> Markdown version of [Load Testing Thresholds](https://vaadin.com/docs/next/flow/testing/load-testing/thresholds). Section index: [llms.txt](https://vaadin.com/docs/next/flow/llms.txt)

# Load Testing Thresholds (since V25.2)

## <a id="overview"></a>Overview

k6 thresholds define pass/fail criteria for your load tests.

When a threshold is breached, k6 marks the test as failed, and the Maven build fails if `k6.failOnThreshold=true` (the default).

The TestBench k6 converter plugin generates some default thresholds automatically in every k6 script produced. You can configure the default thresholds, disable individual ones, or add custom thresholds for any k6 metric.

## <a id="default-thresholds"></a>Default Thresholds

Every generated k6 script includes these thresholds out of the box:

| Metric              | Expression                                   | Default                               |
| ------------------- | -------------------------------------------- | ------------------------------------- |
| `http_req_duration` | 95th percentile response time                | `p(95)<2000` (2 seconds)              |
| `http_req_duration` | 99th percentile response time                | `p(99)<5000` (5 seconds)              |
| `checks`            | Check success rate (1% failure rate allowed) | `rate>=0.99` with `abortOnFail: true` |

This generates the following block in the k6 script:

```javascript
export const options = {
  thresholds: {
    checks: [{ threshold: 'rate>=0.99', abortOnFail: true, delayAbortEval: '5s' }],
    http_req_duration: ['p(95)<2000', 'p(99)<5000'],
  },
}
```

## <a id="editing-default-thresholds"></a>Editing Default Thresholds

You can change the default threshold values with Maven properties or through configuration in the POM.

### <a id="via-command-line"></a>Via Command Line

```bash
# Tighter response time requirements
mvn loadtest:convert -Dk6.harFile=recording.har \
    -Dk6.threshold.httpReqDurationP95=1000 \
    -Dk6.threshold.httpReqDurationP99=3000

# Allow checks to fail without aborting the test
mvn loadtest:convert -Dk6.harFile=recording.har \
    -Dk6.threshold.checksAbortOnFail=false

# Allow up to 5% of checks to fail (generates rate>=0.95)
mvn loadtest:convert -Dk6.harFile=recording.har \
    -Dk6.threshold.checksAllowedFailureRate=0.05

# Require all checks to pass (generates rate==1)
mvn loadtest:convert -Dk6.harFile=recording.har \
    -Dk6.threshold.checksAllowedFailureRate=0

# Disable the p95 threshold entirely (set to 0)
mvn loadtest:convert -Dk6.harFile=recording.har \
    -Dk6.threshold.httpReqDurationP95=0
```

### <a id="via-pom-configuration"></a>Via POM Configuration

```xml
<plugin>
    <groupId>com.vaadin</groupId>
    <artifactId>testbench-converter-plugin</artifactId>
    <configuration>
        <!-- 95th percentile response time in ms (0 to disable) -->
        <httpReqDurationP95>1000</httpReqDurationP95>
        <!-- 99th percentile response time in ms (0 to disable) -->
        <httpReqDurationP99>3000</httpReqDurationP99>
        <!-- Set to false to continue the test even when checks fail -->
        <checksAbortOnFail>false</checksAbortOnFail>
    </configuration>
</plugin>
```

### <a id="default-threshold-parameters"></a>Default Threshold Parameters

| Parameter                               | Default | Description                                                                                                                                                             |
| --------------------------------------- | ------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `k6.threshold.httpReqDurationP95`       | `2000`  | 95th percentile response time threshold in ms. Set to `0` to disable.                                                                                                   |
| `k6.threshold.httpReqDurationP99`       | `5000`  | 99th percentile response time threshold in ms. Set to `0` to disable.                                                                                                   |
| `k6.threshold.checksAbortOnFail`        | `true`  | When `true`, the test aborts immediately on the first check failure. When `false`, failures are recorded but the test continues.                                        |
| `k6.threshold.checksAllowedFailureRate` | `0.01`  | Fraction of checks allowed to fail, between `0` and `1`. The default `0.01` generates the threshold `rate>=0.99`. Set to `0` to require all checks to pass (`rate==1`). |

## <a id="adding-custom-thresholds"></a>Adding Custom Thresholds

You can add pass/fail thresholds for any [k6 built-in metric](https://grafana.com/docs/k6/latest/using-k6/metrics/) using the `k6.threshold.custom` property.

The format is a comma-separated list of `metric:expression` pairs:

```
metric1:expression1,metric2:expression2,...
```

### <a id="via-command-line-2"></a>Via Command Line

```bash
# Fail if more than 1% of requests fail
mvn loadtest:run -Dk6.testFile=test.js \
    -Dk6.threshold.custom="http_req_failed:rate<0.01"

# Multiple custom thresholds
mvn loadtest:run -Dk6.testFile=test.js \
    -Dk6.threshold.custom="http_req_failed:rate<0.01,http_req_waiting:p(95)<500,http_reqs:count>100"
```

### <a id="via-pom-configuration-2"></a>Via POM Configuration

```xml
<plugin>
    <groupId>com.vaadin</groupId>
    <artifactId>testbench-converter-plugin</artifactId>
    <configuration>
        <!-- Custom thresholds in metric:expression format -->
        <customThresholds>http_req_failed:rate&lt;0.01,http_req_waiting:p(95)&lt;500</customThresholds>
    </configuration>
</plugin>
```

> **Note:** In XML, use `&lt;` instead of `<` inside threshold expressions.

### <a id="combining-defaults-and-custom-thresholds"></a>Combining Defaults and Custom Thresholds

Custom thresholds are added alongside the defaults.

If you add a custom `http_req_duration` expression, it is merged with the default p95/p99 thresholds:

```bash
# Adds a median threshold alongside the existing p95 and p99
mvn loadtest:convert -Dk6.harFile=recording.har \
    -Dk6.threshold.custom="http_req_duration:p(50)<1000"
```

This produces:

```javascript
export const options = {
  thresholds: {
    checks: [{ threshold: 'rate>=0.99', abortOnFail: true, delayAbortEval: '5s' }],
    http_req_duration: ['p(95)<2000', 'p(99)<5000', 'p(50)<1000'],
  },
}
```

If a custom threshold contains same target as the default, the default gets overridden by the custom one and not duplicated.

```bash
# Overrides existing default p95 median threshold
mvn loadtest:convert -Dk6.harFile=recording.har \
    -Dk6.threshold.custom="http_req_duration:p(95)<500"
```

This produces:

```javascript
export const options = {
  thresholds: {
    checks: [{ threshold: 'rate>=0.99', abortOnFail: true, delayAbortEval: '5s' }],
    http_req_duration: ['p(95)<500', 'p(99)<5000'],
  },
}
```

## <a id="common-threshold-examples"></a>Common Threshold Examples

Below are commonly used threshold configurations for Vaadin load tests.

### <a id="strict-performance-requirements"></a>Strict Performance Requirements

```bash
mvn loadtest:run -Dk6.testFile=test.js \
    -Dk6.threshold.httpReqDurationP95=500 \
    -Dk6.threshold.httpReqDurationP99=1000 \
    -Dk6.threshold.custom="http_req_failed:rate<0.001,http_req_waiting:p(95)<300"
```

Generated output:

```javascript
thresholds: {
  checks: [{ threshold: 'rate>=0.99', abortOnFail: true, delayAbortEval: '5s' }],
  http_req_duration: ['p(95)<500', 'p(99)<1000'],
  http_req_failed: ['rate<0.001'],
  http_req_waiting: ['p(95)<300'],
},
```

### <a id="relaxed-thresholds-for-stress-testing"></a>Relaxed Thresholds for Stress Testing

```bash
mvn loadtest:run -Dk6.testFile=test.js \
    -Dk6.threshold.httpReqDurationP95=10000 \
    -Dk6.threshold.httpReqDurationP99=0 \
    -Dk6.threshold.checksAbortOnFail=false \
    -Dk6.threshold.custom="http_req_failed:rate<0.05"
```

Generated output:

```javascript
thresholds: {
  checks: ['rate>=0.99'],
  http_req_duration: ['p(95)<10000'],
  http_req_failed: ['rate<0.05'],
},
```

### <a id="throughput-minimum"></a>Throughput Minimum

```bash
mvn loadtest:run -Dk6.testFile=test.js \
    -Dk6.threshold.custom="http_reqs:count>1000"
```

## <a id="k6-metric-reference"></a>k6 Metric Reference

The following k6 built-in metrics can be used with custom thresholds. For the full reference, see the [k6 metrics documentation](https://grafana.com/docs/k6/latest/using-k6/metrics/reference/).

| Metric                | Type    | Description                                          |
| --------------------- | ------- | ---------------------------------------------------- |
| `http_req_duration`   | Trend   | Total time for the request (send + wait + receive)   |
| `http_req_waiting`    | Trend   | Time spent waiting for response (Time to First Byte) |
| `http_req_connecting` | Trend   | Time spent establishing TCP connection               |
| `http_req_sending`    | Trend   | Time spent sending data                              |
| `http_req_receiving`  | Trend   | Time spent receiving data                            |
| `http_req_failed`     | Rate    | Rate of failed requests                              |
| `http_reqs`           | Counter | Total number of requests                             |
| `checks`              | Rate    | Rate of successful checks                            |

**Trend** metrics support: `p(N)<value`, `avg<value`, `min<value`, `max<value`, `med<value`\
**Rate** metrics support: `rate<value`, `rate>value`\
**Counter** metrics support: `count<value`, `count>value`