ome.services.db

Class SelfCorrectingDataSource

java.lang.Object

org.springframework.jdbc.datasource.DelegatingDataSource

ome.services.db.SelfCorrectingDataSource

All Implemented Interfaces:

java.sql.Wrapper, java.util.EventListener, javax.sql.CommonDataSource, javax.sql.DataSource, org.springframework.beans.factory.InitializingBean, org.springframework.context.ApplicationListener<ome.util.messages.UserSignalMessage>

public class SelfCorrectingDataSource
extends org.springframework.jdbc.datasource.DelegatingDataSource
implements org.springframework.context.ApplicationListener<ome.util.messages.UserSignalMessage>

DataSource delegate which wraps the

Constructor Summary

Constructors

Constructor and Description
SelfCorrectingDataSource(javax.sql.DataSource delegate, long timeoutInMilliseconds)
SelfCorrectingDataSource(javax.sql.DataSource delegate, long timeoutInMilliseconds, int maxRetries, long maxBackOff)

Method Summary

Modifier and Type	Method and Description
protected long	calculateBackOff(int numberOfErrors)
protected java.sql.Connection	call(java.lang.String username, java.lang.String password, boolean useArgs)
protected java.sql.Connection	callWithRetries(java.lang.String username, java.lang.String password, boolean useArgs)
java.sql.Connection	getConnection()
java.sql.Connection	getConnection(java.lang.String username, java.lang.String password)
protected long	markAndSweep() First removes all entries in errorTimes that are older than some given time and then uses the remaining number of errors to determine the backoff : (#^1/2)*1000 milliseconds.
void	onApplicationEvent(ome.util.messages.UserSignalMessage usm) Handles the USR1 posix signal by calling close on the underlying data source via reflection.

Methods inherited from class org.springframework.jdbc.datasource.DelegatingDataSource

afterPropertiesSet, getLoginTimeout, getLogWriter, getParentLogger, getTargetDataSource, isWrapperFor, setLoginTimeout, setLogWriter, setTargetDataSource, unwrap

Methods inherited from class java.lang.Object

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

Constructor Detail

SelfCorrectingDataSource

public SelfCorrectingDataSource(javax.sql.DataSource delegate,
                                long timeoutInMilliseconds)

SelfCorrectingDataSource

public SelfCorrectingDataSource(javax.sql.DataSource delegate,
                                long timeoutInMilliseconds,
                                int maxRetries,
                                long maxBackOff)

Method Detail

getConnection

public java.sql.Connection getConnection()
                                  throws java.sql.SQLException

Specified by:

getConnection in interface javax.sql.DataSource

Overrides:

getConnection in class org.springframework.jdbc.datasource.DelegatingDataSource

Throws:

java.sql.SQLException

getConnection

public java.sql.Connection getConnection(java.lang.String username,
                                         java.lang.String password)
                                  throws java.sql.SQLException

Specified by:

getConnection in interface javax.sql.DataSource

Overrides:

getConnection in class org.springframework.jdbc.datasource.DelegatingDataSource

Throws:

java.sql.SQLException

onApplicationEvent

public void onApplicationEvent(ome.util.messages.UserSignalMessage usm)

Handles the USR1 posix signal by calling close on the underlying data source via reflection. The assumption is that the next call to any methods will re-initialize the data source. This is the case with bitronix.tm.resource.jdbc.PoolingDataSource

Specified by:

onApplicationEvent in interface org.springframework.context.ApplicationListener<ome.util.messages.UserSignalMessage>

See Also:

ticket:4210

callWithRetries

protected java.sql.Connection callWithRetries(java.lang.String username,
                                              java.lang.String password,
                                              boolean useArgs)
                                       throws java.sql.SQLException

Throws:

java.sql.SQLException

call

protected java.sql.Connection call(java.lang.String username,
                                   java.lang.String password,
                                   boolean useArgs)
                            throws java.sql.SQLException

Throws:

java.sql.SQLException

markAndSweep

protected long markAndSweep()

First removes all entries in errorTimes that are older than some given time and then uses the remaining number of errors to determine the backoff : (#^1/2)*1000 milliseconds.

calculateBackOff

protected long calculateBackOff(int numberOfErrors)