de.is24.util.monitoring.database
Class MonitoringDataSource

java.lang.Object
  de.is24.util.monitoring.database.MonitoringDataSource

All Implemented Interfaces:

Wrapper, CommonDataSource, DataSource

public class MonitoringDataSource
extends Object
implements DataSource

The MonitoringDataSource wraps a given DataSource and the subsequently returned Connections. The combination of MonitoringDataSource and MonitoringDataSource.MonitoringConnection monitor

• the number of requested database connections split into
• unpersonalised (getConnection()) and
• personalised connections getConnection(String, String)
• the maximum number of connections used in parallel
• the number of errors thrown when calling
• Connection.commit()
• Connection.rollback()
• Connection.rollback(java.sql.Savepoint)

Additionally, the returned Statements are wrapped and attempt to log the SQL being executed in case an exception is thrown.

If you want to use this Class, you need to require springframework core.

Author:

Sebastian Kirsch

See Also:

getConnection(), getConnection(String, String)

Nested Class Summary

private class	MonitoringDataSource.MonitoringConnection The MonitoringConnection is integral part of the MonitoringDataSource.
(package private) static class	MonitoringDataSource.SqlExceptionPredicate
private static class	MonitoringDataSource.SqlLoggingInvocationHandler

Field Summary

private AtomicInteger	currentConnections This field is a helper to determine the correct for maxConnections.
private static org.apache.log4j.Logger	LOGGER
(package private) Set<com.google.common.base.Predicate<SQLException>>	loggingFilters These predicates indicate if a the executed SQL should be logged at INFO level.
private AtomicInteger	maxConnections This field is used to trace the maximum number of connections being use in parallel.
private String	monitorBaseName The base name for all monitor values.
private DataSource	original The wrapped DataSource.

Constructor Summary

MonitoringDataSource(DataSource dataSource)
Creates a new instance of MonitoringDataSource without a specific monitoring base name.

MonitoringDataSource(DataSource dataSource, String monitorBaseName)
Creates a new instance of MonitoringDataSource.

Method Summary

void	addExceptionLogFilter(com.google.common.base.Predicate<SQLException> predicate)
private void	configureSqlExceptionPredicates(String configuration)
private <T> T	delegateViaReflectionDuringMigrationFromJava6ToJava7(String methodName, Object target, Class<T> expectedReturnType, Object... args)
private void	doConnectionMonitoring(long startingInstant, String monitorSuffix) Handles the monitoring for retrieving connections and adapts the max connection counter if appropriate.
Connection	getConnection() Delegates the call to the wrapped data source, wraps the returned connection and counts the connections returned.
private Connection	getConnection(Callable<Connection> callable, String monitorSuffix) Executes the specified Callable to fetch a connection.
Connection	getConnection(String username, String password) Delegates the call to the wrapped data source, wraps the returned connection and counts the connections returned.
int	getLoginTimeout()
PrintWriter	getLogWriter()
Logger	getParentLogger()
boolean	isWrapperFor(Class<?> iface)
private void	monitorFailedConnectionAttempt() Increases the error count for the getConnection method.
void	setExceptionLogFilters(String configuration)
void	setLoginTimeout(int seconds)
void	setLogWriter(PrintWriter out)
String	toString() Returns a String representation of this object.
<T> T	unwrap(Class<T> iface)

Methods inherited from class java.lang.Object

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

Field Detail

LOGGER

private static final org.apache.log4j.Logger LOGGER

original

private final DataSource original

The wrapped DataSource.

monitorBaseName

private final String monitorBaseName

The base name for all monitor values.

maxConnections

private final AtomicInteger maxConnections

This field is used to trace the maximum number of connections being use in parallel.

currentConnections

private final AtomicInteger currentConnections

This field is a helper to determine the correct for maxConnections.

loggingFilters

final Set<com.google.common.base.Predicate<SQLException>> loggingFilters

These predicates indicate if a the executed SQL should be logged at INFO level.

Constructor Detail

MonitoringDataSource

public MonitoringDataSource(DataSource dataSource,
                            String monitorBaseName)

Creates a new instance of MonitoringDataSource.

Parameters:

dataSource - the DataSource to wrap

monitorBaseName - the monitor name to insert such that "de.is24.common.database.MonitoringDataSource.monitorBaseName.monitoringKey" is reported

Throws:

IllegalArgumentException - if dataSource is null

MonitoringDataSource

public MonitoringDataSource(DataSource dataSource)

Creates a new instance of MonitoringDataSource without a specific monitoring base name.

Parameters:

dataSource - the DataSource to wrap

Throws:

IllegalArgumentException - if dataSource is null

Method Detail

addExceptionLogFilter

public void addExceptionLogFilter(com.google.common.base.Predicate<SQLException> predicate)

setExceptionLogFilters

public void setExceptionLogFilters(String configuration)

configureSqlExceptionPredicates

private void configureSqlExceptionPredicates(String configuration)

doConnectionMonitoring

private void doConnectionMonitoring(long startingInstant,
                                    String monitorSuffix)

Handles the monitoring for retrieving connections and adapts the max connection counter if appropriate.

Parameters:

startingInstant - the instant a database connection was requested

monitorSuffix - the suffix for the monitor name to increase

monitorFailedConnectionAttempt

private void monitorFailedConnectionAttempt()

Increases the error count for the getConnection method.

getConnection

private Connection getConnection(Callable<Connection> callable,
                                 String monitorSuffix)
                          throws SQLException

Executes the specified Callable to fetch a connection. Monitors occurring exceptions/errors.

Parameters:

callable - the Callable that actually fetches a Connection

monitorSuffix - the suffix for the monitor name to increase (forwarded to doConnectionMonitoring(long, String))

Returns:

a database Connection

Throws:

SQLException - if fetching a Connection fails

RuntimeException

toString

public String toString()

Returns a String representation of this object.

Overrides:

toString in class Object

Returns:

a String representing this instance

getConnection

public Connection getConnection()
                         throws SQLException

Delegates the call to the wrapped data source, wraps the returned connection and counts the connections returned.

Specified by:

getConnection in interface DataSource

Returns:

a database Connection

Throws:

SQLException - as a result of the delegation

getConnection

public Connection getConnection(String username,
                                String password)
                         throws SQLException

Delegates the call to the wrapped data source, wraps the returned connection and counts the connections returned.

Specified by:

getConnection in interface DataSource

Parameters:

username - the name of the database user on whose behalf the connection isbeing made

password - the user's password

Returns:

a database Connection

Throws:

SQLException - as a result of the delegation

getLogWriter

public PrintWriter getLogWriter()
                         throws SQLException

Specified by:

getLogWriter in interface CommonDataSource

Throws:

SQLException

getLoginTimeout

public int getLoginTimeout()
                    throws SQLException

Specified by:

getLoginTimeout in interface CommonDataSource

Throws:

SQLException

getParentLogger

public Logger getParentLogger()
                       throws SQLFeatureNotSupportedException

Throws:

SQLFeatureNotSupportedException

setLogWriter

public void setLogWriter(PrintWriter out)
                  throws SQLException

Specified by:

setLogWriter in interface CommonDataSource

Throws:

SQLException

setLoginTimeout

public void setLoginTimeout(int seconds)
                     throws SQLException

Specified by:

setLoginTimeout in interface CommonDataSource

Throws:

SQLException

isWrapperFor

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

Specified by:

isWrapperFor in interface Wrapper

Throws:

SQLException

unwrap

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

Specified by:

unwrap in interface Wrapper

Throws:

SQLException

delegateViaReflectionDuringMigrationFromJava6ToJava7

private <T> T delegateViaReflectionDuringMigrationFromJava6ToJava7(String methodName,
                                                                   Object target,
                                                                   Class<T> expectedReturnType,
                                                                   Object... args)