software.amazon.jdbc.hostlistprovider

Class RdsHostListProvider

java.lang.Object

software.amazon.jdbc.hostlistprovider.RdsHostListProvider

All Implemented Interfaces:

HostListProvider, DynamicHostListProvider

Direct Known Subclasses:

AuroraHostListProvider

public class RdsHostListProvider
extends java.lang.Object
implements DynamicHostListProvider

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 ConnectionUrlParser	connectionUrlParser
protected boolean	isInitialized
protected boolean	isPrimaryClusterId
static CacheMap<java.lang.String,java.lang.Boolean>	primaryClusterIdCache
static CacheMap<java.lang.String,java.lang.String>	suggestedPrimaryClusterIdCache
static CacheMap<java.lang.String,java.util.List<HostSpec>>	topologyCache

Constructor Summary

Constructors

Constructor and Description
RdsHostListProvider(java.util.Properties properties, java.lang.String originalUrl, HostListProviderService hostListProviderService, 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.
java.util.List<HostSpec>	forceRefresh()
java.util.List<HostSpec>	forceRefresh(java.sql.Connection connection)
@Nullable java.util.List<HostSpec>	getCachedTopology() Get cached topology.
HostRole	getHostRole(java.sql.Connection conn) Evaluates the host role of the given connection - either a writer or a reader.
RdsUrlType	getRdsUrlType()
software.amazon.jdbc.hostlistprovider.RdsHostListProvider.FetchTopologyResult	getTopology(java.sql.Connection conn, boolean forceUpdate) Get cluster topology.
HostSpec	identifyConnection(java.sql.Connection connection)
protected void	init()
static void	logCache()
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

topologyCache

public static final CacheMap<java.lang.String,java.util.List<HostSpec>> topologyCache

suggestedPrimaryClusterIdCache

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

primaryClusterIdCache

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

clusterId

protected java.lang.String clusterId

clusterInstanceTemplate

protected HostSpec clusterInstanceTemplate

connectionUrlParser

protected ConnectionUrlParser connectionUrlParser

isPrimaryClusterId

protected boolean isPrimaryClusterId

isInitialized

protected boolean isInitialized

Constructor Detail

RdsHostListProvider

public RdsHostListProvider(java.util.Properties properties,
                           java.lang.String originalUrl,
                           HostListProviderService hostListProviderService,
                           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

public software.amazon.jdbc.hostlistprovider.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.

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.

getCachedTopology

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

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

logCache

public static void logCache()

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