Cold start detection and marking

README.md

@@ -56,7 +56,8 @@ Environment Variable | Description | Default
 | `SW_AGENT_SECURE` | Whether to use secure connection to backend OAP server | `false` |
 | `SW_AGENT_AUTHENTICATION` | The authentication token to verify that the agent is trusted by the backend OAP, as for how to configure the backend, refer to [the yaml](https://github.com/apache/skywalking/blob/4f0f39ffccdc9b41049903cc540b8904f7c9728e/oap-server/server-bootstrap/src/main/resources/application.yml#L155-L158). | not set |
 | `SW_AGENT_LOGGING_LEVEL` | The logging level, could be one of `error`, `warn`, `info`, `debug` | `info` |
-| `SW_AGENT_DISABLE_PLUGINS` | Comma-delimited list of plugins to disable in the plugins directory (e.g. "mysql", "express"). | `` |
+| `SW_AGENT_DISABLE_PLUGINS` | Comma-delimited list of plugins to disable in the plugins directory (e.g. "mysql", "express") | `` |
+| `SW_COLD_ENDPOINT` | Cold start detection is as follows: First span to run within 1 second of skywalking init is considered a cold start. This span gets the tag `coldStart` set to 'true'. This span also optionally gets the text '\<cold\>' appended to the endpoint name if SW_COLD_ENDPOINT is set to 'true'. | `false` |
 | `SW_IGNORE_SUFFIX` | The suffices of endpoints that will be ignored (not traced), comma separated | `.jpg,.jpeg,.js,.css,.png,.bmp,.gif,.ico,.mp3,.mp4,.html,.svg` |
 | `SW_TRACE_IGNORE_PATH` | The paths of endpoints that will be ignored (not traced), comma separated | `` |
 | `SW_HTTP_IGNORE_METHOD` | Comma-delimited list of http methods to ignore (GET, POST, HEAD, OPTIONS, etc...) | `` |

src/Tag.ts

@@ -24,6 +24,7 @@ export interface Tag {
 }
 
 export default {
+  coldStartKey: 'coldStart',
   httpStatusCodeKey: 'http.status.code',  // TODO: maybe find a better place to put these?
   httpStatusMsgKey: 'http.status.msg',
   httpURLKey: 'http.url',
@@ -37,6 +38,13 @@ export default {
   mqTopicKey: 'mq.topic',
   mqQueueKey: 'mq.queue',
 
+  coldStart(val: boolean = true): Tag {
+    return {
+      key: this.coldStartKey,
+      overridable: true,
+      val: `${val}`,
+    } as Tag;
+  },
   httpStatusCode(val: string | number | undefined): Tag {
     return {
       key: this.httpStatusCodeKey,

src/azure/AzureHttpTriggerPlugin.ts

@@ -49,7 +49,7 @@ class AzureHttpTriggerPlugin {
         : ContextManager.current.newEntrySpan(operation, carrier);
 
       span.layer = SpanLayer.HTTP;
-      span.component = Component.AZURE_HTTPTRIGGER  ;
+      span.component = Component.AZURE_HTTPTRIGGER;
       span.peer = (req.headers['x-forwarded-for'] || '???').split(',').shift();
 
       span.tag(Tag.httpMethod(req.method));

src/config/AgentConfig.ts

@@ -26,6 +26,7 @@ export type AgentConfig = {
   secure?: boolean;
   authorization?: string;
   maxBufferSize?: number;
+  coldEndpoint?: boolean;
   disablePlugins?: string;
   ignoreSuffix?: string;
   traceIgnorePath?: string;
@@ -66,10 +67,11 @@ const _config = {
       return os.hostname();
     })(),
   collectorAddress: process.env.SW_AGENT_COLLECTOR_BACKEND_SERVICES || '127.0.0.1:11800',
-  secure: process.env.SW_AGENT_SECURE?.toLocaleLowerCase() === 'true',
+  secure: process.env.SW_AGENT_SECURE?.toLowerCase() === 'true',
   authorization: process.env.SW_AGENT_AUTHENTICATION,
   maxBufferSize: Number.isSafeInteger(process.env.SW_AGENT_MAX_BUFFER_SIZE) ?
     Number.parseInt(process.env.SW_AGENT_MAX_BUFFER_SIZE as string, 10) : 1000,
+  coldEndpoint: process.env.SW_COLD_ENDPOINT?.toLowerCase() === 'true',
   disablePlugins: process.env.SW_AGENT_DISABLE_PLUGINS || '',
   ignoreSuffix: process.env.SW_IGNORE_SUFFIX ?? '.jpg,.jpeg,.js,.css,.png,.bmp,.gif,.ico,.mp3,.mp4,.html,.svg',
   traceIgnorePath: process.env.SW_TRACE_IGNORE_PATH || '',

src/trace/context/ContextManager.ts

@@ -59,6 +59,19 @@ if (async_hooks.AsyncLocalStorage) {
 }
 
 class ContextManager {
+  isCold = true;
+
+  cosntructor() {
+    setTimeout(() => this.isCold = false, 1000).unref();
+  }
+
+  checkCold(): boolean {
+    const isCold = this.isCold;
+    this.isCold = false;
+
+    return isCold;
+  }
+
   get asyncState(): AsyncState {
     let asyncState = store.getStore();
 

src/trace/context/DummyContext.ts

@@ -42,18 +42,20 @@ export default class DummyContext implements Context {
     return DummySpan.create(this);
   }
 
-  start(span: Span): Context {
+  start(span: DummySpan): Context {
     const spans = ContextManager.spansDup();
 
     if (!this.nSpans++) {
+      ContextManager.checkCold();  // set cold to false
+
       if (spans.indexOf(span) === -1)
         spans.push(span);
     }
 
     return this;
   }
 
-  stop(span: Span): boolean {
+  stop(span: DummySpan): boolean {
     if (--this.nSpans)
       return false;
 
@@ -62,11 +64,11 @@ export default class DummyContext implements Context {
     return true;
   }
 
-  async(span: Span) {
+  async(span: DummySpan) {
     ContextManager.clear(span);
   }
 
-  resync(span: Span) {
+  resync(span: DummySpan) {
     ContextManager.restore(span);
   }
 }

src/trace/context/SpanContext.ts

@@ -27,6 +27,7 @@ import ExitSpan from '../../trace/span/ExitSpan';
 import LocalSpan from '../../trace/span/LocalSpan';
 import SegmentRef from './SegmentRef';
 import ContextManager from './ContextManager';
+import Tag from '../../Tag';
 import { Component } from '../../trace/Component';
 import { createLogger } from '../../logging';
 import { ContextCarrier } from './ContextCarrier';
@@ -173,8 +174,13 @@ export default class SpanContext implements Context {
       nSpans: this.nSpans,
     });
 
-    if (!this.nSpans++)
+    if (!this.nSpans++) {
       SpanContext.nActiveSegments += 1;
+      span.isCold = ContextManager.checkCold();
+
+      if (span.isCold)
+        span.tag(Tag.coldStart(), true);
+    }
 
     if (spans.indexOf(span) === -1)
       spans.push(span);

src/trace/span/Span.ts

@@ -17,6 +17,7 @@
  *
  */
 
+import config from '../../config/AgentConfig';
 import Context from '../../trace/context/Context';
 import { Component } from '../Component';
 import { Tag } from '../../Tag';
@@ -51,6 +52,7 @@ export default abstract class Span {
   layer = SpanLayer.UNKNOWN;
   component = Component.UNKNOWN;
   depth = 0;
+  isCold = false;
   inherit?: Component;
 
   readonly tags: Tag[] = [];
@@ -95,6 +97,9 @@ export default abstract class Span {
   }
 
   finish(segment: Segment): boolean {
+    if (this.isCold && config.coldEndpoint)
+      this.operation = this.operation + '<cold>';
+
     this.endTime = new Date().getTime();
     segment.archive(this);
     return true;
@@ -118,19 +123,24 @@ export default abstract class Span {
     return !this.tags.every((t) => t.key !== key);
   }
 
-  tag(tag: Tag): this {
-    if (!tag.overridable) {
-      this.tags.push(Object.assign({}, tag));
-    }
+  tag(tag: Tag, insert?: boolean): this {
+    if (tag.overridable) {
+      const sameTags = this.tags.filter((it) => it.key === tag.key);
 
-    const sameTags = this.tags.filter((it) => it.key === tag.key);
+      if (sameTags.length) {
+        sameTags.forEach((it) => (it.val = tag.val));
 
-    if (sameTags.length) {
-      sameTags.forEach((it) => (it.val = tag.val));
-    } else {
-      this.tags.push(Object.assign({}, tag));
+        return this;
+      }
     }
 
+    const tagObj = Object.assign({}, tag);
+
+    if (!insert)
+      this.tags.push(tagObj);
+    else
+      this.tags.unshift(tagObj)
+
     return this;
   }
 

tests/plugins/axios/expected.data.yaml

@@ -53,6 +53,8 @@ segmentItems:
             peer: not null
             skipAnalysis: false
             tags:
+              - key: coldStart
+                value: 'true'
               - key: http.url
                 value: http://server:5000/axios
               - key: http.method
@@ -101,6 +103,8 @@ segmentItems:
             spanId: 0
             spanLayer: Http
             tags:
+              - key: coldStart
+                value: 'true'
               - key: http.url
                 value: http://localhost:5001/axios
               - key: http.method

tests/plugins/express/expected.data.yaml

@@ -27,6 +27,8 @@ segmentItems:
             spanId: 0
             spanLayer: Http
             tags:
+              - key: coldStart
+                value: 'true'
               - key: http.url
                 value: http://server:5000/express
               - key: http.method
@@ -81,6 +83,8 @@ segmentItems:
             spanId: 0
             spanLayer: Http
             tags:
+              - key: coldStart
+                value: 'true'
               - key: http.url
                 value: http://localhost:5001/express
               - key: http.method

tests/plugins/http/expected.data.yaml

@@ -33,6 +33,8 @@ segmentItems:
             peer: not null
             skipAnalysis: false
             tags:
+              - key: coldStart
+                value: 'true'
               - key: http.url
                 value: http://server:5000/test
               - key: http.method
@@ -87,6 +89,8 @@ segmentItems:
             peer: not null
             skipAnalysis: false
             tags:
+              - key: coldStart
+                value: 'true'
               - key: http.url
                 value: http://localhost:5001/test
               - key: http.method

tests/plugins/mongodb/expected.data.yaml

@@ -63,6 +63,7 @@ segmentItems:
             peer: not null
             skipAnalysis: false
             tags:
+              - { key: coldStart, value: 'true' }
               - { key: http.url, value: 'http://server:5000/mongo' }
               - { key: http.method, value: GET }
               - { key: http.status.code, value: '200' }
@@ -93,6 +94,7 @@ segmentItems:
             peer: not null
             skipAnalysis: false
             tags:
+              - { key: coldStart, value: 'true' }
               - { key: http.url, value: 'http://localhost:5001/mongo' }
               - { key: http.method, value: GET }
               - { key: http.status.code, value: '200' }

tests/plugins/mongoose/expected.data.yaml

@@ -77,6 +77,7 @@ segmentItems:
             peer: not null
             skipAnalysis: false
             tags:
+              - { key: coldStart, value: 'true' }
               - { key: http.url, value: 'http://server:5000/mongoose' }
               - { key: http.method, value: GET }
               - { key: http.status.code, value: '200' }
@@ -107,6 +108,7 @@ segmentItems:
             peer: not null
             skipAnalysis: false
             tags:
+              - { key: coldStart, value: 'true' }
               - { key: http.url, value: 'http://localhost:5001/mongoose' }
               - { key: http.method, value: GET }
               - { key: http.status.code, value: '200' }

tests/plugins/mysql/expected.data.yaml

@@ -51,6 +51,8 @@ segmentItems:
             peer: not null
             skipAnalysis: false
             tags:
+              - key: coldStart
+                value: 'true'
               - key: http.url
                 value: http://server:5000/mysql
               - key: http.method
@@ -85,6 +87,8 @@ segmentItems:
             peer: not null
             skipAnalysis: false
             tags:
+              - key: coldStart
+                value: 'true'
               - key: http.url
                 value: http://localhost:5001/mysql
               - key: http.method

tests/plugins/pg/expected.data.yaml

@@ -48,6 +48,7 @@ segmentItems:
             peer: not null
             skipAnalysis: false
             tags:
+              - { key: coldStart, value: 'true' }
               - { key: http.url, value: 'http://server:5000/postgres' }
               - { key: http.method, value: GET }
               - { key: http.status.code, value: '200' }
@@ -78,6 +79,7 @@ segmentItems:
             peer: not null
             skipAnalysis: false
             tags:
+              - { key: coldStart, value: 'true' }
               - { key: http.url, value: 'http://localhost:5001/postgres' }
               - { key: http.method, value: GET }
               - { key: http.status.code, value: '200' }