It led to a neo-go dead-lock in the `subscriber` component. Subscribing to
notifications is the same RPC as any others, so it could also be blocked
forever if no async listening (reading the notification channel) routine
exists. If a number of subscriptions is big enough (or a caller is lucky
enough) subscribing loop might have not finished subscribing before the
first notification is received and then: subscribing RPC is blocked by
received notification (non)handling and listening notifications routine is
blocked by not finished subscription loop.
That commit starts listening notification channel _before_ any subscription
actions.
Signed-off-by: Pavel Karpy <p.karpy@yadro.com>
Make it store its internal `zap.Logger`'s level. Also, make all the
components to accept internal `logger.Logger` instead of `zap.Logger`; it
will simplify future refactor.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Sometimes it is useful to track sidechain events processed by the node.
For example, we need some easy way to look up for log messages about new
epoch notifications.
Make `subscriber.Subscriber` to log names of all events received from
the sidechain notification channel.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
`WSClient` of Neo Go v0.97.3 sets value of notification with
`NotificationEventID` to `subscriptions.NotificationEvent` type which wraps
previously used `state.NotificationEvent`.
Change type cast and pull `state.NotificationEvent` structure from new type.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Remote RPC node might be in the transition state and produce
events from the past. We should avoid listening such nodes.
To do that subscriber component can await minimal height of
remote node. If minimal height is not reached, then throw
error.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
Replace WSClient.Init call from the body of BlockNotifications method to
constructor New since Init should be called before working with client
according to neo-go docs.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Replace block channel's initialization from BlockNotifications method body
to Subscriber's constructor in order to prevent potential writing to nil
channel.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Extend Listener with RegisterBlockHandler method. All block handlers are
called on each block read from Subscriber.BlockNotifications channel.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Call SubscribeForNewBlocks in Subscriber's constructor. Provide
BlockNotifications interface method that returns block channel. Write new
blocks to the channel on notification events with BlockEventID type.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Neo-go does not use smartcontract.Parameter to return values
anymore, so it's convertes partly removed from neofs-node.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
RPC node closes websocket notification channel if it was terminated
or something wrong happened. Subscriber has to check this condition
and alert about this in upper context by closing it's own channel.
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
