assume handoff if vnode exits 'normal' during queue requeuest #68
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The pipe_verify_handoff_blocking test in riak_test PR 154 demonstrated that the monitor used by riak_pipe_vnode:queue_work_send may fire while handoff is taking place. This situation is further described in riak_pipe issue 63. This commit addresses the problem by first checking whether the Reason for the vnode's exit was 'normal'. If it was not 'normal', the vnode_down error is returned as before. If it was 'normal', then it is assumed that handoff happened, and the monitor is moved to the new vnode, as indicated by riak_core_ring:next_owner/2.
| {'DOWN',MonRef,process,VnodePid,normal} -> | ||
| %% the vnode likely just shut down after completing handoff | ||
| {ok, Ring} = riak_core_ring_manager:get_my_ring(), | ||
| case riak_core_ring:next_owner(Ring, Index) of |
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Emacs erlang-flymake complains about exporting Next from this case statement. I'm a recent, zealotus convert to this stylistic preference. I think it makes the provenance of bindings much, much easier to find. I this case Next is used very close to this case statement, so is less of an issue.
Russell's review says this makes Emacs erlang-flymake happier.
As Russell pointed out, it's possible that two+ transfers could happen in the time between receiving the DOWN and checking the owner. Ignore where the transfer is _from_, and just monitor wherever it's going to.
|
Ran basho/riak_test#154 before and after and got fail and pass as you'd expect. WFM +1. |
ghost
assigned 
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RE-OPENING…#64 closed in error.
The pipe_verify_handoff_blocking test in riak_test PR 154 demonstrated
that the monitor used by riak_pipe_vnode:queue_work_send may fire while
handoff is taking place. This situation is further described in
riak_pipe issue 63.
This commit addresses the problem by first checking whether the Reason
for the vnode's exit was 'normal'. If it was not 'normal', the
vnode_down error is returned as before. If it was 'normal', then it is
assumed that handoff happened, and the monitor is moved to the new
vnode, as indicated by riak_core_ring:next_owner/2.