org.jgroups.protocols
Class PING

java.lang.Object
  org.jgroups.stack.Protocol
      org.jgroups.protocols.Discovery
          org.jgroups.protocols.PING

Direct Known Subclasses:

BPING, MPING

public class PING
extends Discovery

The PING protocol retrieves the initial membership by mcasting a discovery request (via the multicast capable transport) to all current cluster members

The responses should allow us to determine the coordinator which we have to contact, e.g. in case we want to join the group. When we are a server (after having received the BECOME_SERVER event), we'll respond to discovery requests with a discovery response.

Author:

Bela Ban

Nested Class Summary

Nested classes/interfaces inherited from class org.jgroups.protocols.Discovery

Discovery.Responses

Field Summary

Fields inherited from class org.jgroups.protocols.Discovery

break_on_coord_rsp, current_coord, force_sending_discovery_rsps, group_addr, is_coord, is_leaving, is_server, local_addr, members, num_discovery_requests, num_initial_members, num_initial_srv_members, ping_responses, return_entire_cache, stagger_timeout, timeout, timer, use_disk_cache, view

Fields inherited from class org.jgroups.stack.Protocol

down_prot, ergonomics, id, log, name, stack, stats, up_prot

Constructor Summary

PING()

Method Summary

java.util.Collection<PhysicalAddress>	fetchClusterMembers(java.lang.String cluster_name) Grab all current cluster members
boolean	isDynamic()
boolean	sendDiscoveryRequestsInParallel() Whether or not to send each discovery request on a separate (timer) thread.

Methods inherited from class org.jgroups.protocols.Discovery

deserialize, discoveryRequestReceived, down, findAllViews, findAllViewsAsString, findInitialMembers, findInitialMembersAsString, findMembers, getCurrentCoord, getNumberOfDiscoveryRequestsSent, getNumInitialMembers, getTimeout, getView, getViewId, handleConnect, handleDisconnect, init, isMergeRunning, providedUpServices, resetStats, sendDiscoveryRequest, sendDiscoveryResponse, sendMcastDiscoveryRequest, serializeWithoutView, setForceSendingDiscoveryRsps, setNumInitialMembers, setTimeout, start, stop, up

Methods inherited from class org.jgroups.stack.Protocol

destroy, dumpStats, enableStats, getConfigurableObjects, getDownProtocol, getDownServices, getId, getIdsAbove, getLevel, getName, getProtocolStack, getSocketFactory, getThreadFactory, getTransport, getUpProtocol, getUpServices, getValue, isErgonomics, printStats, providedDownServices, requiredDownServices, requiredUpServices, resetStatistics, setDownProtocol, setErgonomics, setId, setLevel, setProtocolStack, setSocketFactory, setUpProtocol, setValue, setValues, statsEnabled

Methods inherited from class java.lang.Object

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

Constructor Detail

PING

public PING()

Method Detail

isDynamic

public boolean isDynamic()

Specified by:

isDynamic in class Discovery

fetchClusterMembers

public java.util.Collection<PhysicalAddress> fetchClusterMembers(java.lang.String cluster_name)

Description copied from class: Discovery

Grab all current cluster members

Specified by:

fetchClusterMembers in class Discovery

Returns:

A list of the cluster members (usually IpAddresses), or null if the transport is multicast-enabled. Returns an empty list if no cluster members could be found.

sendDiscoveryRequestsInParallel

public boolean sendDiscoveryRequestsInParallel()

Description copied from class: Discovery

Whether or not to send each discovery request on a separate (timer) thread. If disabled, a discovery request will be sent to all members fetched by Discovery.fetchClusterMembers(String) sequentially

Specified by:

sendDiscoveryRequestsInParallel in class Discovery