another daemon running on the local host, or (ii) some other application is using the specified port. The former case may also occur before the other daemon has managed to register its reference in the bootstrap registry, thus we need to retry a few times before concluding that it is some other application.

Returns:

The remote DaemonService object

Throws:

JgroupException - Raised if no daemon could be found (e.g., not stored in the registry).

quickLookupLocalDaemon

public static DaemonService quickLookupLocalDaemon()

Lookup a local daemon without retrying.

getMemberId

public MemberId getMemberId(EndPoint localEndPoint)
                     throws java.rmi.RemoteException

Returns a new member id for a new member. The new member id is obtained by concatenating the endpoint of this daemon, the incarnation number used to distinguish different incarnation of the same endpoint, and a sequence number used to distinguish different members.

Specified by:

getMemberId in interface DaemonService

Throws:

java.rmi.RemoteException

members

public int members()
            throws java.rmi.RemoteException

Returns the number of members associated with this Jgroup daemon.

Specified by:

members in interface DaemonService

Throws:

java.rmi.RemoteException

addEvent

public void addEvent(Event event)
              throws java.rmi.RemoteException

Adds an event generated by a member to the local queue of events.

Specified by:

addEvent in interface DaemonService

Throws:

java.rmi.RemoteException

remoteReceive

public void remoteReceive(byte tag,
                          InMessage stream,
                          EndPoint src)

Handles a message received from a remote host.

Specified by:

remoteReceive in interface MssUser

Parameters:

tag - the tag identifying the type of message

stream - the message, represented by a InMessage object

src - the sender of the message

localReceive

public void localReceive(Event event)

Handles a message received by a local member.

Specified by:

localReceive in interface MssUser

Parameters:

event - represents the received message

remoteSuspect

public void remoteSuspect(EndPoint[] trset,
                          EndPoint[] nrset,
                          EndPoint[] nuset,
                          EndPoint[] newinc)

Handles variations in the mss-reachability

Specified by:

remoteSuspect in interface MssUser

Parameters:

trset - set of all (total) reachable hosts

nrset - set of reachable hosts that were unreachable

nuset - set of unreachable hosts that were reachable

newinc - set of hosts who has a new incarnation identifier

localSuspect

public void localSuspect(MemberId memberId)

Invoked to notify the objects implementing this interface that a remote object is not responding to remote method invocations, and thus should be crashed.

Specified by:

localSuspect in interface MssUser

Parameters:

memberId - a callback object identifying the suspected object; this object has been stored in the Mss through the addPingListener invocation on the Mss.