diff --git a/rhodecode/apps/admin/views/permissions.py b/rhodecode/apps/admin/views/permissions.py
--- a/rhodecode/apps/admin/views/permissions.py
+++ b/rhodecode/apps/admin/views/permissions.py
@@ -36,7 +36,7 @@ from rhodecode import events
 from rhodecode.lib import helpers as h
 from rhodecode.lib.auth import (
     LoginRequired, HasPermissionAllDecorator, CSRFRequired)
-from rhodecode.lib.utils2 import aslist, safe_unicode
+from rhodecode.lib.utils2 import aslist, safe_str
 from rhodecode.model.db import (
     or_, coalesce, User, UserIpMap, UserSshKeys)
 from rhodecode.model.forms import (
@@ -410,7 +410,7 @@ class AdminPermissionsView(BaseAppView, 
         base_q = UserSshKeys.query().join(UserSshKeys.user)
 
         if search_q:
-            like_expression = u'%{}%'.format(safe_unicode(search_q))
+            like_expression = u'%{}%'.format(safe_str(search_q))
             base_q = base_q.filter(or_(
                 User.username.ilike(like_expression),
                 UserSshKeys.ssh_key_fingerprint.ilike(like_expression),
diff --git a/rhodecode/apps/admin/views/repo_groups.py b/rhodecode/apps/admin/views/repo_groups.py
--- a/rhodecode/apps/admin/views/repo_groups.py
+++ b/rhodecode/apps/admin/views/repo_groups.py
@@ -36,7 +36,7 @@ from rhodecode.lib.auth import (
     LoginRequired, CSRFRequired, NotAnonymous,
     HasPermissionAny, HasRepoGroupPermissionAny)
 from rhodecode.lib import helpers as h, audit_logger
-from rhodecode.lib.utils2 import safe_int, safe_unicode, datetime_to_time
+from rhodecode.lib.str_utils import safe_int, safe_str
 from rhodecode.model.forms import RepoGroupForm
 from rhodecode.model.permission import PermissionModel
 from rhodecode.model.repo_group import RepoGroupModel
diff --git a/rhodecode/apps/admin/views/repositories.py b/rhodecode/apps/admin/views/repositories.py
--- a/rhodecode/apps/admin/views/repositories.py
+++ b/rhodecode/apps/admin/views/repositories.py
@@ -36,7 +36,7 @@ from rhodecode.lib.auth import (
     HasPermissionAny, HasRepoGroupPermissionAny)
 from rhodecode.lib import helpers as h
 from rhodecode.lib.utils import repo_name_slug
-from rhodecode.lib.utils2 import safe_int, safe_unicode
+from rhodecode.lib.utils2 import safe_int, safe_str
 from rhodecode.model.forms import RepoForm
 from rhodecode.model.permission import PermissionModel
 from rhodecode.model.repo import RepoModel
@@ -58,7 +58,7 @@ class AdminReposView(BaseAppView, DataGr
         acl_groups = RepoGroupList(RepoGroup.query().all(),
                                    perm_set=['group.write', 'group.admin'])
         c.repo_groups = RepoGroup.groups_choices(groups=acl_groups)
-        c.repo_groups_choices = map(lambda k: safe_unicode(k[0]), c.repo_groups)
+        c.repo_groups_choices = list(map(lambda k: safe_str(k[0]), c.repo_groups))
         c.personal_repo_group = self._rhodecode_user.personal_repo_group
 
     @LoginRequired()
@@ -114,7 +114,7 @@ class AdminReposView(BaseAppView, DataGr
             .group_by(Repository, User)
 
         if search_q:
-            like_expression = u'%{}%'.format(safe_unicode(search_q))
+            like_expression = u'%{}%'.format(safe_str(search_q))
             base_q = base_q.filter(or_(
                 Repository.repo_name.ilike(like_expression),
             ))
diff --git a/rhodecode/apps/admin/views/settings.py b/rhodecode/apps/admin/views/settings.py
--- a/rhodecode/apps/admin/views/settings.py
+++ b/rhodecode/apps/admin/views/settings.py
@@ -38,8 +38,9 @@ from rhodecode.lib import helpers as h
 from rhodecode.lib.auth import (
     LoginRequired, HasPermissionAllDecorator, CSRFRequired)
 from rhodecode.lib.celerylib import tasks, run_task
+from rhodecode.lib.str_utils import safe_str
 from rhodecode.lib.utils import repo2db_mapper
-from rhodecode.lib.utils2 import str2bool, safe_unicode, AttributeDict
+from rhodecode.lib.utils2 import str2bool, AttributeDict
 from rhodecode.lib.index import searcher_from_config
 
 from rhodecode.model.db import RhodeCodeUi, Repository
@@ -248,7 +249,8 @@ class AdminSettingsView(BaseAppView):
         added, removed = repo2db_mapper(filesystem_repos, rm_obsolete)
         PermissionModel().trigger_permission_flush()
 
-        _repr = lambda l: ', '.join(map(safe_unicode, l)) or '-'
+        def _repr(l):
+            return ', '.join(map(safe_str, l)) or '-'
         h.flash(_('Repositories successfully '
                   'rescanned added: %s ; removed: %s') %
                 (_repr(added), _repr(removed)),
@@ -311,6 +313,7 @@ class AdminSettingsView(BaseAppView):
             ('create_personal_repo_group', 'rhodecode_create_personal_repo_group', 'bool'),
             ('personal_repo_group_pattern', 'rhodecode_personal_repo_group_pattern', 'unicode'),
         ]
+
         try:
             for setting, form_key, type_ in settings:
                 sett = SettingsModel().create_or_update_setting(
diff --git a/rhodecode/apps/admin/views/system_info.py b/rhodecode/apps/admin/views/system_info.py
--- a/rhodecode/apps/admin/views/system_info.py
+++ b/rhodecode/apps/admin/views/system_info.py
@@ -19,7 +19,9 @@
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
 import logging
-import urllib.request, urllib.error, urllib.parse
+import urllib.request
+import urllib.error
+import urllib.parse
 import os
 
 import rhodecode
@@ -206,7 +208,8 @@ class AdminSystemInfoSettingsView(BaseAp
 
         update_url = UpdateModel().get_update_url()
 
-        _err = lambda s: '<div style="color:#ff8888; padding:4px 0px">{}</div>'.format(s)
+        def _err(s):
+            return '<div style="color:#ff8888; padding:4px 0px">{}</div>'.format(s)
         try:
             data = UpdateModel().get_update_data(update_url)
         except urllib.error.URLError as e:
diff --git a/rhodecode/apps/admin/views/user_groups.py b/rhodecode/apps/admin/views/user_groups.py
--- a/rhodecode/apps/admin/views/user_groups.py
+++ b/rhodecode/apps/admin/views/user_groups.py
@@ -33,11 +33,10 @@ from rhodecode.apps._base import BaseApp
 from rhodecode.lib.auth import (
     LoginRequired, NotAnonymous, CSRFRequired, HasPermissionAnyDecorator)
 from rhodecode.lib import helpers as h, audit_logger
-from rhodecode.lib.utils2 import safe_unicode
+from rhodecode.lib.str_utils import safe_str
 
 from rhodecode.model.forms import UserGroupForm
 from rhodecode.model.permission import PermissionModel
-from rhodecode.model.scm import UserGroupList
 from rhodecode.model.db import (
     or_, count, User, UserGroup, UserGroupMember, in_filter_generator)
 from rhodecode.model.meta import Session
@@ -129,7 +128,7 @@ class AdminUserGroupsView(BaseAppView, D
         base_q_inactive = base_q.filter(UserGroup.users_group_active != true())
 
         if search_q:
-            like_expression = u'%{}%'.format(safe_unicode(search_q))
+            like_expression = u'%{}%'.format(safe_str(search_q))
             base_q = base_q.filter(or_(
                 UserGroup.users_group_name.ilike(like_expression),
             ))
diff --git a/rhodecode/apps/admin/views/users.py b/rhodecode/apps/admin/views/users.py
--- a/rhodecode/apps/admin/views/users.py
+++ b/rhodecode/apps/admin/views/users.py
@@ -45,7 +45,7 @@ from rhodecode.lib.auth import (
     LoginRequired, HasPermissionAllDecorator, CSRFRequired)
 from rhodecode.lib import helpers as h
 from rhodecode.lib.helpers import SqlPage
-from rhodecode.lib.utils2 import safe_int, safe_unicode, AttributeDict
+from rhodecode.lib.utils2 import safe_int, safe_str, AttributeDict
 from rhodecode.model.auth_token import AuthTokenModel
 from rhodecode.model.forms import (
     UserForm, UserIndividualPermissionsForm, UserPermissionsForm,
@@ -106,7 +106,7 @@ class AdminUsersView(BaseAppView, DataGr
         base_inactive_q = base_q.filter(User.active != true())
 
         if search_q:
-            like_expression = '%{}%'.format(safe_unicode(search_q))
+            like_expression = '%{}%'.format(safe_str(search_q))
             base_q = base_q.filter(or_(
                 User.username.ilike(like_expression),
                 User._email.ilike(like_expression),
@@ -223,7 +223,7 @@ class AdminUsersView(BaseAppView, DataGr
             )
             return Response(html)
         except UserCreationError as e:
-            h.flash(safe_unicode(e), 'error')
+            h.flash(safe_str(e), 'error')
         except Exception:
             log.exception("Exception creation of user")
             h.flash(_('Error occurred during creation of user %s')
@@ -347,7 +347,7 @@ class UsersView(UserAppView):
             )
             return Response(html)
         except UserCreationError as e:
-            h.flash(safe_unicode(e), 'error')
+            h.flash(safe_str(e), 'error')
         except Exception:
             log.exception("Exception updating user")
             h.flash(_('Error occurred during update of user %s')
@@ -470,7 +470,8 @@ class UsersView(UserAppView):
         except (UserOwnsReposException, UserOwnsRepoGroupsException,
                 UserOwnsUserGroupsException, UserOwnsPullRequestsException,
                 UserOwnsArtifactsException, DefaultUserException) as e:
-            h.flash(e, category='warning')
+
+            h.flash(safe_str(e), category='warning')
         except Exception:
             log.exception("Exception during deletion of user")
             h.flash(_('An error occurred during deletion of user'),
diff --git a/rhodecode/apps/channelstream/__init__.py b/rhodecode/apps/channelstream/__init__.py
--- a/rhodecode/apps/channelstream/__init__.py
+++ b/rhodecode/apps/channelstream/__init__.py
@@ -23,8 +23,8 @@ from pyramid.events import ApplicationCr
 from pyramid.settings import asbool
 
 from rhodecode.apps._base import ADMIN_PREFIX
-from rhodecode.lib.ext_json import json
-from rhodecode.lib.str_utils import safe_str
+from rhodecode.lib.ext_json import str_json
+
 
 
 def url_gen(request):
@@ -38,7 +38,7 @@ def url_gen(request):
         'longpoll': longpoll_url or proxy_url,
         'ws': ws_url or proxy_url.replace('http', 'ws')
     }
-    return safe_str(json.dumps(urls))
+    return str_json(urls)
 
 
 PLUGIN_DEFINITION = {
diff --git a/rhodecode/apps/home/__init__.py b/rhodecode/apps/home/__init__.py
--- a/rhodecode/apps/home/__init__.py
+++ b/rhodecode/apps/home/__init__.py
@@ -25,7 +25,7 @@ class VCSCallPredicate(object):
         self.val = val
 
     def text(self):
-        return 'vcs_call route = %s' % self.val
+        return f'vcs_call route = {self.val}'
 
     phash = text
 
diff --git a/rhodecode/apps/home/views.py b/rhodecode/apps/home/views.py
--- a/rhodecode/apps/home/views.py
+++ b/rhodecode/apps/home/views.py
@@ -31,7 +31,7 @@ from rhodecode.lib.auth import (
     HasRepoGroupPermissionAny, AuthUser)
 from rhodecode.lib.codeblocks import filenode_as_lines_tokens
 from rhodecode.lib.index import searcher_from_config
-from rhodecode.lib.utils2 import safe_unicode, str2bool, safe_int, safe_str
+from rhodecode.lib.utils2 import str2bool, safe_int, safe_str
 from rhodecode.lib.vcs.nodes import FileNode
 from rhodecode.model.db import (
     func, true, or_, case, cast, in_filter_generator, String, Session,
@@ -129,7 +129,7 @@ class HomeView(BaseAppView, DataGridAppV
             query = query.filter(Repository.repo_type == repo_type)
 
         if name_contains:
-            ilike_expression = u'%{}%'.format(safe_unicode(name_contains))
+            ilike_expression = '%{}%'.format(safe_str(name_contains))
             query = query.filter(
                 Repository.repo_name.ilike(ilike_expression))
             query = query.limit(limit)
@@ -174,7 +174,7 @@ class HomeView(BaseAppView, DataGridAppV
         query = query.order_by(RepoGroup.group_name)
 
         if name_contains:
-            ilike_expression = u'%{}%'.format(safe_unicode(name_contains))
+            ilike_expression = u'%{}%'.format(safe_str(name_contains))
             query = query.filter(
                 RepoGroup.group_name.ilike(ilike_expression))
             query = query.limit(limit)
@@ -216,7 +216,7 @@ class HomeView(BaseAppView, DataGridAppV
             .filter(User.username != User.DEFAULT_USER)
 
         if name_contains:
-            ilike_expression = u'%{}%'.format(safe_unicode(name_contains))
+            ilike_expression = u'%{}%'.format(safe_str(name_contains))
             query = query.filter(
                 User.username.ilike(ilike_expression))
             query = query.limit(limit)
@@ -256,7 +256,7 @@ class HomeView(BaseAppView, DataGridAppV
             .order_by(UserGroup.users_group_name)
 
         if name_contains:
-            ilike_expression = u'%{}%'.format(safe_unicode(name_contains))
+            ilike_expression = u'%{}%'.format(safe_str(name_contains))
             query = query.filter(
                 UserGroup.users_group_name.ilike(ilike_expression))
             query = query.limit(limit)
@@ -308,7 +308,7 @@ class HomeView(BaseAppView, DataGridAppV
         query = query.order_by(PullRequest.pull_request_id)
 
         if name_contains:
-            ilike_expression = u'%{}%'.format(safe_unicode(name_contains))
+            ilike_expression = u'%{}%'.format(safe_str(name_contains))
             query = query.filter(or_(
                 cast(PullRequest.pull_request_id, String).ilike(ilike_expression),
                 PullRequest.title.ilike(ilike_expression),
diff --git a/rhodecode/apps/hovercards/views.py b/rhodecode/apps/hovercards/views.py
--- a/rhodecode/apps/hovercards/views.py
+++ b/rhodecode/apps/hovercards/views.py
@@ -32,7 +32,7 @@ from rhodecode.lib.auth import (
     HasRepoPermissionAnyDecorator)
 from rhodecode.lib.codeblocks import filenode_as_lines_tokens
 from rhodecode.lib.index import searcher_from_config
-from rhodecode.lib.utils2 import safe_unicode, str2bool, safe_int
+from rhodecode.lib.utils2 import str2bool, safe_int
 from rhodecode.lib.ext_json import json
 from rhodecode.lib.vcs.exceptions import CommitDoesNotExistError, EmptyRepositoryError
 from rhodecode.lib.vcs.nodes import FileNode
diff --git a/rhodecode/apps/journal/views.py b/rhodecode/apps/journal/views.py
--- a/rhodecode/apps/journal/views.py
+++ b/rhodecode/apps/journal/views.py
@@ -118,7 +118,7 @@ class JournalView(BaseAppView):
         return journal
 
     def feed_uid(self, entry_id):
-        return '{}:{}'.format('journal', md5_safe(entry_id))
+        return '{}:{}'.format('journal', md5_safe(str(entry_id)))
 
     def _atom_feed(self, repos, search_term, public=True):
         _ = self.request.translate
diff --git a/rhodecode/apps/my_account/views/my_account.py b/rhodecode/apps/my_account/views/my_account.py
--- a/rhodecode/apps/my_account/views/my_account.py
+++ b/rhodecode/apps/my_account/views/my_account.py
@@ -37,6 +37,7 @@ from rhodecode.lib.auth import (
     HasRepoPermissionAny, HasRepoGroupPermissionAny, AuthUser)
 from rhodecode.lib.channelstream import (
     channelstream_request, ChannelstreamException)
+from rhodecode.lib.hash_utils import md5_safe
 from rhodecode.lib.utils2 import safe_int, md5, str2bool
 from rhodecode.model.auth_token import AuthTokenModel
 from rhodecode.model.comment import CommentsModel
@@ -114,7 +115,7 @@ class MyAccountView(BaseAppView, DataGri
         form = forms.RcForm(
             schema, buttons=(forms.buttons.save, forms.buttons.reset))
 
-        controls = self.request.POST.items()
+        controls = list(self.request.POST.items())
         try:
             valid_data = form.validate(controls)
             skip_attrs = ['admin', 'active', 'extern_type', 'extern_name',
@@ -179,7 +180,7 @@ class MyAccountView(BaseAppView, DataGri
         if c.extern_type != 'rhodecode':
             raise HTTPFound(self.request.route_path('my_account_password'))
 
-        controls = self.request.POST.items()
+        controls = list(self.request.POST.items())
         try:
             valid_data = form.validate(controls)
             UserModel().update_user(c.user.user_id, **valid_data)
@@ -196,7 +197,7 @@ class MyAccountView(BaseAppView, DataGri
         else:
             instance = c.auth_user.get_instance()
             self.session.setdefault('rhodecode_user', {}).update(
-                {'password': md5(instance.password)})
+                {'password': md5_safe(instance.password)})
             self.session.save()
             h.flash(_("Successfully updated password"), category='success')
 
@@ -326,7 +327,7 @@ class MyAccountView(BaseAppView, DataGri
             schema, action=h.route_path('my_account_emails_add'),
             buttons=(forms.buttons.save, forms.buttons.reset))
 
-        controls = self.request.POST.items()
+        controls = list(self.request.POST.items())
         try:
             valid_data = form.validate(controls)
             UserModel().add_extra_email(c.user.user_id, valid_data['email'])
diff --git a/rhodecode/apps/repository/views/repo_caches.py b/rhodecode/apps/repository/views/repo_caches.py
--- a/rhodecode/apps/repository/views/repo_caches.py
+++ b/rhodecode/apps/repository/views/repo_caches.py
@@ -52,7 +52,7 @@ class RepoCachesView(RepoAppView):
             c.cached_diff_size = system_info.get_storage_size(cached_diffs_dir)
         c.shadow_repos = c.rhodecode_db_repo.shadow_repos()
 
-        cache_namespace_uid = 'cache_repo.{}'.format(self.db_repo.repo_id)
+        cache_namespace_uid = 'repo.{}'.format(self.db_repo.repo_id)
         c.region = rc_cache.get_or_create_region('cache_repo', cache_namespace_uid)
         c.backend = c.region.backend
         c.repo_keys = sorted(c.region.backend.list_keys(prefix=cache_namespace_uid))
diff --git a/rhodecode/apps/repository/views/repo_changelog.py b/rhodecode/apps/repository/views/repo_changelog.py
--- a/rhodecode/apps/repository/views/repo_changelog.py
+++ b/rhodecode/apps/repository/views/repo_changelog.py
@@ -31,10 +31,10 @@ from rhodecode.lib import ext_json
 from rhodecode.lib.auth import (
     LoginRequired, HasRepoPermissionAnyDecorator)
 
-from rhodecode.lib.ext_json import json
 from rhodecode.lib.graphmod import _colored, _dagwalker
 from rhodecode.lib.helpers import RepoPage
-from rhodecode.lib.utils2 import safe_int, safe_str, str2bool, safe_unicode
+from rhodecode.lib.utils2 import str2bool
+from rhodecode.lib.str_utils import safe_int, safe_str
 from rhodecode.lib.vcs.exceptions import (
     RepositoryError, CommitDoesNotExistError,
     CommitError, NodeDoesNotExistError, EmptyRepositoryError)
@@ -83,7 +83,7 @@ class RepoChangelogView(RepoAppView):
         :param commits: list of commits
         """
         if not commits:
-            return json.dumps([]), json.dumps([])
+            return ext_json.str_json([]), ext_json.str_json([])
 
         def serialize(commit, parents=True):
             data = dict(
@@ -100,6 +100,7 @@ class RepoChangelogView(RepoAppView):
         next_data = next_data or []
 
         current = [serialize(x) for x in commits]
+
         commits = prev_data + current + next_data
 
         dag = _dagwalker(repo, commits)
@@ -110,7 +111,7 @@ class RepoChangelogView(RepoAppView):
 
     def _check_if_valid_branch(self, branch_name, repo_name, f_path):
         if branch_name not in self.rhodecode_vcs_repo.branches_all:
-            h.flash(u'Branch {} is not found.'.format(h.escape(safe_unicode(branch_name))),
+            h.flash(u'Branch {} is not found.'.format(h.escape(safe_str(branch_name))),
                     category='warning')
             redirect_url = h.route_path(
                 'repo_commits_file', repo_name=repo_name,
@@ -334,8 +335,8 @@ class RepoChangelogView(RepoAppView):
         next_data = None
 
         try:
-            prev_graph = json.loads(self.request.POST.get('graph') or '{}')
-        except json.JSONDecodeError:
+            prev_graph = ext_json.json.loads(self.request.POST.get('graph') or '{}')
+        except ext_json.json.JSONDecodeError:
             prev_graph = {}
 
         if self.request.GET.get('chunk') == 'prev':
diff --git a/rhodecode/apps/repository/views/repo_commits.py b/rhodecode/apps/repository/views/repo_commits.py
--- a/rhodecode/apps/repository/views/repo_commits.py
+++ b/rhodecode/apps/repository/views/repo_commits.py
@@ -39,7 +39,7 @@ from rhodecode.lib.diffs import (
     get_diff_whitespace_flag)
 from rhodecode.lib.exceptions import StatusChangeOnClosedPullRequestError, CommentVersionMismatch
 import rhodecode.lib.helpers as h
-from rhodecode.lib.utils2 import safe_unicode, str2bool, StrictAttributeDict, safe_str
+from rhodecode.lib.utils2 import str2bool, StrictAttributeDict, safe_str
 from rhodecode.lib.vcs.backends.base import EmptyCommit
 from rhodecode.lib.vcs.exceptions import (
     RepositoryError, CommitDoesNotExistError)
@@ -308,7 +308,8 @@ class RepoCommitsView(RepoAppView):
                 'attachment; filename=%s.diff' % commit_id_range[:12])
             return response
         elif method == 'patch':
-            c.diff = safe_unicode(diff)
+
+            c.diff = safe_str(diff)
             patch = render(
                 'rhodecode:templates/changeset/patch_changeset.mako',
                 self._get_template_context(c), self.request)
@@ -381,7 +382,7 @@ class RepoCommitsView(RepoAppView):
             resolves_comment_id = entry['resolves_comment_id']
             f_path = entry['f_path']
             line_no = entry['line']
-            target_elem_id = 'file-{}'.format(h.safeid(h.safe_unicode(f_path)))
+            target_elem_id = 'file-{}'.format(h.safeid(h.safe_str(f_path)))
 
             if status:
                 text = text or (_('Status change %(transition_icon)s %(status)s')
@@ -626,7 +627,7 @@ class RepoCommitsView(RepoAppView):
                 file_uid=store_uid, filename=metadata["filename"],
                 file_hash=metadata["sha256"], file_size=metadata["size"],
                 file_display_name=file_display_name,
-                file_description=u'comment attachment `{}`'.format(safe_unicode(filename)),
+                file_description=u'comment attachment `{}`'.format(safe_str(filename)),
                 hidden=True, check_acl=True, user_id=self._rhodecode_user.user_id,
                 scope_repo_id=self.db_repo.repo_id
             )
diff --git a/rhodecode/apps/repository/views/repo_compare.py b/rhodecode/apps/repository/views/repo_compare.py
--- a/rhodecode/apps/repository/views/repo_compare.py
+++ b/rhodecode/apps/repository/views/repo_compare.py
@@ -32,7 +32,7 @@ from rhodecode.lib import helpers as h
 from rhodecode.lib import diffs, codeblocks
 from rhodecode.lib.auth import LoginRequired, HasRepoPermissionAnyDecorator
 from rhodecode.lib.utils import safe_str
-from rhodecode.lib.utils2 import safe_unicode, str2bool
+from rhodecode.lib.utils2 import str2bool
 from rhodecode.lib.view_utils import parse_path_ref, get_commit_from_ref_name
 from rhodecode.lib.vcs.exceptions import (
     EmptyRepositoryError, RepositoryError, RepositoryRequirementError,
@@ -259,9 +259,10 @@ class RepoCompareView(RepoAppView):
         log.debug('calculating diff between '
                   'source_ref:%s and target_ref:%s for repo `%s`',
                   source_commit, target_commit,
-                  safe_unicode(source_repo.scm_instance().path))
+                  safe_str(source_repo.scm_instance().path))
 
         if source_commit.repository != target_commit.repository:
+
             msg = _(
                 "Repositories unrelated. "
                 "Cannot compare commit %(commit1)s from repository %(repo1)s "
diff --git a/rhodecode/apps/repository/views/repo_forks.py b/rhodecode/apps/repository/views/repo_forks.py
--- a/rhodecode/apps/repository/views/repo_forks.py
+++ b/rhodecode/apps/repository/views/repo_forks.py
@@ -34,13 +34,13 @@ from rhodecode.lib.auth import (
     LoginRequired, HasRepoPermissionAnyDecorator, NotAnonymous,
     HasRepoPermissionAny, HasPermissionAnyDecorator, CSRFRequired)
 import rhodecode.lib.helpers as h
+from rhodecode.lib.str_utils import safe_str
 from rhodecode.lib.celerylib.utils import get_task_id
 from rhodecode.model.db import coalesce, or_, Repository, RepoGroup
 from rhodecode.model.permission import PermissionModel
 from rhodecode.model.repo import RepoModel
 from rhodecode.model.forms import RepoForkForm
 from rhodecode.model.scm import ScmModel, RepoGroupList
-from rhodecode.lib.utils2 import safe_int, safe_unicode
 
 log = logging.getLogger(__name__)
 
@@ -55,7 +55,7 @@ class RepoForksView(RepoAppView, DataGri
             RepoGroup.query().all(),
             perm_set=['group.write', 'group.admin'])
         c.repo_groups = RepoGroup.groups_choices(groups=acl_groups)
-        c.repo_groups_choices = map(lambda k: safe_unicode(k[0]), c.repo_groups)
+        c.repo_groups_choices = list(map(lambda k: safe_str(k[0]), c.repo_groups))
 
         c.personal_repo_group = c.rhodecode_user.personal_repo_group
 
@@ -102,7 +102,7 @@ class RepoForksView(RepoAppView, DataGri
             .filter(Repository.repo_id.in_(allowed_ids))\
 
         if search_q:
-            like_expression = u'%{}%'.format(safe_unicode(search_q))
+            like_expression = u'%{}%'.format(safe_str(search_q))
             base_q = base_q.filter(or_(
                 Repository.repo_name.ilike(like_expression),
                 Repository.description.ilike(like_expression),
diff --git a/rhodecode/apps/repository/views/repo_pull_requests.py b/rhodecode/apps/repository/views/repo_pull_requests.py
--- a/rhodecode/apps/repository/views/repo_pull_requests.py
+++ b/rhodecode/apps/repository/views/repo_pull_requests.py
@@ -39,7 +39,7 @@ from rhodecode.lib import ext_json
 from rhodecode.lib.auth import (
     LoginRequired, HasRepoPermissionAny, HasRepoPermissionAnyDecorator,
     NotAnonymous, CSRFRequired)
-from rhodecode.lib.utils2 import str2bool, safe_str, safe_unicode, safe_int, aslist, retry
+from rhodecode.lib.utils2 import str2bool, safe_str, safe_int, aslist, retry
 from rhodecode.lib.vcs.backends.base import (
     EmptyCommit, UpdateFailureReason, unicode_to_reference)
 from rhodecode.lib.vcs.exceptions import (
@@ -953,7 +953,7 @@ class RepoPullRequestsView(RepoAppView, 
             .filter(~Repository.repo_id.in_([x.repo_id for x in parent_target_repos]))
 
         if filter_query:
-            ilike_expression = u'%{}%'.format(safe_unicode(filter_query))
+            ilike_expression = u'%{}%'.format(safe_str(filter_query))
             query = query.filter(Repository.repo_name.ilike(ilike_expression))
 
         limit = max(20 - len(parent_target_repos), 5)  # not less then 5
@@ -1120,7 +1120,7 @@ class RepoPullRequestsView(RepoAppView, 
             _form = form.to_python(controls)
         except formencode.Invalid as errors:
             if errors.error_dict.get('revisions'):
-                msg = 'Revisions: %s' % errors.error_dict['revisions']
+                msg = 'Revisions: {}'.format(errors.error_dict['revisions'])
             elif errors.error_dict.get('pullrequest_title'):
                 msg = errors.error_dict.get('pullrequest_title')
             else:
@@ -1567,7 +1567,7 @@ class RepoPullRequestsView(RepoAppView, 
             close_pull_request = entry['close_pull_request']
             f_path = entry['f_path']
             line_no = entry['line']
-            target_elem_id = 'file-{}'.format(h.safeid(h.safe_unicode(f_path)))
+            target_elem_id = 'file-{}'.format(h.safeid(h.safe_str(f_path)))
 
             # the logic here should work like following, if we submit close
             # pr comment, use `close_pull_request_with_comment` function
@@ -1867,7 +1867,7 @@ class RepoPullRequestsView(RepoAppView, 
                 'comment_id': comment.comment_id,
                 'comment_version': comment_history.version,
                 'comment_author_username': comment_history.author.username,
-                'comment_author_gravatar': h.gravatar_url(comment_history.author.email, 16),
+                'comment_author_gravatar': h.gravatar_url(comment_history.author.email, 16, request=self.request),
                 'comment_created_on': h.age_component(comment_history.created_on,
                                                       time_is_local=True),
             }
diff --git a/rhodecode/apps/repository/views/repo_settings.py b/rhodecode/apps/repository/views/repo_settings.py
--- a/rhodecode/apps/repository/views/repo_settings.py
+++ b/rhodecode/apps/repository/views/repo_settings.py
@@ -49,7 +49,7 @@ class RepoSettingsView(RepoAppView):
             RepoGroup.query().all(),
             perm_set=['group.write', 'group.admin'])
         c.repo_groups = RepoGroup.groups_choices(groups=acl_groups)
-        c.repo_groups_choices = map(lambda k: k[0], c.repo_groups)
+        c.repo_groups_choices = list(map(lambda k: k[0], c.repo_groups))
 
         # in case someone no longer have a group.write access to a repository
         # pre fill the list with this entry, we don't care if this is the same
@@ -114,7 +114,7 @@ class RepoSettingsView(RepoAppView):
         schema = self._get_schema(c, old_values=old_values)
 
         c.form = RcForm(schema)
-        pstruct = self.request.POST.items()
+        pstruct = list(self.request.POST.items())
         pstruct.append(('repo_type', self.db_repo.repo_type))
         try:
             schema_data = c.form.validate(pstruct)
diff --git a/rhodecode/apps/repository/views/repo_summary.py b/rhodecode/apps/repository/views/repo_summary.py
--- a/rhodecode/apps/repository/views/repo_summary.py
+++ b/rhodecode/apps/repository/views/repo_summary.py
@@ -161,7 +161,7 @@ class RepoSummaryView(RepoAppView):
             'with caching: %s[TTL: %ss]' % (
                 repo_id, landing_commit, cache_on, cache_seconds or 0))
 
-        cache_namespace_uid = 'cache_repo.{}'.format(repo_id)
+        cache_namespace_uid = 'repo.{}'.format(repo_id)
         region = rc_cache.get_or_create_region('cache_repo', cache_namespace_uid)
 
         @region.conditional_cache_on_arguments(namespace=cache_namespace_uid,
diff --git a/rhodecode/apps/search/views.py b/rhodecode/apps/search/views.py
--- a/rhodecode/apps/search/views.py
+++ b/rhodecode/apps/search/views.py
@@ -19,7 +19,9 @@
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
 import logging
-import urllib.request, urllib.parse, urllib.error
+import urllib.request
+import urllib.parse
+import urllib.error
 
 from webhelpers2.html.tools import update_params
 
diff --git a/rhodecode/apps/ssh_support/lib/backends/base.py b/rhodecode/apps/ssh_support/lib/backends/base.py
--- a/rhodecode/apps/ssh_support/lib/backends/base.py
+++ b/rhodecode/apps/ssh_support/lib/backends/base.py
@@ -20,10 +20,10 @@
 
 import os
 import sys
-import json
 import logging
 
 from rhodecode.lib.hooks_daemon import prepare_callback_daemon
+from rhodecode.lib.ext_json import sjson as json
 from rhodecode.lib.vcs.conf import settings as vcs_settings
 from rhodecode.model.scm import ScmModel
 
diff --git a/rhodecode/apps/ssh_support/lib/backends/svn.py b/rhodecode/apps/ssh_support/lib/backends/svn.py
--- a/rhodecode/apps/ssh_support/lib/backends/svn.py
+++ b/rhodecode/apps/ssh_support/lib/backends/svn.py
@@ -1,4 +1,4 @@
-# -*- coding: utf-8 -*-
+
 
 # Copyright (C) 2016-2020 RhodeCode GmbH
 #
diff --git a/rhodecode/forms/__init__.py b/rhodecode/forms/__init__.py
--- a/rhodecode/forms/__init__.py
+++ b/rhodecode/forms/__init__.py
@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 
 # Copyright (C) 2010-2020 RhodeCode GmbH
 #
diff --git a/rhodecode/lib/audit_logger.py b/rhodecode/lib/audit_logger.py
--- a/rhodecode/lib/audit_logger.py
+++ b/rhodecode/lib/audit_logger.py
@@ -24,6 +24,7 @@ import datetime
 from rhodecode.lib.jsonalchemy import JsonRaw
 from rhodecode.model import meta
 from rhodecode.model.db import User, UserLog, Repository
+from rhodecode.lib.str_utils import safe_str
 
 
 log = logging.getLogger(__name__)
@@ -215,7 +216,6 @@ def store(action, user, action_data=None
                     ip_addr=self.request.remote_addr))
 
     """
-    from rhodecode.lib.utils2 import safe_unicode
     from rhodecode.lib.auth import AuthUser
 
     action_spec = ACTIONS.get(action, None)
@@ -257,8 +257,8 @@ def store(action, user, action_data=None
                 repository_id = getattr(
                     Repository.get_by_repo_name(repository_name), 'repo_id', None)
 
-        action_name = safe_unicode(action)
-        ip_address = safe_unicode(ip_addr)
+        action_name = safe_str(action)
+        ip_address = safe_str(ip_addr)
 
         with sa_session.no_autoflush:
 
diff --git a/rhodecode/lib/celerylib/utils.py b/rhodecode/lib/celerylib/utils.py
--- a/rhodecode/lib/celerylib/utils.py
+++ b/rhodecode/lib/celerylib/utils.py
@@ -17,8 +17,6 @@
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
-import os
-import json
 import logging
 import datetime
 import time
@@ -30,6 +28,8 @@ from celery.result import AsyncResult
 import celery.loaders.base
 import celery.schedules
 
+from rhodecode.lib.ext_json import sjson as json
+
 log = logging.getLogger(__name__)
 
 
diff --git a/rhodecode/lib/datelib.py b/rhodecode/lib/datelib.py
--- a/rhodecode/lib/datelib.py
+++ b/rhodecode/lib/datelib.py
@@ -64,7 +64,7 @@ def date_to_timestamp_plus_offset(value)
         assert not is_aware(value), (
             "This code is not prepared to handle aware datetime instances")
         value = date_astimestamp(value)
-    return (value, time.timezone)
+    return value, time.timezone
 
 
 def is_aware(value):
diff --git a/rhodecode/lib/feedgenerator/utils.py b/rhodecode/lib/feedgenerator/utils.py
--- a/rhodecode/lib/feedgenerator/utils.py
+++ b/rhodecode/lib/feedgenerator/utils.py
@@ -6,7 +6,7 @@ import six
 
 from xml.sax.saxutils import XMLGenerator, quoteattr
 from urllib.parse import quote
-from rhodecode.lib.utils import safe_str, safe_unicode
+from rhodecode.lib.str_utils import safe_str
 
 
 class SimplerXMLGenerator(XMLGenerator):
@@ -54,4 +54,4 @@ def iri_to_uri(iri):
 
 
 def force_text(text, strings_only=False):
-    return safe_unicode(text)
+    return safe_str(text)
diff --git a/rhodecode/lib/html_filters.py b/rhodecode/lib/html_filters.py
--- a/rhodecode/lib/html_filters.py
+++ b/rhodecode/lib/html_filters.py
@@ -20,6 +20,6 @@
 
 # base64 filter e.g ${ example | base64,n }
 def base64(text):
-    import base64
-    from rhodecode.lib.helpers import safe_str, safe_bytes
-    return safe_str(base64.encodebytes(safe_bytes(text)))
+    from rhodecode.lib.str_utils import base64_to_str
+    return base64_to_str(text)
+
diff --git a/rhodecode/lib/index/whoosh.py b/rhodecode/lib/index/whoosh.py
--- a/rhodecode/lib/index/whoosh.py
+++ b/rhodecode/lib/index/whoosh.py
@@ -34,7 +34,7 @@ from whoosh.qparser import QueryParser, 
 
 import rhodecode.lib.helpers as h
 from rhodecode.lib.index import BaseSearcher
-from rhodecode.lib.utils2 import safe_unicode
+from rhodecode.lib.str_utils import safe_str
 
 log = logging.getLogger(__name__)
 
@@ -144,7 +144,7 @@ class WhooshSearcher(BaseSearcher):
             allowed_repos_filter = self._get_repo_filter(
                 search_user, repo_name)
             try:
-                query = qp.parse(safe_unicode(query))
+                query = qp.parse(safe_str(query))
                 log.debug('query: %s (%s)', query, repr(query))
 
                 reverse, sorted_by = False, None
diff --git a/rhodecode/lib/middleware/simplesvn.py b/rhodecode/lib/middleware/simplesvn.py
--- a/rhodecode/lib/middleware/simplesvn.py
+++ b/rhodecode/lib/middleware/simplesvn.py
@@ -19,7 +19,9 @@
 
 import base64
 import logging
-import urllib.request, urllib.parse, urllib.error
+import urllib.request
+import urllib.parse
+import urllib.error
 import urllib.parse
 
 import requests
@@ -29,7 +31,8 @@ from rhodecode.lib import rc_cache
 from rhodecode.lib.middleware import simplevcs
 from rhodecode.lib.middleware.utils import get_path_info
 from rhodecode.lib.utils import is_valid_repo
-from rhodecode.lib.utils2 import str2bool, safe_int, safe_str
+from rhodecode.lib.str_utils import safe_str, safe_int
+from rhodecode.lib.type_utils import str2bool
 from rhodecode.lib.ext_json import json
 from rhodecode.lib.hooks_daemon import store_txn_id_data
 
@@ -99,7 +102,6 @@ class SimpleSvnApp(object):
             raise
 
         if response.status_code not in [200, 401]:
-            from rhodecode.lib.utils2 import safe_str
             text = '\n{}'.format(safe_str(response.text)) if response.text else ''
             if response.status_code >= 500:
                 log.error('Got SVN response:%s with text:`%s`', response, text)
diff --git a/rhodecode/lib/middleware/simplevcs.py b/rhodecode/lib/middleware/simplevcs.py
--- a/rhodecode/lib/middleware/simplevcs.py
+++ b/rhodecode/lib/middleware/simplevcs.py
@@ -50,7 +50,7 @@ from rhodecode.lib.middleware import app
 from rhodecode.lib.middleware.utils import scm_app_http
 from rhodecode.lib.str_utils import safe_bytes
 from rhodecode.lib.utils import is_valid_repo, SLUG_RE
-from rhodecode.lib.utils2 import safe_str, fix_PATH, str2bool, safe_unicode
+from rhodecode.lib.utils2 import safe_str, fix_PATH, str2bool
 from rhodecode.lib.vcs.conf import settings as vcs_settings
 from rhodecode.lib.vcs.backends import base
 
@@ -194,7 +194,7 @@ class SimpleVCS(object):
             match_dict = match.groupdict()
 
             # Build acl repo name from regex match.
-            acl_repo_name = safe_unicode('{groups}{target}'.format(
+            acl_repo_name = safe_str('{groups}{target}'.format(
                 groups=match_dict['groups'] or '',
                 target=match_dict['target']))
 
@@ -471,8 +471,9 @@ class SimpleVCS(object):
                               'authentication')
 
                 if not anonymous_perm:
-                    log.debug('Not enough credentials to access this '
-                              'repository as anonymous user')
+                    log.debug('Not enough credentials to access repo: `%s` '
+                              'repository as anonymous user', self.acl_repo_name)
+
 
                 username = None
                 # ==============================================================
@@ -481,13 +482,16 @@ class SimpleVCS(object):
                 # ==============================================================
 
                 # try to auth based on environ, container auth methods
-                log.debug('Running PRE-AUTH for container based authentication')
+                log.debug('Running PRE-AUTH for container|headers based authentication')
+
+                # headers auth, by just reading special headers and bypass the auth with user/passwd
                 pre_auth = authenticate(
                     '', '', environ, VCS_TYPE, registry=self.registry,
                     acl_repo_name=self.acl_repo_name)
+
                 if pre_auth and pre_auth.get('username'):
                     username = pre_auth['username']
-                log.debug('PRE-AUTH got %s as username', username)
+                log.debug('PRE-AUTH got `%s` as username', username)
                 if pre_auth:
                     log.debug('PRE-AUTH successful from %s',
                               pre_auth.get('auth_data', {}).get('_plugin'))
@@ -498,6 +502,8 @@ class SimpleVCS(object):
 
                 plugin_cache_active, cache_ttl = False, 0
                 plugin = None
+
+                # regular auth chain
                 if not username:
                     self.authenticate.realm = self.authenticate.get_rc_realm()
 
@@ -546,7 +552,7 @@ class SimpleVCS(object):
                     plugin, plugin_cache_active, cache_ttl)
                 if not perm:
                     return HTTPForbidden()(environ, start_response)
-                environ['rc_auth_user_id'] = user_id
+                environ['rc_auth_user_id'] = str(user_id)
 
             if action == 'push':
                 perms = auth_user.get_branch_permissions(self.acl_repo_name)
diff --git a/rhodecode/lib/pagination.py b/rhodecode/lib/pagination.py
--- a/rhodecode/lib/pagination.py
+++ b/rhodecode/lib/pagination.py
@@ -870,7 +870,6 @@ class _Page(list):
         return make_html_tag("a", text=text, href=target_url, **item["attrs"])
 
 # Below is RhodeCode custom code
-
 # Copyright (C) 2010-2020 RhodeCode GmbH
 #
 # This program is free software: you can redistribute it and/or modify
diff --git a/rhodecode/lib/paster_commands/ishell.py b/rhodecode/lib/paster_commands/ishell.py
--- a/rhodecode/lib/paster_commands/ishell.py
+++ b/rhodecode/lib/paster_commands/ishell.py
@@ -1,4 +1,4 @@
-# -*- coding: utf-8 -*-
+
 
 # Copyright (C) 2013-2020 RhodeCode GmbH
 #
diff --git a/rhodecode/lib/str_utils.py b/rhodecode/lib/str_utils.py
--- a/rhodecode/lib/str_utils.py
+++ b/rhodecode/lib/str_utils.py
@@ -17,11 +17,15 @@
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
+import typing
+import base64
 import logging
+from unidecode import unidecode
+
 import rhodecode
-import unicodedata
 from rhodecode.lib.type_utils import aslist
 
+
 log = logging.getLogger(__name__)
 
 
@@ -42,18 +46,40 @@ def safe_int(val, default=None) -> int:
     return val
 
 
-def get_default_encodings():
+def safe_float(val, default=None) -> float:
+    """
+    Returns float() of val if val is not convertable to float use default
+    instead
+
+    :param val:
+    :param default:
+    """
+
+    try:
+        val = float(val)
+    except (ValueError, TypeError):
+        val = default
+
+    return val
+
+
+def base64_to_str(text) -> str:
+    return safe_str(base64.encodebytes(safe_bytes(text))).strip()
+
+
+def get_default_encodings() -> typing.List[str]:
     return aslist(rhodecode.CONFIG.get('default_encoding', 'utf8'), sep=',')
 
 
+DEFAULT_ENCODINGS = get_default_encodings()
+
+
 def safe_str(str_, to_encoding=None) -> str:
     """
     safe str function. Does few trick to turn unicode_ into string
 
     :param str_: str to encode
     :param to_encoding: encode to this type UTF8 default
-    :rtype: str
-    :returns: str object
     """
     if isinstance(str_, str):
         return str_
@@ -62,7 +88,7 @@ def safe_str(str_, to_encoding=None) -> 
     if not isinstance(str_, bytes):
         return str(str_)
 
-    to_encoding = to_encoding or get_default_encodings()
+    to_encoding = to_encoding or DEFAULT_ENCODINGS
     if not isinstance(to_encoding, (list, tuple)):
         to_encoding = [to_encoding]
 
@@ -81,14 +107,12 @@ def safe_bytes(str_, from_encoding=None)
 
     :param str_: string to decode
     :param from_encoding: encode from this type UTF8 default
-    :rtype: unicode
-    :returns: unicode object
     """
     if isinstance(str_, bytes):
         return str_
 
     if not isinstance(str_, str):
-        raise ValueError('safe_bytes cannot convert other types than str: got: {}'.format(type(str_)))
+        raise ValueError(f'safe_bytes cannot convert other types than str: got: {type(str_)}')
 
     from_encoding = from_encoding or get_default_encodings()
     if not isinstance(from_encoding, (list, tuple)):
@@ -116,11 +140,11 @@ def ascii_bytes(str_, allow_bytes=False)
         return str_
 
     if not isinstance(str_, str):
-        raise ValueError('ascii_bytes cannot convert other types than str: got: {}'.format(type(str_)))
+        raise ValueError(f'ascii_bytes cannot convert other types than str: got: {type(str_)}')
     return str_.encode('ascii')
 
 
-def ascii_str(str_):
+def ascii_str(str_) -> str:
     """
     Simple conversion from bytes to str, with assumption that str_ is pure ASCII.
     Fails with UnicodeError on invalid input.
@@ -131,16 +155,16 @@ def ascii_str(str_):
     """
 
     if not isinstance(str_, bytes):
-        raise ValueError('ascii_str cannot convert other types than bytes: got: {}'.format(type(str_)))
+        raise ValueError(f'ascii_str cannot convert other types than bytes: got: {type(str_)}')
     return str_.decode('ascii')
 
 
-def convert_special_chars(str_):
+def convert_special_chars(str_) -> str:
     """
         trie to replace non-ascii letters to their ascii representation eg::
 
             `żołw` converts into `zolw`
     """
     value = safe_str(str_)
-    converted_value = unicodedata.normalize('NFKD', value).encode('ascii', 'ignore').decode()
+    converted_value = unidecode(value)
     return converted_value
diff --git a/rhodecode/lib/system_info.py b/rhodecode/lib/system_info.py
--- a/rhodecode/lib/system_info.py
+++ b/rhodecode/lib/system_info.py
@@ -191,7 +191,7 @@ def locale_info():
             return f'FAILED_LOCALE_GET:{locale_name}'
 
     value = dict(
-        locale_default=locale.getdefaultlocale(),
+        locale_default=locale.getlocale(),
         locale_lc_all=safe_get_locale(locale.LC_ALL),
         locale_lc_ctype=safe_get_locale(locale.LC_CTYPE),
         lang_env=os.environ.get('LANG'),
@@ -404,9 +404,9 @@ def storage_archives():
     from rhodecode.lib.utils import safe_str
     from rhodecode.lib.helpers import format_byte_size_binary
 
-    msg = 'Enable this by setting ' \
-          'archive_cache_dir=/path/to/cache option in the .ini file'
-    path = safe_str(rhodecode.CONFIG.get('archive_cache_dir', msg))
+    msg = 'Archive cache storage is controlled by ' \
+          'archive_cache.store_dir=/path/to/cache option in the .ini file'
+    path = safe_str(rhodecode.CONFIG.get('archive_cache.store_dir', msg))
 
     value = dict(percent=0, used=0, total=0, items=0, path=path, text='')
     state = STATE_OK_DEFAULT
@@ -415,7 +415,7 @@ def storage_archives():
         used = 0
         for root, dirs, files in os.walk(path):
             if root == path:
-                items_count = len(files)
+                items_count = len(dirs)
 
             for f in files:
                 try:
@@ -726,7 +726,8 @@ def rhodecode_config():
 def database_info():
     import rhodecode
     from sqlalchemy.engine import url as engine_url
-    from rhodecode.model.meta import Base as sql_base, Session
+    from rhodecode.model import meta
+    from rhodecode.model.meta import Session
     from rhodecode.model.db import DbMigrateVersion
 
     state = STATE_OK_DEFAULT
@@ -737,7 +738,7 @@ def database_info():
     db_url_obj = engine_url.make_url(rhodecode.CONFIG['sqlalchemy.db1.url'])
 
     try:
-        engine = sql_base.metadata.bind
+        engine = meta.get_engine()
         db_server_info = engine.dialect._get_server_version_info(
             Session.connection(bind=engine))
         db_version = '.'.join(map(str, db_server_info))
diff --git a/rhodecode/lib/type_utils.py b/rhodecode/lib/type_utils.py
--- a/rhodecode/lib/type_utils.py
+++ b/rhodecode/lib/type_utils.py
@@ -40,7 +40,7 @@ def str2bool(str_):
     return str_ in ('t', 'true', 'y', 'yes', 'on', '1')
 
 
-def aslist(obj, sep=None, strip=True):
+def aslist(obj, sep=None, strip=True) -> list:
     """
     Returns given string separated by sep as list
 
@@ -49,6 +49,9 @@ def aslist(obj, sep=None, strip=True):
     :param strip:
     """
     if isinstance(obj, str):
+        if obj in ['', ""]:
+            return []
+
         lst = obj.split(sep)
         if strip:
             lst = [v.strip() for v in lst]
@@ -59,3 +62,32 @@ def aslist(obj, sep=None, strip=True):
         return []
     else:
         return [obj]
+
+
+class AttributeDictBase(dict):
+    def __getstate__(self):
+        odict = self.__dict__  # get attribute dictionary
+        return odict
+
+    def __setstate__(self, dict):
+        self.__dict__ = dict
+
+    __setattr__ = dict.__setitem__
+    __delattr__ = dict.__delitem__
+
+
+class StrictAttributeDict(AttributeDictBase):
+    """
+    Strict Version of Attribute dict which raises an Attribute error when
+    requested attribute is not set
+    """
+    def __getattr__(self, attr):
+        try:
+            return self[attr]
+        except KeyError:
+            raise AttributeError(f'{self.__class__} object has no attribute {attr}')
+
+
+class AttributeDict(AttributeDictBase):
+    def __getattr__(self, attr):
+        return self.get(attr, None)
diff --git a/rhodecode/lib/user_log_filter.py b/rhodecode/lib/user_log_filter.py
--- a/rhodecode/lib/user_log_filter.py
+++ b/rhodecode/lib/user_log_filter.py
@@ -25,7 +25,9 @@ from whoosh.fields import (TEXT, Schema,
 from sqlalchemy.sql.expression import or_, and_, not_, func
 
 from rhodecode.model.db import UserLog
-from rhodecode.lib.utils2 import remove_prefix, remove_suffix, safe_unicode
+from rhodecode.lib.utils2 import remove_prefix, remove_suffix
+from rhodecode.lib.str_utils import safe_str
+
 
 # JOURNAL SCHEMA used only to generate queries in journal. We use whoosh
 # querylang to build sql queries and filter journals
@@ -54,7 +56,7 @@ def user_log_filter(user_log, search_ter
     if search_term:
         qp = QueryParser('repository', schema=AUDIT_LOG_SCHEMA)
         qp.add_plugin(DateParserPlugin())
-        qry = qp.parse(safe_unicode(search_term))
+        qry = qp.parse(safe_str(search_term))
         log.debug('Filtering using parsed query %r', qry)
 
     def wildcard_handler(col, wc_term):
diff --git a/rhodecode/lib/user_sessions.py b/rhodecode/lib/user_sessions.py
--- a/rhodecode/lib/user_sessions.py
+++ b/rhodecode/lib/user_sessions.py
@@ -38,7 +38,7 @@ class BaseAuthSessions(object):
 
     def __init__(self, config):
         session_conf = {}
-        for k, v in config.items():
+        for k, v in list(config.items()):
             if k.startswith('beaker.session'):
                 session_conf[k] = v
         self.config = session_conf
diff --git a/rhodecode/lib/utils2.py b/rhodecode/lib/utils2.py
--- a/rhodecode/lib/utils2.py
+++ b/rhodecode/lib/utils2.py
@@ -30,7 +30,9 @@ import logging
 import re
 import sys
 import time
-import urllib.request, urllib.parse, urllib.error
+import urllib.request
+import urllib.parse
+import urllib.error
 import urlobject
 import uuid
 import getpass
diff --git a/rhodecode/lib/vcs/backends/base.py b/rhodecode/lib/vcs/backends/base.py
--- a/rhodecode/lib/vcs/backends/base.py
+++ b/rhodecode/lib/vcs/backends/base.py
@@ -37,8 +37,7 @@ from zope.cachedescriptors.property impo
 
 import rhodecode
 from rhodecode.translation import lazy_ugettext
-from rhodecode.lib.utils2 import safe_str, safe_unicode, CachedProperty
-from rhodecode.lib.vcs import connection
+from rhodecode.lib.utils2 import safe_str, CachedProperty
 from rhodecode.lib.vcs.utils import author_name, author_email
 from rhodecode.lib.vcs.conf import settings
 from rhodecode.lib.vcs.exceptions import (
@@ -72,7 +71,7 @@ class Reference(_Reference):
             return self.name
 
     @property
-    def to_unicode(self):
+    def to_str(self):
         return reference_to_unicode(self)
 
 
@@ -88,13 +87,13 @@ def unicode_to_reference(raw):
         return None
 
 
-def reference_to_unicode(ref):
+def reference_to_unicode(ref: Reference):
     """
     Convert a reference object to unicode.
     If reference is None it returns None.
     """
     if ref:
-        return u':'.join(ref)
+        return ':'.join(ref)
     else:
         return None
 
@@ -187,37 +186,37 @@ class MergeResponse(object):
     # uses .format(**metadata) for variables
     MERGE_STATUS_MESSAGES = {
         MergeFailureReason.NONE: lazy_ugettext(
-            u'This pull request can be automatically merged.'),
+            'This pull request can be automatically merged.'),
         MergeFailureReason.UNKNOWN: lazy_ugettext(
-            u'This pull request cannot be merged because of an unhandled exception. '
-            u'{exception}'),
+            'This pull request cannot be merged because of an unhandled exception. '
+            '{exception}'),
         MergeFailureReason.MERGE_FAILED: lazy_ugettext(
-            u'This pull request cannot be merged because of merge conflicts. {unresolved_files}'),
+            'This pull request cannot be merged because of merge conflicts. {unresolved_files}'),
         MergeFailureReason.PUSH_FAILED: lazy_ugettext(
-            u'This pull request could not be merged because push to '
-            u'target:`{target}@{merge_commit}` failed.'),
+            'This pull request could not be merged because push to '
+            'target:`{target}@{merge_commit}` failed.'),
         MergeFailureReason.TARGET_IS_NOT_HEAD: lazy_ugettext(
-            u'This pull request cannot be merged because the target '
-            u'`{target_ref.name}` is not a head.'),
+            'This pull request cannot be merged because the target '
+            '`{target_ref.name}` is not a head.'),
         MergeFailureReason.HG_SOURCE_HAS_MORE_BRANCHES: lazy_ugettext(
-            u'This pull request cannot be merged because the source contains '
-            u'more branches than the target.'),
+            'This pull request cannot be merged because the source contains '
+            'more branches than the target.'),
         MergeFailureReason.HG_TARGET_HAS_MULTIPLE_HEADS: lazy_ugettext(
-            u'This pull request cannot be merged because the target `{target_ref.name}` '
-            u'has multiple heads: `{heads}`.'),
+            'This pull request cannot be merged because the target `{target_ref.name}` '
+            'has multiple heads: `{heads}`.'),
         MergeFailureReason.TARGET_IS_LOCKED: lazy_ugettext(
-            u'This pull request cannot be merged because the target repository is '
-            u'locked by {locked_by}.'),
+            'This pull request cannot be merged because the target repository is '
+            'locked by {locked_by}.'),
 
         MergeFailureReason.MISSING_TARGET_REF: lazy_ugettext(
-            u'This pull request cannot be merged because the target '
-            u'reference `{target_ref.name}` is missing.'),
+            'This pull request cannot be merged because the target '
+            'reference `{target_ref.name}` is missing.'),
         MergeFailureReason.MISSING_SOURCE_REF: lazy_ugettext(
-            u'This pull request cannot be merged because the source '
-            u'reference `{source_ref.name}` is missing.'),
+            'This pull request cannot be merged because the source '
+            'reference `{source_ref.name}` is missing.'),
         MergeFailureReason.SUBREPO_MERGE_FAILED: lazy_ugettext(
-            u'This pull request cannot be merged because of conflicts related '
-            u'to sub repositories.'),
+            'This pull request cannot be merged because of conflicts related '
+            'to sub repositories.'),
 
         # Deprecations
         MergeFailureReason._DEPRECATED_MISSING_COMMIT: lazy_ugettext(
@@ -254,7 +253,7 @@ class MergeResponse(object):
         """
         Return a human friendly error message for the given merge status code.
         """
-        msg = safe_unicode(self.MERGE_STATUS_MESSAGES[self.failure_reason])
+        msg = safe_str(self.MERGE_STATUS_MESSAGES[self.failure_reason])
 
         try:
             return msg.format(**self.metadata)
@@ -379,7 +378,7 @@ class BaseRepository(object):
 
     @LazyProperty
     def name(self):
-        return safe_unicode(os.path.basename(self.path))
+        return safe_str(os.path.basename(self.path))
 
     @LazyProperty
     def description(self):
@@ -785,11 +784,11 @@ class BaseRepository(object):
 
     def _validate_commit_id(self, commit_id):
         if not isinstance(commit_id, str):
-            raise TypeError("commit_id must be a string value got {} instead".format(type(commit_id)))
+            raise TypeError(f"commit_id must be a string value got {type(commit_id)} instead")
 
     def _validate_commit_idx(self, commit_idx):
         if not isinstance(commit_idx, int):
-            raise TypeError("commit_idx must be a numeric value")
+            raise TypeError(f"commit_idx must be a numeric value, got {type(commit_idx)}")
 
     def _validate_branch_name(self, branch_name):
         if branch_name and branch_name not in self.branches_all:
@@ -931,21 +930,17 @@ class BaseCommit(object):
     value as ``None``.
     """
 
-    _ARCHIVE_PREFIX_TEMPLATE = b'{repo_name}-{short_id}'
+    _ARCHIVE_PREFIX_TEMPLATE = '{repo_name}-{short_id}'
     """
     This template is used to generate a default prefix for repository archives
     if no prefix has been specified.
     """
 
-    def __str__(self):
-        return '<%s at %s:%s>' % (
-            self.__class__.__name__, self.idx, self.short_id)
-
     def __repr__(self):
         return self.__str__()
 
-    def __unicode__(self):
-        return u'%s:%s' % (self.idx, self.short_id)
+    def __str__(self):
+        return f'<{self.__class__.__name__} at {self.idx}:{self.short_id}>'
 
     def __eq__(self, other):
         same_instance = isinstance(other, self.__class__)