diff --git a/code/ryzom/tools/server/ryzom_ams/ams_lib/autoload/sync.php b/code/ryzom/tools/server/ryzom_ams/ams_lib/autoload/sync.php
index c41985cfc..0a223bc48 100644
--- a/code/ryzom/tools/server/ryzom_ams/ams_lib/autoload/sync.php
+++ b/code/ryzom/tools/server/ryzom_ams/ams_lib/autoload/sync.php
@@ -14,58 +14,75 @@ class Sync{
      * These changes are: createPermissions, createUser, change_pass, change_mail
      */
     static public function syncdata ($display = true) {
-
-        try {
-            $dbl = new DBLayer("lib");
-            $statement = $dbl->executeWithoutParams("SELECT * FROM ams_querycache");
-            $rows = $statement->fetchAll();           
-            foreach ($rows as $record) {
+    
+    if (function_exists('pcntl_fork')) {
+        $pid = pcntl_fork();
+    }
+    $pidfile = '/tmp/ams_cron_pid';
+    if(isset($pid)) {
+    // We're the main process.
+    } else {
+        if(!file_exists($pidfile)) {
+            $pid = getmypid();
+            $file = fopen($pidfile, 'w');
                 
-                $db = new DBLayer($record['db']);
-                switch($record['type']) {
-                    case 'createPermissions':
-                        $decode = json_decode($record['query']);
-                        $values = array('username' => $decode[0]);
-                        //make connection with and put into shard db & delete from the lib
-                        $sth = $db->execute("SELECT UId FROM user WHERE Login= :username;", $values);
-                        $result = $sth->fetchAll();
-                        foreach ($result as $UId) {
-                            $ins_values = array('id' => $UId['UId']);
-                            $db->execute("INSERT INTO permission (UId, ClientApplication, AccessPrivilege) VALUES (:id, 'r2', 'OPEN');", $ins_values);
-                            $db->execute("INSERT INTO permission (UId, ClientApplication, AccessPrivilege) VALUES (:id , 'ryzom_open', 'OPEN');", $ins_values);
-                        }
-                        break;
-                    case 'change_pass':
-                        $decode = json_decode($record['query']);
-                        $values = array('user' => $decode[0], 'pass' => $decode[1]);
-                        //make connection with and put into shard db & delete from the lib
-                        $db->execute("UPDATE user SET Password = :pass WHERE Login = :user",$values);              
-                        break;
-                    case 'change_mail':
-                        $decode = json_decode($record['query']);
-                        $values = array('user' => $decode[0], 'mail' => $decode[1]);
-                        //make connection with and put into shard db & delete from the lib
-                        $db->execute("UPDATE user SET Email = :mail WHERE Login = :user",$values);              
-                        break;
-                    case 'createUser': 
-                        $decode = json_decode($record['query']);
-                        $values = array('login' => $decode[0], 'pass' => $decode[1], 'mail' => $decode[2] );
-                        //make connection with and put into shard db & delete from the lib
-                        $db->execute("INSERT INTO user (Login, Password, Email) VALUES (:login, :pass, :mail)",$values);              
-                        break;
+            fwrite($file, $pid);
+            fclose($file);
+
+            try {
+                $dbl = new DBLayer("lib");
+                $statement = $dbl->executeWithoutParams("SELECT * FROM ams_querycache");
+                $rows = $statement->fetchAll();           
+                foreach ($rows as $record) {
+                    
+                    $db = new DBLayer($record['db']);
+                    switch($record['type']) {
+                        case 'createPermissions':
+                            $decode = json_decode($record['query']);
+                            $values = array('username' => $decode[0]);
+                            //make connection with and put into shard db & delete from the lib
+                            $sth = $db->execute("SELECT UId FROM user WHERE Login= :username;", $values);
+                            $result = $sth->fetchAll();
+                            foreach ($result as $UId) {
+                                $ins_values = array('id' => $UId['UId']);
+                                $db->execute("INSERT INTO permission (UId, ClientApplication, AccessPrivilege) VALUES (:id, 'r2', 'OPEN');", $ins_values);
+                                $db->execute("INSERT INTO permission (UId, ClientApplication, AccessPrivilege) VALUES (:id , 'ryzom_open', 'OPEN');", $ins_values);
+                            }
+                            break;
+                        case 'change_pass':
+                            $decode = json_decode($record['query']);
+                            $values = array('user' => $decode[0], 'pass' => $decode[1]);
+                            //make connection with and put into shard db & delete from the lib
+                            $db->execute("UPDATE user SET Password = :pass WHERE Login = :user",$values);              
+                            break;
+                        case 'change_mail':
+                            $decode = json_decode($record['query']);
+                            $values = array('user' => $decode[0], 'mail' => $decode[1]);
+                            //make connection with and put into shard db & delete from the lib
+                            $db->execute("UPDATE user SET Email = :mail WHERE Login = :user",$values);              
+                            break;
+                        case 'createUser': 
+                            $decode = json_decode($record['query']);
+                            $values = array('login' => $decode[0], 'pass' => $decode[1], 'mail' => $decode[2] );
+                            //make connection with and put into shard db & delete from the lib
+                            $db->execute("INSERT INTO user (Login, Password, Email) VALUES (:login, :pass, :mail)",$values);              
+                            break;
+                    }
+                    $dbl->execute("DELETE FROM ams_querycache WHERE SID=:SID",array('SID' => $record['SID']));
+                }
+                if ($display == true) {
+                    print('Syncing completed');
                 }
-                $dbl->execute("DELETE FROM ams_querycache WHERE SID=:SID",array('SID' => $record['SID']));
-            }
-            if ($display == true) {
-                print('Syncing completed');
             }
-        }
-        catch (PDOException $e) {
-            if ($display == true) {
-                print('Something went wrong! The shard is probably still offline!');
-                print_r($e);
+            catch (PDOException $e) {
+                if ($display == true) {
+                    print('Something went wrong! The shard is probably still offline!');
+                    print_r($e);
+                }
             }
+            unlink($pidfile);
         }
 
     }
+    }
 }