cmd/jujud: single mongodb connection appears to be used by multiple presence sessions

conn30 appears to be authenticating several times over it's lifetime.

I was under the impression that one connection == one authentication, and it should not be reused or reauthenticated again.

Wed Aug 6 05:39:41.950 [conn30] authenticate db: juju { authenticate: 1, nonce: "1d75e50cd2e37c87", user: "machine-0", key: "322d574b26a3706edce1c78ce7deb3e6" }
Wed Aug 6 05:39:41.951 [conn30] warning: No such role, "readWriteAnyDatabase", in database juju. No privileges will be acquired from this role
Wed Aug 6 05:39:41.951 [conn30] warning: No such role, "clusterAdmin", in database juju. No privileges will be acquired from this role
Wed Aug 6 05:39:41.952 [conn30] authenticate db: presence { authenticate: 1, nonce: "531e071f3a650c8e", user: "machine-0", key: "e38535f099fbe8f59ab039297769dd3e" }
Wed Aug 6 05:39:41.952 [conn30] warning: No such role, "readWriteAnyDatabase", in database presence. No privileges will be acquired from this role
Wed Aug 6 05:39:41.952 [conn30] warning: No such role, "clusterAdmin", in database presence. No privileges will be acquired from this role
Wed Aug 6 05:39:41.953 [conn30] authenticate db: admin { authenticate: 1, nonce: "4d057e8386ca4cb3", user: "machine-0", key: "b01b280424eec619e011493832c32f61" }
Wed Aug 6 05:39:42.890 [conn30] authenticate db: juju { authenticate: 1, nonce: "7e7f00a5102608fb", user: "machine-0", key: "9e06a9e2c73e9eb7c6ff0edbbcef6966" }
Wed Aug 6 05:39:42.891 [conn30] warning: No such role, "readWriteAnyDatabase", in database juju. No privileges will be acquired from this role
Wed Aug 6 05:39:42.891 [conn30] warning: No such role, "clusterAdmin", in database juju. No privileges will be acquired from this role
Wed Aug 6 05:39:42.892 [conn30] authenticate db: presence { authenticate: 1, nonce: "8cfefcadc3a4de4b", user: "machine-0", key: "c25e786d5c736ec4f3307d5c3db7bd47" }
Wed Aug 6 05:39:42.892 [conn30] warning: No such role, "readWriteAnyDatabase", in database presence. No privileges will be acquired from this role
Wed Aug 6 05:39:42.892 [conn30] warning: No such role, "clusterAdmin", in database presence. No privileges will be acquired from this role
Wed Aug 6 05:39:42.893 [conn30] authenticate db: admin { authenticate: 1, nonce: "83cd4f15f4515677", user: "machine-0", key: "17b17b48cd6c7eb35059fe1e00a15357" }
Wed Aug 6 05:39:42.896 [conn30] authenticate db: juju { authenticate: 1, nonce: "6f8c26fdb0ebe10d", user: "machine-0", key: "8e4e84d0a6f4b2897017aba6a8fb632d" }
Wed Aug 6 05:39:42.897 [conn30] warning: No such role, "readWriteAnyDatabase", in database juju. No privileges will be acquired from this role
Wed Aug 6 05:39:42.897 [conn30] warning: No such role, "clusterAdmin", in database juju. No privileges will be acquired from this role
Wed Aug 6 05:39:42.898 [conn30] authenticate db: presence { authenticate: 1, nonce: "79c581f2f90edbd5", user: "machine-0", key: "9b906ae5c251656cf21b6dd607dde08c" }
Wed Aug 6 05:39:42.898 [conn30] warning: No such role, "readWriteAnyDatabase", in database presence. No privileges will be acquired from this role
Wed Aug 6 05:39:42.898 [conn30] warning: No such role, "clusterAdmin", in database presence. No privileges will be acquired from this role
Wed Aug 6 05:39:42.947 [conn30] authenticate db: admin { authenticate: 1, nonce: "9842e34f17a1e319", user: "machine-0", key: "4095bc8151873ff0018f4a980ac81a3b" }