Multitenant Cassandra Query in Clojure

Question

The following code handles querying for user data in a multitenant Cassandra database. Each tenant has their own keyspace and within that keyspace data about each tenants users is stored.

This code will run as part of a webservice.

I'm looking on comments for how I handled managing the session so that connection pooling is used and only one session is made.

(defn- session []
  (cc/connect ["localhost"]
              {:credentials
               {:username "" 
                :password ""}}))

(def memo-session (memoize session))

(defn get-recs-by-user-id [client-name client-id user-id]
    (cql/use-keyspace (memo-session) client-name)
    (cql/select (memo-session) "user_recommendations"
                (where [[= :client_id client-id] [= :user_id user-id]])
                (limit 1)))

Answer 1

This doesn't feel idiomatic to me.

I would prefer to use an atom or a dynamic variable if you must store the session outside, but really you should probably be passing the session in on each call.