Add warning when using SQLite as the database backend.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

HISTORY.rst

@@ -145,6 +145,7 @@
 - Make error messages persistent and increase the timeout of warning to 10 seconds.
 - Improve rendering of the details form.
 - Update rendering of the readonly multiselect widget to conform to Django's updated field class interface.
+- Add warning when using SQLite as the database backend.
 
 2.7.3 (2017-09-11)
 ==================

docs/releases/3.0.rst

@@ -339,6 +339,16 @@ transfer the rights to submissions. With these agreements in place
 we now have a documented and legally sound method to accept
 submissions that we couldn't before.
 
+SQLite
+------
+Starting with version 3.0, a warning message will be shown in the console and
+in the user interface when using SQLite as the database engine. When it comes to
+Mayan EDMS, SQLite should only be used for development or testing, never for
+production. This is due to Mayan EDMS exceeding the concurrency capabilities of
+SQLite. The results are duplicated documents, frequency database locked errors,
+among other issues. Suggested database backends are PostgreSQL and MySQL
+(or MariaDB) using a transaction aware storage engine like InnoDB.
+
 Other changes worth mentioning
 ------------------------------
 - Add Makefile target to check the format of the README.rst file.

mayan/apps/appearance/templates/appearance/base.html

@@ -26,7 +26,15 @@
     <div class="container-fluid">
         <div class="row">
             <div class="col-xs-12">
-                {% block messages %}{% endblock %}
+                {% check_sqlite as check_sqlite %}
+                {% if check_sqlite %}
+                    <div class="alert alert-dismissible alert-warning">
+                        <button type="button" class="close" data-dismiss="alert">&times;</button>
+                        <p><strong>{% trans 'Warning' %}</strong> {{ check_sqlite }}</p>
+                    </div>
+                {% endif %}
+                {% block messages %}
+                {% endblock %}
             </div>
         </div>
 

mayan/apps/common/apps.py

@@ -2,6 +2,7 @@ from __future__ import absolute_import, unicode_literals
 
 from datetime import timedelta
 import logging
+import warnings
 
 from kombu import Exchange, Queue
 
@@ -27,7 +28,7 @@ from .links import (
     link_packages_licenses, link_setup, link_support, link_tools
 )
 
-from .literals import DELETE_STALE_UPLOADS_INTERVAL
+from .literals import DELETE_STALE_UPLOADS_INTERVAL, MESSAGE_SQLITE_WARNING
 from .menus import (
     menu_about, menu_main, menu_secondary, menu_user
 )
@@ -36,6 +37,7 @@ from .queues import *  # NOQA - Force queues registration
 from .settings import setting_auto_logging, setting_production_error_log_path
 from .signals import pre_initial_setup, pre_upgrade
 from .tasks import task_delete_stale_uploads  # NOQA - Force task registration
+from .utils import check_for_sqlite
 
 logger = logging.getLogger(__name__)
 
@@ -87,6 +89,8 @@ class CommonApp(MayanAppConfig):
 
     def ready(self):
         super(CommonApp, self).ready()
+        if check_for_sqlite():
+            warnings.warn(force_text(MESSAGE_SQLITE_WARNING))
 
         app.conf.CELERYBEAT_SCHEDULE.update(
             {

mayan/apps/common/literals.py

@@ -3,7 +3,12 @@ from __future__ import unicode_literals
 from django.utils.translation import ugettext_lazy as _
 
 DELETE_STALE_UPLOADS_INTERVAL = 60 * 10  # 10 minutes
+DJANGO_SQLITE_BACKEND = 'django.db.backends.sqlite3'
 MAYAN_PYPI_NAME = 'mayan-edms'
+MESSAGE_SQLITE_WARNING = _(
+    'Your database backend is set to use SQLite. SQLite should only be used '
+    'for development and testing, not for production.'
+)
 PYPI_URL = 'https://pypi.python.org/pypi'
 TIME_DELTA_UNIT_DAYS = 'days'
 TIME_DELTA_UNIT_HOURS = 'hours'

mayan/apps/common/templatetags/common_tags.py

@@ -4,6 +4,7 @@ from json import dumps
 
 import sh
 
+from django.conf import settings
 from django.template import Context, Library
 from django.template.loader import get_template
 from django.utils.encoding import force_text
@@ -11,7 +12,8 @@ from django.utils.encoding import force_text
 import mayan
 
 from ..classes import Collection, Dashboard
-from ..utils import return_attrib
+from ..literals import MESSAGE_SQLITE_WARNING
+from ..utils import check_for_sqlite, return_attrib
 
 register = Library()
 
@@ -23,6 +25,23 @@ except sh.CommandNotFound:
     DATE = None
 
 
+@register.simple_tag
+def build():
+    if BUILD:
+        try:
+            return '{} {}'.format(BUILD(), DATE())
+        except sh.ErrorReturnCode_128:
+            return ''
+    else:
+        return ''
+
+
+@register.simple_tag
+def check_sqlite():
+    if check_for_sqlite():
+        return MESSAGE_SQLITE_WARNING
+
+
 @register.simple_tag
 def get_collections():
     return Collection.get_all()
@@ -41,9 +60,9 @@ def get_encoded_parameter(item, parameters_dict):
     return dumps(result)
 
 
-@register.simple_tag
-def project_information(attribute_name):
-    return getattr(mayan, attribute_name)
+@register.filter
+def get_type(value):
+    return force_text(type(value))
 
 
 @register.filter
@@ -51,6 +70,11 @@ def object_property(value, arg):
     return return_attrib(value, arg)
 
 
+@register.simple_tag
+def project_information(attribute_name):
+    return getattr(mayan, attribute_name)
+
+
 @register.simple_tag(takes_context=True)
 def render_subtemplate(context, template_name, template_context):
     """
@@ -61,18 +85,3 @@ def render_subtemplate(context, template_name, template_context):
     new_context.update(Context(template_context))
     return get_template(template_name).render(new_context.flatten())
 
-
-@register.simple_tag
-def build():
-    if BUILD:
-        try:
-            return '{} {}'.format(BUILD(), DATE())
-        except sh.ErrorReturnCode_128:
-            return ''
-    else:
-        return ''
-
-
-@register.filter
-def get_type(value):
-    return force_text(type(value))

mayan/apps/common/utils.py

@@ -20,12 +20,16 @@ from common.compat import dict_type, dictionary_type
 import mayan
 
 from .exceptions import NotLatestVersion
-from .literals import MAYAN_PYPI_NAME, PYPI_URL
+from .literals import DJANGO_SQLITE_BACKEND, MAYAN_PYPI_NAME, PYPI_URL
 from .settings import setting_temporary_directory
 
 logger = logging.getLogger(__name__)
 
 
+def check_for_sqlite():
+    return settings.DATABASES['default']['ENGINE'] == DJANGO_SQLITE_BACKEND
+
+
 def check_version():
     pypi = xmlrpc_client.ServerProxy(PYPI_URL)
     versions = pypi.package_releases(MAYAN_PYPI_NAME)