I think this will prevents some random tests failures
when we realize that we are not anymore in the peerset
and trigger a shutdown but Raft has not finished fully
committing the operation, which then triggers an error,
and a retry. But the contexts are cancelled in the retry
so it won't find a leader and will error finally error
with that message.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
This change removes the duplicities of the PeerManager component:
* No more commiting PeerAdd and PeerRm log entries
* The Raft peer set is the source of truth
* Basic broadcasting is used to communicate peer multiaddresses
in the cluster
* A peer can only be added in a healthy cluster
* A peer can be removed from any cluster which can still commit
* This also adds support for multiple multiaddresses per peer
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
This is the third implementation attempt. This time, rather than
broadcasting PeerAdd/Join requests to the whole cluster, we use the
consensus log to broadcast new peers joining.
This makes it easier to recover from errors and to know who exactly
is member of a cluster and who is not. The consensus is, after all,
meant to agree on things, and the list of cluster peers is something
everyone has to agree on.
Raft itself uses a special log operation to maintain the peer set.
The tests are almost unchanged from the previous attempts so it should
be the same, except it doesn't seem possible to bootstrap a bunch of nodes
at the same time using different bootstrap nodes. It works when using
the same. I'm not sure this worked before either, but the code is
simpler than recursively contacting peers, and scales better for
larger clusters.
Nodes have to be careful about joining clusters while keeping the state
from a different cluster (disjoint logs). This may cause problems with
Raft.
License: MIT
Signed-off-by: Hector Sanjuan <hector@protocol.ai>
