private int resolveInstanceLeaseDuration(final InstanceInfo info) {
		int leaseDuration = Lease.DEFAULT_DURATION_IN_SECS;
		if (info.getLeaseInfo() != null && info.getLeaseInfo().getDurationInSecs() > 0) {
			leaseDuration = info.getLeaseInfo().getDurationInSecs();
		}
		return leaseDuration;
	}
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