com.netflix.turbine.monitor.instance

Class InstanceMonitor

java.lang.Object

com.netflix.turbine.monitor.TurbineDataMonitor<DataFromSingleInstance>

com.netflix.turbine.monitor.instance.InstanceMonitor

public class InstanceMonitor
extends TurbineDataMonitor<DataFromSingleInstance>

Class that represents a single connection to an Instance.

The InstanceMonitor connects to the host as prescribed by the InstanceUrlClosure and then streams data down. It assumes that the data format is json.

The monitor looks for 1st class attributes name and type and the rest of the attributes are parsed into one of 2 attribute maps i.e either numericAttributes or stringAttributes.

The monitor also keeps retrying the host connection unless told to do otherwise. It gives up reconnecting when it finds a bad status code such as a 404 not found or UnknownHostException.

However the monitor continues to retry the connection even when it receives an IOException in order to be resilient against network flakiness.

Each InstanceMonitor has access to the TurbineDataDispatcher to dispatch data to. This helps it be decoupled from the TurbineDataHandler underneath. If the dispatcher tells the monitor that there is no one listening then the monitor shuts itself down for efficiency.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	InstanceMonitor.UnitTest

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.concurrent.ExecutorService	ThreadPool

Constructor Summary

Constructors

Constructor and Description
InstanceMonitor(Instance host, InstanceUrlClosure urlClosure, TurbineDataDispatcher<DataFromSingleInstance> dispatcher, MonitorConsole<DataFromSingleInstance> monitorConsole)

Method Summary

Methods

Modifier and Type	Method and Description
TurbineDataDispatcher<DataFromSingleInstance>	getDispatcher()
long	getLastEventUpdateTime() Method that determines when this monitor last received an update.
java.lang.String	getName() The name of the InstanceMonitor.
Instance	getStatsInstance()
boolean	hasStopped()
boolean	monitorRunning()
void	startMonitor() Start monitoring
static void	stop()
void	stopMonitor() Request monitor to stop

Methods inherited from class com.netflix.turbine.monitor.TurbineDataMonitor

getEventDiscarded, getEventProcessed, getRolling2MinuteStats, markEventDiscarded, markEventProcessed

Methods inherited from class java.lang.Object

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

Field Detail

ThreadPool

public static final java.util.concurrent.ExecutorService ThreadPool

Constructor Detail

InstanceMonitor

public InstanceMonitor(Instance host,
               InstanceUrlClosure urlClosure,
               TurbineDataDispatcher<DataFromSingleInstance> dispatcher,
               MonitorConsole<DataFromSingleInstance> monitorConsole)

Parameters:

host - - the host to monitor

urlClosure - - config on how to connect to host

dispatcher - - the dispatcher to send data to

monitorConsole - - the console to manage itself in on startup and shutdown

Method Detail

getName

public java.lang.String getName()

The name of the InstanceMonitor.

Specified by:

getName in class TurbineDataMonitor<DataFromSingleInstance>

Returns:

String

getStatsInstance

public Instance getStatsInstance()

Specified by:

getStatsInstance in class TurbineDataMonitor<DataFromSingleInstance>

Returns:

Instance

getDispatcher

public TurbineDataDispatcher<DataFromSingleInstance> getDispatcher()

Specified by:

getDispatcher in class TurbineDataMonitor<DataFromSingleInstance>

Returns:

TurbineDataDispatcher<DataFromSingleInstance>

startMonitor

public void startMonitor()
                  throws java.lang.Exception

Start monitoring

Specified by:

startMonitor in class TurbineDataMonitor<DataFromSingleInstance>

Throws:

java.lang.Exception

stopMonitor

public void stopMonitor()

Request monitor to stop

Specified by:

stopMonitor in class TurbineDataMonitor<DataFromSingleInstance>

getLastEventUpdateTime

public long getLastEventUpdateTime()

Description copied from class: TurbineDataMonitor

Method that determines when this monitor last received an update. This is used for checking and reaping stale monitors, especially due to stale connections in the cloud.

Overrides:

getLastEventUpdateTime in class TurbineDataMonitor<DataFromSingleInstance>

Returns:

-1 as a default to opt out from implementing this functionality. Else return the timestamp in millis marking the last update occurance.

monitorRunning

public boolean monitorRunning()

Returns:

true/false

hasStopped

public boolean hasStopped()

Returns:

true/false

stop

public static void stop()