diff --git a/sources/queued-daemon/src/main.cpp b/sources/queued-daemon/src/main.cpp
index e9ae4e3..b42a302 100644
--- a/sources/queued-daemon/src/main.cpp
+++ b/sources/queued-daemon/src/main.cpp
@@ -100,7 +100,7 @@ int main(int argc, char *argv[])
     }
 
     // check if exists
-    if (existingSessionOperation(QString("Active"))) {
+    if (existingSessionOperation("Active")) {
         qCWarning(LOG_APP) << "Another session is active";
         return 1;
     }
diff --git a/sources/queued-server/src/QueuedTcpServerResponseHelperPermissions.cpp b/sources/queued-server/src/QueuedTcpServerResponseHelperPermissions.cpp
index a5a854c..9a1c907 100644
--- a/sources/queued-server/src/QueuedTcpServerResponseHelperPermissions.cpp
+++ b/sources/queued-server/src/QueuedTcpServerResponseHelperPermissions.cpp
@@ -52,9 +52,8 @@ QVariantHash QueuedTcpServerResponseHelperPermissions::removePermission(
     if (permission == QueuedEnums::Permission::Invalid)
         return {{"code", 400}, {"message", "Invalid permission"}};
 
-    return {
-        {"code",
-         QueuedCoreAdaptor::sendUserPermissionRemove(_id, permission, _token)
-             ? 200
-             : 400}};
+    return {{"code", QueuedCoreAdaptor::sendUserPermissionRemove(
+                         _id, permission, _token)
+                         ? 200
+                         : 400}};
 }
diff --git a/sources/queued/QueuedConfig.h.in b/sources/queued/QueuedConfig.h.in
index d0e8e4e..ffa1cf9 100644
--- a/sources/queued/QueuedConfig.h.in
+++ b/sources/queued/QueuedConfig.h.in
@@ -41,7 +41,7 @@ namespace QueuedConfig
  */
 const char DBUS_SERVICE[] = DBUS_SERVICE_NAME;
 /**
- * @brief DBus object path for applicaiton
+ * @brief DBus object path for application
  */
 const char DBUS_APPLICATION_PATH[] = "/application";
 /**
@@ -103,6 +103,12 @@ const char WEBAPI_TOKEN_HEADER[] = "x-queued-token";
  */
 const int WEBAPI_VERSIONS[] = {1};
 
+// cgroups configuration
+/**
+ * @brief path to root directory of cgroups
+ */
+const char CG_FS_PATH[] = "/sys/fs/cgroup";
+
 // plugin interfaces
 /**
  * @brief plugin interface name
diff --git a/sources/queued/include/queued/Queued.h b/sources/queued/include/queued/Queued.h
index de1651a..6519544 100644
--- a/sources/queued/include/queued/Queued.h
+++ b/sources/queued/include/queued/Queued.h
@@ -25,6 +25,7 @@
 #define QUEUED_H
 
 #include "QueuedAdvancedSettings.h"
+#include "QueuedControlGroupsAdaptor.h"
 #include "QueuedCore.h"
 #include "QueuedCoreAdaptor.h"
 #include "QueuedCoreInterface.h"
diff --git a/sources/queued/include/queued/QueuedControlGroupsAdaptor.h b/sources/queued/include/queued/QueuedControlGroupsAdaptor.h
new file mode 100644
index 0000000..e0f9973
--- /dev/null
+++ b/sources/queued/include/queued/QueuedControlGroupsAdaptor.h
@@ -0,0 +1,142 @@
+/*
+ * Copyright (c) 2017 Queued team
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ *
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ */
+/**
+ * @file QueuedControlGroupsAdaptor.h
+ * Header of Queued library
+ * @author Queued team
+ * @copyright MIT
+ * @bug https://github.com/arcan1s/queued/issues
+ */
+
+
+#ifndef QUEUEDCONTROLGROUPSADAPTOR_H
+#define QUEUEDCONTROLGROUPSADAPTOR_H
+
+#include <QObject>
+
+
+/**
+ * @brief adaptor to control processes by using control groups
+ */
+class QueuedControlGroupsAdaptor : public QObject
+{
+    Q_OBJECT
+    // static
+    Q_PROPERTY(QStringList controlPaths READ controlPaths)
+    Q_PROPERTY(QString cpuPath READ cpuPath)
+    Q_PROPERTY(QString memoryPath READ memoryPath)
+    // dynamic
+    Q_PROPERTY(QString name READ name)
+    Q_PROPERTY(long long cpuLimit READ cpuLimit WRITE setCpuLimit)
+    Q_PROPERTY(long long memoryLimit READ memoryLimit WRITE setMemoryLimit)
+
+public:
+    // constants
+    /**
+     * @brief name of file contains processes list
+     */
+    const char *CG_PROC_FILE = "cgroup.procs";
+
+    /**
+     * @brief QueuedControlGroupsAdaptor class constructor
+     * @param _parent
+     * pointer to parent object
+     * @param _name
+     * control group name
+     */
+    explicit QueuedControlGroupsAdaptor(QObject *_parent, QString &_name);
+    /**
+     * @brief QueuedControlGroupsAdaptor class destructor
+     */
+    virtual ~QueuedControlGroupsAdaptor();
+    // static properties
+    /**
+     * @brief paths to all control directories
+     * @return full paths to all known control directories
+     */
+    static QStringList controlPaths();
+    /**
+     * @brief path to CPU control
+     * @return full path to CPU control directory
+     */
+    static QString cpuPath();
+    /**
+     * @brief path to memory control
+     * @return full path to memory control directory
+     */
+    static QString memoryPath();
+    // instance depended properties
+    /**
+     * @brief CPU limit
+     * @return current CPU limit level
+     */
+    long long cpuLimit() const;
+    /**
+     * @brief memory limit
+     * @return current memory limit level
+     */
+    long long memoryLimit() const;
+    /**
+     * @brief control group name
+     * @return control group name
+     */
+    QString name() const;
+    /**
+     * @brief set CPU limit
+     * @param _value
+     * new CPU limit level
+     */
+    void setCpuLimit(const long long _value);
+    /**
+     * @brief set memory limit
+     * @param _value
+     * new memory limit level
+     */
+    void setMemoryLimit(const long long _value);
+    // methods
+    /**
+     * @brief assign control group to process
+     * @param _pid
+     * process ID
+     * @param _name
+     * control group name
+     * @return process assignment status
+     */
+    bool addProcess(const uint _pid);
+    /**
+     * @brief create empty group
+     * @param _name
+     * control group name
+     * @return group creation status
+     */
+    bool createGroup();
+    /**
+     * @brief remove control group
+     * @param _name
+     * control group name
+     * @return group removal status
+     */
+    bool removeGroup();
+
+private:
+    // properties
+    /**
+     * @brief control group name
+     */
+    QString m_name;
+};
+
+
+#endif /* QUEUEDCONTROLGROUPSADAPTOR_H */
diff --git a/sources/queued/include/queued/QueuedDatabase.h b/sources/queued/include/queued/QueuedDatabase.h
index 88ec627..d55bb97 100644
--- a/sources/queued/include/queued/QueuedDatabase.h
+++ b/sources/queued/include/queued/QueuedDatabase.h
@@ -74,7 +74,7 @@ public:
      * @return list of records from table
      */
     QList<QVariantHash> get(const QString &_table,
-                            const QString &_condition = QString());
+                            const QString &_condition = "");
     /**
      * @brief get record from table with given id
      * @param _table
diff --git a/sources/queued/include/queued/QueuedDatabaseSchema.h b/sources/queued/include/queued/QueuedDatabaseSchema.h
index 54f0ca5..5bca573 100644
--- a/sources/queued/include/queued/QueuedDatabaseSchema.h
+++ b/sources/queued/include/queued/QueuedDatabaseSchema.h
@@ -39,29 +39,29 @@ namespace QueuedDB
  */
 const char SETTINGS_TABLE[] = "settings";
 /**
-* @brief tasks table name
-*/
+ * @brief tasks table name
+ */
 const char TASKS_TABLE[] = "tasks";
 /**
-* @brief tokens table name
-*/
+ * @brief tokens table name
+ */
 const char TOKENS_TABLE[] = "tokens";
 /**
-* @brief users table name
-*/
+ * @brief users table name
+ */
 const char USERS_TABLE[] = "users";
 /**
-* @struct QueuedDBField
-* @brief describes database column
-* @var QueuedDBField::name
-* column name
-* @var QueuedDBField::sqlDescription
-* description to create column
-* @var QueuedDBField::type
-* Qt type of column for cast
-* @var QueuedDBField::adminField
-* is admin permissions required to edit or not
-*/
+ * @struct QueuedDBField
+ * @brief describes database column
+ * @var QueuedDBField::name
+ * column name
+ * @var QueuedDBField::sqlDescription
+ * description to create column
+ * @var QueuedDBField::type
+ * Qt type of column for cast
+ * @var QueuedDBField::adminField
+ * is admin permissions required to edit or not
+ */
 typedef struct {
     QString name;
     QString sqlDescription;
diff --git a/sources/queued/include/queued/QueuedExceptions.h b/sources/queued/include/queued/QueuedExceptions.h
index 5b8f0d4..aea06ad 100644
--- a/sources/queued/include/queued/QueuedExceptions.h
+++ b/sources/queued/include/queued/QueuedExceptions.h
@@ -58,7 +58,7 @@ public:
     /**
      * @brief raise QueuedException
      */
-    void raise() const override { throw * this; }
+    void raise() const override { throw *this; }
 
 private:
     /**
diff --git a/sources/queued/include/queued/QueuedLimits.h b/sources/queued/include/queued/QueuedLimits.h
index 53a5082..4e8209d 100644
--- a/sources/queued/include/queued/QueuedLimits.h
+++ b/sources/queued/include/queued/QueuedLimits.h
@@ -87,9 +87,9 @@ struct Limits {
     explicit Limits(const QString &_stringLimits)
         : Limits()
     {
-        QStringList limits = _stringLimits.split(QChar('\n'));
+        QStringList limits = _stringLimits.split('\n');
         while (limits.count() < 5)
-            limits.append(QString("0"));
+            limits.append("0");
 
         cpu = limits.at(0).toLongLong();
         gpu = limits.at(1).toLongLong();
diff --git a/sources/queued/src/QueuedAdvancedSettings.cpp b/sources/queued/src/QueuedAdvancedSettings.cpp
index bcb60c6..bd45fa3 100644
--- a/sources/queued/src/QueuedAdvancedSettings.cpp
+++ b/sources/queued/src/QueuedAdvancedSettings.cpp
@@ -117,7 +117,7 @@ QString QueuedAdvancedSettings::internalId(const QString &_key)
         return internal;
     }
 
-    return QString();
+    return "";
 }
 
 
@@ -135,7 +135,7 @@ QueuedAdvancedSettings::internalId(const QueuedConfig::QueuedSettings _key)
         return internal;
     }
 
-    return QString();
+    return "";
 }
 
 
@@ -160,8 +160,8 @@ void QueuedAdvancedSettings::set(const QList<QVariantHash> &_values)
     qCDebug(LOG_LIB) << "Set values from" << _values;
 
     for (auto &pair : _values) {
-        QString key = pair[QString("key")].toString().toLower();
-        m_ids[key] = pair[QString("_id")].toLongLong();
-        set(key, pair[QString("value")]);
+        QString key = pair["key"].toString().toLower();
+        m_ids[key] = pair["_id"].toLongLong();
+        set(key, pair["value"]);
     }
 }
diff --git a/sources/queued/src/QueuedControlGroupsAdaptor.cpp b/sources/queued/src/QueuedControlGroupsAdaptor.cpp
new file mode 100644
index 0000000..e3188f3
--- /dev/null
+++ b/sources/queued/src/QueuedControlGroupsAdaptor.cpp
@@ -0,0 +1,232 @@
+/*
+ * Copyright (c) 2017 Queued team
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ *
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ */
+/**
+ * @file QueuedControlGroupsAdaptor.cpp
+ * Source code of queued library
+ * @author Queued team
+ * @copyright GPLv3
+ * @bug https://github.com/arcan1s/queued/issues
+ */
+
+
+#include <queued/Queued.h>
+
+#include <QDir>
+
+
+/**
+ * @class QueuedControlGroupsAdaptor
+ */
+/**
+ * @fn QueuedControlGroupsAdaptor
+ */
+QueuedControlGroupsAdaptor::QueuedControlGroupsAdaptor(QObject *_parent,
+                                                       QString &_name)
+    : QObject(_parent)
+    , m_name(_name)
+{
+    qCDebug(LOG_LIB) << __PRETTY_FUNCTION__;
+
+    createGroup();
+}
+
+
+/**
+ * @fn ~QueuedControlGroupsAdaptor
+ */
+QueuedControlGroupsAdaptor::~QueuedControlGroupsAdaptor()
+{
+    qCDebug(LOG_LIB) << __PRETTY_FUNCTION__;
+
+    removeGroup();
+}
+
+
+/**
+ * @fn controlPaths
+ */
+QStringList QueuedControlGroupsAdaptor::controlPaths()
+{
+    return {cpuPath(), memoryPath()};
+}
+
+
+/**
+ * @fn cpuPath
+ */
+QString QueuedControlGroupsAdaptor::cpuPath()
+{
+    return QDir(QueuedConfig::CG_FS_PATH).filePath("cpu");
+}
+
+
+/**
+ * @fn memoryPath
+ */
+QString QueuedControlGroupsAdaptor::memoryPath()
+{
+    return QDir(QueuedConfig::CG_FS_PATH).filePath("memory");
+}
+
+
+/**
+ * @fn cpuLimit
+ */
+long long QueuedControlGroupsAdaptor::cpuLimit() const
+{
+    QFile file(QDir(cpuPath()).filePath("cpu.cfs_quota_us"));
+
+    long long limit = 0;
+    if (file.open(QIODevice::ReadOnly | QFile::Text)) {
+        QTextStream stream(&file);
+        limit = stream.readAll().toLongLong();
+    } else {
+        qCCritical(LOG_LIB) << "Could not get CPU limit" << name();
+        return 0;
+    }
+    file.close();
+
+    return limit * QueuedSystemInfo::cpuCount() / 1000;
+}
+
+
+/**
+ * @fn memoryLimit
+ */
+long long QueuedControlGroupsAdaptor::memoryLimit() const
+{
+    QFile file(QDir(memoryPath()).filePath("memory.limit_in_bytes"));
+
+    long long limit = 0;
+    if (file.open(QIODevice::ReadOnly | QFile::Text)) {
+        QTextStream stream(&file);
+        limit = stream.readAll().toLongLong();
+    } else {
+        qCCritical(LOG_LIB) << "Could not get memory limit" << name();
+        return 0;
+    }
+    file.close();
+
+    return limit;
+}
+
+
+/**
+ * @fn name
+ */
+QString QueuedControlGroupsAdaptor::name() const
+{
+    return m_name;
+}
+
+
+/**
+ * @fn setCpuLimit
+ */
+void QueuedControlGroupsAdaptor::setCpuLimit(const long long _value)
+{
+    qCDebug(LOG_LIB) << "Set new CPU limit to" << _value;
+
+    QFile file(QDir(cpuPath()).filePath("cpu.cfs_quota_us"));
+
+    if (file.open(QIODevice::ReadWrite)) {
+        QTextStream stream(&file);
+        stream << _value;
+    } else {
+        qCCritical(LOG_LIB)
+            << "Could not set CPU limit" << name() << "to" << _value;
+        return;
+    }
+    file.close();
+}
+
+
+/**
+ * @fn setMemoryLimit
+ */
+void QueuedControlGroupsAdaptor::setMemoryLimit(const long long _value)
+{
+    qCDebug(LOG_LIB) << "Set new memory limit to" << _value;
+
+    QFile file(QDir(cpuPath()).filePath("memory.limit_in_bytes"));
+
+    if (file.open(QIODevice::ReadWrite)) {
+        QTextStream stream(&file);
+        stream << _value;
+    } else {
+        qCCritical(LOG_LIB)
+            << "Could not set memory limit" << name() << "to" << _value;
+        return;
+    }
+    file.close();
+}
+
+
+/**
+ * @fn assignGroup
+ */
+bool QueuedControlGroupsAdaptor::addProcess(const uint _pid)
+{
+    qCDebug(LOG_LIB) << "Assign add process" << _pid;
+
+    for (auto &path : controlPaths()) {
+        auto proc = QDir(QDir(path).filePath(name())).filePath(CG_PROC_FILE);
+        QFile file(proc);
+
+        if (file.open(QIODevice::ReadWrite)) {
+            QTextStream stream(&file);
+            stream << _pid;
+        } else {
+            qCCritical(LOG_LIB)
+                << "Cound not assign pid" << _pid << "to" << proc;
+            return false;
+        }
+
+        file.close();
+    }
+
+    return true;
+}
+
+
+/**
+ * @fn createGroup
+ */
+bool QueuedControlGroupsAdaptor::createGroup()
+{
+    qCDebug(LOG_LIB) << "Create empty group";
+
+    auto paths = controlPaths();
+
+    return std::all_of(
+        paths.cbegin(), paths.cend(),
+        [this](const QString &path) { return QDir(path).mkpath(name()); });
+}
+
+
+/**
+ * @fn removeGroup
+ */
+bool QueuedControlGroupsAdaptor::removeGroup()
+{
+    qCDebug(LOG_LIB) << "Remove group";
+
+    auto paths = controlPaths();
+
+    return std::all_of(
+        paths.cbegin(), paths.cend(), [this](const QString &path) {
+            return QDir(QDir(path).filePath(name())).removeRecursively();
+        });
+}
diff --git a/sources/queued/src/QueuedCore.cpp b/sources/queued/src/QueuedCore.cpp
index 4702ca3..ba93b44 100644
--- a/sources/queued/src/QueuedCore.cpp
+++ b/sources/queued/src/QueuedCore.cpp
@@ -602,12 +602,13 @@ void QueuedCore::init(const QString &_configuration)
     initProcesses();
 
     // settings update notifier
-    m_connections += connect(
-        m_advancedSettings,
-        SIGNAL(valueUpdated(const QueuedConfig::QueuedSettings, const QString &,
-                            const QVariant &)),
-        this, SLOT(updateSettings(const QueuedConfig::QueuedSettings,
-                                  const QString &, const QVariant &)));
+    m_connections
+        += connect(m_advancedSettings,
+                   SIGNAL(valueUpdated(const QueuedConfig::QueuedSettings,
+                                       const QString &, const QVariant &)),
+                   this,
+                   SLOT(updateSettings(const QueuedConfig::QueuedSettings,
+                                       const QString &, const QVariant &)));
 
     // dbus session
     initDBus();
@@ -671,7 +672,7 @@ void QueuedCore::updateSettings(const QueuedConfig::QueuedSettings _id,
 
 
 /**
-* @fn updateTaskTime
+ * @fn updateTaskTime
  */
 void QueuedCore::updateTaskTime(const long long _id,
                                 const QDateTime &_startTime,
@@ -682,12 +683,12 @@ void QueuedCore::updateTaskTime(const long long _id,
 
     QVariantHash record;
     if (_startTime.isValid()) {
-        record[QString("startTime")] = _startTime.toString(Qt::ISODateWithMs);
+        record["startTime"] = _startTime.toString(Qt::ISODateWithMs);
         if (m_plugins)
             emit(m_plugins->interface()->onStartTask(_id));
     }
     if (_endTime.isValid()) {
-        record[QString("endTime")] = _endTime.toString(Qt::ISODateWithMs);
+        record["endTime"] = _endTime.toString(Qt::ISODateWithMs);
         if (m_plugins)
             emit(m_plugins->interface()->onStopTask(_id));
     }
@@ -807,8 +808,8 @@ void QueuedCore::initProcesses()
               .toString();
 
     m_processes = new QueuedProcessManager(this, processLine, onExitAction);
-    auto dbProcesses = m_database->get(QueuedDB::TASKS_TABLE,
-                                       QString("WHERE endTime IS NULL"));
+    auto dbProcesses
+        = m_database->get(QueuedDB::TASKS_TABLE, "WHERE endTime IS NULL");
     m_processes->loadProcesses(dbProcesses);
 
     m_connections
@@ -837,7 +838,7 @@ void QueuedCore::initSettings(const QString &_configuration)
     bool status = m_database->open(dbSetup.hostname, dbSetup.port,
                                    dbSetup.username, dbSetup.password);
     if (!status) {
-        QString message = QString("Could not open database");
+        QString message = "Could not open database";
         qCCritical(LOG_LIB) << message;
         throw QueuedDatabaseException(message);
     }
diff --git a/sources/queued/src/QueuedCoreAdaptor.cpp b/sources/queued/src/QueuedCoreAdaptor.cpp
index 2224e2f..da07c35 100644
--- a/sources/queued/src/QueuedCoreAdaptor.cpp
+++ b/sources/queued/src/QueuedCoreAdaptor.cpp
@@ -261,7 +261,7 @@ bool QueuedCoreAdaptor::sendUserEdit(
 
 
 /**
- * sendUserPermissionAdd
+ * @fn sendUserPermissionAdd
  */
 bool QueuedCoreAdaptor::sendUserPermissionAdd(
     const long long _id, const QueuedEnums::Permission _permission,
@@ -280,7 +280,7 @@ bool QueuedCoreAdaptor::sendUserPermissionAdd(
 
 
 /**
- * sendUserPermissionRemove
+ * @fn sendUserPermissionRemove
  */
 bool QueuedCoreAdaptor::sendUserPermissionRemove(
     const long long _id, const QueuedEnums::Permission _permission,
diff --git a/sources/queued/src/QueuedCoreInterface.cpp b/sources/queued/src/QueuedCoreInterface.cpp
index 2cf911c..852c617 100644
--- a/sources/queued/src/QueuedCoreInterface.cpp
+++ b/sources/queued/src/QueuedCoreInterface.cpp
@@ -135,19 +135,19 @@ bool QueuedCoreInterface::TaskEdit(
     // build payload
     QVariantHash data;
     if (!command.isEmpty())
-        data[QString("command")] = command;
+        data["command"] = command;
     if (!arguments.isEmpty())
-        data[QString("arguments")] = arguments;
+        data["arguments"] = arguments;
     if (!directory.isEmpty())
-        data[QString("directory")] = directory;
+        data["directory"] = directory;
     if (nice > 0)
-        data[QString("nice")] = nice;
+        data["nice"] = nice;
     if (uid > 0)
-        data[QString("uid")] = uid;
+        data["uid"] = uid;
     if (gid > 0)
-        data[QString("gid")] = gid;
+        data["gid"] = gid;
     if (user > 0)
-        data[QString("user")] = user;
+        data["user"] = user;
     // append limits now
     auto limits = task->nativeLimits();
     if (cpu > -1)
@@ -160,7 +160,7 @@ bool QueuedCoreInterface::TaskEdit(
         limits.gpumemory = gpumemory;
     if (storage > -1)
         limits.storage = storage;
-    data[QString("limits")] = limits.toString();
+    data["limits"] = limits.toString();
 
     return m_core->editTask(id, data, token);
 }
@@ -240,11 +240,11 @@ bool QueuedCoreInterface::UserEdit(const qlonglong id, const QString &name,
     // build payload
     QVariantHash data;
     if (!name.isEmpty())
-        data[QString("name")] = name;
+        data["name"] = name;
     if (!password.isEmpty())
-        data[QString("password")] = password;
+        data["password"] = password;
     if (!email.isEmpty())
-        data[QString("email")] = email;
+        data["email"] = email;
     // append limits now
     auto limits = user->nativeLimits();
     if (cpu > -1)
@@ -257,7 +257,7 @@ bool QueuedCoreInterface::UserEdit(const qlonglong id, const QString &name,
         limits.gpumemory = gpumemory;
     if (storage > -1)
         limits.storage = storage;
-    data[QString("limits")] = limits.toString();
+    data["limits"] = limits.toString();
 
     return m_core->editUser(id, data, token);
 }
diff --git a/sources/queued/src/QueuedDatabase.cpp b/sources/queued/src/QueuedDatabase.cpp
index 4377704..0031fc5 100644
--- a/sources/queued/src/QueuedDatabase.cpp
+++ b/sources/queued/src/QueuedDatabase.cpp
@@ -201,11 +201,10 @@ long long QueuedDatabase::add(const QString &_table, const QVariantHash &_value)
 
     auto payload = getQueryPayload(_table, _value);
     // build query
-    QSqlQuery query
-        = m_database.exec(QString("INSERT INTO %1 (%2) VALUES (%3)")
-                              .arg(_table)
-                              .arg(payload.first.join(QChar(',')))
-                              .arg(payload.second.join(QChar(','))));
+    QSqlQuery query = m_database.exec(QString("INSERT INTO %1 (%2) VALUES (%3)")
+                                          .arg(_table)
+                                          .arg(payload.first.join(','))
+                                          .arg(payload.second.join(',')));
     QSqlError error = query.lastError();
     if (error.isValid()) {
         qCCritical(LOG_LIB) << "Could not add record" << _value << "to table"
@@ -235,7 +234,7 @@ bool QueuedDatabase::modify(const QString &_table, const long long _id,
     // build query
     QSqlQuery query = m_database.exec(QString("UPDATE %1 SET %2 WHERE _id=%3")
                                           .arg(_table)
-                                          .arg(stringPayload.join(QChar(',')))
+                                          .arg(stringPayload.join(','))
                                           .arg(_id));
     QSqlError error = query.lastError();
     if (error.isValid()) {
@@ -434,7 +433,7 @@ QueuedDatabase::getQueryPayload(const QString &_table,
                 << "No key" << key << "found in schema of" << _table;
             continue;
         }
-        if (key == QString("_id")) {
+        if (key == "_id") {
             qCWarning(LOG_LIB) << "Modifying record ID is not allowed";
             continue;
         }
diff --git a/sources/queued/src/QueuedDebug.cpp b/sources/queued/src/QueuedDebug.cpp
index 3b28b7a..17e9440 100644
--- a/sources/queued/src/QueuedDebug.cpp
+++ b/sources/queued/src/QueuedDebug.cpp
@@ -48,7 +48,7 @@ void QueuedDebug::applyLogFormat()
  */
 void QueuedDebug::enableDebug()
 {
-    QLoggingCategory::setFilterRules(QString("org.queued.*=true"));
+    QLoggingCategory::setFilterRules("org.queued.*=true");
 }
 
 
diff --git a/sources/queued/src/QueuedLimits.cpp b/sources/queued/src/QueuedLimits.cpp
index 8ae1ec6..fd64257 100644
--- a/sources/queued/src/QueuedLimits.cpp
+++ b/sources/queued/src/QueuedLimits.cpp
@@ -30,14 +30,12 @@
 long long QueuedLimits::convertMemory(QString _value, bool *_status)
 {
     long long intValue;
-    if (_value.endsWith(QString("K")))
-        intValue = _value.remove(QString("K")).toLongLong(_status) * 1024;
-    else if (_value.endsWith(QString("M")))
-        intValue
-            = _value.remove(QString("M")).toLongLong(_status) * 1024 * 1024;
-    else if (_value.endsWith(QString("G")))
-        intValue = _value.remove(QString("G")).toLongLong(_status) * 1024 * 1024
-                   * 1024;
+    if (_value.endsWith("K"))
+        intValue = _value.remove("K").toLongLong(_status) * 1024;
+    else if (_value.endsWith("M"))
+        intValue = _value.remove("M").toLongLong(_status) * 1024 * 1024;
+    else if (_value.endsWith("G"))
+        intValue = _value.remove("G").toLongLong(_status) * 1024 * 1024 * 1024;
     else
         intValue = _value.toInt(_status);
 
diff --git a/sources/queued/src/QueuedProcess.cpp b/sources/queued/src/QueuedProcess.cpp
index 0279eef..02c7273 100644
--- a/sources/queued/src/QueuedProcess.cpp
+++ b/sources/queued/src/QueuedProcess.cpp
@@ -80,10 +80,9 @@ void QueuedProcess::updateArguments()
 
     // replace limits now
     application.replace(
-        "{cpu}",
-        QString("%1").arg(QueuedSystemInfo::cpuWeight(nativeLimits().cpu)
-                              * 100.0,
-                          0, 'f', 0));
+        "{cpu}", QString("%1").arg(
+                     QueuedSystemInfo::cpuWeight(nativeLimits().cpu) * 100.0, 0,
+                     'f', 0));
     application.replace(
         "{memory}",
         QString("%1").arg(QueuedSystemInfo::memoryWeight(nativeLimits().memory)
diff --git a/sources/queued/src/QueuedProcessManager.cpp b/sources/queued/src/QueuedProcessManager.cpp
index b2507f9..8fd2131 100644
--- a/sources/queued/src/QueuedProcessManager.cpp
+++ b/sources/queued/src/QueuedProcessManager.cpp
@@ -69,21 +69,20 @@ QueuedProcess *QueuedProcessManager::add(const QVariantHash &_properties,
 
     QueuedProcess::QueuedProcessDefinitions defs;
     // parameters
-    defs.command = _properties[QString("command")].toString();
-    defs.arguments = _properties[QString("commandArguments")].toString().split(
-        QChar('\n'));
-    defs.workingDirectory = _properties[QString("workDirectory")].toString();
-    defs.nice = _properties[QString("nice")].toUInt();
-    defs.limits = _properties[QString("limits")].toString();
+    defs.command = _properties["command"].toString();
+    defs.arguments = _properties["commandArguments"].toString().split('\n');
+    defs.workingDirectory = _properties["workDirectory"].toString();
+    defs.nice = _properties["nice"].toUInt();
+    defs.limits = _properties["limits"].toString();
     // user data
-    defs.uid = _properties[QString("uid")].toUInt();
-    defs.gid = _properties[QString("gid")].toUInt();
-    defs.user = _properties[QString("user")].toLongLong();
+    defs.uid = _properties["uid"].toUInt();
+    defs.gid = _properties["gid"].toUInt();
+    defs.user = _properties["user"].toLongLong();
     // metadata
-    defs.startTime = QDateTime::fromString(
-        _properties[QString("startTime")].toString(), Qt::ISODateWithMs);
-    defs.endTime = QDateTime::fromString(
-        _properties[QString("endTime")].toString(), Qt::ISODateWithMs);
+    defs.startTime = QDateTime::fromString(_properties["startTime"].toString(),
+                                           Qt::ISODateWithMs);
+    defs.endTime = QDateTime::fromString(_properties["endTime"].toString(),
+                                         Qt::ISODateWithMs);
 
     return add(defs, _index);
 }
@@ -107,8 +106,9 @@ QueuedProcess *QueuedProcessManager::add(
     m_processes[_index] = process;
     // connect to signal
     m_connections[_index] = connect(
-        process, static_cast<void (QProcess::*)(int, QProcess::ExitStatus)>(
-                     &QProcess::finished),
+        process,
+        static_cast<void (QProcess::*)(int, QProcess::ExitStatus)>(
+            &QProcess::finished),
         [=](const int exitCode, const QProcess::ExitStatus exitStatus) {
             return taskFinished(exitCode, exitStatus, _index);
         });
@@ -127,7 +127,7 @@ void QueuedProcessManager::loadProcesses(const QList<QVariantHash> &_processes)
     qCDebug(LOG_LIB) << "Add tasks from" << _processes;
 
     for (auto &processData : _processes)
-        add(processData, processData[QString("_id")].toLongLong());
+        add(processData, processData["_id"].toLongLong());
 }
 
 
@@ -235,6 +235,7 @@ void QueuedProcessManager::start(const long long _index)
 
     QDateTime start = QDateTime::currentDateTimeUtc();
     pr->start();
+    // emit start time
     pr->setStartTime(start);
     emit(taskStartTimeReceived(_index, start));
 }
diff --git a/sources/queued/src/QueuedSettings.cpp b/sources/queued/src/QueuedSettings.cpp
index d8c0c49..50f9559 100644
--- a/sources/queued/src/QueuedSettings.cpp
+++ b/sources/queued/src/QueuedSettings.cpp
@@ -80,8 +80,8 @@ QueuedConfig::QueuedDBSetup QueuedSettings::db() const
  */
 QString QueuedSettings::defaultPath()
 {
-    QString fileName = QStandardPaths::locate(QStandardPaths::ConfigLocation,
-                                              QString("queued.ini"));
+    QString fileName
+        = QStandardPaths::locate(QStandardPaths::ConfigLocation, "queued.ini");
     qCInfo(LOG_LIB) << "Found configuration file" << fileName;
 
     return fileName;
diff --git a/sources/queued/src/QueuedTokenManager.cpp b/sources/queued/src/QueuedTokenManager.cpp
index 3008ad6..988d42b 100644
--- a/sources/queued/src/QueuedTokenManager.cpp
+++ b/sources/queued/src/QueuedTokenManager.cpp
@@ -59,7 +59,7 @@ QString QueuedTokenManager::isTokenValid(const QString &_token) const
         && (tokenExpiration(_token) > QDateTime::currentDateTimeUtc()))
         return m_tokens[_token].user;
     else
-        return QString();
+        return "";
 }
 
 
@@ -95,9 +95,9 @@ void QueuedTokenManager::loadTokens(const QList<QVariantHash> &_values)
 
     for (auto &token : _values) {
         QDateTime validUntil = QDateTime::fromString(
-            token[QString("validUntil")].toString(), Qt::ISODateWithMs);
-        loadToken({token[QString("token")].toString(),
-                   token[QString("user")].toString(), validUntil});
+            token["validUntil"].toString(), Qt::ISODateWithMs);
+        loadToken(
+            {token["token"].toString(), token["user"].toString(), validUntil});
     }
 }
 
diff --git a/sources/queued/src/QueuedUserManager.cpp b/sources/queued/src/QueuedUserManager.cpp
index 67a17eb..c9ca7cb 100644
--- a/sources/queued/src/QueuedUserManager.cpp
+++ b/sources/queued/src/QueuedUserManager.cpp
@@ -60,11 +60,11 @@ QueuedUser *QueuedUserManager::add(const QVariantHash &_properties,
     qCDebug(LOG_LIB) << "Add user" << _properties << "with ID" << _id;
 
     QueuedUser::QueuedUserDefinitions defs;
-    defs.name = _properties[QString("name")].toString();
-    defs.email = _properties[QString("email")].toString();
-    defs.password = _properties[QString("password")].toString();
-    defs.permissions = _properties[QString("permissions")].toUInt();
-    defs.limits = _properties[QString("limits")].toString();
+    defs.name = _properties["name"].toString();
+    defs.email = _properties["email"].toString();
+    defs.password = _properties["password"].toString();
+    defs.permissions = _properties["permissions"].toUInt();
+    defs.limits = _properties["limits"].toString();
 
     return add(defs, _id);
 }
@@ -116,13 +116,13 @@ QString QueuedUserManager::authorize(const QString &_user,
     auto userObj = user(_user, false);
     if (!userObj) {
         qCInfo(LOG_LIB) << "No user found" << _user;
-        return QString();
+        return "";
     }
 
     bool status = userObj->isPasswordValid(_password);
     if (!status) {
         qCInfo(LOG_LIB) << "User password invalid for" << _user;
-        return QString();
+        return "";
     }
 
     auto time = QDateTime::currentDateTimeUtc();
@@ -208,7 +208,7 @@ void QueuedUserManager::loadUsers(const QList<QVariantHash> &_users)
 
     // load now
     for (auto &userData : _users)
-        add(userData, userData[QString("_id")].toLongLong());
+        add(userData, userData["_id"].toLongLong());
 }
 
 
diff --git a/sources/queuedctl/src/QueuedctlAuth.cpp b/sources/queuedctl/src/QueuedctlAuth.cpp
index 8961729..395583a 100644
--- a/sources/queuedctl/src/QueuedctlAuth.cpp
+++ b/sources/queuedctl/src/QueuedctlAuth.cpp
@@ -47,9 +47,7 @@ QString QueuedctlAuth::getToken(const QString &_cache, const QString &_user)
 }
 
 
-void QueuedctlAuth::parser(QCommandLineParser &_parser)
-{
-}
+void QueuedctlAuth::parser(QCommandLineParser &_parser) {}
 
 
 void QueuedctlAuth::setToken(const QString &_token, const QString &_user,
diff --git a/sources/queuedctl/src/QueuedctlCommon.cpp b/sources/queuedctl/src/QueuedctlCommon.cpp
index edec6bd..b4bea8e 100644
--- a/sources/queuedctl/src/QueuedctlCommon.cpp
+++ b/sources/queuedctl/src/QueuedctlCommon.cpp
@@ -122,7 +122,7 @@ void QueuedctlCommon::preprocess(const QStringList &_args,
 {
     qCDebug(LOG_APP) << "Preprocess command" << _args;
 
-    QString command = _args.isEmpty() ? QString() : _args.first();
+    QString command = _args.isEmpty() ? "" : _args.first();
     // HACK: workaround to show valid help message
     auto id = QueuedctlArguments.contains(command)
                   ? QueuedctlArguments[command].id
@@ -212,7 +212,7 @@ QueuedctlCommon::process(QCommandLineParser &_parser, const QString &_cache,
 
     auto result = QueuedctlResult();
     QStringList args = _parser.positionalArguments();
-    QString command = args.isEmpty() ? QString() : args.first();
+    QString command = args.isEmpty() ? "" : args.first();
 
     auto id = QueuedctlArguments.contains(command)
                   ? QueuedctlArguments[command].id
@@ -321,7 +321,7 @@ QueuedctlCommon::process(QCommandLineParser &_parser, const QString &_cache,
         if (result.status)
             result.output = QString("Task %1 added").arg(taskId);
         else
-            result.output = QString("Could not add task");
+            result.output = "Could not add task";
         break;
     }
     case QueuedctlArgument::TaskGet: {
@@ -365,7 +365,7 @@ QueuedctlCommon::process(QCommandLineParser &_parser, const QString &_cache,
         if (result.status)
             result.output = QString("User %1 added").arg(userId);
         else
-            result.output = QString("Could not add user");
+            result.output = "Could not add user";
         break;
     }
     case QueuedctlArgument::UserGet: {