com.netflix.eureka.registry

Class PeerAwareInstanceRegistryImpl

java.lang.Object

com.netflix.eureka.registry.AbstractInstanceRegistry

com.netflix.eureka.registry.PeerAwareInstanceRegistryImpl

All Implemented Interfaces:

com.netflix.discovery.shared.LookupService<java.lang.String>, LeaseManager<com.netflix.appinfo.InstanceInfo>, InstanceRegistry, PeerAwareInstanceRegistry

Direct Known Subclasses:

AwsInstanceRegistry

@Singleton
public class PeerAwareInstanceRegistryImpl
extends AbstractInstanceRegistry
implements PeerAwareInstanceRegistry

Handles replication of all operations to AbstractInstanceRegistry to peer Eureka nodes to keep them all in sync.

Primary operations that are replicated are the Registers,Renewals,Cancels,Expirations and Status Changes

When the eureka server starts up it tries to fetch all the registry information from the peer eureka nodes.If for some reason this operation fails, the server does not allow the user to get the registry information for a period specified in EurekaServerConfig.getWaitTimeInMsWhenSyncEmpty().

One important thing to note about renewals.If the renewal drops more than the specified threshold as specified in EurekaServerConfig.getRenewalPercentThreshold() within a period of EurekaServerConfig.getRenewalThresholdUpdateIntervalMs(), eureka perceives this as a danger and stops expiring instances.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PeerAwareInstanceRegistryImpl.Action

Field Summary

Fields

Modifier and Type	Field and Description
protected com.netflix.discovery.EurekaClientConfig	clientConfig
protected com.netflix.discovery.EurekaClient	eurekaClient
protected PeerEurekaNodes	peerEurekaNodes
protected ServerCodecs	serverCodecs

Fields inherited from class com.netflix.eureka.registry.AbstractInstanceRegistry

allKnownRemoteRegions, expectedNumberOfRenewsPerMin, lock, numberOfRenewsPerMinThreshold, overriddenInstanceStatusMap, regionNameVSRemoteRegistry, responseCache, serverConfig

Constructor Summary

Constructors

Constructor and Description
PeerAwareInstanceRegistryImpl(EurekaServerConfig serverConfig, com.netflix.discovery.EurekaClientConfig clientConfig, ServerCodecs serverCodecs, com.netflix.discovery.EurekaClient eurekaClient)

Method Summary

Modifier and Type	Method and Description
boolean	cancel(java.lang.String appName, java.lang.String id, boolean isReplication) Cancels the registration of an instance.
boolean	deleteStatusOverride(java.lang.String appName, java.lang.String id, com.netflix.appinfo.InstanceInfo.InstanceStatus newStatus, java.lang.String lastDirtyTimestamp, boolean isReplication) Removes status override for a give instance.
long	getLocalRegistrySize()
com.netflix.appinfo.InstanceInfo	getNextServerFromEureka(java.lang.String virtualHostname, boolean secure)
long	getNumOfReplicationsInLastMin() Gets the number of renewals in the last minute.
protected com.netflix.appinfo.InstanceInfo.InstanceStatus	getOverriddenInstanceStatus(com.netflix.appinfo.InstanceInfo r, Lease<com.netflix.appinfo.InstanceInfo> existingLease, boolean isReplication)
java.util.List<PeerEurekaNode>	getReplicaNodes() Deprecated. use PeerEurekaNodes.getPeerEurekaNodes() directly. Gets the list of peer eureka nodes which is the list to replicate information to.
java.util.List<com.netflix.discovery.shared.Application>	getSortedApplications() Gets the list of all Applications from the registry in sorted lexical order of Application.getName().
void	init(PeerEurekaNodes peerEurekaNodes)
int	isBelowRenewThresold() Checks if the number of renewals is lesser than threshold.
boolean	isLeaseExpirationEnabled() Checks whether lease expiration is enabled.
boolean	isRegisterable(com.netflix.appinfo.InstanceInfo instanceInfo) Checks if an instance is registerable in this region.
boolean	isSelfPreservationModeEnabled() Checks to see if the self-preservation mode is enabled.
void	openForTraffic(com.netflix.appinfo.ApplicationInfoManager applicationInfoManager, int count)
void	register(com.netflix.appinfo.InstanceInfo info, boolean isReplication) Registers the information about the InstanceInfo and replicates this information to all peer eureka nodes.
boolean	renew(java.lang.String appName, java.lang.String id, boolean isReplication) Marks the given instance of the given app name as renewed, and also marks whether it originated from replication.
boolean	shouldAllowAccess()
boolean	shouldAllowAccess(boolean remoteRegionRequired) Checks to see if the registry access is allowed or the server is in a situation where it does not all getting registry information.
void	shutdown() Perform all cleanup and shutdown operations.
void	statusUpdate(java.lang.String asgName, ASGResource.ASGStatus newStatus, boolean isReplication) Replicate the ASG status updates to peer eureka nodes.
boolean	statusUpdate(java.lang.String appName, java.lang.String id, com.netflix.appinfo.InstanceInfo.InstanceStatus newStatus, java.lang.String lastDirtyTimestamp, boolean isReplication) Updates the status of an instance.
int	syncUp() Populates the registry information from a peer eureka node.

Methods inherited from class com.netflix.eureka.registry.AbstractInstanceRegistry

clearRegistry, evict, evict, getApplication, getApplication, getApplicationDeltas, getApplicationDeltasFromMultipleRegions, getApplications, getApplications, getApplicationsFromAllRemoteRegions, getApplicationsFromLocalRegionOnly, getApplicationsFromMultipleRegions, getInstanceByAppAndId, getInstanceByAppAndId, getInstancesById, getInstancesById, getLastNCanceledInstances, getLastNRegisteredInstances, getNumberofElementsininstanceCache, getNumOfRenewsInLastMin, getNumOfRenewsPerMinThreshold, getResponseCache, initializedResponseCache, initRemoteRegionRegistry, internalCancel, overriddenInstanceStatusesSnapshot, postInit, register, storeOverriddenStatusIfRequired, storeOverriddenStatusIfRequired

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.netflix.eureka.registry.InstanceRegistry

clearRegistry, getApplication, getApplicationsFromLocalRegionOnly, getInstanceByAppAndId, getInstanceByAppAndId, getLastNCanceledInstances, getLastNRegisteredInstances, getNumOfRenewsInLastMin, getNumOfRenewsPerMinThreshold, getResponseCache, initializedResponseCache, overriddenInstanceStatusesSnapshot, storeOverriddenStatusIfRequired, storeOverriddenStatusIfRequired

Methods inherited from interface com.netflix.eureka.lease.LeaseManager

evict, register

Methods inherited from interface com.netflix.discovery.shared.LookupService

getApplication, getApplications, getInstancesById

Field Detail

clientConfig

protected final com.netflix.discovery.EurekaClientConfig clientConfig

serverCodecs

protected final ServerCodecs serverCodecs

eurekaClient

protected final com.netflix.discovery.EurekaClient eurekaClient

peerEurekaNodes

protected volatile PeerEurekaNodes peerEurekaNodes

Constructor Detail

PeerAwareInstanceRegistryImpl

@Inject
public PeerAwareInstanceRegistryImpl(EurekaServerConfig serverConfig,
                                             com.netflix.discovery.EurekaClientConfig clientConfig,
                                             ServerCodecs serverCodecs,
                                             com.netflix.discovery.EurekaClient eurekaClient)

Method Detail

init

public void init(PeerEurekaNodes peerEurekaNodes)
          throws java.lang.Exception

Specified by:

init in interface PeerAwareInstanceRegistry

Throws:

java.lang.Exception

shutdown

public void shutdown()

Perform all cleanup and shutdown operations.

Specified by:

shutdown in interface InstanceRegistry

Overrides:

shutdown in class AbstractInstanceRegistry

syncUp

public int syncUp()

Populates the registry information from a peer eureka node. This operation fails over to other nodes until the list is exhausted if the communication fails.

Specified by:

syncUp in interface PeerAwareInstanceRegistry

openForTraffic

public void openForTraffic(com.netflix.appinfo.ApplicationInfoManager applicationInfoManager,
                           int count)

Specified by:

openForTraffic in interface InstanceRegistry

shouldAllowAccess

public boolean shouldAllowAccess(boolean remoteRegionRequired)

Checks to see if the registry access is allowed or the server is in a situation where it does not all getting registry information. The server does not return registry information for a period specified in EurekaServerConfig.getWaitTimeInMsWhenSyncEmpty(), if it cannot get the registry information from the peer eureka nodes at start up.

Specified by:

shouldAllowAccess in interface PeerAwareInstanceRegistry

Returns:

false - if the instances count from a replica transfer returned zero and if the wait time has not elapsed, otherwise returns true

shouldAllowAccess

public boolean shouldAllowAccess()

getReplicaNodes

@Deprecated
public java.util.List<PeerEurekaNode> getReplicaNodes()

Deprecated. use PeerEurekaNodes.getPeerEurekaNodes() directly. Gets the list of peer eureka nodes which is the list to replicate information to.

Returns:

the list of replica nodes.

cancel

public boolean cancel(java.lang.String appName,
                      java.lang.String id,
                      boolean isReplication)

Description copied from class: AbstractInstanceRegistry

Cancels the registration of an instance.

This is normally invoked by a client when it shuts down informing the server to remove the instance from traffic.

Specified by:

cancel in interface LeaseManager<com.netflix.appinfo.InstanceInfo>

Overrides:

cancel in class AbstractInstanceRegistry

Parameters:

appName - the application name of the application.

id - the unique identifier of the instance.

isReplication - true if this is a replication event from other nodes, false otherwise.

Returns:

true if the instance was removed from the AbstractInstanceRegistry successfully, false otherwise.

register

public void register(com.netflix.appinfo.InstanceInfo info,
                     boolean isReplication)

Registers the information about the InstanceInfo and replicates this information to all peer eureka nodes. If this is replication event from other replica nodes then it is not replicated.

Specified by:

register in interface PeerAwareInstanceRegistry

Parameters:

info - the InstanceInfo to be registered and replicated.

isReplication - true if this is a replication event from other replica nodes, false otherwise.

renew

public boolean renew(java.lang.String appName,
                     java.lang.String id,
                     boolean isReplication)

Description copied from class: AbstractInstanceRegistry

Marks the given instance of the given app name as renewed, and also marks whether it originated from replication.

Specified by:

renew in interface LeaseManager<com.netflix.appinfo.InstanceInfo>

Overrides:

renew in class AbstractInstanceRegistry

id - - unique id within appName

isReplication - - whether this is a replicated entry from another ds node

Returns:

whether the operation of successful

See Also:

LeaseManager.renew(java.lang.String, java.lang.String, boolean)

statusUpdate

public boolean statusUpdate(java.lang.String appName,
                            java.lang.String id,
                            com.netflix.appinfo.InstanceInfo.InstanceStatus newStatus,
                            java.lang.String lastDirtyTimestamp,
                            boolean isReplication)

Description copied from class: AbstractInstanceRegistry

Updates the status of an instance. Normally happens to put an instance between InstanceInfo.InstanceStatus.OUT_OF_SERVICE and InstanceInfo.InstanceStatus.UP to put the instance in and out of traffic.

Specified by:

statusUpdate in interface InstanceRegistry

Overrides:

statusUpdate in class AbstractInstanceRegistry

Parameters:

appName - the application name of the instance.

id - the unique identifier of the instance.

newStatus - the new InstanceInfo.InstanceStatus.

lastDirtyTimestamp - last timestamp when this instance information was updated.

isReplication - true if this is a replication event from other nodes, false otherwise.

Returns:

true if the status was successfully updated, false otherwise.

deleteStatusOverride

public boolean deleteStatusOverride(java.lang.String appName,
                                    java.lang.String id,
                                    com.netflix.appinfo.InstanceInfo.InstanceStatus newStatus,
                                    java.lang.String lastDirtyTimestamp,
                                    boolean isReplication)

Description copied from class: AbstractInstanceRegistry

Removes status override for a give instance.

Specified by:

deleteStatusOverride in interface InstanceRegistry

Overrides:

deleteStatusOverride in class AbstractInstanceRegistry

Parameters:

appName - the application name of the instance.

id - the unique identifier of the instance.

newStatus - the new InstanceInfo.InstanceStatus.

lastDirtyTimestamp - last timestamp when this instance information was updated.

isReplication - true if this is a replication event from other nodes, false otherwise.

Returns:

true if the status was successfully updated, false otherwise.

statusUpdate

public void statusUpdate(java.lang.String asgName,
                         ASGResource.ASGStatus newStatus,
                         boolean isReplication)

Replicate the ASG status updates to peer eureka nodes. If this event is a replication from other nodes, then it is not replicated to other nodes.

Specified by:

statusUpdate in interface PeerAwareInstanceRegistry

Parameters:

asgName - the asg name for which the status needs to be replicated.

newStatus - the ASGResource.ASGStatus information that needs to be replicated.

isReplication - true if this is a replication event from other nodes, false otherwise.

isLeaseExpirationEnabled

public boolean isLeaseExpirationEnabled()

Description copied from interface: InstanceRegistry

Checks whether lease expiration is enabled.

Specified by:

isLeaseExpirationEnabled in interface InstanceRegistry

Returns:

true if enabled

isSelfPreservationModeEnabled

public boolean isSelfPreservationModeEnabled()

Checks to see if the self-preservation mode is enabled.

The self-preservation mode is enabled if the expected number of renewals per minute AbstractInstanceRegistry.getNumOfRenewsInLastMin() is lesser than the expected threshold which is determined by AbstractInstanceRegistry.getNumOfRenewsPerMinThreshold() . Eureka perceives this as a danger and stops expiring instances as this is most likely because of a network event. The mode is disabled only when the renewals get back to above the threshold or if the flag EurekaServerConfig.shouldEnableSelfPreservation() is set to false.

Specified by:

isSelfPreservationModeEnabled in interface InstanceRegistry

Returns:

true if the self-preservation mode is enabled, false otherwise.

getNextServerFromEureka

public com.netflix.appinfo.InstanceInfo getNextServerFromEureka(java.lang.String virtualHostname,
                                                                boolean secure)

Specified by:

getNextServerFromEureka in interface com.netflix.discovery.shared.LookupService<java.lang.String>

getSortedApplications

public java.util.List<com.netflix.discovery.shared.Application> getSortedApplications()

Gets the list of all Applications from the registry in sorted lexical order of Application.getName().

Specified by:

getSortedApplications in interface InstanceRegistry

Returns:

the list of Applications in lexical order.

getNumOfReplicationsInLastMin

@Monitor(name="numOfReplicationsInLastMin",
         description="Number of total replications received in the last minute",
         type=GAUGE)
public long getNumOfReplicationsInLastMin()

Gets the number of renewals in the last minute.

Returns:

a long value representing the number of renewals in the last minute.

isBelowRenewThresold

@Monitor(name="isBelowRenewThreshold",
         description="0 = false, 1 = true",
         type=GAUGE)
public int isBelowRenewThresold()

Checks if the number of renewals is lesser than threshold.

Specified by:

isBelowRenewThresold in interface InstanceRegistry

Returns:

0 if the renewals are greater than threshold, 1 otherwise.

isRegisterable

public boolean isRegisterable(com.netflix.appinfo.InstanceInfo instanceInfo)

Checks if an instance is registerable in this region. Instances from other regions are rejected.

Parameters:

instanceInfo - th instance info information of the instance

Returns:

true, if it can be registered in this server, false otherwise.

getLocalRegistrySize

@Monitor(name="localRegistrySize",
         description="Current registry size",
         type=GAUGE)
public long getLocalRegistrySize()

Overrides:

getLocalRegistrySize in class AbstractInstanceRegistry

getOverriddenInstanceStatus

protected com.netflix.appinfo.InstanceInfo.InstanceStatus getOverriddenInstanceStatus(com.netflix.appinfo.InstanceInfo r,
                                                                                      Lease<com.netflix.appinfo.InstanceInfo> existingLease,
                                                                                      boolean isReplication)

Specified by:

getOverriddenInstanceStatus in class AbstractInstanceRegistry