Generic database utilities, including connection clustering and routing so you can scale like a pro.
The following example creates a Redis connection cluster which will distribute reads and writes based on a simple modulus lookup of the hashed key:
>>> from nydus.db import create_cluster
>>>
>>> redis = create_cluster({
>>> 'engine': 'nydus.db.backends.redis.Redis',
>>> 'router': 'nydus.db.routers.redis.PartitionRouter',
>>> 'hosts': {
>>> 0: {'db': 0},
>>> 1: {'db': 1},
>>> 2: {'db': 2},
>>> }
>>> })
>>>
>>> res = redis.incr('foo')
>>>
>>> assert res == 1In some cases you may want to execute a query on many nodes (in parallel). Nydus has built-in support for this when any routing function returns a cluster of nodes:
>>> from nydus.db import create_cluster
>>>
>>> # by not specifying a router all queries are executed on all hosts
>>> redis = create_cluster({
>>> 'engine': 'nydus.db.backends.redis.Redis',
>>> 'hosts': {
>>> 0: {'db': 0},
>>> 1: {'db': 1},
>>> 2: {'db': 2},
>>> }
>>> })
>>>
>>> # map the query over all connections returned by the default router
>>> res = redis.incr('foo')
>>>
>>> assert type(res) == list
>>> assert len(res) == 3You can also map many queries (utilizing an internal queue) over connections (again, returned by the router):
>>> with redis.map() as conn: >>> results = [conn.incr(k) for k in keys]