"format": "time_series",
          "hide": true,
          "intervalFactor": 2,
          "legendFormat": "heap alloc",
          "refId": "D"
        },
        {
          "datasource": {
            "type": "prometheus",
            "uid": "${datasource}"
          },
          "expr": "go_memstats_alloc_bytes{app=\"istiod\"}",
          "format": "time_series",
          "intervalFactor": 2,

	// 0 means that there is no limit.
	XdsViaAgentsLimit int
}

var DefaultOptions = Options{
	MessageWriter:     os.Stdout,
	XdsViaAgents:      false,
	XdsViaAgentsLimit: 0,
}

// RequestAndProcessXds merges XDS responses from 1 central or 1..N K8s cluster-based XDS servers
// Deprecated This method makes multiple responses appear to come from a single control plane;
// consider using AllRequestAndProcessXds or FirstRequestAndProcessXds

  // across all of the NetworkPolicy objects whose podSelector matches the pod. If
  // this field is empty then this NetworkPolicy does not allow any traffic (and serves
  // solely to ensure that the pods it selects are isolated by default)
  // +optional
  repeated NetworkPolicyIngressRule ingress = 2;

## Background and motivation

Motivations to implement ztunnel generally came from two areas.

First, and most importantly, it serves as a means to implement the real goal: waypoints.
For various reasons outside the scope of this document, there is a desire to move from a sidecar based architecture to a "remote proxy" architecture.

  // separated by commas. The numbers are listed in increasing order. Three or
  // more consecutive numbers are compressed and represented by the first and
  // last element of the series, separated by a hyphen.
  // For example, if the completed indexes are 1, 3, 4, 5 and 7, they are
  // represented as "1,3-5,7".
  // +optional
  optional string completedIndexes = 7;

// Exactly one "target" type should be set.
message ExternalMetricSource {
  // metricName is the name of the metric in question.
  optional string metricName = 1;

  // metricSelector is used to identify a specific time series
  // within a given metric.
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.LabelSelector metricSelector = 2;

  // targetValue is the target value of the metric (as a quantity).

  // OR if the traffic matches at least one ingress rule across all of the NetworkPolicy
  // objects whose podSelector matches the pod.
  // If this field is empty then this NetworkPolicy does not allow any traffic
  // (and serves solely to ensure that the pods it selects are isolated by default).
  // +optional
  repeated NetworkPolicyIngressRule ingress = 2;

  // List of egress rules to be applied to the selected pods. Outgoing traffic is

          },
          "expr": "sum(rate(istio_requests_total{reporter=\"source\", response_code!~\"5.*\"}[1m])) / sum(rate(istio_requests_total{reporter=\"source\"}[1m]))",
          "format": "time_series",
          "intervalFactor": 1,
          "refId": "A",
          "step": 4
        }
      ],
      "title": "Global Success Rate (non-5xx responses)",
      "type": "stat"
    },
    {

          "datasource": {
            "type": "prometheus",
            "uid": "${datasource}"
          },
          "expr": "sum(container_memory_working_set_bytes{container=\"istio-proxy\"})",
          "format": "time_series",
          "hide": false,
          "intervalFactor": 2,
          "legendFormat": "Total (k8s)",
          "refId": "A",
          "step": 2
        }
      ],
      "title": "Memory",

message ExternalMetricSource {
  // metricName is the name of the metric in question.
  optional string metricName = 1;

  // metricSelector is used to identify a specific time series
  // within a given metric.
  // +optional
  optional k8s.io.apimachinery.pkg.apis.meta.v1.LabelSelector metricSelector = 2;

  // targetValue is the target value of the metric (as a quantity).