com.bigdata.util

Class ClocksNotSynchronizedException

java.lang.Object

java.lang.Throwable

java.lang.Exception

java.lang.RuntimeException

com.bigdata.util.ClocksNotSynchronizedException

All Implemented Interfaces:

Serializable

public class ClocksNotSynchronizedException
extends RuntimeException

An instance of this class is thrown if we observe that the timestamps generated by two or more services violate a requirement for synchronized clocks.

Author:

Bryan Thompson

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ClocksNotSynchronizedException()
ClocksNotSynchronizedException(String msg)

Method Summary

Methods

Modifier and Type	Method and Description
static void	assertBefore(UUID serviceId1, UUID serviceId2, long t1, long t2, long maxSkew) Assert that t1 LT t2, where t1 and t2 are timestamps obtain such that this relation will be true if the clocks on the nodes are synchronized.

Methods inherited from class java.lang.Throwable

addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ClocksNotSynchronizedException

public ClocksNotSynchronizedException()

ClocksNotSynchronizedException

public ClocksNotSynchronizedException(String msg)

Method Detail

assertBefore

public static void assertBefore(UUID serviceId1,
                UUID serviceId2,
                long t1,
                long t2,
                long maxSkew)
                         throws ClocksNotSynchronizedException

Assert that t1 LT t2, where t1 and t2 are timestamps obtain such that this relation will be true if the clocks on the nodes are synchronized.

Note: Clock synchronization errors can arise across nodes if the nodes are not using a common network time source.

Note: Synchronization errors can arise on a single node if the clock is changed on that node - specifically if the clock is move backwards to before the most recent commit timestamp. For example, if the timezone is changed.

Parameters:

serviceId1 - The service that reported the timestamp t1.

serviceId2 - The service that reported the timestamp t2.

t1 - A timestamp from one service.

t2 - A timestamp from the another service.

maxSkew - The maximum allowed clock skew (typically on the order of seconds).

Throws:

ClocksNotSynchronizedException