Multiple DB API backend support.
Supported configuration options:
db_backend: DB backend name or full module path to DB backend module. dbapi_use_tpool: Enable thread pooling of DB API calls.
A DB backend module should implement a method named ‘get_backend’ which takes no arguments. The method can return any object that implements DB API methods.
NOTE: There are bugs in eventlet when using tpool combined with threading locks. The python logging module happens to use such locks. To work around this issue, be sure to specify thread=False with eventlet.monkey_patch().
A bug for eventlet has been filed here:
https://bitbucket.org/eventlet/eventlet/issue/137/
Bases: object