org.deeplearning4j.spark.time

Class NTPTimeSource

java.lang.Object

org.deeplearning4j.spark.time.NTPTimeSource

All Implemented Interfaces:

TimeSource

public class NTPTimeSource
extends java.lang.Object
implements TimeSource

A TimeSource that utilize Network Time Protocol to determine the system clock offset
Instances should be obtained via getInstance() or TimeSourceProvider; one instance may be used per machine
Specifically, the implementation uses Apache Commons Net (already a dependency in Spark) to query a NTP server. This querying is done periodically (default: once upon initialization and then every 30 minutes thereafter).
The following configuration options can be set via system properties:
To set the time update frequency (for querying the NTP server, in milliseconds): org.deeplearning4j.spark.time.NTPTimeSource.frequencyms
To set the NTP server address: org.deeplearning4j.spark.time.NTPTimeSource.server
Default NTP server: DEFAULT_NTP_SERVER

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	DEFAULT_NTP_SERVER
static int	DEFAULT_NTP_TIMEOUT_MS
static long	DEFAULT_UPDATE_FREQUENCY
static int	MAX_QUERY_RETRIES
static long	MIN_UPDATE_FREQUENCY
static java.lang.String	NTP_SOURCE_SERVER_PROPERTY
static java.lang.String	NTP_SOURCE_UPDATE_FREQUENCY_MS_PROPERTY

Method Summary

Modifier and Type	Method and Description
long	currentTimeMillis() Get the current time in milliseconds, according to this TimeSource
static TimeSource	getInstance()

Methods inherited from class java.lang.Object

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

Field Detail

NTP_SOURCE_UPDATE_FREQUENCY_MS_PROPERTY

public static final java.lang.String NTP_SOURCE_UPDATE_FREQUENCY_MS_PROPERTY

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Constant Field Values

NTP_SOURCE_SERVER_PROPERTY

public static final java.lang.String NTP_SOURCE_SERVER_PROPERTY

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Constant Field Values

MAX_QUERY_RETRIES

public static final int MAX_QUERY_RETRIES

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Constant Field Values

DEFAULT_NTP_TIMEOUT_MS

public static final int DEFAULT_NTP_TIMEOUT_MS

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Constant Field Values

DEFAULT_UPDATE_FREQUENCY

public static final long DEFAULT_UPDATE_FREQUENCY

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Constant Field Values

MIN_UPDATE_FREQUENCY

public static final long MIN_UPDATE_FREQUENCY

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Constant Field Values

DEFAULT_NTP_SERVER

public static final java.lang.String DEFAULT_NTP_SERVER

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Constant Field Values

Method Detail

getInstance

public static TimeSource getInstance()

currentTimeMillis

public long currentTimeMillis()

Description copied from interface: TimeSource

Get the current time in milliseconds, according to this TimeSource

Specified by:

currentTimeMillis in interface TimeSource

Returns:

Current time, since epoch