> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ton.org/llms.txt
> Use this file to discover all available pages before exploring further.

<AgentInstructions>

## Submitting Feedback

If you encounter incorrect, outdated, or confusing documentation on this page, submit feedback:

POST https://docs.ton.org/feedback

```json
{
  "path": "/ecosystem/nodes/rust/probes",
  "feedback": "Description of the issue"
}
```

Only submit feedback when you have something specific and actionable to report.

</AgentInstructions>

# Health probes

export const Aside = ({type = "note", title = "", icon = "", iconType = "regular", children}) => {
  const asideVariants = ["note", "tip", "caution", "danger"];
  const asideComponents = {
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  const iconVariants = ["regular", "solid", "light", "thin", "sharp-solid", "duotone", "brands"];
  if (!iconVariants.includes(iconType)) {
    iconType = "regular";
  }
  return <>
      <div className={`callout my-4 px-5 py-4 overflow-hidden rounded-2xl flex gap-3 border ${asideComponents[variant].outerStyle}`} data-callout-type={asideComponents[variant].calloutType}>
        <div className="mt-0.5 w-4" data-component-part="callout-icon">
          {}
          {icon === "" ? asideComponents[variant].icon : <Icon icon={icon} iconType={iconType} size={14} />}
        </div>
        <div className={`text-sm prose min-w-0 w-full ${asideComponents[variant].innerStyle}`} data-component-part="callout-content">
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              <span className="font-bold">
                Invalid <code>type</code> passed!
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              <br />
              <span className="font-bold">Received: </span>
              {type}
              <br />
              <span className="font-bold">Expected one of: </span>
              {asideVariants.join(", ")}
            </p> : <>
              {title && <p className="font-bold">{title}</p>}
              {children}
            </>}
        </div>
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};

Kubernetes liveness, readiness, and startup probes for the TON node.

## Available endpoints

The TON node metrics HTTP server exposes two health endpoints:

| Endpoint   | Purpose         | Kubernetes probe |
| ---------- | --------------- | ---------------- |
| `/healthz` | Liveness check  | `livenessProbe`  |
| `/readyz`  | Readiness check | `readinessProbe` |

Both endpoints return `HTTP 200` with a JSON body:

```json theme={"theme":{"light":"github-light-default","dark":"dark-plus"},"languages":{"custom":["/resources/grammars/tolk.tmLanguage.json","/resources/grammars/tlb.tmLanguage.json","/resources/grammars/fift.tmLanguage.json","/resources/grammars/tasm.tmLanguage.json","/resources/grammars/func.tmLanguage.json"]}}
{
  "status": "ok",
  "sync_status": 6,
  "last_mc_block_seqno": 12345678,
  "validation_status": 3
}
```

These endpoints are served by the same HTTP server as `/metrics` and require the `metrics` section in the [node config](/ecosystem/nodes/rust/node-config).

<Aside type="note">
  Both `/healthz` and `/readyz` return 200 if the metrics HTTP server is running. They do not check sync status or other internal health criteria.
</Aside>

## Enabling probes

Probes require `ports.metrics` to be set in the Helm values:

```yaml theme={"theme":{"light":"github-light-default","dark":"dark-plus"},"languages":{"custom":["/resources/grammars/tolk.tmLanguage.json","/resources/grammars/tlb.tmLanguage.json","/resources/grammars/fift.tmLanguage.json","/resources/grammars/tasm.tmLanguage.json","/resources/grammars/func.tmLanguage.json"]}}
ports:
  metrics: 9100

probes:
  startup:
    httpGet:
      path: /healthz
      port: metrics
    failureThreshold: 60
    periodSeconds: 10
  liveness:
    httpGet:
      path: /healthz
      port: metrics
    periodSeconds: 30
    failureThreshold: 3
  readiness:
    httpGet:
      path: /readyz
      port: metrics
    periodSeconds: 10
    failureThreshold: 3
```

The `port: metrics` value references the named container port and resolves to the value defined in `ports.metrics`.

## Startup probe

The startup probe is critical for TON nodes. The node may take several minutes to start, depending on:

* Database size and integrity checks.
* State loading and Merkle tree reconstruction.
* Network bootstrap and peer discovery.

Without a startup probe, the liveness probe may restart the pod before the node finishes initializing.

Recommended settings:

| Parameter          | Value  | Rationale                                             |
| ------------------ | ------ | ----------------------------------------------------- |
| `failureThreshold` | `60`   | Allows up to 10 minutes for initialization (60 x 10s) |
| `periodSeconds`    | `10` s | Checks every 10 seconds                               |

Once the startup probe succeeds, Kubernetes switches to the liveness and readiness probes.

## Tuning

### Validators

Validators have stricter uptime requirements. Use tighter probe settings:

```yaml theme={"theme":{"light":"github-light-default","dark":"dark-plus"},"languages":{"custom":["/resources/grammars/tolk.tmLanguage.json","/resources/grammars/tlb.tmLanguage.json","/resources/grammars/fift.tmLanguage.json","/resources/grammars/tasm.tmLanguage.json","/resources/grammars/func.tmLanguage.json"]}}
probes:
  startup:
    httpGet:
      path: /healthz
      port: metrics
    failureThreshold: 60
    periodSeconds: 10
  liveness:
    httpGet:
      path: /healthz
      port: metrics
    periodSeconds: 15
    failureThreshold: 3
  readiness:
    httpGet:
      path: /readyz
      port: metrics
    periodSeconds: 5
    failureThreshold: 2
```

### Full nodes and liteservers

Full nodes are more tolerant of brief interruptions. The default values from the enabling probes are appropriate.

### Without the metrics port

If the metrics HTTP server cannot be enabled, configure a TCP socket probe on the control port as a basic liveness check:

```yaml theme={"theme":{"light":"github-light-default","dark":"dark-plus"},"languages":{"custom":["/resources/grammars/tolk.tmLanguage.json","/resources/grammars/tlb.tmLanguage.json","/resources/grammars/fift.tmLanguage.json","/resources/grammars/tasm.tmLanguage.json","/resources/grammars/func.tmLanguage.json"]}}
ports:
  control: 50000

probes:
  liveness:
    tcpSocket:
      port: control
    periodSeconds: 30
    failureThreshold: 3
```

A TCP socket probe only verifies that the port accepts connections. It does not check node health. Use this approach only when the metrics endpoint cannot be enabled.