@Override
	public boolean cancel(String appName, String serverId, boolean isReplication) {
		final boolean cancelled = super.cancel(appName, serverId, isReplication);
		if (cancelled) {
			handleCancelation(appName, serverId, isReplication);
		}
		return cancelled;
	}
If
{@link PeerAwareInstanceRegistryImpl#openForTraffic(ApplicationInfoManager, int)}
is called with a zero argument, it means that leases are not automatically
cancelled if the instance hasn't sent any renewals recently. This happens for a
standalone server. It seems like a bad default, so we set it to the smallest
non-zero value we can, so that any instances that subsequently register can bump up
the threshold.
spring-cloud-netflix-eureka-server/src/main/java/org/springframework/cloud/netflix/eureka/server/InstanceRegistry.java