Another job polls this queue and triggers each client to start a push.

```mermaid
graph TD
    subgraph Config Flow
        cu(Config Update)
        db(Debounce)
        pc(Recompute Push Context)
        pq(Push Queue)
        cu-->db

message RollingUpdateDaemonSet {
  // The maximum number of DaemonSet pods that can be unavailable during the
  // update. Value can be an absolute number (ex: 5) or a percentage of total
  // number of DaemonSet pods at the start of the update (ex: 10%). Absolute
  // number is calculated from percentage by rounding up.
  // This cannot be 0 if MaxSurge is 0
  // Default value is 1.

  // will be included in the response, as long as their keys are after the "next key".
  //
  // This field is not supported when watch is true. Clients may start a watch from the last
  // resourceVersion value returned by the server and not miss any modifications.
  optional string continue = 8;

  // `sendInitialEvents=true` may be set together with `watch=true`.

  // fs group then supply a single range with the same start and end. Required for MustRunAs.
  // +optional
  repeated IDRange ranges = 2;
}

// HostPortRange defines a range of host ports that will be enabled by a policy
// for pods to use.  It requires both the start and end to be defined.
message HostPortRange {
  // min is the start of the range, inclusive.
  optional int32 min = 1;

Often, these handlers are adding something to the queue like `client.AddEventHandler(controllers.ObjectHandler(queue.AddObject))`.
Construction should NOT actually start running all of these things, do I/O, or block in anyway.

Running the controller actually starts processing things.
Normally, this just means running the queue.

message StatefulSetOrdinals {
  // start is the number representing the first replica's index. It may be used
  // to number replicas from an alternate index (eg: 1-indexed) over the default
  // 0-indexed names, or to orchestrate progressive movement of replicas from
  // one StatefulSet to another.
  // If set, replica indices will be in the range:
  //   [.spec.ordinals.start, .spec.ordinals.start + .spec.replicas).

  // the associated expression.
  // Name must be a qualified name consisting of alphanumeric characters, '-', '_' or '.', and
  // must start and end with an alphanumeric character (e.g. 'MyName',  or 'my.name',  or
  // '123-abc', regex used for validation is '([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9]') with an