Top Description Fields Constructors Methods
com.mysql.cj.jdbc.ha

public Class SequentialBalanceStrategy

extends Object
implements BalanceStrategy
Class Inheritance
All Implemented Interfaces
com.mysql.cj.jdbc.ha.BalanceStrategy
Imports
java.lang.reflect.InvocationHandler, java.sql.SQLException, java.util.List, .Map, com.mysql.cj.jdbc.ConnectionImpl, .JdbcConnection
A balancing strategy that starts at a random point, and then advances in the list (wrapping around) for each new pickConnection() call. The initial point selection, and subsequent point selections are blocklist-aware.

Field Summary

Modifier and TypeField and Description
private int
currentHostIndex

Constructor Summary

AccessConstructor and Description
public
SequentialBalanceStrategy()

Method Summary

Modifier and TypeMethod and Description
public ConnectionImpl
pickConnection(InvocationHandler
the InvocationHandler that deals with actual method calls to the JDBC connection, and serves as a factory for new connections for this strategy via the createConnectionForHost() method. This proxy takes care of maintaining the response time list, map of host/ports to live connections, and taking connections out of the live connections map if they receive a network-related error while they are in use by the application.
proxy, List<String>
the list of hosts/ports (in "host:port" form) as passed in by the user.
configuredHosts, Map<String, JdbcConnection>
a map of host/ports to "live" connections to them.
liveConnections, long[]
the list of response times for a transaction for each host in the configured hosts list.
responseTimes, int
the number of times the driver expects this strategy to re-try connection attempts if creating a new connection fails.
numRetries)

Implements com.mysql.cj.jdbc.ha.BalanceStrategy.pickConnection.

Called by the driver to pick a new connection to route requests over.

Inherited from java.lang.Object:
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Field Detail

currentHostIndexback to summary
private int currentHostIndex

Constructor Detail

SequentialBalanceStrategyback to summary
public SequentialBalanceStrategy()

Method Detail

pickConnectionback to summary
public ConnectionImpl pickConnection(InvocationHandler proxy, List<String> configuredHosts, Map<String, JdbcConnection> liveConnections, long[] responseTimes, int numRetries) throws SQLException

Implements com.mysql.cj.jdbc.ha.BalanceStrategy.pickConnection.

Doc from com.mysql.cj.jdbc.ha.BalanceStrategy.pickConnection.

Called by the driver to pick a new connection to route requests over. See LoadBalancedConnectionProxy.createConnectionForHost(String)

Parameters
proxy:InvocationHandler

the InvocationHandler that deals with actual method calls to the JDBC connection, and serves as a factory for new connections for this strategy via the createConnectionForHost() method. This proxy takes care of maintaining the response time list, map of host/ports to live connections, and taking connections out of the live connections map if they receive a network-related error while they are in use by the application.

configuredHosts:List<String>

the list of hosts/ports (in "host:port" form) as passed in by the user.

liveConnections:Map<String, JdbcConnection>

a map of host/ports to "live" connections to them.

responseTimes:long[]

the list of response times for a transaction for each host in the configured hosts list.

numRetries:int

the number of times the driver expects this strategy to re-try connection attempts if creating a new connection fails.

Returns:ConnectionImpl

the physical JDBC connection for the application to use, based upon the strategy employed.

Annotations
@Override
Exceptions
SQLException:
if a new connection can not be found or created by this strategy.