diff --git a/scripts/reset-password.js b/scripts/reset-password.js
index e5f59a267..6a00b37eb 100755
--- a/scripts/reset-password.js
+++ b/scripts/reset-password.js
@@ -6,7 +6,6 @@
 
 const program = require('commander')
 
-const constants = require('../server/initializers/constants')
 const db = require('../server/initializers/database')
 
 program
diff --git a/server/controllers/api/remote/videos.js b/server/controllers/api/remote/videos.js
index 9d007246f..33b521c5f 100644
--- a/server/controllers/api/remote/videos.js
+++ b/server/controllers/api/remote/videos.js
@@ -10,7 +10,7 @@ const secureMiddleware = middlewares.secure
 const videosValidators = middlewares.validators.remote.videos
 const signatureValidators = middlewares.validators.remote.signature
 const logger = require('../../../helpers/logger')
-const utils = require('../../../helpers/utils')
+const databaseUtils = require('../../../helpers/database-utils')
 
 const router = express.Router()
 
@@ -71,7 +71,7 @@ function addRemoteVideoRetryWrapper (videoToCreateData, fromPod, finalCallback)
     errorMessage: 'Cannot insert the remote video with many retries.'
   }
 
-  utils.retryWrapper(addRemoteVideo, options, finalCallback)
+  databaseUtils.retryTransactionWrapper(addRemoteVideo, options, finalCallback)
 }
 
 function addRemoteVideo (videoToCreateData, fromPod, finalCallback) {
@@ -79,11 +79,7 @@ function addRemoteVideo (videoToCreateData, fromPod, finalCallback) {
 
   waterfall([
 
-    function startTransaction (callback) {
-      db.sequelize.transaction({ isolationLevel: 'SERIALIZABLE' }).asCallback(function (err, t) {
-        return callback(err, t)
-      })
-    },
+    databaseUtils.startSerializableTransaction,
 
     function findOrCreateAuthor (t, callback) {
       const name = videoToCreateData.author
@@ -180,7 +176,7 @@ function updateRemoteVideoRetryWrapper (videoAttributesToUpdate, fromPod, finalC
     errorMessage: 'Cannot update the remote video with many retries'
   }
 
-  utils.retryWrapper(updateRemoteVideo, options, finalCallback)
+  databaseUtils.retryWrapper(updateRemoteVideo, options, finalCallback)
 }
 
 function updateRemoteVideo (videoAttributesToUpdate, fromPod, finalCallback) {
@@ -188,11 +184,7 @@ function updateRemoteVideo (videoAttributesToUpdate, fromPod, finalCallback) {
 
   waterfall([
 
-    function startTransaction (callback) {
-      db.sequelize.transaction({ isolationLevel: 'SERIALIZABLE' }).asCallback(function (err, t) {
-        return callback(err, t)
-      })
-    },
+    databaseUtils.startSerializableTransaction,
 
     function findVideo (t, callback) {
       fetchVideo(fromPod.host, videoAttributesToUpdate.remoteId, function (err, videoInstance) {
diff --git a/server/controllers/api/videos.js b/server/controllers/api/videos.js
index 9a50a29be..ebfdb32f9 100644
--- a/server/controllers/api/videos.js
+++ b/server/controllers/api/videos.js
@@ -20,6 +20,7 @@ const validatorsSort = validators.sort
 const validatorsVideos = validators.videos
 const search = middlewares.search
 const sort = middlewares.sort
+const databaseUtils = require('../../helpers/database-utils')
 const utils = require('../../helpers/utils')
 
 const router = express.Router()
@@ -111,7 +112,7 @@ function addVideoRetryWrapper (req, res, next) {
     errorMessage: 'Cannot insert the video with many retries.'
   }
 
-  utils.retryWrapper(addVideo, options, function (err) {
+  databaseUtils.retryTransactionWrapper(addVideo, options, function (err) {
     if (err) return next(err)
 
     // TODO : include Location of the new video -> 201
@@ -124,11 +125,7 @@ function addVideo (req, res, videoFile, callback) {
 
   waterfall([
 
-    function startTransaction (callbackWaterfall) {
-      db.sequelize.transaction({ isolationLevel: 'SERIALIZABLE' }).asCallback(function (err, t) {
-        return callbackWaterfall(err, t)
-      })
-    },
+    databaseUtils.startSerializableTransaction,
 
     function findOrCreateAuthor (t, callbackWaterfall) {
       const user = res.locals.oauth.token.User
@@ -243,7 +240,7 @@ function updateVideoRetryWrapper (req, res, next) {
     errorMessage: 'Cannot update the video with many retries.'
   }
 
-  utils.retryWrapper(updateVideo, options, function (err) {
+  databaseUtils.retryTransactionWrapper(updateVideo, options, function (err) {
     if (err) return next(err)
 
     // TODO : include Location of the new video -> 201
@@ -258,11 +255,7 @@ function updateVideo (req, res, finalCallback) {
 
   waterfall([
 
-    function startTransaction (callback) {
-      db.sequelize.transaction({ isolationLevel: 'SERIALIZABLE' }).asCallback(function (err, t) {
-        return callback(err, t)
-      })
-    },
+    databaseUtils.startSerializableTransaction,
 
     function findOrCreateTags (t, callback) {
       if (videoInfosToUpdate.tags) {
@@ -384,19 +377,16 @@ function listVideoAbuses (req, res, next) {
 }
 
 function reportVideoAbuseRetryWrapper (req, res, next) {
-  utils.transactionRetryer(
-    function (callback) {
-      return reportVideoAbuse(req, res, callback)
-    },
-    function (err) {
-      if (err) {
-        logger.error('Cannot report abuse to the video with many retries.', { error: err })
-        return next(err)
-      }
+  const options = {
+    arguments: [ req, res ],
+    errorMessage: 'Cannot report abuse to the video with many retries.'
+  }
 
-      return res.type('json').status(204).end()
-    }
-  )
+  databaseUtils.retryTransactionWrapper(reportVideoAbuse, options, function (err) {
+    if (err) return next(err)
+
+    return res.type('json').status(204).end()
+  })
 }
 
 function reportVideoAbuse (req, res, finalCallback) {
diff --git a/server/helpers/database-utils.js b/server/helpers/database-utils.js
new file mode 100644
index 000000000..046717517
--- /dev/null
+++ b/server/helpers/database-utils.js
@@ -0,0 +1,55 @@
+'use strict'
+
+const retry = require('async/retry')
+
+const db = require('../initializers/database')
+const logger = require('./logger')
+
+const utils = {
+  retryTransactionWrapper,
+  transactionRetryer,
+  startSerializableTransaction
+}
+
+// { arguments, errorMessage }
+function retryTransactionWrapper (functionToRetry, options, finalCallback) {
+  const args = options.arguments ? options.arguments : []
+
+  utils.transactionRetryer(
+    function (callback) {
+      return functionToRetry.apply(this, args.concat([ callback ]))
+    },
+    function (err) {
+      if (err) {
+        logger.error(options.errorMessage, { error: err })
+      }
+
+      // Do not return the error, continue the process
+      return finalCallback(null)
+    }
+  )
+}
+
+function transactionRetryer (func, callback) {
+  retry({
+    times: 5,
+
+    errorFilter: function (err) {
+      const willRetry = (err.name === 'SequelizeDatabaseError')
+      logger.debug('Maybe retrying the transaction function.', { willRetry })
+      return willRetry
+    }
+  }, func, callback)
+}
+
+function startSerializableTransaction (callback) {
+  console.log(db)
+  db.sequelize.transaction({ isolationLevel: 'SERIALIZABLE' }).asCallback(function (err, t) {
+    // We force to return only two parameters
+    return callback(err, t)
+  })
+}
+
+// ---------------------------------------------------------------------------
+
+module.exports = utils
diff --git a/server/helpers/utils.js b/server/helpers/utils.js
index fb4dd08cc..9f4b14582 100644
--- a/server/helpers/utils.js
+++ b/server/helpers/utils.js
@@ -1,7 +1,6 @@
 'use strict'
 
 const crypto = require('crypto')
-const retry = require('async/retry')
 
 const logger = require('./logger')
 
@@ -10,9 +9,7 @@ const utils = {
   cleanForExit,
   generateRandomString,
   isTestInstance,
-  getFormatedObjects,
-  retryWrapper,
-  transactionRetryer
+  getFormatedObjects
 }
 
 function badRequest (req, res, next) {
@@ -49,37 +46,6 @@ function getFormatedObjects (objects, objectsTotal) {
   }
 }
 
-// { arguments, errorMessage }
-function retryWrapper (functionToRetry, options, finalCallback) {
-  const args = options.arguments ? options.arguments : []
-
-  utils.transactionRetryer(
-    function (callback) {
-      return functionToRetry.apply(this, args.concat([ callback ]))
-    },
-    function (err) {
-      if (err) {
-        logger.error(options.errorMessage, { error: err })
-      }
-
-      // Do not return the error, continue the process
-      return finalCallback(null)
-    }
-  )
-}
-
-function transactionRetryer (func, callback) {
-  retry({
-    times: 5,
-
-    errorFilter: function (err) {
-      const willRetry = (err.name === 'SequelizeDatabaseError')
-      logger.debug('Maybe retrying the transaction function.', { willRetry })
-      return willRetry
-    }
-  }, func, callback)
-}
-
 // ---------------------------------------------------------------------------
 
 module.exports = utils