software.amazon.jdbc.plugin.failover

Class FailoverConnectionPlugin

java.lang.Object

software.amazon.jdbc.plugin.AbstractConnectionPlugin

software.amazon.jdbc.plugin.failover.FailoverConnectionPlugin

All Implemented Interfaces:

ConnectionPlugin

public class FailoverConnectionPlugin
extends AbstractConnectionPlugin

This plugin provides cluster-aware failover features. The plugin switches connections upon detecting communication related exceptions and/or cluster topology changes.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.String	closedReason
static AwsWrapperProperty	ENABLE_CLUSTER_AWARE_FAILOVER
protected boolean	enableFailoverSetting
static AwsWrapperProperty	FAILOVER_CLUSTER_TOPOLOGY_REFRESH_RATE_MS
static AwsWrapperProperty	FAILOVER_MODE
static AwsWrapperProperty	FAILOVER_READER_CONNECT_TIMEOUT_MS
static AwsWrapperProperty	FAILOVER_TIMEOUT_MS
static AwsWrapperProperty	FAILOVER_WRITER_RECONNECT_INTERVAL_MS
protected int	failoverClusterTopologyRefreshRateMsSetting
protected FailoverMode	failoverMode
protected int	failoverReaderConnectTimeoutMsSetting
protected int	failoverTimeoutMsSetting
protected int	failoverWriterReconnectIntervalMsSetting
protected boolean	isClosed
protected java.util.Properties	properties
protected ReaderFailoverHandler	readerFailoverHandler
protected WriterFailoverHandler	writerFailoverHandler

Constructor Summary

Constructors

Constructor and Description
FailoverConnectionPlugin(PluginService pluginService, java.util.Properties properties)

Method Summary

Modifier and Type	Method and Description
java.sql.Connection	connect(java.lang.String driverProtocol, HostSpec hostSpec, java.util.Properties props, boolean isInitialConnection, JdbcCallable<java.sql.Connection,java.sql.SQLException> connectFunc) Establishes a connection to the given host using the given driver protocol and properties.
protected java.sql.Connection	createConnectionForHost(HostSpec baseHostSpec) Creates a new physical connection for the given HostSpec.
protected <E extends java.lang.Exception> void	dealWithIllegalStateException(java.lang.IllegalStateException e, java.lang.Class<E> exceptionClass)
<T,E extends java.lang.Exception> T	execute(java.lang.Class<T> resultClass, java.lang.Class<E> exceptionClass, java.lang.Object methodInvokeOn, java.lang.String methodName, JdbcCallable<T,E> jdbcMethodFunc, java.lang.Object[] jdbcMethodArgs)
protected void	failover(HostSpec failedHost) Initiates the failover procedure.
protected void	failoverReader(HostSpec failedHostSpec)
protected void	failoverWriter()
java.sql.Connection	forceConnect(java.lang.String driverProtocol, HostSpec hostSpec, java.util.Properties props, boolean isInitialConnection, JdbcCallable<java.sql.Connection,java.sql.SQLException> forceConnectFunc) Establishes a connection to the given host using the given driver protocol and properties.
java.util.Set<java.lang.String>	getSubscribedMethods()
void	initHostProvider(java.lang.String driverProtocol, java.lang.String initialUrl, java.util.Properties properties, HostListProviderService hostListProviderService, JdbcCallable<java.lang.Void,java.sql.SQLException> initHostProviderFunc)
protected void	invalidateCurrentConnection()
boolean	isFailoverEnabled()
OldConnectionSuggestedAction	notifyConnectionChanged(java.util.EnumSet<NodeChangeOptions> changes)
void	notifyNodeListChanged(java.util.Map<java.lang.String,java.util.EnumSet<NodeChangeOptions>> changes)
protected void	pickNewConnection()
protected boolean	shouldExceptionTriggerConnectionSwitch(java.lang.Throwable t)
protected void	transferSessionState(java.sql.Connection from, java.sql.Connection to) Transfers basic session state from one connection to another.
protected void	updateTopology(boolean forceUpdate)

Methods inherited from class software.amazon.jdbc.plugin.AbstractConnectionPlugin

acceptsStrategy, getHostSpecByStrategy

Methods inherited from class java.lang.Object

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

Field Detail

properties

protected final java.util.Properties properties

enableFailoverSetting

protected boolean enableFailoverSetting

failoverTimeoutMsSetting

protected int failoverTimeoutMsSetting

failoverClusterTopologyRefreshRateMsSetting

protected int failoverClusterTopologyRefreshRateMsSetting

failoverWriterReconnectIntervalMsSetting

protected int failoverWriterReconnectIntervalMsSetting

failoverReaderConnectTimeoutMsSetting

protected int failoverReaderConnectTimeoutMsSetting

failoverMode

protected FailoverMode failoverMode

isClosed

protected boolean isClosed

closedReason

protected java.lang.String closedReason

writerFailoverHandler

protected WriterFailoverHandler writerFailoverHandler

readerFailoverHandler

protected ReaderFailoverHandler readerFailoverHandler

FAILOVER_CLUSTER_TOPOLOGY_REFRESH_RATE_MS

public static final AwsWrapperProperty FAILOVER_CLUSTER_TOPOLOGY_REFRESH_RATE_MS

FAILOVER_TIMEOUT_MS

public static final AwsWrapperProperty FAILOVER_TIMEOUT_MS

FAILOVER_WRITER_RECONNECT_INTERVAL_MS

public static final AwsWrapperProperty FAILOVER_WRITER_RECONNECT_INTERVAL_MS

FAILOVER_READER_CONNECT_TIMEOUT_MS

public static final AwsWrapperProperty FAILOVER_READER_CONNECT_TIMEOUT_MS

ENABLE_CLUSTER_AWARE_FAILOVER

public static final AwsWrapperProperty ENABLE_CLUSTER_AWARE_FAILOVER

FAILOVER_MODE

public static final AwsWrapperProperty FAILOVER_MODE

Constructor Detail

FailoverConnectionPlugin

public FailoverConnectionPlugin(PluginService pluginService,
                                java.util.Properties properties)

Method Detail

getSubscribedMethods

public java.util.Set<java.lang.String> getSubscribedMethods()

Specified by:

getSubscribedMethods in interface ConnectionPlugin

Specified by:

getSubscribedMethods in class AbstractConnectionPlugin

execute

public <T,E extends java.lang.Exception> T execute(java.lang.Class<T> resultClass,
                                                   java.lang.Class<E> exceptionClass,
                                                   java.lang.Object methodInvokeOn,
                                                   java.lang.String methodName,
                                                   JdbcCallable<T,E> jdbcMethodFunc,
                                                   java.lang.Object[] jdbcMethodArgs)
                                            throws E extends java.lang.Exception

Specified by:

execute in interface ConnectionPlugin

Overrides:

execute in class AbstractConnectionPlugin

Throws:

E extends java.lang.Exception

initHostProvider

public void initHostProvider(java.lang.String driverProtocol,
                             java.lang.String initialUrl,
                             java.util.Properties properties,
                             HostListProviderService hostListProviderService,
                             JdbcCallable<java.lang.Void,java.sql.SQLException> initHostProviderFunc)
                      throws java.sql.SQLException

Specified by:

initHostProvider in interface ConnectionPlugin

Overrides:

initHostProvider in class AbstractConnectionPlugin

Throws:

java.sql.SQLException

notifyConnectionChanged

public OldConnectionSuggestedAction notifyConnectionChanged(java.util.EnumSet<NodeChangeOptions> changes)

Specified by:

notifyConnectionChanged in interface ConnectionPlugin

Overrides:

notifyConnectionChanged in class AbstractConnectionPlugin

notifyNodeListChanged

public void notifyNodeListChanged(java.util.Map<java.lang.String,java.util.EnumSet<NodeChangeOptions>> changes)

Specified by:

notifyNodeListChanged in interface ConnectionPlugin

Overrides:

notifyNodeListChanged in class AbstractConnectionPlugin

isFailoverEnabled

public boolean isFailoverEnabled()

updateTopology

protected void updateTopology(boolean forceUpdate)
                       throws java.sql.SQLException

Throws:

java.sql.SQLException

transferSessionState

protected void transferSessionState(java.sql.Connection from,
                                    java.sql.Connection to)
                             throws java.sql.SQLException

Transfers basic session state from one connection to another.

Parameters:

from - The connection to transfer state from

to - The connection to transfer state to

Throws:

java.sql.SQLException - if a database access error occurs, this method is called on a closed connection, this method is called during a distributed transaction, or this method is called during a transaction

createConnectionForHost

protected java.sql.Connection createConnectionForHost(HostSpec baseHostSpec)
                                               throws java.sql.SQLException

Creates a new physical connection for the given HostSpec.

Parameters:

baseHostSpec - The host info instance to base the connection off of.

Returns:

The new Connection instance.

Throws:

java.sql.SQLException - if an error occurs

dealWithIllegalStateException

protected <E extends java.lang.Exception> void dealWithIllegalStateException(java.lang.IllegalStateException e,
                                                                             java.lang.Class<E> exceptionClass)
                                                                      throws E extends java.lang.Exception

Throws:

E extends java.lang.Exception

failover

protected void failover(HostSpec failedHost)
                 throws java.sql.SQLException

Initiates the failover procedure. This process tries to establish a new connection to an instance in the topology.

Parameters:

failedHost - The host with network errors.

Throws:

java.sql.SQLException - if an error occurs

failoverReader

protected void failoverReader(HostSpec failedHostSpec)
                       throws java.sql.SQLException

Throws:

java.sql.SQLException

failoverWriter

protected void failoverWriter()
                       throws java.sql.SQLException

Throws:

java.sql.SQLException

invalidateCurrentConnection

protected void invalidateCurrentConnection()

pickNewConnection

protected void pickNewConnection()
                          throws java.sql.SQLException

Throws:

java.sql.SQLException

shouldExceptionTriggerConnectionSwitch

protected boolean shouldExceptionTriggerConnectionSwitch(java.lang.Throwable t)

connect

public java.sql.Connection connect(java.lang.String driverProtocol,
                                   HostSpec hostSpec,
                                   java.util.Properties props,
                                   boolean isInitialConnection,
                                   JdbcCallable<java.sql.Connection,java.sql.SQLException> connectFunc)
                            throws java.sql.SQLException

Description copied from interface: ConnectionPlugin

Establishes a connection to the given host using the given driver protocol and properties. If a non-default ConnectionProvider has been set with ConnectionProviderManager.setConnectionProvider(software.amazon.jdbc.ConnectionProvider) and ConnectionProvider.acceptsUrl(String, HostSpec, Properties) returns true for the given protocol, host, and properties, the connection will be created by the non-default ConnectionProvider. Otherwise, the connection will be created by the default ConnectionProvider. The default ConnectionProvider will be DriverConnectionProvider for connections requested via the DriverManager and DataSourceConnectionProvider for connections requested via an AwsWrapperDataSource.

Specified by:

connect in interface ConnectionPlugin

Overrides:

connect in class AbstractConnectionPlugin

Parameters:

driverProtocol - the driver protocol that should be used to establish the connection

hostSpec - the host details for the desired connection

props - the connection properties

isInitialConnection - a boolean indicating whether the current Connection is establishing an initial physical connection to the database or has already established a physical connection in the past

connectFunc - the function to call to continue the connect request down the connect pipeline

Returns:

a Connection to the requested host

Throws:

java.sql.SQLException - if there was an error establishing a Connection to the requested host

forceConnect

public java.sql.Connection forceConnect(java.lang.String driverProtocol,
                                        HostSpec hostSpec,
                                        java.util.Properties props,
                                        boolean isInitialConnection,
                                        JdbcCallable<java.sql.Connection,java.sql.SQLException> forceConnectFunc)
                                 throws java.sql.SQLException

Description copied from interface: ConnectionPlugin

Establishes a connection to the given host using the given driver protocol and properties. This call differs from ConnectionPlugin.connect(java.lang.String, software.amazon.jdbc.HostSpec, java.util.Properties, boolean, software.amazon.jdbc.JdbcCallable<java.sql.Connection, java.sql.SQLException>) in that the default ConnectionProvider will be used to establish the connection even if a non-default ConnectionProvider has been set via ConnectionProviderManager.setConnectionProvider(software.amazon.jdbc.ConnectionProvider). The default ConnectionProvider will be DriverConnectionProvider for connections requested via the DriverManager and DataSourceConnectionProvider for connections requested via an AwsWrapperDataSource.

Specified by:

forceConnect in interface ConnectionPlugin

Overrides:

forceConnect in class AbstractConnectionPlugin

Parameters:

driverProtocol - the driver protocol that should be used to establish the connection

hostSpec - the host details for the desired connection

props - the connection properties

isInitialConnection - a boolean indicating whether the current Connection is establishing an initial physical connection to the database or has already established a physical connection in the past

forceConnectFunc - the function to call to continue the forceConnect request down the forceConnect pipeline

Returns:

a Connection to the requested host

Throws:

java.sql.SQLException - if there was an error establishing a Connection to the requested host