Merge pull request #469 from solarwinds/NH-94218

Add back lambda JSON sampling

.yarn/versions/91299f24.yml

@@ -0,0 +1,9 @@
+releases:
+  "@solarwinds-apm/dependencies": patch
+  "@solarwinds-apm/sampling": major
+  "@solarwinds-apm/test": patch
+  solarwinds-apm: minor
+
+declined:
+  - "@solarwinds-apm/bindings"
+  - "@solarwinds-apm/compat"

packages/dependencies/src/node-modules.ts

@@ -16,7 +16,7 @@ limitations under the License.
 
 import { type Dirent, promises as fs } from "node:fs"
 import { createRequire } from "node:module"
-import * as path from "node:path"
+import path from "node:path"
 
 import { type Dependencies, type Package } from "./index.js"
 

packages/dependencies/src/pnp-api.ts

@@ -14,8 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import * as fs from "node:fs/promises"
-import * as path from "node:path"
+import fs from "node:fs/promises"
+import path from "node:path"
 
 import { type Dependencies, type Package } from "./index.js"
 

packages/sampling/src/metrics.ts

@@ -16,27 +16,31 @@ limitations under the License.
 
 import { metrics, ValueType } from "@opentelemetry/api"
 
-const meter = metrics.getMeter("sw.apm.sampling.metrics")
-
-export const counters = {
-  requestCount: meter.createCounter("trace.service.request_count", {
-    valueType: ValueType.INT,
-  }),
-  sampleCount: meter.createCounter("trace.service.samplecount", {
-    valueType: ValueType.INT,
-  }),
-  traceCount: meter.createCounter("trace.service.tracecount", {
-    valueType: ValueType.INT,
-  }),
-  throughTraceCount: meter.createCounter("trace.service.through_trace_count", {
-    valueType: ValueType.INT,
-  }),
-  triggeredTraceCount: meter.createCounter(
-    "trace.service.triggered_trace_count",
-    { valueType: ValueType.INT },
-  ),
-  tokenBucketExhaustionCount: meter.createCounter(
-    "trace.service.tokenbucket_exhaustion_count",
-    { valueType: ValueType.INT },
-  ),
+export const counters = () => {
+  const meter = metrics.getMeter("sw.apm.sampling.metrics")
+  return {
+    requestCount: meter.createCounter("trace.service.request_count", {
+      valueType: ValueType.INT,
+    }),
+    sampleCount: meter.createCounter("trace.service.samplecount", {
+      valueType: ValueType.INT,
+    }),
+    traceCount: meter.createCounter("trace.service.tracecount", {
+      valueType: ValueType.INT,
+    }),
+    throughTraceCount: meter.createCounter(
+      "trace.service.through_trace_count",
+      {
+        valueType: ValueType.INT,
+      },
+    ),
+    triggeredTraceCount: meter.createCounter(
+      "trace.service.triggered_trace_count",
+      { valueType: ValueType.INT },
+    ),
+    tokenBucketExhaustionCount: meter.createCounter(
+      "trace.service.tokenbucket_exhaustion_count",
+      { valueType: ValueType.INT },
+    ),
+  }
 }

packages/sampling/src/sampler.ts

@@ -94,6 +94,7 @@ interface SampleState {
  * By extending this class neither needs to reimplement shared sampling logic.
  */
 export abstract class OboeSampler implements Sampler {
+  readonly #counters = counters()
   readonly #buckets: Record<BucketType, TokenBucket> = {
     [BucketType.DEFAULT]: new TokenBucket({
       interval: BUCKET_INTERVAL,
@@ -106,7 +107,6 @@ export abstract class OboeSampler implements Sampler {
     }),
   }
   #settings: Settings | undefined = undefined
-  #updated: number = Date.now()
 
   constructor(protected readonly logger: DiagLogger) {
     for (const bucket of Object.values(this.#buckets)) {
@@ -142,6 +142,8 @@ export abstract class OboeSampler implements Sampler {
       headers: this.requestHeaders(...params),
     }
 
+    this.#counters.requestCount.add(1, {}, context)
+
     if (s.headers["X-Trace-Options"]) {
       s.traceOptions = {
         ...parseTraceOptions(s.headers["X-Trace-Options"], this.logger),
@@ -202,8 +204,6 @@ export abstract class OboeSampler implements Sampler {
       return { decision: SamplingDecision.NOT_RECORD, attributes: s.attributes }
     }
 
-    counters.requestCount.add(1, {}, context)
-
     // https://swicloud.atlassian.net/wiki/spaces/NIT/pages/3815473156/Tracing+Decision+Tree
     if (s.traceState && TRACESTATE_REGEXP.test(s.traceState)) {
       this.logger.debug("context is valid for parent-based sampling")
@@ -248,8 +248,8 @@ export abstract class OboeSampler implements Sampler {
       if (sampled) {
         this.logger.debug("parent is sampled; record and sample")
 
-        counters.traceCount.add(1, {}, context)
-        counters.throughTraceCount.add(1, {}, context)
+        this.#counters.traceCount.add(1, {}, context)
+        this.#counters.throughTraceCount.add(1, {}, context)
 
         s.decision = SamplingDecision.RECORD_AND_SAMPLED
       } else {
@@ -293,8 +293,8 @@ export abstract class OboeSampler implements Sampler {
       if (bucket.consume()) {
         this.logger.debug("sufficient capacity; record and sample")
 
-        counters.triggeredTraceCount.add(1, {}, context)
-        counters.traceCount.add(1, {}, context)
+        this.#counters.triggeredTraceCount.add(1, {}, context)
+        this.#counters.traceCount.add(1, {}, context)
 
         s.traceOptions!.response.triggerTrace = TriggerTrace.OK
         s.decision = SamplingDecision.RECORD_AND_SAMPLED
@@ -320,7 +320,7 @@ export abstract class OboeSampler implements Sampler {
     s.attributes[SAMPLE_RATE_ATTRIBUTE] = dice.rate
     s.attributes[SAMPLE_SOURCE_ATTRIBUTE] = s.settings!.sampleSource
 
-    counters.sampleCount.add(1, {}, context)
+    this.#counters.sampleCount.add(1, {}, context)
 
     if (dice.roll()) {
       this.logger.debug("dice roll success; checking capacity")
@@ -332,13 +332,13 @@ export abstract class OboeSampler implements Sampler {
       if (bucket.consume()) {
         this.logger.debug("sufficient capacity; record and sample")
 
-        counters.traceCount.add(1, {}, context)
+        this.#counters.traceCount.add(1, {}, context)
 
         s.decision = SamplingDecision.RECORD_AND_SAMPLED
       } else {
         this.logger.debug("insufficient capacity; record only")
 
-        counters.tokenBucketExhaustionCount.add(1, {}, context)
+        this.#counters.tokenBucketExhaustionCount.add(1, {}, context)
 
         s.decision = SamplingDecision.RECORD
       }
@@ -370,13 +370,14 @@ export abstract class OboeSampler implements Sampler {
   protected updateSettings(settings: Settings): void {
     this.logger.debug("settings updated", settings)
 
-    this.#settings = settings
-    this.#updated = Date.now()
+    if (settings.timestamp > (this.#settings?.timestamp ?? 0)) {
+      this.#settings = settings
 
-    for (const [type, bucket] of Object.entries(this.#buckets)) {
-      const settings = this.#settings.buckets[type as BucketType]
-      if (settings) {
-        bucket.update(settings)
+      for (const [type, bucket] of Object.entries(this.#buckets)) {
+        const settings = this.#settings.buckets[type as BucketType]
+        if (settings) {
+          bucket.update(settings)
+        }
       }
     }
   }
@@ -428,7 +429,7 @@ export abstract class OboeSampler implements Sampler {
       return
     }
 
-    const expiry = this.#updated + this.#settings.ttl * 1000
+    const expiry = (this.#settings.timestamp + this.#settings.ttl) * 1000
     if (Date.now() > expiry) {
       this.logger.debug("settings expired, removing")
       this.#settings = undefined

packages/sampling/src/settings.ts

@@ -20,6 +20,7 @@ export interface Settings {
   flags: number
   buckets: Partial<Record<BucketType, BucketSettings>>
   signatureKey?: Uint8Array
+  timestamp: number
   ttl: number
 }