feat: 초기 프로젝트 설정 및 룰.md 파일 추가

api.hyungi.net/node_modules/@pm2/io/NOTES.md

@@ -0,0 +1,73 @@
+
+## API idea
+
+require('pm2-bundle-monitoring')
+
+// or
+
+require('pm2-io').connect({
+  secret: '',
+  public: ''
+})
+
+require('pm2-exception-catching')
+require('pm2-transaction-tracing').config({
+  ignore_route: '/ws'
+})
+
+require('pm2-frontend-monitoring')
+var pm2_metrics = require('pm2-metrics')
+
+pm2_metrics.variable('BLE pairing mode', permit_join)
+pm2_metrics.variable('In memory users', () => Object.keys(users).length)
+
+NOTES:
+- watch parameters is not reset on pm2 restart. only after pm2 delete
+
+
+----
+
+
+pm2-io-apm features are in src/features/:
+
+```
+src/features/
+├── dependencies.ts
+├── entrypoint.ts
+├── events.ts
+├── metrics.ts
+├── notify.ts
+├── profiling.ts
+└── tracing.ts
+```
+
+## Tracing
+
+- `./src/census` folder is essentially a dump of https://github.com/census-instrumentation/opencensus-node/tree/master/packages/opencensus-nodejs-base/src/trace with plugins added
+- Only traces higher than `MINIMUM_TRACE_DURATION: 1000 * 1000` are sent to transporter (sent in /src/census/exporter.ts:72)
+
+Trace sent looks like:
+
+```
+{
+  traceId: 'fac7052e9129416185a26d4935229620',
+  name: '/slow',
+  id: '66358f0a48be82c5',
+  parentId: '',
+  kind: 'SERVER',
+  timestamp: 1586380086251000,
+  duration: 2007559,
+  debug: false,
+  shared: false,
+  localEndpoint: { serviceName: 'tototransaction' },
+  tags: {
+    'http.host': 'localhost',
+    'http.method': 'GET',
+    'http.path': '/slow',
+    'http.route': '/slow',
+    'http.user_agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.70 Safari/537.36',
+    'http.status_code': '304',
+    'result.code': undefined
+  }
+}
+```