software.amazon.jdbc.hostlistprovider

Class RdsHostListProvider

java.lang.Object

software.amazon.jdbc.hostlistprovider.RdsHostListProvider

All Implemented Interfaces:

HostListProvider, DynamicHostListProvider

Direct Known Subclasses:

AuroraHostListProvider, MonitoringRdsHostListProvider, RdsMultiAzDbClusterListProvider

public class RdsHostListProvider
extends java.lang.Object
implements DynamicHostListProvider

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RdsHostListProvider.ClusterSuggestedResult
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_REFRESH_RATE_MS
protected java.lang.String	clusterId
protected HostSpec	clusterInstanceTemplate
protected static ConnectionUrlParser	connectionUrlParser
protected static int	defaultTopologyQueryTimeoutMs
protected java.util.List<HostSpec>	hostList
protected HostListProviderService	hostListProviderService
protected java.util.List<HostSpec>	initialHostList
protected HostSpec	initialHostSpec
protected boolean	isInitialized
protected boolean	isPrimaryClusterId
protected java.lang.String	isReaderQuery
protected java.util.concurrent.locks.ReentrantLock	lock
protected static java.util.concurrent.Executor	networkTimeoutExecutor
protected java.lang.String	nodeIdQuery
protected java.lang.String	originalUrl
protected static CacheMap<java.lang.String,java.lang.Boolean>	primaryClusterIdCache
protected java.util.Properties	properties
protected static RdsUtils	rdsHelper
protected RdsUrlType	rdsUrlType
protected long	refreshRateNano
protected FullServicesContainer	servicesContainer
protected static long	suggestedClusterIdRefreshRateNano
protected static CacheMap<java.lang.String,java.lang.String>	suggestedPrimaryClusterIdCache
protected java.lang.String	topologyQuery

Constructor Summary

Constructors

Constructor and Description
RdsHostListProvider(java.util.Properties properties, java.lang.String originalUrl, FullServicesContainer servicesContainer, java.lang.String topologyQuery, java.lang.String nodeIdQuery, java.lang.String isReaderQuery)

Method Summary

Modifier and Type	Method and Description
void	clear() Clear topology cache for the current cluster.
static void	clearAll() Clear topology cache for all clusters.
protected void	clusterIdChanged(java.lang.String oldClusterId)
protected HostSpec	createHost(java.sql.ResultSet resultSet) Creates an instance of HostSpec which captures details about a connectable host.
protected HostSpec	createHost(java.lang.String host, boolean isWriter, long weight, java.sql.Timestamp lastUpdateTime)
java.util.List<HostSpec>	forceRefresh()
java.util.List<HostSpec>	forceRefresh(java.sql.Connection connection)
java.lang.String	getClusterId()
protected java.lang.String	getHostEndpoint(java.lang.String nodeName) Build a host dns endpoint based on host/node name.
HostRole	getHostRole(java.sql.Connection conn) Evaluates the host role of the given connection - either a writer or a reader.
RdsUrlType	getRdsUrlType()
@Nullable java.util.List<HostSpec>	getStoredTopology() Get cached topology.
protected RdsHostListProvider.ClusterSuggestedResult	getSuggestedClusterId(java.lang.String url)
protected RdsHostListProvider.FetchTopologyResult	getTopology(java.sql.Connection conn, boolean forceUpdate) Get cluster topology.
HostSpec	identifyConnection(java.sql.Connection connection)
protected void	init()
protected java.util.List<HostSpec>	queryForTopology(java.sql.Connection conn) Obtain a cluster topology from database.
java.util.List<HostSpec>	refresh()
java.util.List<HostSpec>	refresh(java.sql.Connection connection)
protected void	suggestPrimaryCluster(@NonNull java.util.List<HostSpec> primaryClusterHosts)

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

networkTimeoutExecutor

protected static final java.util.concurrent.Executor networkTimeoutExecutor

rdsHelper

protected static final RdsUtils rdsHelper

connectionUrlParser

protected static final ConnectionUrlParser connectionUrlParser

defaultTopologyQueryTimeoutMs

protected static final int defaultTopologyQueryTimeoutMs

See Also:

Constant Field Values

suggestedClusterIdRefreshRateNano

protected static final long suggestedClusterIdRefreshRateNano

suggestedPrimaryClusterIdCache

protected static final CacheMap<java.lang.String,java.lang.String> suggestedPrimaryClusterIdCache

primaryClusterIdCache

protected static final CacheMap<java.lang.String,java.lang.Boolean> primaryClusterIdCache

servicesContainer

protected final FullServicesContainer servicesContainer

hostListProviderService

protected final HostListProviderService hostListProviderService

originalUrl

protected final java.lang.String originalUrl

topologyQuery

protected final java.lang.String topologyQuery

nodeIdQuery

protected final java.lang.String nodeIdQuery

isReaderQuery

protected final java.lang.String isReaderQuery

rdsUrlType

protected RdsUrlType rdsUrlType

refreshRateNano

protected long refreshRateNano

hostList

protected java.util.List<HostSpec> hostList

initialHostList

protected java.util.List<HostSpec> initialHostList

initialHostSpec

protected HostSpec initialHostSpec

lock

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

clusterId

protected java.lang.String clusterId

clusterInstanceTemplate

protected HostSpec clusterInstanceTemplate

isPrimaryClusterId

protected boolean isPrimaryClusterId

isInitialized

protected volatile boolean isInitialized

properties

protected java.util.Properties properties

Constructor Detail

RdsHostListProvider

public RdsHostListProvider(java.util.Properties properties,
                           java.lang.String originalUrl,
                           FullServicesContainer servicesContainer,
                           java.lang.String topologyQuery,
                           java.lang.String nodeIdQuery,
                           java.lang.String isReaderQuery)

Method Detail

init

protected void init()
             throws java.sql.SQLException

Throws:

java.sql.SQLException

getTopology

protected RdsHostListProvider.FetchTopologyResult getTopology(java.sql.Connection conn,
                                                              boolean forceUpdate)
                                                       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).

Parameters:

conn - A connection to database to fetch the latest topology, if needed.

forceUpdate - If true, it forces a service to ignore cached copy of topology and to fetch a fresh one.

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.

clusterIdChanged

protected void clusterIdChanged(java.lang.String oldClusterId)
                         throws java.sql.SQLException

Throws:

java.sql.SQLException

getSuggestedClusterId

protected RdsHostListProvider.ClusterSuggestedResult getSuggestedClusterId(java.lang.String url)

suggestPrimaryCluster

protected void suggestPrimaryCluster(@NonNull java.util.List<HostSpec> primaryClusterHosts)

queryForTopology

protected java.util.List<HostSpec> queryForTopology(java.sql.Connection conn)
                                             throws java.sql.SQLException

Obtain a cluster topology from database.

Parameters:

conn - A connection to database to fetch the latest topology.

Returns:

a list of HostSpec objects representing the topology

Throws:

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

createHost

protected HostSpec createHost(java.sql.ResultSet resultSet)
                       throws java.sql.SQLException

Creates an instance of HostSpec which captures details about a connectable host.

Parameters:

resultSet - the result set from querying the topology

Returns:

a HostSpec instance for a specific instance from the cluster

Throws:

java.sql.SQLException - If unable to retrieve the hostName from the result set

createHost

protected HostSpec createHost(java.lang.String host,
                              boolean isWriter,
                              long weight,
                              java.sql.Timestamp lastUpdateTime)

getHostEndpoint

protected java.lang.String getHostEndpoint(java.lang.String nodeName)

Build a host dns endpoint based on host/node name.

Parameters:

nodeName - A host name.

Returns:

Host dns endpoint

getStoredTopology

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

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.

clearAll

public static void clearAll()

Clear topology cache for all clusters.

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

refresh

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

Specified by:

refresh in interface HostListProvider

Throws:

java.sql.SQLException

forceRefresh

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

Specified by:

forceRefresh in interface HostListProvider

Throws:

java.sql.SQLException

forceRefresh

public java.util.List<HostSpec> forceRefresh(java.sql.Connection connection)
                                      throws java.sql.SQLException

Specified by:

forceRefresh in interface HostListProvider

Throws:

java.sql.SQLException

getRdsUrlType

public RdsUrlType getRdsUrlType()
                         throws java.sql.SQLException

Throws:

java.sql.SQLException

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 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.lang.UnsupportedOperationException,
                                     java.sql.SQLException

Specified by:

getClusterId in interface HostListProvider

Throws:

java.lang.UnsupportedOperationException

java.sql.SQLException