org.jgroups.protocols

Class JDBC_PING

java.lang.Object

org.jgroups.stack.Protocol

org.jgroups.protocols.Discovery

org.jgroups.protocols.JDBC_PING

public class JDBC_PING
extends Discovery

Discovery protocol using a JDBC connection to a shared database. Connection options can be defined as configuration properties, or the JNDI name of a DataSource can be provided (avoid providing both).

Both the schema and the used SQL statements can be customized; make sure the order of parameters of such customized SQL statements is maintained and that compatible types are used for the columns. The recommended schema uses a single table, with two String columns being used primary key (local address, cluster name) and a third column to store the serialized form of the objects needed by JGroups.

A default table will be created at first connection, errors during this operation are not considered critical. Set the initialize_sql to an empty value to prevent this initial table creation, or change it to create a customized table.

Since:

2.12

Author:

Sanne Grinovero

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	JDBC_PING.InfoWriter Class which calls writeOwnInformation 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 java.lang.String	clear_sql
protected boolean	clear_table_on_view_change
protected java.lang.String	connection_driver
protected java.lang.String	connection_password
protected java.lang.String	connection_url
protected java.lang.String	connection_username
protected java.lang.String	contains_sql
protected java.lang.String	datasource_jndi_name
protected java.lang.String	delete_single_sql
protected java.util.concurrent.Future<?>	info_writer
protected int	info_writer_max_writes_after_view
protected long	info_writer_sleep_time
protected java.lang.String	initialize_sql
protected java.lang.String	insert_single_sql
protected boolean	register_shutdown_hook
protected java.lang.String	select_all_pingdata_sql

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
JDBC_PING()

Method Summary

Modifier and Type	Method and Description
protected void	attemptSchemaInitialization()
protected void	clearTable()
protected void	closeConnection(java.sql.Connection connection)
protected boolean	contains(java.lang.String cluster_name, Address addr)
protected void	delete(java.sql.Connection connection, java.lang.String clustername, java.lang.String addressToDelete)
protected void	delete(java.lang.String clustername, java.lang.String addressToDelete)
protected void	deleteSelf()
java.lang.Object	down(Event evt) An event is to be sent down the stack.
void	findMembers(java.util.List<Address> members, boolean initial_discovery, Responses responses) Fetches information (e.g.
protected java.sql.Connection	getConnection()
protected javax.sql.DataSource	getDataSourceFromJNDI(java.lang.String name)
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.
protected void	insert(java.sql.Connection connection, PingData data, java.lang.String clustername, java.lang.String address)
boolean	isDynamic()
boolean	isInfoWriterRunning()
protected void	loadDriver()
protected void	readAll(java.sql.Connection connection, java.util.List<Address> members, java.lang.String clustername, Responses rsps)
protected void	readAll(java.util.List<Address> members, java.lang.String clustername, Responses responses)
protected void	remove(java.lang.String clustername, Address addr)
protected void	startInfoWriter()
void	stop() This method is called on a Channel.disconnect().
protected void	stopInfoWriter()
protected void	verifyconfigurationParameters()
void	writeInfo()
protected void	writeOwnInformation(boolean overwrite) Write my own UUID,logical name and physical address to a file
protected void	writeToDB(PingData data, java.lang.String clustername, boolean overwrite)

Methods inherited from class org.jgroups.protocols.Discovery

addDiscoveryResponseToCaches, 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, read, readPingData, resetStats, returnEntireCache, returnEntireCache, sendCacheInformation, sendDiscoveryResponse, serializeWithoutView, setForceSendingDiscoveryRsps, setNumInitialMembers, setTimeout, staggerTimeout, staggerTimeout, start, startCacheDissemination, timeout, timeout, up, useDiskCache, useDiskCache, weedOutCompletedDiscoveryResponses, write

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

connection_url

protected java.lang.String connection_url

connection_username

protected java.lang.String connection_username

connection_password

protected java.lang.String connection_password

connection_driver

protected java.lang.String connection_driver

initialize_sql

protected java.lang.String initialize_sql

insert_single_sql

protected java.lang.String insert_single_sql

delete_single_sql

protected java.lang.String delete_single_sql

clear_sql

protected java.lang.String clear_sql

select_all_pingdata_sql

protected java.lang.String select_all_pingdata_sql

contains_sql

protected java.lang.String contains_sql

datasource_jndi_name

protected java.lang.String datasource_jndi_name

register_shutdown_hook

protected boolean register_shutdown_hook

info_writer_max_writes_after_view

protected int info_writer_max_writes_after_view

info_writer_sleep_time

protected long info_writer_sleep_time

clear_table_on_view_change

protected boolean clear_table_on_view_change

info_writer

protected java.util.concurrent.Future<?> info_writer

Constructor Detail

JDBC_PING

public JDBC_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 java.lang.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:

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

stop

public void stop()

Description copied from class: Protocol

This method is called on a Channel.disconnect(). Stops work (e.g. by closing multicast socket). Will be called from top to bottom. This means that at the time of the method invocation the neighbor protocol below is still working. This method will replace the STOP, STOP_OK, CLEANUP and CLEANUP_OK events. The ProtocolStack guarantees that when this method is called all messages in the down queue will have been flushed

Overrides:

stop in class Discovery

down

public java.lang.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(java.util.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

handleView

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

writeOwnInformation

protected void writeOwnInformation(boolean overwrite)

Write my own UUID,logical name and physical address to a file

writeToDB

protected void writeToDB(PingData data,
                         java.lang.String clustername,
                         boolean overwrite)

contains

protected boolean contains(java.lang.String cluster_name,
                           Address addr)

remove

protected void remove(java.lang.String clustername,
                      Address addr)

readAll

protected void readAll(java.util.List<Address> members,
                       java.lang.String clustername,
                       Responses responses)

readAll

protected void readAll(java.sql.Connection connection,
                       java.util.List<Address> members,
                       java.lang.String clustername,
                       Responses rsps)
                throws java.sql.SQLException

Throws:

java.sql.SQLException

attemptSchemaInitialization

protected void attemptSchemaInitialization()

loadDriver

protected void loadDriver()

getConnection

protected java.sql.Connection getConnection()

insert

protected void insert(java.sql.Connection connection,
                      PingData data,
                      java.lang.String clustername,
                      java.lang.String address)
               throws java.sql.SQLException

Throws:

java.sql.SQLException

delete

protected void delete(java.sql.Connection connection,
                      java.lang.String clustername,
                      java.lang.String addressToDelete)
               throws java.sql.SQLException

Throws:

java.sql.SQLException

delete

protected void delete(java.lang.String clustername,
                      java.lang.String addressToDelete)
               throws java.sql.SQLException

Throws:

java.sql.SQLException

deleteSelf

protected void deleteSelf()
                   throws java.sql.SQLException

Throws:

java.sql.SQLException

clearTable

protected void clearTable()

closeConnection

protected void closeConnection(java.sql.Connection connection)

getDataSourceFromJNDI

protected javax.sql.DataSource getDataSourceFromJNDI(java.lang.String name)

verifyconfigurationParameters

protected void verifyconfigurationParameters()

startInfoWriter

protected void startInfoWriter()

stopInfoWriter

protected void stopInfoWriter()