MySQL Connector/J 9.2.0 · com.mysql.cj.jdbc.ha.BalanceStrategy

Implement this interface to provide a new load balancing strategy for URLs of the form "jdbc:mysql:loadbalance://..", and provide the implementation class name as the configuration parameter "loadBalanceStrategy". The driver will not pass in a Connection instance when calling init(), but it will pass in the Properties, otherwise it acts like a normal Extension. One instance of a strategy *per* JDBC connection instance will be created. If you need singleton-like behavior, you're on your own to provide it.

Method Summary

Modifier and Type	Method and Description
public JdbcConnection	Returns: the physical JDBC connection for the application to use, based upon the strategy employed. 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) Called by the driver to pick a new connection to route requests over.

Modifier and Type

Method and Description

public JdbcConnection

Returns:

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

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)

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

Method Detail

pickConnection	back to summary
public JdbcConnection pickConnection(InvocationHandler proxy, List<String> configuredHosts, Map<String, JdbcConnection> liveConnections, long[] responseTimes, int numRetries) throws SQLException 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:JdbcConnection the physical JDBC connection for the application to use, based upon the strategy employed. Exceptions SQLException: if a new connection can not be found or created by this strategy.

pickConnection

back to summary

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

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:JdbcConnection

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

Exceptions

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

public Interface BalanceStrategy

Method Summary

Method Detail