Summary: Support selecion session/otk data store. Add redis as data store. Allow admin to select the backend data store. Compatibility matrix: main\/ session>| anydbm | sqlite | redis | mysql | postgresql | anydbm | D | | X | | | sqlite | X | D | X | | | mysql | | | | D | | postgresql | | | | | D | --------------------------------------------------------------+ D - default if unconfigured, X - compatible choice DETAILS roundup/configuration.py: add config.ini section sessiondb with settings: backend and redis_url. CHANGES.txt, doc/admin_guide.txt, doc/installation.txt, doc/upgrading.txt: doc on config of session db and redis. Plus some other fixes: admin - clarified why we do not drop __words and __testids table in native-fts conversion. TYpo fix. upgrading - doc how you can keep using anydbm for session data with sqlite. Fix dupe sentence in an upgrading config.ini section. roundup/backends/back_anydbm.py, roundup/backends/back_sqlite.py: code to support redis, redis/anydbm backends respectively. roundup/backends/sessions_redis.py new storage backend for redis. roundup/rest.py, roundup/cgi/actions.py, roundup/cgi/templating.py redis uses a different way of calculating lifetime/timestamp. Since expiration of an item occurred if its timestamp was more than 1 week old, code would calculate: now - 1 week + lifetime. But this results in faster expiration in redis if used for lifetime/timestamp. Convert code to use the lifetime() method in BasicDatabase that generates the right timestamp for each backend. test/session_common.py: added tests for more cases, get without default, getall non-existing key etc. timestamp test changed to use new self.get_ts which is overridden in other tests. Test that datatypes survive storage. test/test_redis_session.py: test redis session store with sqlite and anydbm primary databases test/test_anydbm.py, test/test_sqlite.py add test to make sure the databases are properly set up sqlite - add test cases where anydbm is used as datastore anydbm - remove updateTimestamp override add get_ts(). test/test_config.py tests on redis_url and compatibility on choice of sessiondb backend .travis.yml: add redis db and redis-py

--- a/doc/installation.txt	Wed Aug 03 17:34:58 2022 -0400
+++ b/doc/installation.txt	Thu Aug 04 14:41:58 2022 -0400
@@ -137,10 +137,20 @@
   compress the response from roundup as they transmit/proxy it to the
   client.
 
+redis
+  Storing ephemeral data: session keys, CSRF tokens etc. can be 
+  performance bottleneck. You can choose to deploy a Redis_ database
+  using the redis-py_ pypi package. See the section on
+  `Using Redis for Session Databases`_ in the `administration
+  guide`_ for details.
+
 Windows Service
   You can run Roundup as a Windows service if pywin32_ is installed.
   Otherwise it must be started manually.
 
+.. _Using Redis for Session Databases:
+   admin_guide.html#using-redis-for-session-databases
+
 Getting Roundup
 ===============
 
@@ -1770,6 +1780,8 @@
 .. _pysqlite: https://pysqlite.org/
 .. _pytz: https://pypi.org/project/pytz/
 .. _pywin32: https://pypi.org/project/pywin32/
+.. _Redis: https://redis.io
+.. _redis-py: https://pypi.org/project/redis/
 .. _Whoosh: https://whoosh.readthedocs.org/en/latest
 .. _Xapian: https://xapian.org/
 .. _zstd: https://pypi.org/project/zstd/