LmdbSessions is an almost drag-and-drop substitute for CherryPy's built-in file backed sessions, but with much better performance, e.g. 6x faster reads and 3x faster writes.
Installation should be as easy as:
$ pip install lmdb_sessions
To install from source:
$ cd /path/to/lmdb_sessions && pip install . --upgrade
The script server.py in the examples directory demonstrates how to setup
LmdbSessions on a CherryPy server and use it to show a user how many times
they have visited the site.
To use, you first need to import the LmdbSession class:
from lmdb_sessions.sessions import LmdbSession
Then you have to configure your server to use LmdbSession based sessions:
cherrypy.config.update({
'tools.sessions.on': True,
'tools.sessions.storage_class': LmdbSession,
'tools.sessions.storage_path': '/path/to/sessions/directory')
})
After that, usage should be exactly the same as any other CherryPy sessions backend, i.e. totally transparent.
You can compare the performance of LmdbSessions vs. CherryPy's built-in file
based sessions yourself by running examples/perf.py. On my MacBook Pro,
LmdbSessions performs reads roughly 6x faster and writes roughly 3x faster.
By Default, the LMDB session backend has a maximum size of 10MB; if you exceed this limit, new sessions will raise exceptions. You can increase the size limit of the backing store by adding the following config option:
cherrypy.config.update({
'tools.sessions.map_size': map_size
})
Where map_size is the maximum size in bytes.