Package org.jgroups.protocols.dns

Class DNS_PING

java.lang.Object

org.jgroups.stack.Protocol

org.jgroups.protocols.Discovery

org.jgroups.protocols.dns.DNS_PING

All Implemented Interfaces:

Lifecycle

public class DNS_PING
extends Discovery

Nested Class Summary

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

Discovery.DiscoveryCacheDisseminationTask

Field Summary

Fields

Modifier and Type	Field	Description
private static final String	DEFAULT_DNS_FACTORY
private static final String	DEFAULT_DNS_RECORD_TYPE
protected String	dns_address
protected String	dns_context_factory
protected String	dns_query
protected String	dns_record_type
protected DNSResolver	dns_resolver
private int	portRange
protected boolean	probe_transport_ports
private int	transportPort

Fields inherited from class org.jgroups.protocols.Discovery

async_discovery, async_discovery_use_separate_thread_per_request, break_on_coord_rsp, cluster_name, current_coord, discovery_req_futures, discovery_rsp_callback, discovery_rsp_expiry_time, is_coord, is_leaving, is_server, max_members_in_discovery_request, max_rank_to_reply, num_discovery_requests, num_discovery_runs, ping_responses, return_entire_cache, send_cache_on_join, sends_can_block, stagger_timeout, timer, transport, transport_supports_multicasting, use_disk_cache, view, WHITESPACE

Fields inherited from class org.jgroups.stack.Protocol

after_creation_hook, down_prot, ergonomics, id, local_addr, log, policies, stack, stats, up_prot

Constructor Summary

Constructors

Constructor	Description
DNS_PING()

Method Summary

Modifier and Type	Method	Description
void	destroy()	This method is called on a JChannel.close().
String	fetchFromDns()
void	findMembers(List<Address> members, boolean initial_discovery, Responses responses)	Fetches information (e.g.
String	getDNSAddress()
String	getDNSContextFactory()
(package private) List<Address>	getMembers(String dns_query, DNSResolver.DNSRecordType dns_record_type)	Gets a list of IP addresses for the provided DNS query list and record type.
void	init()	Called after a protocol has been created and before the protocol is started.
boolean	isDynamic()
protected void	sendDiscoveryRequest(Message req)
DNS_PING	setDNSQuery(String query)
DNS_PING	setDNSResolver(DNSResolver resolver)
protected void	validateProperties()

Methods inherited from class org.jgroups.protocols.Discovery

addDiscoveryResponseToCaches, addResponse, addResponse, addressAsString, addToCache, breakOnCoordResponse, breakOnCoordResponse, callFindMembersInAllDiscoveryProtocols, clearRequestFutures, deserialize, discoveryRequestReceived, discoveryRspExpiryTime, disseminateDiscoveryInformation, down, dumpCache, findInitialMembersAsString, findMembers, findTopmostDiscoveryProtocol, getClusterName, getCurrentCoord, getNumberOfDiscoveryRequestsSent, getView, getViewId, handle, handleConnect, handleDisconnect, handleDiscoveryResponse, handleDiscoveryResponse, isCoord, isMergeRunning, marshal, marshal, marshal, print, providedUpServices, read, readPingData, resetStats, returnEntireCache, returnEntireCache, sendCacheInformation, sendCacheOnJoin, sendCacheOnJoin, sendDiscoveryResponse, sendDiscoveryResponse, serializeWithoutView, setClusterName, staggerTimeout, staggerTimeout, start, startCacheDissemination, stop, up, up, up, useDiskCache, useDiskCache, weedOutCompletedDiscoveryResponses, write

Methods inherited from class org.jgroups.stack.Protocol

accept, addPolicy, addr, addr, afterCreationHook, down, down, enableStats, getAddress, getComponents, getDownProtocol, getDownServices, getId, getIdsAbove, getLevel, getLog, getName, getPolicies, getProtocolStack, getSocketFactory, getThreadFactory, getTransport, getUpProtocol, getUpServices, getValue, isErgonomics, level, parse, policies, providedDownServices, removePolicy, requiredDownServices, requiredUpServices, resetStatistics, setAddress, setDownProtocol, setErgonomics, setId, setLevel, setPolicies, setProtocolStack, setSocketFactory, setUpProtocol, setValue, statsEnabled, toString

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_DNS_FACTORY

private static final String DEFAULT_DNS_FACTORY

See Also:

• Constant Field Values

DEFAULT_DNS_RECORD_TYPE

private static final String DEFAULT_DNS_RECORD_TYPE

See Also:

• Constant Field Values

dns_context_factory

protected String dns_context_factory

dns_address

protected String dns_address

dns_record_type

protected String dns_record_type

dns_query

protected String dns_query

probe_transport_ports

protected boolean probe_transport_ports

dns_resolver

protected volatile DNSResolver dns_resolver

transportPort

private int transportPort

portRange

private int portRange

Constructor Details

DNS_PING

public DNS_PING()

Method Details

init

public void init()
          throws Exception

Description copied from class: Protocol

Called after a protocol has been created and before the protocol is started. Attributes are already set. Other protocols are not yet connected and events cannot yet be sent.

Specified by:

init in interface Lifecycle

Overrides:

init in class Discovery

Throws:

Exception - Thrown if protocol cannot be initialized successfully. This will cause the ProtocolStack to fail, so the the channel constructor will throw an exception

setDNSResolver

public DNS_PING setDNSResolver(DNSResolver resolver)

setDNSQuery

public DNS_PING setDNSQuery(String query)

getDNSContextFactory

public String getDNSContextFactory()

getDNSAddress

public String getDNSAddress()

validateProperties

protected void validateProperties()

destroy

public void destroy()

Description copied from class: Protocol

This method is called on a JChannel.close(). Does some cleanup; after the call, the VM will terminate

Specified by:

destroy in interface Lifecycle

Overrides:

destroy in class Protocol

isDynamic

public boolean isDynamic()

Specified by:

isDynamic in class Discovery

getMembers

List<Address> getMembers(String dns_query,
 DNSResolver.DNSRecordType dns_record_type)

Gets a list of IP addresses for the provided DNS query list and record type.

Parameters:

dns_query - A comma-separated list of DNS queries. Must not be null.

dns_record_type - The DNS record type.

Returns:

A list of IP addresses corresponding to the provided DNS query list and record type. An empty list is returned if the provided DNS query does not resolve to any IP addresses.

Throws:

NullPointerException - if dns_query is null.

fetchFromDns

public String fetchFromDns()

findMembers

public void findMembers(List<Address> members,
 boolean initial_discovery,
 Responses responses)

Description copied from class: Discovery

Fetches information (e.g. physical address, logical name) for the given member addresses. Needs to add responses to the Responses object. If Discovery.async_discovery is true, this method will be called in a separate thread, otherwise the caller's thread will be used.

Specified by:

findMembers in class Discovery

Parameters:

members - A list of logical addresses (typically UUIDs). If null, then information for all members is fetched

initial_discovery - Set to true if this is for the initial membership discovery. Some protocols (e.g. file based ones) may return only the information for the coordinator(s).

responses - The list to which responses should be added

sendDiscoveryRequest

protected void sendDiscoveryRequest(Message req)