diff --git a/emitter.js b/emitter.js
new file mode 100644
index 0000000..992e6de
--- /dev/null
+++ b/emitter.js
@@ -0,0 +1,4 @@
+const EventEmitter = require('events')
+const emitter = new EventEmitter()
+
+module.exports = emitter;
\ No newline at end of file
diff --git a/index.js b/index.js
index b099d5e..c54cf2e 100644
--- a/index.js
+++ b/index.js
@@ -3,34 +3,6 @@ const { FORMAT_HTTP_HEADERS, FORMAT_TEXT_MAP } = require("opentracing");
 const { tagObject, isExcludedPath } = require("./helper");
 const { getContext, setContext } = require("./context");
 const {registration,signUpEvent} = require('./instruments')
-const EventEmitter = require('events')
-
-global.tracer=null;
-global.emitter = new EventEmitter()
-
-const {
-  PerformanceObserver,
-  performance
-} = require('perf_hooks');
-
-const obs = new PerformanceObserver((items) => {
-  if (global.tracer){
-    const span = globalTracer.startSpan("performance_hooks")
-  span.setTag("operation_name",items.getEntries()[0].name)
-  span.log({
-    originTime: performance.timeOrigin,
-    data: items.getEntries()[0],
-    message: "origin time in MS, duration in MS"
-  })
-  span.finish()
- 
-  performance.clearMarks();
-  }
-  
-});
-obs.observe({
-  entryTypes: ['measure']
-});
 
 const buildSpanName = req => {
   const params = req.pathParams || req.params;
@@ -213,8 +185,6 @@ class JaegerMiddleware {
         "response.body": stringify(res.resBody)
       };
       span.log(info);
-
-      span.finish();
     } catch (error) {
       console.log(error);
     } finally {
diff --git a/instruments.js b/instruments.js
index d2661d5..f18afc3 100644
--- a/instruments.js
+++ b/instruments.js
@@ -1,6 +1,7 @@
 'use strict'
 const log4js = require('log4js')
 const helper = require('./helper')
+const emitter = require('./emitter')
 
 log4js.levels = process.env.LOG_LEVEL || 'info'
 const logger = log4js.getLogger('jaeger-client-nodejs-instruments')
@@ -20,7 +21,9 @@ const registration = ()=>{
 
 const signUpEvent = span =>{
     for (const module of modules) {
-        emitter.on(module,(db_type,operation_name,data)=>{
+        emitter.on(module,(...agrs)=>{
+            const eventData = agrs[0]
+            const {db_type,operation_name,data}=eventData
             const child_span = global.tracer.startSpan(operation_name,{
                 childOf: span
             })
diff --git a/instruments_modules/mongodb.js b/instruments_modules/mongodb.js
index c53aa11..45f54ea 100644
--- a/instruments_modules/mongodb.js
+++ b/instruments_modules/mongodb.js
@@ -1,34 +1,9 @@
 'use strict'
-const { stringify } = require("flatted/cjs");
-const opentracing = require("opentracing");
-const context = require('../context')
-const helper = require('../helper')
 
+const emitter = require('../emitter')
 const requestIdMap = {}
 
-const onStart = (event)=>{
-    const {
-        databaseName,
-        commandName,
-        command,
-        requestId
-    }= event;
-    const {
-        filter={},
-        projection={},
-        limit,
-        query={}
-    } = command
-    const collection = command[commandName]
-    const operation_name = `${databaseName}.${collection}.${commandName}`
-    // set operation name
-    requestIdMap[requestId]=`${databaseName}.${collection}.${commandName}`
-    emitter.emit('mongodb','mongodb',operation_name,{
-        filter={},
-        projection={},
-        limit,
-        query={}
-    })
+const onStart = (event) => {
     // {
     //     address: '10.60.3.8:27017',
     //     connectionId: 2,
@@ -42,68 +17,67 @@ const onStart = (event)=>{
     //       '$db': 'user_profiler'
     //     }
     //   }
+    const {
+        databaseName,
+        commandName,
+        command,
+        requestId
+    } = event;
+    const {
+        filter = {},
+        projection = {},
+        limit,
+        query = {}
+    } = command
+    const collection = command[commandName]
+    const operation_name = `${databaseName}.${collection}.${commandName}`
+    // set operation name
+    requestIdMap[requestId] = `${databaseName}.${collection}.${commandName}`
+    if (!operation_name.includes('Index')) {
+        emitter.emit('mongodb', {
+            db_type: 'mongodb',
+            operation_name,
+            data: {
+                filter,
+                projection,
+                limit,
+                query,
+            }
+        })
+    }
 }
 
-const onEnd = (event)=>{
+const onEnd = (event) => {
     const {
         requestId,
-        reply={},
-        duration=0
-    }= event;
+        reply = {},
+        duration = 0
+    } = event;
     const {
-        cursor={},
-        value={}
+        cursor = {},
+        value = {}
     } = reply
-    const operation_name = requestIdMap[requestId]+`_response`
-    const firstBatch = cursor?.firstBatch || []
-    emitter.emit('mongodb','mongodb',operation_name,{
-        command_duration_ms: duration,
-        write_operation_response: value,
-        read_operation_response: firstBatch
-    })
-    
+    const operation_name = requestIdMap[requestId] + `_response`
+    const firstBatch = cursor ?.firstBatch || []
+    if (!operation_name.includes('Index')) {
+        emitter.emit('mongodb', {
+            db_type: 'mongodb',
+            operation_name,
+            data: {
+                command_duration_ms: duration,
+                write_operation_response: value,
+                read_operation_response: firstBatch
+            }
+        })
+    }
     delete requestIdMap[requestId]
-    
-    // {
-    //     address: '10.60.3.8:27017',
-    //     connectionId: 2,
-    //     requestId: 3,
-    //     commandName: 'find',
-    //     duration: 16,
-    //     reply: {
-    //       cursor: { firstBatch: [Array], id: 0, ns: 'user_profiler.reasons' },
-    //       ok: 1
-    //     }
-    //   }
-
-    // {
-    //     address: '10.60.3.8:27017',
-    //     connectionId: 1,
-    //     requestId: 6,
-    //     commandName: 'findAndModify',
-    //     duration: 11,
-    //     reply: {
-    //       lastErrorObject: { n: 1, updatedExisting: true },
-    //       value: {
-    //         _id: 60caf63a9d634c2eb2a8b2ed,
-    //         is_deleted: false,
-    //         name: 'abccc',
-    //         created_at: 2021-06-17T07:14:02.702Z,
-    //         updated_at: 2021-06-17T07:27:40.084Z,
-    //         __v: 0
-    //       },
-    //       ok: 1
-    //     }
-    //   }
-
 }
 
-const start = ()=>{
+const start = () => {
     const path = process.cwd()
-    const listener = require(path+'/node_modules/mongodb').instrument()
+    const listener = require(path + '/node_modules/mongodb').instrument()
     listener.on("started", onStart)
     listener.on("succeeded", onEnd)
-    // listener.on("failed", onEnd)
 }
 
 module.exports = {