Nameko Cache Tools¶

A few tools to cache interactions between your nameko services, increasing resiliency and performance at the expense of consistency, when it makes sense.

To use nameko-cachetools in a project:

from nameko.rpc import rpc
from nameko_cachetools import CachedRpcProxy


class Service(object):
    name = "demo"

    other_service = CachedRpcProxy('other_service')

    @rpc
    def do_something(self, request):
        # this rpc response will be cached, further queries will be
        # timed and cached values will be returned if not response is
        # received or an exception is raised at the destination service
        other_service.do_something('hi')

To use a more advanced cache from the cachetools module:

from nameko.rpc import rpc
from nameko_cachetools import CachedRpcProxy
from cachetools import TTLCache


class Service(object):
    name = "demo"

    # use a TTL cache that will only hold 1024 different rpc interactions
    # and expire them afer 30 seconds
    other_service = CachedRpcProxy('other_service', cache=TTLCache(1024, 30))

    @rpc
    def do_something(self, request):
        # this rpc response will be cached. For the next 30 seconds,
        # further queries will not reach the target service but still
        # return the cached response
        other_service.do_something('hi')

Caching strategies:¶

CachedRpcProxy¶

If a cached version of this request exists, a response from the cache is sent instead of hanging forever or raising an exception.

If a cached version doesn’t exist, it will behave like a normal rpc, and wait indefinitey for a reply. All successful replies are cached.

WARNING: Do NOT use this for setters, rpcs meant to modify state in the target service

Arguments:

cache: the cache to use. This should resemble a dict but can be more sophisticated, like the caches provided by the cachetools package.
failover_timeout: if a cached version of this query exists, how long in seconds should your original request wait until it deems the target service as unresponsive and moves on to use a cached response

CacheFirstRpcProxy¶

Stores responses from the original services and keeps them cached.

If further requests come in with the same arguments and found in the cache, a response from the cache is sent instead of hitting the destination service.

WARNING: Do NOT use this for setters, rpcs meant to modify state in the target service

Arguments:

cache: the cache to use. This should resemble a dict but can be more sophisticated, like the caches provided by the cachetools package.

Contents:¶

Feedback¶

If you have any suggestions or questions about Nameko Cache Tools feel free to email me at santiycr@gmail.com.

If you encounter any errors or problems with Nameko Cache Tools, please let me know! Open an Issue at the GitHub http://github.com/santiycr/nameko-cachetools main repository.