org.jgroups.protocols

Class FILE_PING

java.lang.Object

org.jgroups.stack.Protocol

org.jgroups.protocols.Discovery

org.jgroups.protocols.FILE_PING

Direct Known Subclasses:

RACKSPACE_PING, S3_PING, SWIFT_PING

public class FILE_PING
extends Discovery

Simple discovery protocol which uses a file on shared storage such as an SMB share, NFS mount or S3. The local address information, e.g. UUID and physical addresses mappings are written to the file and the content is read and added to our transport's UUID-PhysicalAddress cache.

The design is at doc/design/FILE_PING.txt

Author:

Bela Ban

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	FILE_PING.InfoWriter Class which calls writeAll() a few times.

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

Discovery.DiscoveryCacheDisseminationTask

Field Summary

Fields

Modifier and Type	Field and Description
protected static FilenameFilter	filter
protected Future<?>	info_writer
protected int	info_writer_max_writes_after_view
protected long	info_writer_sleep_time
protected long	interval Deprecated.
protected String	location
protected int	reads
protected static Pattern	regexp
protected boolean	remove_all_files_on_view_change
protected boolean	remove_old_coords_on_view_change
protected File	root_dir
protected static String	SUFFIX
protected int	writes

Fields inherited from class org.jgroups.protocols.Discovery

always_send_physical_addr_with_discovery_request, async_discovery, async_discovery_use_separate_thread_per_request, break_on_coord_rsp, cluster_name, current_coord, discovery_rsp_expiry_time, force_sending_discovery_rsps, is_coord, is_leaving, is_server, local_addr, max_members_in_discovery_request, members, num_discovery_requests, num_initial_members, num_initial_srv_members, ping_responses, return_entire_cache, send_cache_on_join, stagger_timeout, timeout, timer, transport_supports_multicasting, use_disk_cache, view, WHITESPACE

Fields inherited from class org.jgroups.stack.Protocol

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

Constructor Summary

Constructors

Constructor and Description
FILE_PING()

Method Summary

Modifier and Type	Method and Description
protected boolean	addDiscoveryResponseToCaches(Address mbr, String logical_name, PhysicalAddress physical_addr) Only add the discovery response if the logical address is not present or the physical addrs are different
protected static String	addressToFilename(Address mbr)
protected void	createRootDir()
protected boolean	deleteFile(File file)
Object	down(Event evt) An event is to be sent down the stack.
void	findMembers(List<Address> members, boolean initial_discovery, Responses responses) Fetches information (e.g.
protected void	handleView(View new_view, View old_view, boolean coord_changed)
void	init() Called after instance has been created (null constructor) and before protocol is started.
boolean	isDynamic()
boolean	isInfoWriterRunning()
protected List<PingData>	read(File file)
protected List<PingData>	read(InputStream in)
protected void	readAll(List<Address> members, String clustername, Responses responses)
protected void	remove(String clustername, Address addr)
protected void	removeAll(String clustername) Removes all files for the given cluster name
void	resetStats()
protected void	startInfoWriter()
protected void	stopInfoWriter()
protected void	write(List<PingData> list, OutputStream out)
protected void	write(List<PingData> list, String clustername)
protected void	writeAll() Write information about all of the member to file (only if I'm the coord)
void	writeInfo()

Methods inherited from class org.jgroups.protocols.Discovery

addResponse, addressAsString, addToCache, breakOnCoordResponse, breakOnCoordResponse, deserialize, discoveryRequestReceived, discoveryRspExpiryTime, disseminateDiscoveryInformation, dumpCache, findInitialMembersAsString, findMembers, forceDiscoveryResponses, forceDiscoveryResponses, getCurrentCoord, getNumberOfDiscoveryRequestsSent, getNumInitialMembers, getTimeout, getView, getViewId, handleConnect, handleDisconnect, handleDiscoveryResponse, isCoord, isMergeRunning, marshal, numInitialMembers, numInitialMembers, providedUpServices, readPingData, returnEntireCache, returnEntireCache, sendCacheInformation, sendDiscoveryResponse, serializeWithoutView, setForceSendingDiscoveryRsps, setNumInitialMembers, setTimeout, staggerTimeout, staggerTimeout, start, startCacheDissemination, stop, timeout, timeout, up, useDiskCache, useDiskCache, weedOutCompletedDiscoveryResponses

Methods inherited from class org.jgroups.stack.Protocol

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

Methods inherited from class java.lang.Object

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

Field Detail

SUFFIX

protected static final String SUFFIX

See Also:

Constant Field Values

regexp

protected static final Pattern regexp

location

protected String location

interval

@Deprecated
protected long interval

Deprecated.

remove_old_coords_on_view_change

protected boolean remove_old_coords_on_view_change

remove_all_files_on_view_change

protected boolean remove_all_files_on_view_change

info_writer_max_writes_after_view

protected int info_writer_max_writes_after_view

info_writer_sleep_time

protected long info_writer_sleep_time

writes

protected int writes

reads

protected int reads

root_dir

protected File root_dir

filter

protected static final FilenameFilter filter

info_writer

protected Future<?> info_writer

Constructor Detail

FILE_PING

public FILE_PING()

Method Detail

isDynamic

public boolean isDynamic()

Specified by:

isDynamic in class Discovery

isInfoWriterRunning

public boolean isInfoWriterRunning()

writeInfo

public void writeInfo()

init

public void init()
          throws Exception

Description copied from class: Protocol

Called after instance has been created (null constructor) and before protocol is started. Properties are already set. Other protocols are not yet connected and events cannot yet be sent.

Overrides:

init in class Discovery

Throws:

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

resetStats

public void resetStats()

Overrides:

resetStats in class Discovery

down

public Object down(Event evt)

Description copied from class: Protocol

An event is to be sent down the stack. The layer may want to examine its type and perform some action on it, depending on the event's type. If the event is a message MSG, then the layer may need to add a header to it (or do nothing at all) before sending it down the stack using down_prot.down(). In case of a GET_ADDRESS event (which tries to retrieve the stack's address from one of the bottom layers), the layer may need to send a new response event back up the stack using up_prot.up().

Overrides:

down in class Discovery

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

addDiscoveryResponseToCaches

protected boolean addDiscoveryResponseToCaches(Address mbr,
                                               String logical_name,
                                               PhysicalAddress physical_addr)

Only add the discovery response if the logical address is not present or the physical addrs are different

Overrides:

addDiscoveryResponseToCaches in class Discovery

addressToFilename

protected static String addressToFilename(Address mbr)

createRootDir

protected void createRootDir()

handleView

protected void handleView(View new_view,
                          View old_view,
                          boolean coord_changed)

remove

protected void remove(String clustername,
                      Address addr)

removeAll

protected void removeAll(String clustername)

Removes all files for the given cluster name

readAll

protected void readAll(List<Address> members,
                       String clustername,
                       Responses responses)

read

protected List<PingData> read(File file)
                       throws Exception

Throws:

Exception

read

protected List<PingData> read(InputStream in)

Overrides:

read in class Discovery

writeAll

protected void writeAll()

Write information about all of the member to file (only if I'm the coord)

write

protected void write(List<PingData> list,
                     String clustername)

write

protected void write(List<PingData> list,
                     OutputStream out)
              throws Exception

Overrides:

write in class Discovery

Throws:

Exception

deleteFile

protected boolean deleteFile(File file)

startInfoWriter

protected void startInfoWriter()

stopInfoWriter

protected void stopInfoWriter()