com.netflix.eureka.lease

Class Lease<T>

java.lang.Object

com.netflix.eureka.lease.Lease<T>

public class Lease<T>
extends java.lang.Object

Describes a time-based availability of a T. Purpose is to avoid accumulation of instances in AbstractInstanceRegistry as result of ungraceful shutdowns that is not uncommon in AWS environments. If a lease elapses without renewals, it will eventually expire consequently marking the associated T for immediate eviction - this is similar to an explicit cancellation except that there is no communication between the T and LeaseManager.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_DURATION_IN_SECS

Constructor Summary

Constructors

Constructor and Description
Lease(T r, int durationInSecs)

Method Summary

Modifier and Type	Method and Description
void	cancel() Cancels the lease by updating the eviction time.
long	getEvictionTimestamp() Gets the milliseconds since epoch when the lease was evicted.
T	getHolder() Returns the holder of the lease.
long	getLastRenewalTimestamp() Gets the milliseconds since epoch when the lease was last renewed.
long	getRegistrationTimestamp() Gets the milliseconds since epoch when the lease was registered.
long	getServiceUpTimestamp() Gets the milliseconds since epoch when the service for the lease was marked as up.
boolean	isExpired() Checks if the lease of a given InstanceInfo has expired or not.
boolean	isExpired(long additionalLeaseMs) Checks if the lease of a given InstanceInfo has expired or not.
void	renew() Renew the lease, use renewal duration if it was specified by the associated T during registration, otherwise default duration is DEFAULT_DURATION_IN_SECS.
void	serviceUp() Mark the service as up.
void	setServiceUpTimestamp(long serviceUpTimestamp) Set the leases service UP timestamp.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_DURATION_IN_SECS

public static final int DEFAULT_DURATION_IN_SECS

See Also:

Constant Field Values

Constructor Detail

Lease

public Lease(T r,
             int durationInSecs)

Method Detail

renew

public void renew()

Renew the lease, use renewal duration if it was specified by the associated T during registration, otherwise default duration is DEFAULT_DURATION_IN_SECS.

cancel

public void cancel()

Cancels the lease by updating the eviction time.

serviceUp

public void serviceUp()

Mark the service as up. This will only take affect the first time called, subsequent calls will be ignored.

setServiceUpTimestamp

public void setServiceUpTimestamp(long serviceUpTimestamp)

Set the leases service UP timestamp.

isExpired

public boolean isExpired()

Checks if the lease of a given InstanceInfo has expired or not.

isExpired

public boolean isExpired(long additionalLeaseMs)

Checks if the lease of a given InstanceInfo has expired or not. Note that due to renew() doing the 'wrong" thing and setting lastUpdateTimestamp to +duration more than what it should be, the expiry will actually be 2 * duration. This is a minor bug and should only affect instances that ungracefully shutdown. Due to possible wide ranging impact to existing usage, this will not be fixed.

Parameters:

additionalLeaseMs - any additional lease time to add to the lease evaluation in ms.

getRegistrationTimestamp

public long getRegistrationTimestamp()

Gets the milliseconds since epoch when the lease was registered.

Returns:

the milliseconds since epoch when the lease was registered.

getLastRenewalTimestamp

public long getLastRenewalTimestamp()

Gets the milliseconds since epoch when the lease was last renewed. Note that the value returned here is actually not the last lease renewal time but the renewal + duration.

Returns:

the milliseconds since epoch when the lease was last renewed.

getEvictionTimestamp

public long getEvictionTimestamp()

Gets the milliseconds since epoch when the lease was evicted.

Returns:

the milliseconds since epoch when the lease was evicted.

getServiceUpTimestamp

public long getServiceUpTimestamp()

Gets the milliseconds since epoch when the service for the lease was marked as up.

Returns:

the milliseconds since epoch when the service for the lease was marked as up.

getHolder

public T getHolder()

Returns the holder of the lease.