com.netflix.eureka.util

Class EIPManager

java.lang.Object

com.netflix.eureka.util.EIPManager

public class EIPManager
extends java.lang.Object

An AWS specific elastic ip binding utility for binding eureka servers for a well known IP address.

Eureka clients talk to Eureka servers bound with well known IP addresses since that is the most reliable mechanism to discover the Eureka servers. When Eureka servers come up they bind themselves to a well known elastic ip

This binding mechanism gravitates towards one eureka server per zone for resilience.Atleast one elastic ip should be slotted for each eureka server in a zone. If more than eureka server is launched per zone and there are not enough elastic ips slotted, the server tries to pick a free EIP slotted for other zones and if it still cannot find a free EIP, waits and keeps trying.

Method Summary

Modifier and Type	Method and Description
void	bindEIP() Checks if an EIP is bound and optionally binds the EIP.
java.util.Collection<java.lang.String>	getCandidateEIPs(java.lang.String myInstanceId, java.lang.String myZone) Get the list of EIPs in the order of preference depending on instance zone.
static EIPManager	getInstance()
boolean	isEIPBound() Checks if an EIP is already bound to the instance.
void	unbindEIP() Unbind the EIP that this instance is associated with.

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static EIPManager getInstance()

isEIPBound

public boolean isEIPBound()

Checks if an EIP is already bound to the instance.

Returns:

true if an EIP is bound, false otherwise

bindEIP

public void bindEIP()

Checks if an EIP is bound and optionally binds the EIP. The list of EIPs are arranged with the EIPs allocated in the zone first followed by other EIPs. If an EIP is already bound to this instance this method simply returns. Otherwise, this method tries to find an unused EIP based on information from AWS. If it cannot find any unused EIP this method, it will be retried for a specified interval. One of the following scenarios can happen here : 1) If the instance is already bound to an EIP as deemed by AWS, no action is taken. 2) If an EIP is already bound to another instance as deemed by AWS, that EIP is skipped. 3) If an EIP is not already bound to an instance and if this instance is not bound to an EIP, then the EIP is bound to this instance.

unbindEIP

public void unbindEIP()

Unbind the EIP that this instance is associated with.

getCandidateEIPs

public java.util.Collection<java.lang.String> getCandidateEIPs(java.lang.String myInstanceId,
                                                               java.lang.String myZone)

Get the list of EIPs in the order of preference depending on instance zone.

Parameters:

myInstanceId - the instance id for this instance

myZone - the zone where this instance is in

Returns:

Collection containing the list of available EIPs