* filer: keep the existing peer subscription on a repeated add
A cluster node add for a peer that is already followed restarted the
subscription, dropping the metadata events between the two runs.
* master: tell a connecting client the current cluster membership
Cluster node updates are only broadcast to the clients connected at that
moment. A filer that lost its master stream while a peer came back never
learned about the peer, and stopped replicating its metadata for good.
* test: a filer joining the master learns about the filers already there
* test: a filer resubscribes to a peer that registered while it was disconnected
Runs the reported sequence against real processes: filer2 leaves, filer1
is paused and its master stream is broken, filer2 registers again, and
filer1 has to replicate from it after reconnecting.
Ping previously dialled whatever host:port the caller asked for. Gate
each server's Ping handler on cluster membership: masters check the
topology, registered cluster nodes, and configured master peers; volume
servers only accept their seed/current masters; filers accept tracked
peer filers, the master-learned volume server set, and configured
masters.
Use address-indexed peer lookups to keep Ping target validation O(1):
- topology maintains a pb.ServerAddress -> *DataNode index alongside
the dc/rack/node tree, kept in sync from doLinkChildNode and
UnlinkChildNode plus the ip/port-rewrite branch in
GetOrCreateDataNode. GetTopology now returns nil on a detached
subtree instead of panicking, so the linkage hooks can no-op safely.
- vid_map tracks a refcount per volume-server address so
hasVolumeServer answers without scanning every vid location. The
add path skips empty-address entries the same way the delete path
already does, so a zero-value Location cannot leak a permanent
serverRefCount[""] bucket.
- masters reuse a cached master-address set from MasterClient instead
of walking the configured peer slice on every request.
- volume servers compare against a pre-built seed-master set and
protect currentMaster reads/writes with an RWMutex, fixing the
data race with the heartbeat goroutine. The seed slice is copied
on construction so external mutation cannot desync it from the
frozen lookup set.
- cluster.check drops the direct volume-to-volume sweep; volume
servers no longer carry a peer-volume list, and the note next to
the dropped probe is reworded to make clear that direct
volume-to-volume reachability is intentionally not validated by
this command.
Update the volume-server integration tests that drove Ping through the
new admission gate: success-path coverage now targets the master peer
(the only type a volume server tracks), and the unknown/unreachable
path asserts the InvalidArgument the gate now returns instead of the
old downstream dial error.
Mirror the same admission gate in the Rust volume server crate: a
seed-master HashSet built once at startup plus a tokio RwLock over the
heartbeat-tracked current master, both consulted in is_known_ping_target
on every Ping, with InvalidArgument returned for any target that isn't
a recognised master.
Chris Lu