software.amazon.jdbc.hostlistprovider

Class RdsHostListProvider

java.lang.Object

software.amazon.jdbc.hostlistprovider.RdsHostListProvider

All Implemented Interfaces:

CanReleaseResources, DynamicHostListProvider, HostListProvider

Direct Known Subclasses:

GlobalAuroraHostListProvider

public class RdsHostListProvider
extends java.lang.Object
implements DynamicHostListProvider, CanReleaseResources

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	RdsHostListProvider.FetchTopologyResult

Field Summary

Fields

Modifier and Type	Field and Description
static AwsWrapperProperty	CLUSTER_ID
static AwsWrapperProperty	CLUSTER_INSTANCE_HOST_PATTERN
static AwsWrapperProperty	CLUSTER_TOPOLOGY_HIGH_REFRESH_RATE_MS
static AwsWrapperProperty	CLUSTER_TOPOLOGY_REFRESH_RATE_MS
protected java.lang.String	clusterId
protected static ConnectionUrlParser	connectionUrlParser
protected static int	DEFAULT_TOPOLOGY_QUERY_TIMEOUT_MS
protected long	highRefreshRateNano
protected HostListProviderService	hostListProviderService
protected java.util.List<HostSpec>	initialHostList
protected HostSpec	initialHostSpec
protected HostSpec	instanceTemplate
protected boolean	isInitialized
protected java.util.concurrent.locks.ReentrantLock	lock
protected java.lang.String	originalUrl
protected PluginService	pluginService
protected java.util.Properties	properties
protected static RdsUtils	rdsHelper
protected RdsUrlType	rdsUrlType
protected long	refreshRateNano
protected FullServicesContainer	servicesContainer
protected TopologyUtils	topologyUtils

Constructor Summary

Constructors

Constructor and Description
RdsHostListProvider(TopologyUtils topologyUtils, java.util.Properties properties, java.lang.String originalUrl, FullServicesContainer servicesContainer)

Method Summary

Modifier and Type	Method and Description
void	clear() Clear topology cache for the current cluster.
java.util.List<HostSpec>	forceRefresh() Force a host list provider to update its topology information.
java.util.List<HostSpec>	forceRefresh(boolean shouldVerifyWriter, long timeoutMs) Force a host list provider to update its topology information.
protected java.util.List<HostSpec>	forceRefreshMonitor(boolean shouldVerifyWriter, long timeoutMs)
java.lang.String	getClusterId()
java.util.List<HostSpec>	getCurrentTopology(java.sql.Connection conn, HostSpec initialHostSpec) Get current topology information for the connected database.
HostRole	getHostRole(java.sql.Connection conn) Evaluates the host role of the given connection - either a writer or a reader.
protected ClusterTopologyMonitor	getOrCreateMonitor()
RdsUrlType	getRdsUrlType()
@Nullable java.util.List<HostSpec>	getStoredTopology() Get cached topology.
protected RdsHostListProvider.FetchTopologyResult	getTopology() Get cluster topology.
@Nullable HostSpec	identifyConnection(java.sql.Connection connection)
protected void	init()
protected void	initSettings()
java.util.List<HostSpec>	refresh()
void	releaseResources() An object that implements this interface should release all acquired resources assuming it may be disposed at any time.
void	stopMonitor()
protected void	validateHostPatternSetting(java.lang.String hostPattern)

Methods inherited from class java.lang.Object

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

Field Detail

CLUSTER_TOPOLOGY_REFRESH_RATE_MS

public static final AwsWrapperProperty CLUSTER_TOPOLOGY_REFRESH_RATE_MS

CLUSTER_ID

public static final AwsWrapperProperty CLUSTER_ID

CLUSTER_INSTANCE_HOST_PATTERN

public static final AwsWrapperProperty CLUSTER_INSTANCE_HOST_PATTERN

CLUSTER_TOPOLOGY_HIGH_REFRESH_RATE_MS

public static final AwsWrapperProperty CLUSTER_TOPOLOGY_HIGH_REFRESH_RATE_MS

rdsHelper

protected static final RdsUtils rdsHelper

connectionUrlParser

protected static final ConnectionUrlParser connectionUrlParser

DEFAULT_TOPOLOGY_QUERY_TIMEOUT_MS

protected static final int DEFAULT_TOPOLOGY_QUERY_TIMEOUT_MS

See Also:

Constant Field Values

lock

protected final java.util.concurrent.locks.ReentrantLock lock

properties

protected final java.util.Properties properties

originalUrl

protected final java.lang.String originalUrl

servicesContainer

protected final FullServicesContainer servicesContainer

pluginService

protected final PluginService pluginService

hostListProviderService

protected final HostListProviderService hostListProviderService

topologyUtils

protected final TopologyUtils topologyUtils

refreshRateNano

protected final long refreshRateNano

highRefreshRateNano

protected final long highRefreshRateNano

rdsUrlType

protected RdsUrlType rdsUrlType

initialHostList

protected java.util.List<HostSpec> initialHostList

initialHostSpec

protected HostSpec initialHostSpec

clusterId

protected java.lang.String clusterId

instanceTemplate

protected HostSpec instanceTemplate

isInitialized

protected volatile boolean isInitialized

Constructor Detail

RdsHostListProvider

public RdsHostListProvider(TopologyUtils topologyUtils,
                           java.util.Properties properties,
                           java.lang.String originalUrl,
                           FullServicesContainer servicesContainer)

Method Detail

init

protected void init()
             throws java.sql.SQLException

Throws:

java.sql.SQLException

initSettings

protected void initSettings()
                     throws java.sql.SQLException

Throws:

java.sql.SQLException

getOrCreateMonitor

protected ClusterTopologyMonitor getOrCreateMonitor()
                                             throws java.sql.SQLException

Throws:

java.sql.SQLException

getCurrentTopology

public java.util.List<HostSpec> getCurrentTopology(java.sql.Connection conn,
                                                   HostSpec initialHostSpec)
                                            throws java.sql.SQLException

Description copied from interface: HostListProvider

Get current topology information for the connected database. The returned topology should be the static host list if `this` is a StaticHostListProvider. The returned topology should be fresh info returned from a topology query if `this` is a DynamicHostListProvider,

Specified by:

getCurrentTopology in interface HostListProvider

Parameters:

conn - the connection to use to query the database for topology information, if needed.

initialHostSpec - the host details of the initial connection.

Returns:

the topology information for the connected database.

Throws:

java.sql.SQLException - if an error occurs while attempting to acquire the database topology information.

forceRefreshMonitor

protected java.util.List<HostSpec> forceRefreshMonitor(boolean shouldVerifyWriter,
                                                       long timeoutMs)
                                                throws java.sql.SQLException

Throws:

java.sql.SQLException

getTopology

protected RdsHostListProvider.FetchTopologyResult getTopology()
                                                       throws java.sql.SQLException

Get cluster topology. It may require an extra call to database to fetch the latest topology. A cached copy of topology is returned if it's not yet outdated (controlled by refreshRateNano).

Returns:

a list of hosts that describes cluster topology. A writer is always at position 0. Returns an empty list if isn't available or is invalid (doesn't contain a writer).

Throws:

java.sql.SQLException - if errors occurred while retrieving the topology.

getStoredTopology

public @Nullable java.util.List<HostSpec> getStoredTopology()
                                                     throws java.sql.SQLException

Get cached topology.

Returns:

list of hosts that represents topology. If there's no topology in the cache or the cached topology is outdated, it returns null.

Throws:

java.sql.SQLException

clear

public void clear()

Clear topology cache for the current cluster.

refresh

public java.util.List<HostSpec> refresh()
                                 throws java.sql.SQLException

Specified by:

refresh in interface HostListProvider

Throws:

java.sql.SQLException

getRdsUrlType

public RdsUrlType getRdsUrlType()
                         throws java.sql.SQLException

Throws:

java.sql.SQLException

validateHostPatternSetting

protected void validateHostPatternSetting(java.lang.String hostPattern)

forceRefresh

public java.util.List<HostSpec> forceRefresh()
                                      throws java.sql.SQLException,
                                             java.util.concurrent.TimeoutException

Description copied from interface: HostListProvider

Force a host list provider to update its topology information. Results will be returned when the topology is updated or the writer is verified, unless the default timeout is hit. It the caller needs topology from a verified writer or with a different timeout value, they should call HostListProvider.forceRefresh(boolean, long) instead.

Specified by:

forceRefresh in interface HostListProvider

Returns:

a list of host details representing a cluster topology

Throws:

java.sql.SQLException - if there's errors updating topology

java.util.concurrent.TimeoutException - if topology update takes longer time than expected

forceRefresh

public java.util.List<HostSpec> forceRefresh(boolean shouldVerifyWriter,
                                             long timeoutMs)
                                      throws java.sql.SQLException,
                                             java.util.concurrent.TimeoutException

Description copied from interface: HostListProvider

Force a host list provider to update its topology information. Results will be returned when the topology is updated or the writer is verified, unless the timeout is hit.

Specified by:

forceRefresh in interface HostListProvider

Parameters:

shouldVerifyWriter - a flag indicating that the provider should verify the writer before returning the updated topology.

timeoutMs - timeout in msec to wait until topology is updated or the writer is verified. If a timeout of 0 is provided, a topology update will be initiated but cached topology will be returned. If a non-zero timeout is provided and the timeout is hit, a TimeoutException will be thrown.

Returns:

a list of host details representing a cluster topology

Throws:

java.sql.SQLException - if there's errors updating topology

java.util.concurrent.TimeoutException - if topology update takes longer time than expected

releaseResources

public void releaseResources()

Description copied from interface: CanReleaseResources

An object that implements this interface should release all acquired resources assuming it may be disposed at any time. This method may be called more than once.

Calling this method does NOT mean that an object is disposing and there won't be any further calls. An object should keep its functional state after calling this method.

Specified by:

releaseResources in interface CanReleaseResources

getHostRole

public HostRole getHostRole(java.sql.Connection conn)
                     throws java.sql.SQLException

Description copied from interface: HostListProvider

Evaluates the host role of the given connection - either a writer or a reader.

Specified by:

getHostRole in interface HostListProvider

Parameters:

conn - a connection to the database instance whose role should be determined

Returns:

the role of the given connection - either a writer or a reader

Throws:

java.sql.SQLException - if there is a problem executing or processing the SQL query used to determine the host role

identifyConnection

public @Nullable HostSpec identifyConnection(java.sql.Connection connection)
                                      throws java.sql.SQLException

Specified by:

identifyConnection in interface HostListProvider

Throws:

java.sql.SQLException

getClusterId

public java.lang.String getClusterId()
                              throws java.sql.SQLException

Specified by:

getClusterId in interface HostListProvider

Throws:

java.sql.SQLException

stopMonitor

public void stopMonitor()

Specified by:

stopMonitor in interface HostListProvider