Package com.streambase.sb.monitor

Class StreamBaseMonitor

java.lang.Object

com.streambase.sb.monitor.StreamBaseMonitor

All Implemented Interfaces:

Closeable, AutoCloseable

public class StreamBaseMonitor
extends Object
implements Closeable

Monitors a StreamBase Server, and gathers statistics. Periodically sends Snapshot objects to all registered MonitorListeners.

See Also:

• Snapshot
• MonitorListener

Field Summary

Fields

Modifier and Type	Field	Description
static final Schema	STAT_SCHEMA	The stats schema.
static final Schema	STAT_SCHEMA_V3	The v3 stats schema.

Constructor Summary

Constructors

Constructor	Description
StreamBaseMonitor(StreamBaseClient client)	Create a monitoring object, which will connect to a server with the given StreamBaseClient object.
StreamBaseMonitor(StreamBaseClient sbClient, String streamName)	Constructor
StreamBaseMonitor(StreamBaseURI uri)	Create a monitoring object, which will connect to a server with the given StreamBase URI.
StreamBaseMonitor(String uri)	Create a monitoring object The given uri can either be a StreamBaseURI or a filename.

Method Summary

Modifier and Type	Method	Description
void	addMonitorListener(MonitorListener listener)	Add a listener for snapshot information.
void	close()
boolean	enableOperatorDetail(boolean enable)	Enable or disable operator details in snapshots such as operator type.
protected void	finalize()
StreamBaseClient	getClient()	Get the StreamBaseClient that this monitor is using
Schema	getStatsSchema()	Get the stats schema
String	getStatsStreamName()	Get the stats stream name
boolean	isClosed()	Indicates if the StreamBaseMonitor client is closed
boolean	isStatsEnabled()	Determine if stats are available
void	removeMonitorListener(MonitorListener listener)	Remove a listener that was previously added.
void	removeMonitorListeners()	Remove all listeners.
protected void	reportMonitorStatus()	Report GC and memory usage, if log level debug is enabled.
void	run()	Read and process monitor snapshots from sbd.
void	terminate()	Ask the monitor to terminate.

Methods inherited from class java.lang.Object

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

Field Details

STAT_SCHEMA

public static final Schema STAT_SCHEMA

The stats schema.

STAT_SCHEMA_V3

public static final Schema STAT_SCHEMA_V3

The v3 stats schema.

Constructor Details

StreamBaseMonitor

public StreamBaseMonitor(StreamBaseURI uri)
                  throws StreamBaseException

Create a monitoring object, which will connect to a server with the given StreamBase URI. The connection will not be made until caller calls run().

A null StreamBase URI will get the connection information from the streambase.uri property variable, if set. The default server is "sb://localhost:10000".

Parameters:

uri - URI of StreamBase server

Throws:

StreamBaseException - on error

See Also:

• StreamBaseURI

StreamBaseMonitor

public StreamBaseMonitor(StreamBaseClient client)
                  throws StreamBaseException

Create a monitoring object, which will connect to a server with the given StreamBaseClient object.

Note: The StreamBaseClient object is passed into this StreamBaseMonitor constructor. Therefore this StreamBaseMonitor does not "own" the StreamBaseClient object. It is the responsibility of the caller to close the StreamBaseClient object.

Parameters:

client - an already connected StreamBaseClient

Throws:

StreamBaseException - on error

See Also:

• StreamBaseClient

StreamBaseMonitor

public StreamBaseMonitor(String uri)
                  throws StreamBaseException

Create a monitoring object The given uri can either be a StreamBaseURI or a filename. If it is a StreamBaseURI then the monitor will use it to connect to a StreamBaseServer for live monitoring. If a filename the StreamBaseMonitor will read stats from a file. This file is typically made by sbc dequeue system.stats. A empty or null uri will cause the StreamBaseMonitor to get uri information from the environment.

Parameters:

uri - A StreamBaseURI or filename.

Throws:

StreamBaseException - on error

See Also:

• StreamBaseURI

StreamBaseMonitor

public StreamBaseMonitor(StreamBaseClient sbClient,
 String streamName)
                  throws StreamBaseException

Constructor

Parameters:

sbClient - StreamBase Client

streamName - Stream name

Throws:

StreamBaseException - Error creating monitor

Method Details

finalize

protected void finalize()

Overrides:

finalize in class Object

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

enableOperatorDetail

public boolean enableOperatorDetail(boolean enable)

Enable or disable operator details in snapshots such as operator type. Must be set before StreamBaseMonitor.run() is called. Setting after run is called has no effect.

Parameters:

enable - true: enable collection of Operator details; false: disable collection

Returns:

if operator details were previously enabled or disabled.

Since:

7.0.2

isClosed

public boolean isClosed()

Indicates if the StreamBaseMonitor client is closed

Returns:

true means this StreamBaseMonitor is moribund.

Since:

6.6.9

terminate

public void terminate()

Ask the monitor to terminate. Termination will occur after the next snapshot, or after the current snapshot if terminate() is invoked from within a MonitorListener's snapshotReceived() method.

run

public void run()
         throws StreamBaseException

Read and process monitor snapshots from sbd. This function will block, and will not return until terminate is called or the connection to the StreamBase server is disconnected. Any call to terminate must be either from inside a MonitorListener, or from another thread.

Throws:

StreamBaseException - if a connection cannot be established with the server, or an error occurs while receiving a snapshot

reportMonitorStatus

protected void reportMonitorStatus()

Report GC and memory usage, if log level debug is enabled.

isStatsEnabled

public boolean isStatsEnabled()

Determine if stats are available

Returns:

true=stats are available false=either the server is not available, or stats are disabled on the server

Since:

7.0.2

addMonitorListener

public void addMonitorListener(MonitorListener listener)
                        throws IllegalArgumentException

Add a listener for snapshot information.

If the given listener has already been added just return.

Listeners are called in the order in which they were added.

Parameters:

listener - user-implemented MonitorListener to add

Throws:

IllegalArgumentException - listener is null

removeMonitorListener

public void removeMonitorListener(MonitorListener listener)

Remove a listener that was previously added.

If listener was not previously added this method quietly does nothing

Parameters:

listener - user-implemented MonitorListener to remove

removeMonitorListeners

public void removeMonitorListeners()

Remove all listeners.

getStatsStreamName

public String getStatsStreamName()

Get the stats stream name

Returns:

the stats stream name

getStatsSchema

public Schema getStatsSchema()

Get the stats schema

Returns:

the stats stream schema

getClient

public StreamBaseClient getClient()

Get the StreamBaseClient that this monitor is using

Returns:

StreamBaseClient in use by this monitor