Merge pull request #2526 from grafana/release/v0.38.2

release v0.38.2

lib/consts/consts.go

@@ -28,7 +28,7 @@ import (
 )
 
 // Version contains the current semantic version of k6.
-const Version = "0.38.1"
+const Version = "0.38.2"
 
 // VersionDetails can be set externally as part of the build process
 var VersionDetails = "" // nolint:gochecknoglobals

release notes/v0.38.2.md

@@ -0,0 +1,94 @@
+k6 v0.38.2 is a patch release containing a couple of bugfixes!
+
+### Threshold over sub-metrics without samples would result in `NaN` ([#2520](https://github.com/grafana/k6/issues/2520))
+
+There was a bug in thresholds applied to sub-metrics set to `abortOnFail`: leading k6 to evaluate thresholds that would have likely aborted before they had a chance of passing (because no samples for the given metric were recorded yet). This bug would have led to such thresholds' results value to be `NaN` rather than a numerical value. The following script, for instance:
+
+```javascript
+import { check, sleep } from 'k6';
+
+import http from 'k6/http';
+
+export const options = {
+  scenarios: {
+    iWillFail: {
+      exec: 'iWillFail',
+      executor: 'constant-vus',
+      startTime: '2s',
+      vus: 1,
+      duration: '30s',
+    },
+  },
+
+  thresholds: {
+    'checks{type:read}': [{ threshold: 'rate>0.9', abortOnFail: true }],
+  },
+};
+
+export function iWillFail() {
+  let res = http.get(`https://test-api.k6.io/`);
+
+  check(res, {
+    'read status is 200': (r) => r.status === 200,
+  }, { type: 'read' });
+
+  sleep(1);
+}
+```
+
+
+Would result in the following:
+
+```
+✗ { type:read }...: NaN% ✓ 0 ✗ 0  
+vus...............: 0 min=0 max=0
+vus_max...........: 1 min=1 max=1
+```
+
+This issue was introduced by recent changes to how we handle thresholds in the k6 engine and is now addressed in `v0.38.2`.
+
+### Sub-metrics without values rendered below an incorrect parent metric ([#2518](https://github.com/grafana/k6/issues/2518))
+
+There was in how thresholds over sub-metrics that didn't receive any samples would be displayed under an incorrect parent metric. For instance, the following script:
+
+```javascript
+import { Counter } from 'k6/metrics';
+
+const counter1 = new Counter("one");
+const counter2 = new Counter("two");
+
+export const options = {
+    thresholds: {
+        'one{tag:xyz}': [],
+    },
+};
+
+export default function() {
+    console.log('not submitting metric1');
+    counter2.add(42);
+}
+```
+
+Would have led to the following output, where the {tag:xyz} sub-metric is displayed under `iterations` instead of `one`:
+
+```
+data_received........: 0 B 0 B/s
+data_sent............: 0 B 0 B/s
+iteration_duration...: avg=0s min=0s med=0s max=0s p(90)=0s p(95)=0s
+iterations...........: 1 499.950005/s
+  { tag:xyz }........: 0 0/s
+two..................: 42 20997.90021/s
+```
+
+When we would have expected it to produce:
+
+```
+one..................: 0 0/s
+  { tag:xyz }........: 0 0/s
+two..................: 42
+```
+
+This issue has been addressed in [#2519](https://github.com/grafana/k6/pull/2519), and k6 `v0.38.2` now displays sub-metrics under their actual parents, even when they have received no samples.
+
+
+Special thanks to @efdknittlfrank, who reported and helped us track down the issue.