dahomey-technologies/rustis 0.27.3

on GitHub

Changed

• ssubscribe accepts shard channels of several slots in a cluster. The
  server requires one slot per SSUBSCRIBE, and the client refused a
  cross-slot one with MismatchedKeySlots. A shard subscription is per
  channel, so nothing is lost by splitting it: one SSUBSCRIBE is now sent per
  slot, to the master owning it, and the caller is answered once every master
  has confirmed.

Fixed

• A sharded PubSubStream spanning several slots is released in a cluster.
  A stream may hold shard channels of several slots, added one
  PubSubStream::ssubscribe at a time (or, since the change above, in a single
  ssubscribe). Its close and its Drop then released them all in one
  SUNSUBSCRIBE, which the cluster connection refused before sending it
  (MismatchedKeySlots): close failed, Drop failed silently, every
  subscription stayed on its master, and the next command on the Client could
  stall. A SUNSUBSCRIBE naming several slots, including one passed to
  PubSubStream::sunsubscribe, is now split per slot and sent to the master
  owning each one.

• A command the cluster cannot route no longer poisons the connection. A
  command refused before being sent — keys spanning several slots where one
  is required, or a command the cluster does not support — was refused only
  when the network task fed it, after its bookkeeping had been recorded:

  • a refused SSUBSCRIBE left its pending batch at the head of the
    subscription queue, so the next subscription on the same Client was
    matched against it and never answered;
  • in a pipeline, the commands ahead of the refused one had already been
    written, and their replies were handed to the next callers;
  • the messages queued behind it in the same send batch were not sent until
    another message woke the network task, so their callers could wait
    forever on an idle client, and the refused message's byte charge was
    never released from the send-queue budget.

  Such a command is now refused before anything is recorded or written, and a
  message whose feed fails for any other reason is failed on its own while
  the rest of its batch goes out.