Azure application insights showing duplicate log entry for Node js application

Question

We have a node js application and configured application insight using application insight key in launch.json, but in azure application insight showing duplicate log entry, I tried in google and also stackoverflow but unable to solve the issue.

My appInsights.js code is as follows,

const appInsightsObj = require("applicationinsights");  
  
module.exports.initAppInsights = (appInsightKey, appName) => {  
appInsightsObj.setup(appInsightKey)  
    .setAutoDependencyCorrelation(true)  
    .setAutoCollectRequests(true)  
    .setAutoCollectPerformance(true, true)  
    .setAutoCollectExceptions(true)  
    .setAutoCollectDependencies(true)  
    .setAutoCollectConsole(true, true)  
    .setUseDiskRetryCaching(true)  
    .setSendLiveMetrics(true)  
    .setDistributedTracingMode(appInsightsObj.DistributedTracingModes.AI_AND_W3C);  
appInsightsObj.defaultClient.context.tags[appInsightsObj.defaultClient.context.keys.cloudRole] = appName;  
appInsightsObj.start();  
}  
  
module.exports.trackEvent = (name, properties) => {  
   const telemetry = appInsightsObj.defaultClient  
   telemetry.trackEvent({  
      "name": name,  
       "properties": properties  
 })  
}  
module.exports.insightObj = appInsightsObj;  

and log.js file is as follows,

 const { appConfig } = require('../../config');  
 const appInsights = require('./appinsights')  
 const {AzureApplicationInsightsLogger}  = require('winston-azure-application-insights');  
 const log = require('winston');  
 require('winston-daily-rotate-file');  
 const path = require('path')  
 const _ = require('lodash');  
 appInsights.initAppInsights(appConfig.get("appinsights_key"), appConfig.get("app_name"));  
  
 var transportRotatingFile = new log.transports.DailyRotateFile({  
    filename: 'loyalty_service_%DATE%.log',  
    dirname: appConfig.get('logfile_location'),  
    datePattern: 'YYYY-MM-DD',  
    zippedArchive: true,  
    maxSize: '20m',  
    maxFiles: '14d'  
 });   
 transportRotatingFile.on('rotate', function(oldFilename, newFilename) {  
 // any code while rotating log files.  
});  
  
 log.add (new AzureApplicationInsightsLogger({client: appInsights.insightObj.defaultClient}))  
 log.add(new (log.transports.Console)({level: 'info', 'timestamp':true, 'json': false}))  
 log.add(transportRotatingFile)  
 module.exports = log;  

In launch.json defined the appInsightKey and value and based on that it should read and connect to the application insights.

Azure application insights log entry,

Can anyone suggest me what should be the cause ? and how to resolve the issue.

Answer 1

@Anil Nivargi - Welcome to Microsoft Q&A and thanks for reaching out to us.

Also, thank you for providing the solution that worked for you as it can benefit the broader community here.

So, rephrasing the solution here for broader audience:

Using both winston-azure-application-insights and application insights can cause duplicate entries in Azure Application Insights as they serve the same functionality.

Once you comment the code for winston-azure-application-insights, it should work as expected and you shouldn't see the duplicate entries in the application insights.

in log.js, comment the below line:

//log.add (new AzureApplicationInsightsLogger({client: appInsights.insightObj.defaultClient}))  
log.add(new (log.transports.Console)({level: 'info', 'timestamp':true, 'json': false}))  
log.add(transportRotatingFile)  
module.exports = log;  

Hope this helps. and please feel free to reach out if you have any further questions.

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