the instances.</p><p>In an ordinary Istio installation where the <code>istiod</code> service is running locally on the cluster
(i.e., a <span class=term data-title="Primary Cluster" data-body='<p>A primary cluster is a <a href="/docs/reference/glossary/#cluster">cluster</a> with a
<a href="/docs/reference/glossary/#control-plane">control plane</a>. A single
<a href="/docs/reference/glossary/#service-mesh">mesh</a> can have more than
one primary cluster for HA or to reduce latency. Primary clusters can act a