net.dataforte.cassandra.pool
Class PooledConnection

java.lang.Object
  net.dataforte.cassandra.pool.PooledConnection

public class PooledConnection
extends Object

Represents a pooled connection and holds a reference to the Cassandra.Client and TTransport object Derived from org.apache.tomcat.jdbc.pool.PooledConnection by fhanik

Version:

1.0

Field Summary

protected static AtomicInteger	counter Instance counter
protected ConnectionPool	parent The parent
protected PoolConfiguration	poolProperties The properties for the connection pool
static int	VALIDATE_BORROW Validate when connection is borrowed flag
static int	VALIDATE_IDLE Validate when connection is idle flag
static int	VALIDATE_INIT Validate when connection is initialized flag
static int	VALIDATE_RETURN Validate when connection is returned flag

Constructor Summary

PooledConnection(PoolConfiguration prop, ConnectionPool parent)
Constructor

Method Summary

void	connect()
long	getAbandonTimeout() Returns abandon timeout in milliseconds
HashMap<Object,Object>	getAttributes()
org.apache.cassandra.thrift.Cassandra.Client	getConnection() Returns the underlying connection
long	getLastConnected() Returns the timestamp of when the connection was last connected to the database
long	getLastValidated() Returns the timestamp of the last successful validation query execution.
PoolConfiguration	getPoolProperties() Returns the configuration for this connection and pool
long	getReleaseTime() The time limit for how long the object can remain unused before it is released
String	getStackTrace() Returns the stack trace from when this connection was borrowed.
long	getTimestamp() Return the timestamps of last pool action.
org.apache.thrift.transport.TTransport	getTransport()
boolean	isDiscarded() Returns the discarded flag.
boolean	isInitialized()
boolean	isReleased() Returns true if this connection has been released and wont be reused.
boolean	isSuspect()
void	lock() Locks the connection only if either PoolConfiguration.isPoolSweeperEnabled() or PoolConfiguration.getUseLock() return true.
void	reconnect() Issues a call to disconnect(boolean) with the argument false followed by a call to connect()
boolean	release() This method is called if (Now - timeCheckedIn > getReleaseTime()) This method disconnects the connection, logs an error in debug mode if it happens then sets the released flag to false.
void	setDiscarded(boolean discarded) An interceptor can call this method with the value true, and the connection will be closed when it is returned to the pool.
void	setLastValidated(long lastValidated) Set the timestamp the connection was last validated.
void	setPoolProperties(PoolConfiguration poolProperties) Sets the pool configuration for this connection and connection pool.
void	setStackTrace(String trace) The pool will set the stack trace when it is check out and checked in
void	setSuspect(boolean suspect)
void	setTimestamp(long timestamp) Sets a timestamp on this connection.
String	toString()
void	unlock() Unlocks the connection only if the sweeper is enabled Otherwise this is a noop for performance
boolean	validate(int validateAction) Returns true if the object is still valid. if not the pool will call the getExpiredAction() and follow up with one of the four expired methods

Methods inherited from class java.lang.Object

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

Field Detail

counter

protected static AtomicInteger counter

Instance counter

VALIDATE_BORROW

public static final int VALIDATE_BORROW

Validate when connection is borrowed flag

See Also:

Constant Field Values

VALIDATE_RETURN

public static final int VALIDATE_RETURN

Validate when connection is returned flag

See Also:

Constant Field Values

VALIDATE_IDLE

public static final int VALIDATE_IDLE

Validate when connection is idle flag

See Also:

Constant Field Values

VALIDATE_INIT

public static final int VALIDATE_INIT

Validate when connection is initialized flag

See Also:

Constant Field Values

poolProperties

protected PoolConfiguration poolProperties

The properties for the connection pool

parent

protected ConnectionPool parent

The parent

Constructor Detail

PooledConnection

public PooledConnection(PoolConfiguration prop,
                        ConnectionPool parent)

Constructor

Parameters:

prop - - pool properties

parent - - the parent connection pool

Method Detail

connect

public void connect()
             throws org.apache.thrift.TException

Throws:

org.apache.thrift.TException

isInitialized

public boolean isInitialized()

Returns:

true if connect() was called successfully and disconnect has not yet been called

reconnect

public void reconnect()
               throws org.apache.thrift.TException,
                      org.apache.cassandra.thrift.AuthenticationException,
                      org.apache.cassandra.thrift.AuthorizationException,
                      org.apache.cassandra.thrift.InvalidRequestException

Issues a call to disconnect(boolean) with the argument false followed by a call to connect()

Throws:

org.apache.thrift.TException - if the call to connect() fails.

org.apache.cassandra.thrift.InvalidRequestException

org.apache.cassandra.thrift.AuthorizationException

org.apache.cassandra.thrift.AuthenticationException

getAbandonTimeout

public long getAbandonTimeout()

Returns abandon timeout in milliseconds

Returns:

abandon timeout in milliseconds

validate

public boolean validate(int validateAction)

Returns true if the object is still valid. if not the pool will call the getExpiredAction() and follow up with one of the four expired methods

getReleaseTime

public long getReleaseTime()

The time limit for how long the object can remain unused before it is released

Returns:

PoolConfiguration.getMinEvictableIdleTimeMillis()

release

public boolean release()

This method is called if (Now - timeCheckedIn > getReleaseTime()) This method disconnects the connection, logs an error in debug mode if it happens then sets the released flag to false. Any attempts to connect this cached object again will fail per connect() The connection pool uses the atomic return value to decrement the pool size counter.

Returns:

true if this is the first time this method has been called. false if this method has been called before.

setStackTrace

public void setStackTrace(String trace)

The pool will set the stack trace when it is check out and checked in

Parameters:

trace - the stack trace for this connection

getStackTrace

public String getStackTrace()

Returns the stack trace from when this connection was borrowed. Can return null if no stack trace was set.

Returns:

the stack trace or null of no trace was set

setTimestamp

public void setTimestamp(long timestamp)

Sets a timestamp on this connection. A timestamp usually means that some operation performed successfully.

Parameters:

timestamp - the timestamp as defined by System.currentTimeMillis()

isSuspect

public boolean isSuspect()

setSuspect

public void setSuspect(boolean suspect)

setDiscarded

public void setDiscarded(boolean discarded)

An interceptor can call this method with the value true, and the connection will be closed when it is returned to the pool.

Parameters:

discarded - - only valid value is true

Throws:

IllegalStateException - if this method is called with the value false and the value true has already been set.

setLastValidated

public void setLastValidated(long lastValidated)

Set the timestamp the connection was last validated. This flag is used to keep track when we are using a validation-interval.

Parameters:

lastValidated - a timestamp as defined by System.currentTimeMillis()

setPoolProperties

public void setPoolProperties(PoolConfiguration poolProperties)

Sets the pool configuration for this connection and connection pool. Object is shared with the ConnectionPool

Parameters:

poolProperties -

getTimestamp

public long getTimestamp()

Return the timestamps of last pool action. Timestamps are typically set when connections are borrowed from the pool. It is used to keep track of abandon-timeouts.

Returns:

the timestamp of the last pool action as defined by System.currentTimeMillis()

isDiscarded

public boolean isDiscarded()

Returns the discarded flag.

Returns:

the discarded flag. If the value is true, either disconnect(boolean) has been called or it will be called when the connection is returned to the pool.

getLastValidated

public long getLastValidated()

Returns the timestamp of the last successful validation query execution.

Returns:

the timestamp of the last successful validation query execution as defined by System.currentTimeMillis()

getPoolProperties

public PoolConfiguration getPoolProperties()

Returns the configuration for this connection and pool

Returns:

the configuration for this connection and pool

lock

public void lock()

Locks the connection only if either PoolConfiguration.isPoolSweeperEnabled() or PoolConfiguration.getUseLock() return true. The per connection lock ensures thread safety is multiple threads are performing operations on the connection. Otherwise this is a noop for performance

unlock

public void unlock()

Unlocks the connection only if the sweeper is enabled Otherwise this is a noop for performance

getConnection

public org.apache.cassandra.thrift.Cassandra.Client getConnection()

Returns the underlying connection

Returns:

the underlying Thrift connection

getTransport

public org.apache.thrift.transport.TTransport getTransport()

getLastConnected

public long getLastConnected()

Returns the timestamp of when the connection was last connected to the database. *

Returns:

the timestamp when this connection was created as defined by System.currentTimeMillis()

toString

public String toString()

Overrides:

toString in class Object

isReleased

public boolean isReleased()

Returns true if this connection has been released and wont be reused.

Returns:

true if the method release() has been called

getAttributes

public HashMap<Object,Object> getAttributes()