Class FailoverConnectionProxy

java.lang.Object

com.mysql.jdbc.MultiHostConnectionProxy

com.mysql.jdbc.FailoverConnectionProxy

All Implemented Interfaces:

InvocationHandler

public class FailoverConnectionProxy
extends MultiHostConnectionProxy

A proxy for a dynamic com.mysql.jdbc.Connection implementation that provides failover features for list of hosts. Connection switching occurs on communications related exceptions and/or user defined settings, namely when one of the conditions set in 'secondsBeforeRetryMaster' or 'queriesBeforeRetryMaster' is met.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) class	FailoverConnectionProxy.FailoverJdbcInterfaceProxy	Proxy class to intercept and deal with errors that may occur in any object bound to the current connection.

Nested classes/interfaces inherited from class MultiHostConnectionProxy

MultiHostConnectionProxy.JdbcInterfaceProxy

Field Summary

Fields inherited from class MultiHostConnectionProxy

autoReconnect, closedExplicitly, closedReason, currentConnection, hostList, isClosed, lastExceptionDealtWith, localProps, proxyConnection, thisAsConnection

Method Summary

Modifier and Type	Method	Description
(package private) boolean	connectedToPrimaryHost()	Checks if this proxy is using the primary host in the underlying connection.
(package private) boolean	connectedToSecondaryHost()	Checks if this proxy is using a secondary host in the underlying connection.
(package private) ConnectionImpl	createConnectionForHostIndex(int hostIndex)	Creates a new connection instance for host pointed out by the given host index.
static Connection	createProxyInstance(List<String> hosts, Properties props)
(package private) void	doAbort(Executor executor)	Aborts current connection using the given executor.
(package private) void	doAbortInternal()	Aborts current connection.
(package private) void	doClose()	Closes current connection.
(package private) void	fallBackToPrimaryIfAvailable()	Falls back to primary host or keep current connection if primary not available.
(package private) MultiHostConnectionProxy.JdbcInterfaceProxy	getNewJdbcInterfaceProxy(Object toProxy)	Instantiates a new JdbcInterfaceProxy for the given object.
(package private) void	incrementQueriesIssuedSinceFailover()	Increments counter for query executions.
Object	invokeMore(Object proxy, Method method, Object[] args)	Continuation of the method invocation process, to be implemented within each subclass.
(package private) boolean	isConnected()	Checks if there is a underlying connection for this proxy.
(package private) boolean	isMasterConnection()	Checks if current connection is to a master host.
(package private) boolean	isPrimaryHostIndex(int hostIndex)	Checks if the given host index points to the primary host.
(package private) void	pickNewConnection()	Picks the "best" connection to use from now on.
(package private) boolean	readyToFallBackToPrimaryHost()	Checks if at least one of the required conditions to fall back to primary host is met, which is determined by the properties 'queriesBeforeRetryMaster' and 'secondsBeforeRetryMaster'.
(package private) boolean	shouldExceptionTriggerConnectionSwitch(Throwable t)	Checks if the given throwable should trigger a connection switch.

Methods inherited from class MultiHostConnectionProxy

allowedOnClosedConnection, createConnectionForHost, dealWithInvocationException, getNewWrapperForThisAsConnection, getProxy, initializeHostsSpecs, invalidateConnection, invalidateCurrentConnection, invoke, propagateProxyDown, proxyIfReturnTypeIsJdbcInterface, setProxy, syncSessionState, syncSessionState

Methods inherited from class Object

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

Method Details

createProxyInstance

public static Connection createProxyInstance(List<String> hosts,
 Properties props)
                                      throws SQLException

Throws:

SQLException

getNewJdbcInterfaceProxy

MultiHostConnectionProxy.JdbcInterfaceProxy getNewJdbcInterfaceProxy(Object toProxy)

Description copied from class: MultiHostConnectionProxy

Instantiates a new JdbcInterfaceProxy for the given object. Subclasses can override this to return instances of JdbcInterfaceProxy subclasses.

Overrides:

getNewJdbcInterfaceProxy in class MultiHostConnectionProxy

Parameters:

toProxy - The object instance to be proxied.

Returns:

The new InvocationHandler instance.

shouldExceptionTriggerConnectionSwitch

boolean shouldExceptionTriggerConnectionSwitch(Throwable t)

Description copied from class: MultiHostConnectionProxy

Checks if the given throwable should trigger a connection switch.

Specified by:

shouldExceptionTriggerConnectionSwitch in class MultiHostConnectionProxy

Parameters:

t - The Throwable instance to analyze.

isMasterConnection

boolean isMasterConnection()

Checks if current connection is to a master host.

Specified by:

isMasterConnection in class MultiHostConnectionProxy

pickNewConnection

void pickNewConnection()
                throws SQLException

Description copied from class: MultiHostConnectionProxy

Picks the "best" connection to use from now on. Each subclass needs to implement its connection switch strategy on it.

Specified by:

pickNewConnection in class MultiHostConnectionProxy

Throws:

SQLException

createConnectionForHostIndex

ConnectionImpl createConnectionForHostIndex(int hostIndex)
                                     throws SQLException

Creates a new connection instance for host pointed out by the given host index.

Parameters:

hostIndex - The host index in the global hosts list.

Returns:

The new connection instance.

Throws:

SQLException

fallBackToPrimaryIfAvailable

void fallBackToPrimaryIfAvailable()

Falls back to primary host or keep current connection if primary not available.

incrementQueriesIssuedSinceFailover

void incrementQueriesIssuedSinceFailover()

Increments counter for query executions.

readyToFallBackToPrimaryHost

boolean readyToFallBackToPrimaryHost()

Checks if at least one of the required conditions to fall back to primary host is met, which is determined by the properties 'queriesBeforeRetryMaster' and 'secondsBeforeRetryMaster'.

isConnected

boolean isConnected()

Checks if there is a underlying connection for this proxy.

isPrimaryHostIndex

boolean isPrimaryHostIndex(int hostIndex)

Checks if the given host index points to the primary host.

Parameters:

hostIndex - The host index in the global hosts list.

connectedToPrimaryHost

boolean connectedToPrimaryHost()

Checks if this proxy is using the primary host in the underlying connection.

connectedToSecondaryHost

boolean connectedToSecondaryHost()

Checks if this proxy is using a secondary host in the underlying connection.

doClose

void doClose()
      throws SQLException

Closes current connection.

Specified by:

doClose in class MultiHostConnectionProxy

Throws:

SQLException

doAbortInternal

void doAbortInternal()
              throws SQLException

Aborts current connection.

Specified by:

doAbortInternal in class MultiHostConnectionProxy

Throws:

SQLException

doAbort

void doAbort(Executor executor)
      throws SQLException

Aborts current connection using the given executor.

Specified by:

doAbort in class MultiHostConnectionProxy

Throws:

SQLException

invokeMore

public Object invokeMore(Object proxy,
 Method method,
 Object[] args)
                  throws Throwable

Description copied from class: MultiHostConnectionProxy

Continuation of the method invocation process, to be implemented within each subclass.

Specified by:

invokeMore in class MultiHostConnectionProxy

Throws:

Throwable