com.mysql.cj.jdbc.ha.plugins.failover

Class FailoverConnectionPlugin

java.lang.Object

com.mysql.cj.jdbc.ha.plugins.failover.FailoverConnectionPlugin

All Implemented Interfaces:

IConnectionPlugin, ITransactionContextHandler

public class FailoverConnectionPlugin
extends java.lang.Object
implements IConnectionPlugin

A IConnectionPlugin implementation that provides cluster-aware failover features. Connection switching occurs on communications related exceptions and/or cluster topology changes.

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	autoReconnect
protected boolean	closedExplicitly
protected java.lang.String	closedReason
protected java.lang.String	clusterIdSetting
protected java.lang.String	clusterInstanceHostPatternSetting
protected int	clusterTopologyRefreshRateMsSetting
protected IConnectionProvider	connectionProvider
protected int	currentHostIndex
protected boolean	enableFailoverSetting
protected boolean	enableFailoverStrictReaderSetting
protected boolean	explicitlyAutoCommit
protected java.lang.Boolean	explicitlyReadOnly
protected int	failoverClusterTopologyRefreshRateMsSetting
protected int	failoverConnectTimeoutMs
protected int	failoverReaderConnectTimeoutMsSetting
protected int	failoverSocketTimeoutMs
protected int	failoverTimeoutMsSetting
protected int	failoverWriterReconnectIntervalMsSetting
protected java.util.List<HostInfo>	hosts
protected java.util.Map<java.lang.String,java.lang.String>	initialConnectionProps
protected boolean	inTransaction
protected boolean	isClosed
protected boolean	isClusterTopologyAvailable
protected boolean	isMultiWriterCluster
protected boolean	isRds
protected boolean	isRdsProxy
protected java.lang.Throwable	lastExceptionDealtWith
protected IClusterAwareMetricsContainer	metricsContainer
static int	NO_CONNECTION_INDEX
protected IReaderFailoverHandler	readerFailoverHandler
protected ITopologyService	topologyService
static int	WRITER_CONNECTION_INDEX
protected IWriterFailoverHandler	writerFailoverHandler

Constructor Summary

Constructors

Constructor and Description
FailoverConnectionPlugin(ICurrentConnectionProvider currentConnectionProvider, PropertySet propertySet, IConnectionPlugin nextPlugin, Log logger)

Method Summary

Modifier and Type	Method and Description
protected ConnectionImpl	createConnectionForHost(HostInfo baseHostInfo) Creates a new physical connection for the given HostInfo.
protected void	dealWithIllegalStateException(java.lang.IllegalStateException e)
java.lang.Object	execute(java.lang.Class<?> methodInvokeOn, java.lang.String methodName, java.util.concurrent.Callable<?> executeSqlFunc, java.lang.Object[] args)
protected void	failover(int failedHostIdx) Initiates the failover procedure.
protected void	failoverReader(int failedHostIdx)
protected void	failoverWriter()
protected void	initializeTopology()
protected void	invalidateCurrentConnection()
protected boolean	isCurrentConnectionWriter()
boolean	isFailoverEnabled()
boolean	isRds() Checks if the proxy is connected to an RDS-hosted cluster.
boolean	isRdsProxy() Checks if the proxy is connected to a cluster using RDS proxy.
void	openInitialConnection(ConnectionUrl connectionUrl)
protected void	pickNewConnection()
void	releaseResources()
protected boolean	shouldExceptionTriggerConnectionSwitch(java.lang.Throwable t)
protected void	syncSessionState(JdbcConnection source, JdbcConnection target, boolean readOnly) Synchronizes session state between two connections, allowing to override the read-only status.
void	transactionBegun() Called when the driver has been told by the server that a transaction is now in progress (when one has not been currently in progress).
void	transactionCompleted() Called when the driver has been told by the server that a transaction has completed, and no transaction is currently in progress.
protected void	updateTopologyIfNeeded(boolean forceUpdate)

Methods inherited from class java.lang.Object

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

Field Detail

NO_CONNECTION_INDEX

public static final int NO_CONNECTION_INDEX

See Also:

Constant Field Values

WRITER_CONNECTION_INDEX

public static final int WRITER_CONNECTION_INDEX

See Also:

Constant Field Values

connectionProvider

protected final IConnectionProvider connectionProvider

metricsContainer

protected final IClusterAwareMetricsContainer metricsContainer

writerFailoverHandler

protected IWriterFailoverHandler writerFailoverHandler

readerFailoverHandler

protected IReaderFailoverHandler readerFailoverHandler

currentHostIndex

protected int currentHostIndex

initialConnectionProps

protected java.util.Map<java.lang.String,java.lang.String> initialConnectionProps

explicitlyReadOnly

protected java.lang.Boolean explicitlyReadOnly

inTransaction

protected boolean inTransaction

explicitlyAutoCommit

protected boolean explicitlyAutoCommit

isClusterTopologyAvailable

protected boolean isClusterTopologyAvailable

isMultiWriterCluster

protected boolean isMultiWriterCluster

isRdsProxy

protected boolean isRdsProxy

isRds

protected boolean isRds

topologyService

protected ITopologyService topologyService

hosts

protected java.util.List<HostInfo> hosts

enableFailoverSetting

protected boolean enableFailoverSetting

enableFailoverStrictReaderSetting

protected boolean enableFailoverStrictReaderSetting

clusterTopologyRefreshRateMsSetting

protected int clusterTopologyRefreshRateMsSetting

failoverTimeoutMsSetting

protected int failoverTimeoutMsSetting

failoverClusterTopologyRefreshRateMsSetting

protected int failoverClusterTopologyRefreshRateMsSetting

failoverWriterReconnectIntervalMsSetting

protected int failoverWriterReconnectIntervalMsSetting

failoverReaderConnectTimeoutMsSetting

protected int failoverReaderConnectTimeoutMsSetting

clusterIdSetting

protected java.lang.String clusterIdSetting

clusterInstanceHostPatternSetting

protected java.lang.String clusterInstanceHostPatternSetting

failoverConnectTimeoutMs

protected int failoverConnectTimeoutMs

failoverSocketTimeoutMs

protected int failoverSocketTimeoutMs

isClosed

protected boolean isClosed

closedExplicitly

protected boolean closedExplicitly

closedReason

protected java.lang.String closedReason

lastExceptionDealtWith

protected java.lang.Throwable lastExceptionDealtWith

autoReconnect

protected boolean autoReconnect

Constructor Detail

FailoverConnectionPlugin

public FailoverConnectionPlugin(ICurrentConnectionProvider currentConnectionProvider,
                                PropertySet propertySet,
                                IConnectionPlugin nextPlugin,
                                Log logger)
                         throws java.sql.SQLException

Throws:

java.sql.SQLException

Method Detail

openInitialConnection

public void openInitialConnection(ConnectionUrl connectionUrl)
                           throws java.sql.SQLException

Specified by:

openInitialConnection in interface IConnectionPlugin

Throws:

java.sql.SQLException

execute

public java.lang.Object execute(java.lang.Class<?> methodInvokeOn,
                                java.lang.String methodName,
                                java.util.concurrent.Callable<?> executeSqlFunc,
                                java.lang.Object[] args)
                         throws java.lang.Exception

Specified by:

execute in interface IConnectionPlugin

Throws:

java.lang.Exception

transactionBegun

public void transactionBegun()

Description copied from interface: ITransactionContextHandler

Called when the driver has been told by the server that a transaction is now in progress (when one has not been currently in progress).

Specified by:

transactionBegun in interface ITransactionContextHandler

transactionCompleted

public void transactionCompleted()

Description copied from interface: ITransactionContextHandler

Called when the driver has been told by the server that a transaction has completed, and no transaction is currently in progress.

Specified by:

transactionCompleted in interface ITransactionContextHandler

releaseResources

public void releaseResources()

Specified by:

releaseResources in interface IConnectionPlugin

isFailoverEnabled

public boolean isFailoverEnabled()

isRds

public boolean isRds()

Checks if the proxy is connected to an RDS-hosted cluster.

Returns:

true if the proxy is connected to an RDS-hosted cluster

isRdsProxy

public boolean isRdsProxy()

Checks if the proxy is connected to a cluster using RDS proxy.

Returns:

true if the proxy is connected to a cluster using RDS proxy

initializeTopology

protected void initializeTopology()
                           throws java.sql.SQLException

Throws:

java.sql.SQLException

createConnectionForHost

protected ConnectionImpl createConnectionForHost(HostInfo baseHostInfo)
                                          throws java.sql.SQLException

Creates a new physical connection for the given HostInfo.

Parameters:

baseHostInfo - 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 void dealWithIllegalStateException(java.lang.IllegalStateException e)
                                      throws java.lang.Exception

Throws:

java.lang.Exception

failover

protected void failover(int failedHostIdx)
                 throws java.sql.SQLException

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

Parameters:

failedHostIdx - The index of the host that failed

Throws:

java.sql.SQLException - if an error occurs

failoverReader

protected void failoverReader(int failedHostIdx)
                       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)

syncSessionState

protected void syncSessionState(JdbcConnection source,
                                JdbcConnection target,
                                boolean readOnly)
                         throws java.sql.SQLException

Synchronizes session state between two connections, allowing to override the read-only status.

Parameters:

source - The connection where to get state from.

target - The connection where to set state.

readOnly - The new read-only status.

Throws:

java.sql.SQLException - if an error occurs

updateTopologyIfNeeded

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

Throws:

java.sql.SQLException

isCurrentConnectionWriter

protected boolean isCurrentConnectionWriter()