com.aquenos.cassandra.pvarchiver.server.archiving

Class ChannelStatus

java.lang.Object

com.aquenos.cassandra.pvarchiver.server.archiving.ChannelStatus

public final class ChannelStatus
extends Object

Status of an archived channel. The status can be retrieved from the ArchivingService through the ArchivingService.getChannelStatus(String) and ArchivingService.getChannelStatusForAllChannels() methods.

Author:

Sebastian Marsching

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ChannelStatus.State State of an archived channel.

Constructor Summary

Constructors

Constructor and Description
ChannelStatus(ChannelMetaDataDAO.ChannelConfiguration channelConfiguration, String errorMessage, ChannelStatus.State state, long totalSamplesDropped, long totalSamplesSkippedBack, long totalSamplesWritten) Creates a channel status object.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object obj)
ChannelMetaDataDAO.ChannelConfiguration	getChannelConfiguration() Returns the configuration for the channel.
String	getChannelName() Returns the name of the channel.
String	getErrorMessage() Returns the error message associated with the channel.
ChannelStatus.State	getState() Returns the state of the channel.
long	getTotalSamplesDropped() Returns the total number of samples dropped for this channel.
long	getTotalSamplesSkippedBack() Returns the total number of samples that were discarded because they skipped back in time.
long	getTotalSamplesWritten() Returns the total number of samples written for this channel.
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ChannelStatus

public ChannelStatus(ChannelMetaDataDAO.ChannelConfiguration channelConfiguration,
                     String errorMessage,
                     ChannelStatus.State state,
                     long totalSamplesDropped,
                     long totalSamplesSkippedBack,
                     long totalSamplesWritten)

Creates a channel status object.

Parameters:

channelConfiguration - configuration of the channel.

errorMessage - error message associated with this channel. This parameter may be null. If the state is not ChannelStatus.State.ERROR, it must be null.

state - state of the channel.

totalSamplesDropped - total number of samples that have been dropped (discarded) for the channel because they arrived to quickly and could not be written in time. This counter is reset when a channel is (re-)initialized (e.g. because its configuration has changed).

totalSamplesSkippedBack - total number of samples that have been dropped (discarded) because their time-stamp was less than or equal to a sample that was written earlier. This counter is reset when a channel is (re-)initialized (e.g. because its configuration has changed).

totalSamplesWritten - total number of samples that have been written (persisted) for this channel. This counter is reset when a channel is (re-)initialized (e.g. because its configuration has changed).

Throws:

IllegalArgumentException - if the errorMessage is not null but the state is not ChannelStatus.State.ERROR.

NullPointerException - if channelConfiguration or state is null.

Method Detail

getChannelConfiguration

public ChannelMetaDataDAO.ChannelConfiguration getChannelConfiguration()

Returns the configuration for the channel. This is the version of the configuration that is currently used by the archiving service. This method never returns null.

Returns:

configuration for the channel.

getChannelName

public String getChannelName()

Returns the name of the channel. This method never returns null.

Returns:

name of the channel.

getErrorMessage

public String getErrorMessage()

Returns the error message associated with the channel. If the channel is not in the ChannelStatus.State.ERROR state, the error message is always null. Even if it is in the ChannelStatus.State.ERROR state, the error message is optional and might be null.

Returns:

error message associated with the channel or null if no error message is available.

getState

public ChannelStatus.State getState()

Returns the state of the channel. This method never returns null.

Returns:

state of the channel.

getTotalSamplesDropped

public long getTotalSamplesDropped()

Returns the total number of samples dropped for this channel. Samples are dropped when the queue of samples to be written grows too large. Typically, this happens when samples arrive faster than they can be written to the database. This counter is reset when a channel is (re-)initialized (e.g. because its configuration has changed).

Returns:

total number of samples dropped for this channel.

getTotalSamplesSkippedBack

public long getTotalSamplesSkippedBack()

Returns the total number of samples that were discarded because they skipped back in time. Samples that have a time stamp that is less than or equal to the time stamp of a sample that haws already been written are considered to skip back in time. This might happen when a clock is not stable and skips back in time. However, it might also happen when a channel is disconnected and reconnects and the sample sent by the server is the same one that was already sent at an earlier point in time. This counter is reset when a channel is (re-)initialized (e.g. because its configuration has changed).

Returns:

total number of samples dropped for this channel.

getTotalSamplesWritten

public long getTotalSamplesWritten()

Returns the total number of samples written for this channel. Samples are considered written after they have been successfully persisted to the database. This counter is reset when a channel is (re-)initialized (e.g. because its configuration has changed).

Returns:

total number of samples written for this channel.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object