Alternator's "/localnodes" HTTP requests is supposed to return the list
of nodes in the local DC to which the user can send requests.
Before commit bac7c33313 we used the
gossiper is_alive() method to determine if a node should be returned.
That commit changed the check to is_normal() - because a node can be
alive but in non-normal (e.g., joining) state and not ready for
requests.
However, it turns out that checking is_normal() is not enough, because
if node is stopped abruptly, other nodes will still consider it "normal",
but down (this is so-called "DN" state). So we need to check **both**
is_alive() and is_normal().
This patch also adds a test reproducing this case, where a node is
shut down abruptly. Before this patch, the test failed ("/localnodes"
continued to return the dead node), and after it it passes.
Fixes#21538
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closesscylladb/scylladb#21540
(cherry picked from commit 7607f5e33e)
Closesscylladb/scylladb#21634
6ba0253dd3