No results for

Powered byAlgolia
⚠️ This is the archived documentation for k6 v0.44. Go to the latest version.


k6/execution provides the capability to get information about the current test execution state inside the test script. You can read in your script the execution state during the test execution and change your script logic based on the current state.

The k6/execution module provides the test execution information with the following properties:

import exec from 'k6/execution';
const options = {
scenarios: {
myscenario: {
// this will be the returned name
executor: 'shared-iterations',
maxDuration: '30m',
export default function () {
console.log(; // myscenario

ℹ️ Identifiers

All unique identifiers are sequentially generated starting from a base of zero (iterations) or one (VU IDs). In distributed/cloud test runs, the test-wide iteration numbers and VU identifiers are still going to be unique across instances, though there might be gaps in the sequences when, for example, some instances execute faster iterations than others or allocate more VUs mid-test.


The instance object provides information associated with the load generator instance. You can think of it as the current running k6 process, which will likely be a single process if you are running k6 on your local machine. When running a cloud/distributed test with multiple load generator instances, the values of the following properties can differ across instances.

iterationsInterruptedintegerThe number of prematurely interrupted iterations in the current instance.
iterationsCompletedintegerThe number of completed iterations in the current instance.
vusActiveintegerThe number of active VUs.
vusInitializedintegerThe number of currently initialized VUs.
currentTestRunDurationfloatThe time passed from the start of the current test run in milliseconds.


Meta information and execution details about the current running scenario.

namestringThe assigned name of the running scenario.
executorstringThe name of the running Executor type.
startTimeintegerThe Unix timestamp in milliseconds when the scenario started.
progressfloatPercentage in a 0 to 1 interval of the scenario progress.
iterationInInstanceintegerThe unique and zero-based sequential number of the current iteration in the scenario, across the current instance.
iterationInTestintegerThe unique and zero-based sequential number of the current iteration in the scenario. It is unique in all k6 execution modes - in local, cloud and distributed/segmented test runs. However, while every instance will get non-overlapping index values in cloud/distributed tests, they might iterate over them at different speeds, so the values won't be sequential across them.


Control the test execution.

abort([String])functionIt aborts the test run with the exit code 108, and an optional string parameter can provide an error message. Aborting the test will not prevent the teardown() execution.
optionsObjectIt returns an object with all the test options as properties. The options' values are consolidated following the order of precedence and derived if shortcuts have been used. It returns null for properties where the relative option hasn't been defined.


Meta information and execution details about the current vu.

iterationInInstanceintegerThe identifier of the iteration in the current instance for this VU. This is only unique for current VU and this instance (if multiple instances). This keeps being aggregated if a given VU is reused between multiple scenarios.
iterationInScenariointegerThe identifier of the iteration in the current scenario for this VU. This is only unique for current VU and scenario it is currently executing.
idInInstanceintegerThe identifier of the VU across the instance. Not unique across multiple instances.
idInTestintegerThe globally unique (across the whole test run) identifier of the VU.
tagsobjectThe map that gives control over VU's Tags. The Tags will be included in every metric emitted by the VU and the Tags' state is maintained across different iterations of the same Scenario while the VU exists. Check how to use it in the example below.
Setting vu.tags

Setting a Tag with the same key as a system tag is allowed, but it requires attention to avoid unexpected results. Overwriting system tags will not throw an error, but in most cases will not actually change the value of the emitted metrics as expected. For example, trying to set the url tag value will not result in a changed tag value when http.get() is called, since the tag value is determined by the HTTP request itself. However, it will add the tag url to the metric samples emitted by a check() or metric.add(), which is probably not the desired behavior. On the other hand, setting the name tag will work as expected, since that was already supported for http.* methods, for the purposes of the URL Grouping feature.

Not all the types are accepted as a tag value: k6 supports strings, numbers and boolean types. Under the hood, the tags object handles a Tag as a String key-value pair, so all the types will be implicitly converted into a string. If one of the denied types is used (e.g. Object or Array) and the throw option is set, an exception will be thrown. Otherwise, only a warning is printed and the tag value will be discarded.

Examples and use cases

Getting unique data once

This is a common use case for data parameterization, you can read the examples using scenario.iterationInTest and vu.idInTest.

Timing operations

The startTime property from the scenario object can be used to time operations.

1import exec from 'k6/execution';
3export default function () {
4 // do some long operations
5 // ...
6 console.log(`step1: scenario ran for ${new Date() - new Date(exec.scenario.startTime)}ms`);
8 // some more long operations
9 //...
10 console.log(`step2: scenario ran for ${new Date() - new Date(exec.scenario.startTime)}ms`);

Script naming

The name property can be used for executing the logic based on which script is currently running.

Tip: If you need to run multiple scenarios in your script you can use exec option achieve a similar goal

1import exec from 'k6/execution';
3const options = {
4 scenarios: {
5 'the-first': {
6 // ...
7 },
8 'the-second': {
9 // ...
10 },
11 },
14export default function () {
15 if ( === 'the-first') {
16 // do some logic during this scenario
17 } else {
18 // do some other logic in the others
19 }

Test Abort

Aborting is possible during initialization:

1import exec from 'k6/execution';

As well as inside the default function:

1import exec from 'k6/execution';
3export default function () {
4 // Note that you can abort with a specific message too
5 exec.test.abort('this is the reason');
8export function teardown() {
9 console.log('teardown will still be called after test.abort()');

Get test options

Get the consolidated and derived options' values

1import exec from 'k6/execution';
3export const options = {
4 stages: [
5 { duration: '5s', target: 100 },
6 { duration: '5s', target: 50 },
7 ],
10export default function () {
11 console.log(exec.test.options.paused); // null
12 console.log(exec.test.options.scenarios.default.stages[0].target); // 100


The vu.tags property can be used for getting or setting VU's tags.

1import http from 'k6/http';
2import exec from 'k6/execution';
4export default function () {
5['mytag'] = 'value1';
6['mytag2'] = 2;
8 // the metrics these HTTP requests emit will get tagged with `mytag` and `mytag2`:
9 http.batch(['', '']);