diff --git a/src/config.ts b/src/config.ts
index 0d88fb1..9ded610 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -1,7 +1,7 @@
 import dotenv from 'dotenv';
 dotenv.config();
 
-const isProduction = process.env.NODE_ENV === 'production'
+export const isProduction = process.env.NODE_ENV === 'production'
 
 // MongoDB URI
 export const MONGOURI = isProduction 
diff --git a/src/controllers/createLog.ts b/src/controllers/createLog.ts
index 1fd2746..3b0f4da 100644
--- a/src/controllers/createLog.ts
+++ b/src/controllers/createLog.ts
@@ -19,19 +19,29 @@ interface getLogsRequest extends Request {
 
 const createLog = async (req: getLogsRequest, res: Response) => {
   const { user, logType, questionId, quizId } = req.body
+
+  if (!mongoose.Types.ObjectId.isValid(quizId)) {
+    return res.status(400).json({
+      message: 'Invalid quizId',
+    })
+  }
+
   try {
-    const log = await LogModel.create({
+    const log = new LogModel({
       userId: user.userId,
       logType,
       ...(questionId && { questionId }),
-      quizId,
+      quizId: new mongoose.Types.ObjectId(quizId),
     })
+
+    await log.save()
+
     return res.status(200).json({
       message: 'Log created successfully',
       log,
     })
   } catch (error: unknown) {
-    console.log(error)
+    console.error(error)
     return res.status(500).json({
       message: 'Error in creating log',
       error,
diff --git a/src/server.ts b/src/server.ts
index 0e9f10a..33026eb 100644
--- a/src/server.ts
+++ b/src/server.ts
@@ -14,14 +14,14 @@ import morgan from 'morgan'
 import mongoSanitize from 'express-mongo-sanitize'
 import logger from '@utils/logger'
 import profilePageRouter from '@routers/profilePage'
-import { FRONTEND_URL } from 'config'
+import { isProduction, FRONTEND_URL } from 'config'
 import cluster from 'cluster'
 import os from 'os'
 
 const numInstances = os.cpus().length
 
-if (cluster.isMaster) {
-  console.log(`Master ${process.pid} is running`)
+if (isProduction && cluster.isMaster) {
+  console.log(`Master ${process.pid} is running in production environment`)
 
   // Fork workers.
   for (let i = 0; i < numInstances; i++) {
@@ -84,6 +84,10 @@ if (cluster.isMaster) {
   app.get('/', (req: Request, res: Response) => {
     res.send('Express + TypeScript Server')
   })
+  
+  app.get('/health', (req: Request, res: Response) => {
+    res.status(200).send('Server is up and running')
+  })
 
   server.listen(port, () => {
     logger.silly(`⚡️[server]: Server is running at http://localhost:${port}`)