com.mysql.cj.jdbc.ha

Class SequentialBalanceStrategy

java.lang.Object

com.mysql.cj.jdbc.ha.SequentialBalanceStrategy

All Implemented Interfaces:

BalanceStrategy

public class SequentialBalanceStrategy
extends java.lang.Object
implements BalanceStrategy

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.

Constructor Summary

Constructors

Constructor and Description
SequentialBalanceStrategy()

Method Summary

Modifier and Type	Method and Description
ConnectionImpl	pickConnection(java.lang.reflect.InvocationHandler proxy, java.util.List<java.lang.String> configuredHosts, java.util.Map<java.lang.String,JdbcConnection> liveConnections, long[] responseTimes, int numRetries) Called by the driver to pick a new connection to route requests over.

Methods inherited from class java.lang.Object

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

Constructor Detail

SequentialBalanceStrategy

public SequentialBalanceStrategy()

Method Detail

pickConnection

public ConnectionImpl pickConnection(java.lang.reflect.InvocationHandler proxy,
                                     java.util.List<java.lang.String> configuredHosts,
                                     java.util.Map<java.lang.String,JdbcConnection> liveConnections,
                                     long[] responseTimes,
                                     int numRetries)
                              throws java.sql.SQLException

Description copied from interface: BalanceStrategy

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

Specified by:

pickConnection in interface BalanceStrategy

Parameters:

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

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

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

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

Returns:

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

Throws:

java.sql.SQLException - if a new connection can not be found or created by this strategy.