Alternator's "/localnodes" HTTP request is supposed to return the list of
nodes in the local DC to which the user can send requests.
The existing implementation incorrectly used gossiper::is_alive() to check
for which nodes to return - but "alive" nodes include nodes which are still
joining the cluster and not really usable. These nodes can remain in the
JOINING state for a long time while they are copying data, and an attempt
to send requests to them will fail.
The fix for this bug is trivial: change the call to is_alive() to a call
to is_normal().
But the hard part of this test is the testing:
1. An existing multi-node test for "/localnodes" assummed that right after
a new node was created, it appears on "/localnodes". But after this
patch, it may take a bit more time for the bootstrapping to complete
and the new node to appear in /localnodes - so I had to add a retry loop.
2. I added a test that reproduces the bug fixed here, and verifies its
fix. The test is in the multi-node topology framework. It adds an
injection which delays the bootstrap, which leaves a new node in JOINING
state for a long time. The test then verifies that the new node is
alive (as checked by the REST API), but is not returned by "/localnodes".
3. The new injection for delaying the bootstrap is unfortunately not
very pretty - I had to do it in three places because we have several
code paths of how bootstrap works without repair, with repair, without
Raft and with Raft - and I wanted to delay all of them.
Fixes#19694.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closesscylladb/scylladb#19725
(cherry picked from commit bac7c33313)
(deleted test for cherry-pick)
af39675c38