software.amazon.jdbc.plugin

Class AuroraInitialConnectionStrategyPlugin

java.lang.Object

software.amazon.jdbc.plugin.AbstractConnectionPlugin

software.amazon.jdbc.plugin.AuroraInitialConnectionStrategyPlugin

All Implemented Interfaces:

ConnectionPlugin, StateSnapshotProvider

public class AuroraInitialConnectionStrategyPlugin
extends AbstractConnectionPlugin

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	AuroraInitialConnectionStrategyPlugin.InstanceSubstitutionStrategy
protected static class	AuroraInitialConnectionStrategyPlugin.RoleVerificationSetting

Field Summary

Fields

Modifier and Type	Field and Description
static AwsWrapperProperty	ENDPOINT_SUBSTITUTION_ROLE
static AwsWrapperProperty	HOST_SELECTOR_STRATEGY
static AwsWrapperProperty	INACTIVE_CLUSTER_WRITER_SUBSTITUTION_ROLE
static AwsWrapperProperty	OPEN_CONNECTION_RETRY_INTERVAL_MS
static AwsWrapperProperty	OPEN_CONNECTION_RETRY_TIMEOUT_MS
static AwsWrapperProperty	READER_HOST_SELECTOR_STRATEGY
static AwsWrapperProperty	VERIFY_INACTIVE_CLUSTER_WRITER_CONNECTION_ROLE
static AwsWrapperProperty	VERIFY_OPENED_CONNECTION_ROLE
static AwsWrapperProperty	WAIT_FOR_INITIAL_TOPOLOGY_MS

Constructor Summary

Constructors

Constructor and Description
AuroraInitialConnectionStrategyPlugin(FullServicesContainer servicesContainer, java.util.Properties properties)

Method Summary

Modifier and Type	Method and Description
java.sql.Connection	connect(java.lang.String driverProtocol, HostSpec originalConnectHost, 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 HostSpec	getCandidateHost(@NonNull HostSpec originalConnectHost, @NonNull RdsUrlType urlType, @NonNull AuroraInitialConnectionStrategyPlugin.InstanceSubstitutionStrategy substitutionStrategy)
protected @NonNull AuroraInitialConnectionStrategyPlugin.InstanceSubstitutionStrategy	getInstanceSubstitutionStrategy(java.util.Properties props, RdsUrlType urlType, boolean isInitialConnection, @NonNull java.lang.String originalConnectHost)
protected HostRole	getRoleToVerify(RdsUrlType urlType, boolean isInitialConnection, java.util.Properties props, @NonNull java.lang.String originalConnectHost)
java.util.Set<java.lang.String>	getSubscribedMethods()
protected boolean	hasReaders(@NonNull java.util.List<HostSpec> hosts)
void	initHostProvider(java.lang.String driverProtocol, java.lang.String initialUrl, java.util.Properties props, HostListProviderService hostListProviderService, JdbcCallable<java.lang.Void,java.sql.SQLException> initHostProviderFunc)
protected HostSpec	openCandidateConnection(@NonNull HostSpec originalConnectHost, @NonNull RdsUrlType urlType, @NonNull AuroraInitialConnectionStrategyPlugin.InstanceSubstitutionStrategy substitutionStrategy, @NonNull java.util.Properties props, @NonNull JdbcCallable<java.sql.Connection,java.sql.SQLException> connectFunc, @NonNull AtomicConnection candidateConnHolder) Opens a candidate connection and stores it in candidateConnHolder, returning the HostSpec that was connected to.
protected void	validateSubstitutionStrategy(@NonNull AuroraInitialConnectionStrategyPlugin.InstanceSubstitutionStrategy setting, RdsUrlType urlType)
protected void	validateVerificationSetting(@NonNull AuroraInitialConnectionStrategyPlugin.RoleVerificationSetting setting, @NonNull RdsUrlType urlType)
protected HostSpec	waitForTopologyAndConnectToInstance(@NonNull HostSpec originalConnectHost, @NonNull RdsUrlType urlType, @NonNull AuroraInitialConnectionStrategyPlugin.InstanceSubstitutionStrategy substitutionStrategy, @NonNull java.util.Properties props, @NonNull AtomicConnection candidateConnHolder) Blocks until the topology for this cluster has been fetched, then re-attempts instance selection and connection.

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

acceptsStrategy, execute, forceConnect, getHostSpecByStrategy, getHostSpecByStrategy, getSnapshotState, notifyConnectionChanged, notifyNodeListChanged

Methods inherited from class java.lang.Object

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

Field Detail

READER_HOST_SELECTOR_STRATEGY

public static final AwsWrapperProperty READER_HOST_SELECTOR_STRATEGY

HOST_SELECTOR_STRATEGY

public static final AwsWrapperProperty HOST_SELECTOR_STRATEGY

OPEN_CONNECTION_RETRY_TIMEOUT_MS

public static final AwsWrapperProperty OPEN_CONNECTION_RETRY_TIMEOUT_MS

OPEN_CONNECTION_RETRY_INTERVAL_MS

public static final AwsWrapperProperty OPEN_CONNECTION_RETRY_INTERVAL_MS

WAIT_FOR_INITIAL_TOPOLOGY_MS

public static final AwsWrapperProperty WAIT_FOR_INITIAL_TOPOLOGY_MS

ENDPOINT_SUBSTITUTION_ROLE

public static final AwsWrapperProperty ENDPOINT_SUBSTITUTION_ROLE

INACTIVE_CLUSTER_WRITER_SUBSTITUTION_ROLE

public static final AwsWrapperProperty INACTIVE_CLUSTER_WRITER_SUBSTITUTION_ROLE

VERIFY_OPENED_CONNECTION_ROLE

public static final AwsWrapperProperty VERIFY_OPENED_CONNECTION_ROLE

VERIFY_INACTIVE_CLUSTER_WRITER_CONNECTION_ROLE

public static final AwsWrapperProperty VERIFY_INACTIVE_CLUSTER_WRITER_CONNECTION_ROLE

Constructor Detail

AuroraInitialConnectionStrategyPlugin

public AuroraInitialConnectionStrategyPlugin(FullServicesContainer servicesContainer,
                                             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

initHostProvider

public void initHostProvider(java.lang.String driverProtocol,
                             java.lang.String initialUrl,
                             java.util.Properties props,
                             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

connect

public java.sql.Connection connect(java.lang.String driverProtocol,
                                   HostSpec originalConnectHost,
                                   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 Driver.setCustomConnectionProvider(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

originalConnectHost - 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

openCandidateConnection

protected HostSpec openCandidateConnection(@NonNull HostSpec originalConnectHost,
                                           @NonNull RdsUrlType urlType,
                                           @NonNull AuroraInitialConnectionStrategyPlugin.InstanceSubstitutionStrategy substitutionStrategy,
                                           @NonNull java.util.Properties props,
                                           @NonNull JdbcCallable<java.sql.Connection,java.sql.SQLException> connectFunc,
                                           @NonNull AtomicConnection candidateConnHolder)
                                    throws java.sql.SQLException

Opens a candidate connection and stores it in candidateConnHolder, returning the HostSpec that was connected to.

If no substitution is needed, the original endpoint is used. Otherwise, an instance host is selected from the topology when available; if the topology isn't available yet, a connection is opened via the initial endpoint (which also confirms the dialect and acts as a fallback) and, when waitForInitialTopologyMs > 0, the topology fetch is awaited before re-attempting instance selection.

Throws:

java.sql.SQLException

waitForTopologyAndConnectToInstance

protected HostSpec waitForTopologyAndConnectToInstance(@NonNull HostSpec originalConnectHost,
                                                       @NonNull RdsUrlType urlType,
                                                       @NonNull AuroraInitialConnectionStrategyPlugin.InstanceSubstitutionStrategy substitutionStrategy,
                                                       @NonNull java.util.Properties props,
                                                       @NonNull AtomicConnection candidateConnHolder)
                                                throws java.sql.SQLException

Blocks until the topology for this cluster has been fetched, then re-attempts instance selection and connection. This serializes concurrent/prefill connections (all waiting on the same per-cluster topology monitor) so that the configured host selection strategy can distribute them across instances instead of all relying on the initial endpoint resolved via DNS.

Returns the selected instance host if the topology was fetched and the instance connection succeeded; the connection is then held in candidateConnHolder. Otherwise returns originalConnectHost and the already-opened initial-endpoint connection (still held in candidateConnHolder) is kept as a fallback.

Throws:

java.sql.SQLException

getInstanceSubstitutionStrategy

protected @NonNull AuroraInitialConnectionStrategyPlugin.InstanceSubstitutionStrategy getInstanceSubstitutionStrategy(java.util.Properties props,
                                                                                                                      RdsUrlType urlType,
                                                                                                                      boolean isInitialConnection,
                                                                                                                      @NonNull java.lang.String originalConnectHost)
                                                                                                               throws java.sql.SQLException

Throws:

java.sql.SQLException

validateSubstitutionStrategy

protected void validateSubstitutionStrategy(@NonNull AuroraInitialConnectionStrategyPlugin.InstanceSubstitutionStrategy setting,
                                            RdsUrlType urlType)
                                     throws java.sql.SQLException

Throws:

java.sql.SQLException

getRoleToVerify

@Nullable
protected HostRole getRoleToVerify(RdsUrlType urlType,
                                             boolean isInitialConnection,
                                             java.util.Properties props,
                                             @NonNull java.lang.String originalConnectHost)
                                      throws java.sql.SQLException

Throws:

java.sql.SQLException

validateVerificationSetting

protected void validateVerificationSetting(@NonNull AuroraInitialConnectionStrategyPlugin.RoleVerificationSetting setting,
                                           @NonNull RdsUrlType urlType)
                                    throws java.sql.SQLException

Throws:

java.sql.SQLException

getCandidateHost

@Nullable
protected HostSpec getCandidateHost(@NonNull HostSpec originalConnectHost,
                                              @NonNull RdsUrlType urlType,
                                              @NonNull AuroraInitialConnectionStrategyPlugin.InstanceSubstitutionStrategy substitutionStrategy)
                                       throws java.sql.SQLException

Throws:

java.sql.SQLException

hasReaders

protected boolean hasReaders(@NonNull java.util.List<HostSpec> hosts)