com.datastax.driver.core

Class LoggingMonotonicTimestampGenerator

java.lang.Object

com.datastax.driver.core.AbstractMonotonicTimestampGenerator

com.datastax.driver.core.LoggingMonotonicTimestampGenerator

All Implemented Interfaces:

TimestampGenerator

Direct Known Subclasses:

AtomicMonotonicTimestampGenerator, ThreadLocalMonotonicTimestampGenerator

public abstract class LoggingMonotonicTimestampGenerator
extends AbstractMonotonicTimestampGenerator

A monotonic timestamp generator that logs warnings when timestamps drift in the future (see this class's constructors and onDrift(long, long) for more information).

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	LoggingMonotonicTimestampGenerator(long warningThreshold, TimeUnit warningThresholdUnit, long warningInterval, TimeUnit warningIntervalUnit) Creates a new instance.

Method Summary

Modifier and Type	Method and Description
protected void	onDrift(long currentTick, long lastTimestamp) Called when generated timestamps drift into the future compared to the underlying clock (in other words, if lastTimestamp >= currentTick).

Methods inherited from class com.datastax.driver.core.AbstractMonotonicTimestampGenerator

computeNext

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.datastax.driver.core.TimestampGenerator

next

Constructor Detail

LoggingMonotonicTimestampGenerator

protected LoggingMonotonicTimestampGenerator(long warningThreshold,
                                             TimeUnit warningThresholdUnit,
                                             long warningInterval,
                                             TimeUnit warningIntervalUnit)

Creates a new instance.

Parameters:

warningThreshold - how far in the future timestamps are allowed to drift before a warning is logged.

warningThresholdUnit - the unit for warningThreshold.

warningInterval - how often the warning will be logged if timestamps keep drifting above the threshold.

warningIntervalUnit - the unit for warningIntervalUnit.

Method Detail

onDrift

protected void onDrift(long currentTick,
                       long lastTimestamp)

Called when generated timestamps drift into the future compared to the underlying clock (in other words, if lastTimestamp >= currentTick).

This could happen if timestamps are requested faster than the clock granularity, or on a clock skew (for example because of a leap second).

This implementation logs a warning at regular intervals when timestamps drift more than a specified threshold in the future. These messages are emitted at WARN level in the category com.datastax.driver.core.TimestampGenerator.

Specified by:

onDrift in class AbstractMonotonicTimestampGenerator

Parameters:

currentTick - the current clock tick.

lastTimestamp - the last timestamp that was generated.