update docs + add changeset

Author: Tofel

book/src/libs/wasp/benchspy/loki_std.md

@@ -112,14 +112,9 @@ var compareAverages = func(t *testing.T, metricName string, currentAsStringSlice
 	assert.LessOrEqual(t, math.Abs(diffPrecentage), maxPrecentageDiff, "%s medians are more than 1% different", metricName, fmt.Sprintf("%.4f", diffPrecentage))
 }
 
-compareAverages(
-    t,
-    string(benchspy.MedianLatency),
-    currentAsStringSlice,
-    previousAsStringSlice,
-    1.0,
-)
+compareAverages(t, string(benchspy.MedianLatency), currentAsStringSlice, previousAsStringSlice, 1.0)
 compareAverages(t, string(benchspy.Percentile95Latency), currentAsStringSlice, previousAsStringSlice, 1.0)
+compareAverages(t, string(benchspy.Percentile99Latency), currentAsStringSlice, previousAsStringSlice, 1.0)
 compareAverages(t, string(benchspy.MaxLatency), currentAsStringSlice, previousAsStringSlice, 1.0)
 compareAverages(t, string(benchspy.ErrorRate), currentAsStringSlice, previousAsStringSlice, 1.0)
 ```

book/src/libs/wasp/benchspy/real_world.md

@@ -90,6 +90,7 @@ Let’s assume you want to ensure that none of the performance metrics degrade b
 hasFailed, error := benchspy.CompareDirectWithThresholds(
     1.0, // Max 1% worse median latency
     1.0, // Max 1% worse p95 latency
+    1.0, // Max 1% worse p99 latency
     1.0, // Max 1% worse maximum latency
     0.0, // No increase in error rate
     currentReport, previousReport)

book/src/libs/wasp/benchspy/reports/standard_report.md

@@ -18,6 +18,7 @@ Both query executors focus on the characteristics of the load generated by `WASP
 Predefined metrics for both include:
 - Median latency
 - 95th percentile latency
+- 99th percentile latency
 - Max latency
 - Error rate
 

book/src/libs/wasp/benchspy/simplest_metrics.md

@@ -15,6 +15,7 @@ hasErrors, errors := benchspy.CompareDirectWithThresholds(
     // maximum differences in percentages for:
     1.0, // median latency
     1.0, // p95 latency
+    1.0, // p99 latency
     1.0, // max latency
     1.0, // error rate
     currentReport,
@@ -29,6 +30,7 @@ If there are errors they will be returned as `map[string][]errors`, where key is
 > Both `Direct` and `Loki` query executors support following standard performance metrics out of the box:
 > - `median_latency`
 > - `p95_latency`
+> - `p99_latency`
 > - `max_latency`
 > - `error_rate`
 
@@ -43,6 +45,8 @@ Generator: vu1
 +-------------------------+---------+---------+---------+
 | 95th_percentile_latency | 50.7387 | 50.7622 | 0.0463  |
 +-------------------------+---------+---------+---------+
+| 99th_percentile_latency | 54.8192 | 51.0124 | -7.4624 |
++-------------------------+---------+---------+---------+
 | max_latency             | 55.7195 | 51.7248 | -7.1692 |
 +-------------------------+---------+---------+---------+
 | error_rate              | 0.0000  | 0.0000  | 0.0000  |

wasp/.changeset/v1.51.1.md

@@ -0,0 +1 @@
+- Add p99 metric to BenchSpy's Direct and Loki standard Query Executors

wasp/benchspy/direct.go

@@ -270,10 +270,10 @@ func (dqe *DirectQueryExecutor) standardQuery(standardMetric StandardLoadMetric)
 		}
 		return p95Fn, nil
 	case Percentile99Latency:
-		p95Fn := func(responses *wasp.SliceBuffer[*wasp.Response]) (float64, error) {
+		p99Fn := func(responses *wasp.SliceBuffer[*wasp.Response]) (float64, error) {
 			return stats.Percentile(responsesToDurationFn(responses), 99)
 		}
-		return p95Fn, nil
+		return p99Fn, nil
 	case MaxLatency:
 		maxFn := func(responses *wasp.SliceBuffer[*wasp.Response]) (float64, error) {
 			return stats.Max(responsesToDurationFn(responses))

wasp/benchspy/types.go

@@ -68,7 +68,7 @@ const (
 	ErrorRate           StandardLoadMetric = "error_rate"
 )
 
-var StandardLoadMetrics = []StandardLoadMetric{MedianLatency, Percentile95Latency, MaxLatency, ErrorRate}
+var StandardLoadMetrics = []StandardLoadMetric{MedianLatency, Percentile95Latency, Percentile99Latency, MaxLatency, ErrorRate}
 
 type StandardResourceMetric string