protected boolean shouldUpdate(final Set<String> changedKeys) {
			assert changedKeys != null;

			// if eureka.client.use-dns-for-fetching-service-urls is true, then
			// service-url will not be fetched from environment.
			if (this.clientConfig.shouldUseDnsForFetchingServiceUrls()) {
				return false;
			}

			if (changedKeys.contains("eureka.client.region")) {
				return true;
			}

			for (final String key : changedKeys) {
				// property keys are not expected to be null.
				if (key.startsWith("eureka.client.service-url.")
						|| key.startsWith("eureka.client.availability-zones.")) {
					return true;
				}
			}
			return false;
		}
{@link PeerEurekaNodes} which updates peers when /refresh is invoked. Peers are
updated only if <code>eureka.client.use-dns-for-fetching-service-urls</code> is
<code>false</code> and one of following properties have changed.
<p>
</p>
<ul>
<li><code>eureka.client.availability-zones</code></li>
<li><code>eureka.client.region</code></li>
<li><code>eureka.client.service-url.&lt;zone&gt;</code></li>
</ul>
spring-cloud-netflix-eureka-server/src/main/java/org/springframework/cloud/netflix/eureka/server/EurekaServerAutoConfiguration.java