io.picodata.jdbc.datasource

Class PicodataClusterAwareDataSource

java.lang.Object

io.picodata.jdbc.datasource.PicodataBaseDataSource

io.picodata.jdbc.datasource.PicodataConnectionPoolDataSource

io.picodata.jdbc.datasource.PicodataClusterAwareDataSource

All Implemented Interfaces:

Serializable, AutoCloseable, Wrapper, CommonDataSource, ConnectionPoolDataSource, DataSource

public class PicodataClusterAwareDataSource
extends PicodataConnectionPoolDataSource
implements DataSource, Serializable, AutoCloseable

Picodata implementation of ConnectionPoolDataSource that should be used with external connection pool implementations. This implementation is intended to be used with a cluster-aware load balancer. DefaultLoadBalancerImpl is used if no other load balancer implementation is specified.

Example usage:

 PicodataClusterAwareDataSource ds = new PicodataClusterAwareDataSource();
 ds.setLoadBalancer(new MyCustomLoadBalancer());
 ds.setTopologyUpdateDelay(5000);
 ds.setTopologyUpdateMaxReconnectionAttempts(3);
 

This class can be used e.g. in Spring or HikariCP configuration. Example Spring configuration (the property prefixes can be different):

 spring.datasource.type=io.picodata.jdbc.datasource.PicodataClusterAwareDataSource
 spring.datasource.url=jdbc:picodata://localhost:5432/
 spring.datasource.username=myuser
 spring.datasource.password=mypassword
 

An optional nodes selection strategy can be implemented and used for filtering and reordering the nodes before making a connection. The custom strategy class must implement LoadBalancerNodesSelectionStrategy and be available for the class loader. Then the strategy can be specified for use as follows:

 spring.datasource.nodes-selection-strategy=com.example.MyCustomNodesSelectionStreategyImpl
 

You can specify the lists of allowed and forbidden tiers for the connection nodes. This will allow creating connection only to read-only nodes or skip arbiter nodes, depending on your cluster topology. Let's imagine that your cluster has a dedicated tier for read-only nodes and all arbiter nodes are assigned to an "arbiter" tier. For selecting only suitable nodes for connection, specify the following properties:

 spring.datasource.nodes-allowed-tiers=read-only
 spring.datasource.nodes-forbidden-tiers=arbiter
 

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
PicodataClusterAwareDataSource()

Method Summary

Modifier and Type	Method and Description
void	close()
String	getDataSourceProperty(PicodataDataSourceProperty property)
String	getDescription() Gets a description of this DataSource.
LoadBalancer	getLoadBalancer() Get the load balancer instance.
protected LoadBalancerConfig	getLoadBalancerConfig() Get actual load balancer configuration, containing settings for nodes selection mechanism
String	getNodesAllowedTiers() Get the comma-separated list of allowed tier names for the connection nodes.
String	getNodesForbiddenTiers() Get the comma-separated list of forbidden tier names for the connection nodes.
String	getNodesSelectionStrategy() Set the nodes selection strategy to use.
String	getProperty(String name)
int	getTopologyUpdateDelay() Get the topology update delay
int	getTopologyUpdateMaxReconnectionAttempts() Get the maximum number of reconnection attempts while receiving topology updates.
protected String	internalGetURL(String user, String password)
boolean	isWrapperFor(Class<?> iface)
void	setDataSourceProperty(PicodataDataSourceProperty property, String value)
void	setLoadBalancer(LoadBalancer loadBalancer) Set the load balancer implementation to use.
void	setNodesAllowedTiers(String nodesAllowedTiers) Set the comma-separated list of allowed tier names for the connection nodes.
void	setNodesForbiddenTiers(String nodesForbiddenTiers) Set the comma-separated list of forbidden tier names for the connection nodes.
void	setNodesSelectionStrategy(String nodesSelectionStrategy) Set the nodes selection strategy to use.
void	setProperty(String name, String value)
void	setTopologyUpdateDelay(int topologyUpdateDelay) Set the topology update delay in milliseconds.
void	setTopologyUpdateMaxReconnectionAttempts(int topologyUpdateMaxReconnectionAttempts) Set the maximum number of reconnection attempts while receiving topology updates.
<T> T	unwrap(Class<T> iface)

Methods inherited from class io.picodata.jdbc.datasource.PicodataConnectionPoolDataSource

getPooledConnection, getPooledConnection

Methods inherited from class io.picodata.jdbc.datasource.PicodataBaseDataSource

getApplicationName, getCancelSignalTimeout, getConnection, getConnection, getConnectTimeout, getDatabaseMetadataCacheFields, getDatabaseMetadataCacheFieldsMiB, getDefaultRowFetchSize, getHideUnprivilegedObjects, getHosts, getLocalSocketAddress, getLoginTimeout, getLogServerErrorDetail, getLogWriter, getMaxResultBuffer, getParentLogger, getPassword, getPorts, getPreparedStatementCacheQueries, getPreparedStatementCacheSizeMiB, getPrepareThreshold, getProperty, getReadOnly, getReadOnlyMode, getReceiveBufferSize, getReWriteBatchedInserts, getSendBufferSize, getSocketFactory, getSocketTimeout, getSslCert, getSslFactory, getSslHostnameVerifier, getSslKey, getSslMode, getSslPassword, getSslPasswordCallback, getSslRootCert, getTcpKeepAlive, getTcpNoDelay, getUnknownLength, getURL, getUser, readBaseObject, setApplicationName, setCancelSignalTimeout, setConnectTimeout, setDatabaseMetadataCacheFields, setDatabaseMetadataCacheFieldsMiB, setDefaultRowFetchSize, setHideUnprivilegedObjects, setHosts, setLocalSocketAddress, setLoginTimeout, setLogServerErrorDetail, setLogWriter, setMaxResultBuffer, setPassword, setPorts, setPreparedStatementCacheQueries, setPreparedStatementCacheSizeMiB, setPrepareThreshold, setProperty, setReadOnly, setReadOnlyMode, setReceiveBufferSize, setReWriteBatchedInserts, setSendBufferSize, setSocketFactory, setSocketTimeout, setSslCert, setSslFactory, setSslHostnameVerifier, setSslKey, setSslMode, setSslPassword, setSslPasswordCallback, setSslRootCert, setTcpKeepAlive, setTcpNoDelay, setUnknownLength, setURL, setUser, writeBaseObject

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.sql.DataSource

getConnection, getConnection

Methods inherited from interface javax.sql.CommonDataSource

getLoginTimeout, getLogWriter, getParentLogger, setLoginTimeout, setLogWriter

Constructor Detail

PicodataClusterAwareDataSource

public PicodataClusterAwareDataSource()

Method Detail

getDescription

public String getDescription()

Gets a description of this DataSource.

Overrides:

getDescription in class PicodataConnectionPoolDataSource

getTopologyUpdateDelay

public int getTopologyUpdateDelay()

Get the topology update delay

Returns:

topology update delay in milliseconds

setTopologyUpdateDelay

public void setTopologyUpdateDelay(int topologyUpdateDelay)

Set the topology update delay in milliseconds.

Parameters:

topologyUpdateDelay - delay in milliseconds

getTopologyUpdateMaxReconnectionAttempts

public int getTopologyUpdateMaxReconnectionAttempts()

Get the maximum number of reconnection attempts while receiving topology updates.

Returns:

maximum number of reconnection attempts

setTopologyUpdateMaxReconnectionAttempts

public void setTopologyUpdateMaxReconnectionAttempts(int topologyUpdateMaxReconnectionAttempts)

Set the maximum number of reconnection attempts while receiving topology updates.

Parameters:

topologyUpdateMaxReconnectionAttempts - maximum number of reconnection attempts

getNodesSelectionStrategy

public String getNodesSelectionStrategy()

Set the nodes selection strategy to use.

Returns:

class name of the nodes selection strategy, can be empty

setNodesSelectionStrategy

public void setNodesSelectionStrategy(String nodesSelectionStrategy)

Set the nodes selection strategy to use.

Parameters:

nodesSelectionStrategy - class name of the nodes selection strategy, can be empty

getNodesAllowedTiers

public String getNodesAllowedTiers()

Get the comma-separated list of allowed tier names for the connection nodes. Empty by default.

Returns:

list of allowed tier names

setNodesAllowedTiers

public void setNodesAllowedTiers(String nodesAllowedTiers)

Set the comma-separated list of allowed tier names for the connection nodes. If empty, all active nodes are allowed.

Parameters:

nodesAllowedTiers - list of allowed tier names

getNodesForbiddenTiers

public String getNodesForbiddenTiers()

Get the comma-separated list of forbidden tier names for the connection nodes. Empty by default.

Returns:

list of forbidden tier names

setNodesForbiddenTiers

public void setNodesForbiddenTiers(String nodesForbiddenTiers)

Set the comma-separated list of forbidden tier names for the connection nodes. If empty, no tiers are forbidden.

Parameters:

nodesForbiddenTiers - list of forbidden tier names

setLoadBalancer

public void setLoadBalancer(LoadBalancer loadBalancer)

Set the load balancer implementation to use. The load balancer configuration will be recreated with the actual DataSource parameters.

Parameters:

loadBalancer - load balancer instance

getLoadBalancer

public LoadBalancer getLoadBalancer()

Get the load balancer instance. If it is not set, a default load balancer implementation is used.

Returns:

load balancer instance

getLoadBalancerConfig

protected LoadBalancerConfig getLoadBalancerConfig()

Get actual load balancer configuration, containing settings for nodes selection mechanism

Returns:

load balancer configuration

internalGetURL

protected String internalGetURL(String user,
                                String password)
                         throws SQLException

Overrides:

internalGetURL in class PicodataBaseDataSource

Throws:

SQLException

getProperty

public String getProperty(String name)
                   throws SQLException

Overrides:

getProperty in class PicodataBaseDataSource

Throws:

SQLException

setProperty

public void setProperty(String name,
                        String value)
                 throws SQLException

Overrides:

setProperty in class PicodataBaseDataSource

Throws:

SQLException

getDataSourceProperty

public String getDataSourceProperty(PicodataDataSourceProperty property)

setDataSourceProperty

public void setDataSourceProperty(PicodataDataSourceProperty property,
                                  String value)

unwrap

public <T> T unwrap(Class<T> iface)
             throws SQLException

Specified by:

unwrap in interface Wrapper

Throws:

SQLException

isWrapperFor

public boolean isWrapperFor(Class<?> iface)
                     throws SQLException

Specified by:

isWrapperFor in interface Wrapper

Throws:

SQLException

close

public void close()
           throws Exception

Specified by:

close in interface AutoCloseable

Throws:

Exception