<p>There are 2 questions about Calico applying to k8s cluster.</p>

<ol>
<li><p>Calico creates etcd for own data, but I don't want to create another etcd because k8s already have it. Can I use k8s etcd for Calico?</p></li>
<li><p>Calico prepares Typha for using Kubernetes API Datastore. Then, What does Typha exactly do? I read Typha's code, and assumed that Typha takes snapshots and deltas for adapting network policy and constantly broadcast them to all client which Typha connects to. But I'm not familiar with golang so I don't have confidence of my understanding.</p></li>
</ol>

<p>I'm absolutely new to Calico and k8s, so I'm sorry if I miss some document related to above questions.</p>

<p>We are using shared ETCD for calico as well as kubernetes, we did not face any issue. But it probably depends on the size of the k8s cluster and the kind of workloads being used. If there are too many short jobs, it could be an issue as there would be an increased load on ETCD in comparison to the ones with few - but long running - jobs</p>
