feat: histogram impact metric ingestion

src/lib/features/metrics/impact/batch-histogram.test.ts

@@ -117,9 +117,9 @@ describe('BatchHistogram', () => {
         expect(metrics).toMatch(/test_histogram_count{label1="value1"} 8/);
     });
 
-    test('should record different labels separately', async () => {
+    test('should record different labels separately and handle special characters', async () => {
         histogram.recordBatch(
-            { service: 'api', app: 'my_app' },
+            { service: 'api', url: 'http://example.com:8080/api' },
             {
                 count: 3,
                 sum: 1.5,
@@ -131,7 +131,7 @@ describe('BatchHistogram', () => {
         );
 
         histogram.recordBatch(
-            { service: 'web', app: 'my_app' },
+            { service: 'web', url: 'https://app.example.com/dashboard' },
             {
                 count: 2,
                 sum: 3.0,
@@ -145,29 +145,30 @@ describe('BatchHistogram', () => {
         const metrics = await registry.metrics();
 
         expect(metrics).toMatch(
-            /test_histogram_bucket{app="my_app",service="api",le="1"} 2/,
+            /test_histogram_bucket{service="api",url="http:\/\/example\.com:8080\/api",le="1"} 2/,
         );
         expect(metrics).toMatch(
-            /test_histogram_bucket{app="my_app",service="api",le="\+Inf"} 3/,
+            /test_histogram_bucket{service="api",url="http:\/\/example\.com:8080\/api",le="\+Inf"} 3/,
         );
         expect(metrics).toMatch(
-            /test_histogram_sum{app="my_app",service="api"} 1\.5/,
+            /test_histogram_sum{service="api",url="http:\/\/example\.com:8080\/api"} 1\.5/,
         );
         expect(metrics).toMatch(
-            /test_histogram_count{app="my_app",service="api"} 3/,
+            /test_histogram_count{service="api",url="http:\/\/example\.com:8080\/api"} 3/,
         );
 
+        // Web service metrics (with HTTPS URL)
         expect(metrics).toMatch(
-            /test_histogram_bucket{app="my_app",service="web",le="1"} 1/,
+            /test_histogram_bucket{service="web",url="https:\/\/app\.example\.com\/dashboard",le="1"} 1/,
         );
         expect(metrics).toMatch(
-            /test_histogram_bucket{app="my_app",service="web",le="\+Inf"} 2/,
+            /test_histogram_bucket{service="web",url="https:\/\/app\.example\.com\/dashboard",le="\+Inf"} 2/,
         );
         expect(metrics).toMatch(
-            /test_histogram_sum{app="my_app",service="web"} 3/,
+            /test_histogram_sum{service="web",url="https:\/\/app\.example\.com\/dashboard"} 3/,
         );
         expect(metrics).toMatch(
-            /test_histogram_count{app="my_app",service="web"} 2/,
+            /test_histogram_count{service="web",url="https:\/\/app\.example\.com\/dashboard"} 2/,
         );
     });
 
@@ -193,4 +194,37 @@ describe('BatchHistogram', () => {
         expect(metrics).toMatch(/test_histogram_sum{client="sdk"} 12\.3/);
         expect(metrics).toMatch(/test_histogram_count{client="sdk"} 5/);
     });
+
+    test('should handle unsorted bucket input', async () => {
+        histogram.recordBatch(
+            { service: 'test' },
+            {
+                count: 5,
+                sum: 7.5,
+                buckets: [
+                    { le: '+Inf', count: 5 }, // Infinity first (unsorted)
+                    { le: 2.5, count: 4 }, // Out of order
+                    { le: 0.5, count: 2 }, // Out of order
+                    { le: 1, count: 3 }, // Out of order
+                ],
+            },
+        );
+
+        const metrics = await registry.metrics();
+
+        expect(metrics).toMatch(
+            /test_histogram_bucket{service="test",le="0.5"} 2/,
+        );
+        expect(metrics).toMatch(
+            /test_histogram_bucket{service="test",le="1"} 3/,
+        );
+        expect(metrics).toMatch(
+            /test_histogram_bucket{service="test",le="2.5"} 4/,
+        );
+        expect(metrics).toMatch(
+            /test_histogram_bucket{service="test",le="\+Inf"} 5/,
+        );
+        expect(metrics).toMatch(/test_histogram_sum{service="test"} 7\.5/);
+        expect(metrics).toMatch(/test_histogram_count{service="test"} 5/);
+    });
 });

src/lib/features/metrics/impact/batch-histogram.ts

@@ -15,6 +15,7 @@ export class BatchHistogram {
     private name: string;
     private help: string;
     private registry: Registry;
+    public labelNames: string[] = [];
 
     // Store accumulated data for each label combination
     private store: Map<
@@ -65,7 +66,7 @@ export class BatchHistogram {
 
     private createLabelKey(labels: Record<string, string | number>): string {
         const sortedKeys = Object.keys(labels).sort();
-        return sortedKeys.map((key) => `${key}:${labels[key]}`).join(',');
+        return JSON.stringify(sortedKeys.map((key) => [key, labels[key]]));
     }
 
     reset(): void {
@@ -78,10 +79,12 @@ export class BatchHistogram {
         for (const [labelKey, data] of this.store) {
             const labels: Record<string, string | number> = {};
             if (labelKey) {
-                labelKey.split(',').forEach((pair) => {
+                const parsedLabels = JSON.parse(labelKey);
-                    const [key, value] = pair.split(':');
+                parsedLabels.forEach(
-                    labels[key] = value;
+                    ([key, value]: [string, string | number]) => {
-                });
+                        labels[key] = value;
+                    },
+                );
             }
 
             for (const [le, cumulativeCount] of Array.from(

src/lib/features/metrics/impact/impact-metrics.e2e.test.ts

@@ -180,7 +180,6 @@ test('should store histogram metrics with batch data', async () => {
             name: 'response_time',
             help: 'Response time histogram',
             type: 'histogram',
-            buckets: [1],
             samples: [
                 {
                     labels: { foo: 'bar' },
@@ -200,7 +199,6 @@ test('should store histogram metrics with batch data', async () => {
             name: 'response_time',
             help: 'Response time histogram',
             type: 'histogram',
-            buckets: [1],
             samples: [
                 {
                     labels: { foo: 'bar' },

src/lib/features/metrics/impact/metrics-translator.test.ts

@@ -193,6 +193,22 @@ describe('MetricsTranslator', () => {
                     },
                 ],
             },
+            {
+                name: 'histogram_with_labels',
+                help: 'histogram with labels',
+                type: 'histogram' as const,
+                samples: [
+                    {
+                        labels: { service: 'api' },
+                        count: 5,
+                        sum: 2.5,
+                        buckets: [
+                            { le: 1, count: 3 },
+                            { le: '+Inf' as const, count: 5 },
+                        ],
+                    },
+                ],
+            },
         ];
 
         const result1 = await translator.translateAndSerializeMetrics(metrics1);
@@ -202,6 +218,9 @@ describe('MetricsTranslator', () => {
         expect(result1).toContain(
             'unleash_gauge_gauge_with_labels{unleash_env="prod",unleash_origin="sdk"} 10',
         );
+        expect(result1).toContain(
+            'unleash_histogram_histogram_with_labels_count{unleash_origin="sdk",unleash_service="api"} 5',
+        );
 
         const metrics2 = [
             {
@@ -226,6 +245,23 @@ describe('MetricsTranslator', () => {
                     },
                 ],
             },
+            {
+                name: 'histogram_with_labels',
+                help: 'histogram with labels',
+                type: 'histogram' as const,
+                buckets: [1],
+                samples: [
+                    {
+                        labels: { service: 'api', region: 'us-east' }, // Added a new label
+                        count: 3,
+                        sum: 1.8,
+                        buckets: [
+                            { le: 1, count: 2 },
+                            { le: '+Inf' as const, count: 3 },
+                        ],
+                    },
+                ],
+            },
         ];
 
         const result2 = await translator.translateAndSerializeMetrics(metrics2);
@@ -236,5 +272,11 @@ describe('MetricsTranslator', () => {
         expect(result2).toContain(
             'unleash_gauge_gauge_with_labels{unleash_env="prod",unleash_region="us-east",unleash_origin="sdk"} 20',
         );
+        expect(result2).toContain(
+            'unleash_histogram_histogram_with_labels_count{unleash_origin="sdk",unleash_region="us-east",unleash_service="api"} 3',
+        );
+        expect(result2).not.toContain(
+            'unleash_histogram_histogram_with_labels_count{unleash_origin="sdk",unleash_service="api"} 5',
+        );
     });
 });

src/lib/features/metrics/impact/metrics-translator.ts

@@ -24,7 +24,6 @@ export interface BucketMetric {
     name: string;
     help: string;
     type: 'histogram';
-    buckets: number[];
     samples: BucketMetricSample[];
 }
 
@@ -32,7 +31,6 @@ export type Metric = NumericMetric | BucketMetric;
 
 export class MetricsTranslator {
     private registry: Registry;
-    private histograms: Map<string, BatchHistogram> = new Map();
 
     constructor(registry: Registry) {
         this.registry = registry;
@@ -166,14 +164,26 @@ export class MetricsTranslator {
                 return null;
             }
 
-            let histogram = this.histograms.get(prefixedName);
+            let histogram: BatchHistogram;
-            if (!histogram) {
+
+            if (existingMetric && existingMetric instanceof BatchHistogram) {
+                if (this.hasNewLabels(existingMetric, labelNames)) {
+                    this.registry.removeSingleMetric(prefixedName);
+
+                    histogram = new BatchHistogram({
+                        name: prefixedName,
+                        help: metric.help,
+                        registry: this.registry,
+                    });
+                } else {
+                    histogram = existingMetric as BatchHistogram;
+                }
+            } else {
                 histogram = new BatchHistogram({
                     name: prefixedName,
                     help: metric.help,
                     registry: this.registry,
                 });
-                this.histograms.set(prefixedName, histogram);
             }
 
             for (const sample of metric.samples) {