cluster. In this scenario,
when the PassthroughCluster is hit, <code>istio_requests_total</code> will get increased
like this:</p><pre><code class=language-json data-expandlinks=true data-repo=istio>{
  &#34;metric&#34;: {
    &#34;__name__&#34;: &#34;istio_requests_total&#34;,
    &#34;connection_security_policy&#34;: &#34;unknown&#34;,
    &#34;destination_app&#34;: &#34;unknown&#34;,
    &#34;destination_principal&#34;: &#34;unknown&#34;,
    &#34;destination_service&#34;: &#34;httpbin.org&#34;,
    &#34