diff --git a/app.js b/app.js
index 01c6dcf..a8eb5bd 100644
--- a/app.js
+++ b/app.js
@@ -22,6 +22,14 @@ global.syzoj = {
     console.log(obj);
   },
   async run() {
+    // Check config
+    if (syzoj.config.session_secret === '@SESSION_SECRET@'
+     || syzoj.config.email_jwt_secret === '@EMAIL_JWT_SECRET@'
+     || syzoj.config.db.password === '@DATABASE_PASSWORD@') {
+      console.log('Please generate and fill the secrets in config!');
+      process.exit();
+    }
+
     let Express = require('express');
     global.app = Express();
 
diff --git a/models/common.js b/models/common.js
index bdce62a..48e0c67 100644
--- a/models/common.js
+++ b/models/common.js
@@ -36,7 +36,8 @@ class Model {
     for (let key in obj) this.record.set(key, obj[key]);
 
     let isNew = this.record.isNewRecord;
-    await this.record.save();
+
+    await syzoj.utils.withTimeoutRetry(() => this.record.save());
     if (!isNew) return;
 
     await this.reload();
diff --git a/modules/problem.js b/modules/problem.js
index afa41dc..84df7e2 100644
--- a/modules/problem.js
+++ b/modules/problem.js
@@ -683,7 +683,9 @@ app.post('/problem/:id/submit', app.multer.fields([{ name: 'answer', maxCount: 1
             code: formatted
           });
 
-          await formattedCode.save();
+          try {
+            await formattedCode.save();
+          } catch (e) {}
         }
       }
     }
diff --git a/utility.js b/utility.js
index 54eec06..21936c2 100644
--- a/utility.js
+++ b/utility.js
@@ -294,5 +294,18 @@ module.exports = {
   async saveConfig() {
     let fs = require('fs-extra');
     fs.writeFileAsync(syzoj.configDir, JSON.stringify(syzoj.config, null, 2));
+  },
+  withTimeoutRetry(func) {
+    let attemptCount = 0;
+    return new Promise((resolve, reject) => {
+      function attempt() {
+        if (attemptCount++) console.log(`syzoj.utils.withTimeout(): attemptCount = ${attemptCount}`);
+        Promise.method(func)().timeout(5000)
+        .then(resolve)
+        .catch(Promise.TimeoutError, attempt)
+        .catch(reject);
+      }
+      attempt();
+    });
   }
 };