diff --git a/back/data/cron.ts b/back/data/cron.ts
index 56f0ec81..d6f829cf 100644
--- a/back/data/cron.ts
+++ b/back/data/cron.ts
@@ -49,12 +49,18 @@ export enum CrontabStatus {
 
 interface CronInstance extends Model<Crontab, Crontab>, Crontab {}
 export const CrontabModel = sequelize.define<CronInstance>('Crontab', {
-  name: DataTypes.STRING,
-  command: {
-    unique: 'command',
+  name: {
+    unique: 'compositeIndex',
+    type: DataTypes.STRING,
+  },
+  command: {
+    unique: 'compositeIndex',
+    type: DataTypes.STRING,
+  },
+  schedule: {
+    unique: 'compositeIndex',
     type: DataTypes.STRING,
   },
-  schedule: DataTypes.STRING,
   timestamp: DataTypes.STRING,
   saved: DataTypes.BOOLEAN,
   status: DataTypes.NUMBER,
diff --git a/back/services/cron.ts b/back/services/cron.ts
index aaa91b73..fa4f445b 100644
--- a/back/services/cron.ts
+++ b/back/services/cron.ts
@@ -5,7 +5,7 @@ import { Crontab, CrontabModel, CrontabStatus } from '../data/cron';
 import { exec, execSync, spawn } from 'child_process';
 import fs from 'fs';
 import cron_parser from 'cron-parser';
-import { getFileContentByName, concurrentRun } from '../config/util';
+import { getFileContentByName, concurrentRun, fileExist } from '../config/util';
 import { promises, existsSync } from 'fs';
 import { promisify } from 'util';
 import { Op } from 'sequelize';
@@ -194,7 +194,8 @@ export default class CronService {
         }
       }
       const err = await this.killTask(doc.command);
-      if (doc.log_path) {
+      const logFileExist = await fileExist(doc.log_path);
+      if (doc.log_path && logFileExist) {
         const str = err ? `\n${err}` : '';
         fs.appendFileSync(
           `${doc.log_path}`,