// start dials the remote addr and commences gossip once connected. Upon exit,
// the client is sent on the disconnected channel. This method starts client
// processing in a goroutine and returns immediately.
func (c *client) start(
g *Gossip,
disconnected chan *client,
rpcCtx *rpc.Context,
stopper *stop.Stopper,
nodeID roachpb.NodeID,
breaker *circuit.Breaker,
) {
stopper.RunWorker(func() {
ctx, cancel := context.WithCancel(c.AnnotateCtx(context.Background()))
var wg sync.WaitGroup
defer func() {
// This closes the outgoing stream, causing any attempt to send or
// receive to return an error.
//
// Note: it is still possible for incoming gossip to be processed after
// this point.
cancel()
// The stream is closed, but there may still be some incoming gossip
// being processed. Wait until that is complete to avoid racing the
// client's removal against the discovery of its remote's node ID.
wg.Wait()
disconnected <- c
}()
consecFailures := breaker.ConsecFailures()
var stream Gossip_GossipClient
if err := breaker.Call(func() error {
// Note: avoid using `grpc.WithBlock` here. This code is already
// asynchronous from the caller's perspective, so the only effect of
// `WithBlock` here is blocking shutdown - at the time of this writing,
// that ends ups up making `kv` tests take twice as long.
conn, err := rpcCtx.GRPCDial(c.addr.String())
if err != nil {
return err
}
if stream, err = NewGossipClient(conn).Gossip(ctx); err != nil {
return err
}
return c.requestGossip(g, stream)
}, 0); err != nil {
if consecFailures == 0 {
log.Warningf(ctx, "node %d: failed to start gossip client: %s", nodeID, err)
}
return
}
// Start gossiping.
log.Infof(ctx, "node %d: started gossip client to %s", nodeID, c.addr)
if err := c.gossip(ctx, g, stream, stopper, &wg); err != nil {
if !grpcutil.IsClosedConnection(err) {
g.mu.Lock()
if c.peerID != 0 {
log.Infof(ctx, "node %d: closing client to node %d (%s): %s", nodeID, c.peerID, c.addr, err)
} else {
log.Infof(ctx, "node %d: closing client to %s: %s", nodeID, c.addr, err)
}
g.mu.Unlock()
}
}
})
}
