caches: use individual namespaces per user to prevent beaker caching problems.

- especially for mysql in case large number of data in caches there could be critical errors storing cache, and thus preventing
users from authentication. This is caused by the fact that we used single namespace for ALL users. It means it grew as number of users grew
reaching mysql single column limit.
This changes the behaviour and now we use namespace per-user it means that each user-id will have it's own cache namespace fragmenting maximum column data to
a single user cache. Which we should never reach.

rhodecode/authentication/base.py

@@ -578,14 +578,20 b' def get_authn_registry(registry=None):'
     return authn_registry
 
 
-def get_auth_cache_manager(custom_ttl=None):
+def get_auth_cache_manager(custom_ttl=None, suffix=None):
+    cache_name = 'rhodecode.authentication'
+    if suffix:
+        cache_name = 'rhodecode.authentication.{}'.format(suffix)
     return caches.get_cache_manager(
-        'auth_plugins', 'rhodecode.authentication', custom_ttl)
+        'auth_plugins', cache_name, custom_ttl)
 
 
-def get_perms_cache_manager(custom_ttl=None):
+def get_perms_cache_manager(custom_ttl=None, suffix=None):
+    cache_name = 'rhodecode.permissions'
+    if suffix:
+        cache_name = 'rhodecode.permissions.{}'.format(suffix)
     return caches.get_cache_manager(
-        'auth_plugins', 'rhodecode.permissions', custom_ttl)
+        'auth_plugins', cache_name, custom_ttl)
 
 
 def authenticate(username, password, environ=None, auth_type=None,
@@ -646,7 +652,8 b' def authenticate(username, password, env'
         plugin_cache_active, cache_ttl = plugin.get_ttl_cache(plugin_settings)
 
         # get instance of cache manager configured for a namespace
-        cache_manager = get_auth_cache_manager(custom_ttl=cache_ttl)
+        cache_manager = get_auth_cache_manager(
+            custom_ttl=cache_ttl, suffix=user.user_id)
 
         log.debug('AUTH_CACHE_TTL for plugin `%s` active: %s (TTL: %s)',
                   plugin.get_id(), plugin_cache_active, cache_ttl)

rhodecode/authentication/views.py

@@ -32,6 +32,7 b' from rhodecode.authentication.base impor'
 from rhodecode.lib import helpers as h
 from rhodecode.lib.auth import (
     LoginRequired, HasPermissionAllDecorator, CSRFRequired)
+from rhodecode.lib.caches import clear_cache_manager
 from rhodecode.model.forms import AuthSettingsForm
 from rhodecode.model.meta import Session
 from rhodecode.model.settings import SettingsModel
@@ -101,6 +102,16 b' class AuthnPluginViewBase(BaseAppView):'
             self.plugin.create_or_update_setting(name, value)
         Session().commit()
 
+        # cleanup cache managers in case of change for plugin
+        # TODO(marcink): because we can register multiple namespaces
+        # we should at some point figure out how to retrieve ALL namespace
+        # cache managers and clear them...
+        cache_manager = get_auth_cache_manager()
+        clear_cache_manager(cache_manager)
+
+        cache_manager = get_perms_cache_manager()
+        clear_cache_manager(cache_manager)
+
         # Display success message and redirect.
         h.flash(_('Auth settings updated successfully.'), category='success')
         redirect_to = self.request.resource_path(
@@ -161,12 +172,6 b' class AuthSettingsView(BaseAppView):'
             Session().add(setting)
             Session().commit()
 
-            cache_manager = get_auth_cache_manager()
-            cache_manager.clear()
-
-            cache_manager = get_perms_cache_manager()
-            cache_manager.clear()
-
             h.flash(_('Auth settings updated successfully.'), category='success')
         except formencode.Invalid as errors:
             e = errors.error_dict or {}

rhodecode/lib/middleware/simplevcs.py

@@ -288,7 +288,8 b' class SimpleVCS(object):'
         """
 
         # get instance of cache manager configured for a namespace
-        cache_manager = get_perms_cache_manager(custom_ttl=cache_ttl)
+        cache_manager = get_perms_cache_manager(
+            custom_ttl=cache_ttl, suffix=user.user_id)
         log.debug('AUTH_CACHE_TTL for permissions `%s` active: %s (TTL: %s)',
                   plugin_id, plugin_cache_active, cache_ttl)