When an endpoint is not in ring the snitch/get_{rack|datacenter} API
still return back some value. The value is, in fact, the default one,
because this is how snitch resolves it -- when it cannot find a node in
gossiper and system keyspace it just returns defaults.
When this happens the API should better return some error (bad param?)
but there's a bug in nodetool -- when the 'status' command collects info
about the ring it first collects the endpoints, then gets status for
each. If between getting an endpoint and getting its status the endpoint
disappears, the API would fail, but nodetool doesn't handle it.
Next patches will make .get_rack/_dc calls use in-topology collections
that don't fall-back to default values if the entry is not found in it,
so prepare the API in advance to return back defaults.
refs: #11706
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
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