There was a situation where availableShards on a new
node were not in sync with the cluster, so queries
following a resize were incorrect.
- Start a one-node cluster.
- Write data to shards 0 and 1
- Start a second node.
In the case where the hash algo was moving shard 0 to
node1, then node1 only knew about shard 0, so queries
to node1 would be incomplete.
This PR modifies the ResizeInstruction message to replace
`Schema` with `NodeStatus` (which contains both `Schema` and
`AvailableShards`). So now when a resize instruction is received,
the receiving node is able to sync its schema and availableShards.
gossip now takes a single "MemberServer" which is implemented by server. Several
interfaces have been removed.
MemberServer contains ReceiveMessage which is a superset of the functionality of
ReceiveEvent, LocalStatus and HandleRemoteStatus are all that's left of
StatusHandler - ClusterStatus was not used and is gone. The Node() method is
actually a subset of LocalStatus() functionality. Maybe we should break up
localstatus or remove Node... not sure.
Remove BroadcastReceiver test which was a bit silly.
NodeEvent can now be unexported, and is.
