// 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, ctx *rpc.Context, stopper *stop.Stopper) {
stopper.RunWorker(func() {
defer func() {
disconnected <- c
}()
// 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 := ctx.GRPCDial(c.addr.String())
if err != nil {
log.Errorf("failed to dial: %v", err)
return
}
// Start gossiping.
if err := c.gossip(g, NewGossipClient(conn), stopper); err != nil {
if !grpcutil.IsClosedConnection(err) {
g.mu.Lock()
peerID := c.peerID
g.mu.Unlock()
if peerID != 0 {
log.Infof("closing client to node %d (%s): %s", peerID, c.addr, err)
} else {
log.Infof("closing client to %s: %s", c.addr, err)
}
}
}
})
}
// 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, ctx *rpc.Context, stopper *stop.Stopper) {
stopper.RunWorker(func() {
defer func() {
disconnected <- c
}()
conn, err := ctx.GRPCDial(c.addr.String(), grpc.WithBlock())
if err != nil {
log.Errorf("failed to dial: %v", err)
return
}
// Start gossiping.
if err := c.gossip(g, NewGossipClient(conn), stopper); err != nil {
if !grpcutil.IsClosedConnection(err) {
g.mu.Lock()
peerID := c.peerID
g.mu.Unlock()
if peerID != 0 {
log.Infof("closing client to node %d (%s): %s", peerID, c.addr, err)
} else {
log.Infof("closing client to %s: %s", c.addr, err)
}
}
}
})
}
// grpcTransportFactory is the default TransportFactory, using GRPC.
func grpcTransportFactory(
opts SendOptions,
rpcContext *rpc.Context,
replicas ReplicaSlice,
args roachpb.BatchRequest,
) (Transport, error) {
clients := make([]batchClient, 0, len(replicas))
for _, replica := range replicas {
conn, err := rpcContext.GRPCDial(replica.NodeDesc.Address.String())
if err != nil {
return nil, err
}
argsCopy := args
argsCopy.Replica = replica.ReplicaDescriptor
remoteAddr := replica.NodeDesc.Address.String()
clients = append(clients, batchClient{
remoteAddr: remoteAddr,
conn: conn,
client: roachpb.NewInternalClient(conn),
args: argsCopy,
healthy: rpcContext.IsConnHealthy(remoteAddr),
})
}
// Put known-unhealthy clients last.
splitHealthy(clients)
return &grpcTransport{
opts: opts,
rpcContext: rpcContext,
orderedClients: clients,
}, nil
}
// NewSender returns an implementation of Sender which exposes the Key-Value
// database provided by a Cockroach cluster by connecting via RPC to a
// Cockroach node.
func NewSender(ctx *rpc.Context, target string) (Sender, error) {
conn, err := ctx.GRPCDial(target)
if err != nil {
return nil, err
}
return sender{roachpb.NewExternalClient(conn)}, nil
}
// Send sends one or more RPCs to clients specified by the slice of
// replicas. On success, Send returns the first successful reply. Otherwise,
// Send returns an error if and as soon as the number of failed RPCs exceeds
// the available endpoints less the number of required replies.
func send(opts SendOptions, replicas ReplicaSlice,
args roachpb.BatchRequest, rpcContext *rpc.Context) (*roachpb.BatchResponse, error) {
if len(replicas) < 1 {
return nil, roachpb.NewSendError(
fmt.Sprintf("insufficient replicas (%d) to satisfy send request of %d",
len(replicas), 1), false)
}
done := make(chan batchCall, len(replicas))
clients := make([]batchClient, 0, len(replicas))
for _, replica := range replicas {
conn, err := rpcContext.GRPCDial(replica.NodeDesc.Address.String())
if err != nil {
return nil, err
}
argsCopy := args
argsCopy.Replica = replica.ReplicaDescriptor
clients = append(clients, batchClient{
remoteAddr: replica.NodeDesc.Address.String(),
conn: conn,
client: roachpb.NewInternalClient(conn),
args: argsCopy,
})
}
// Put known-unhealthy clients last.
nHealthy, err := splitHealthy(clients)
if err != nil {
return nil, err
}
var orderedClients []batchClient
switch opts.Ordering {
case orderStable:
orderedClients = clients
case orderRandom:
// Randomly permute order, but keep known-unhealthy clients last.
shuffleClients(clients[:nHealthy])
shuffleClients(clients[nHealthy:])
orderedClients = clients
}
// TODO(spencer): going to need to also sort by affinity; closest
// ping time should win. Makes sense to have the rpc client/server
// heartbeat measure ping times. With a bit of seasoning, each
// node will be able to order the healthy replicas based on latency.
// Send the first request.
sendOneFn(opts, rpcContext, orderedClients[0], done)
orderedClients = orderedClients[1:]
var errors, retryableErrors int
// Wait for completions.
var sendNextTimer util.Timer
defer sendNextTimer.Stop()
for {
sendNextTimer.Reset(opts.SendNextTimeout)
select {
case <-sendNextTimer.C:
sendNextTimer.Read = true
// On successive RPC timeouts, send to additional replicas if available.
if len(orderedClients) > 0 {
log.Trace(opts.Context, "timeout, trying next peer")
sendOneFn(opts, rpcContext, orderedClients[0], done)
orderedClients = orderedClients[1:]
}
case call := <-done:
err := call.err
if err == nil {
if log.V(2) {
log.Infof("successful reply: %+v", call.reply)
}
return call.reply, nil
}
// Error handling.
if log.V(1) {
log.Warningf("error reply: %s", err)
}
errors++
// Since we have a reconnecting client here, disconnect errors are retryable.
disconnected := err == io.ErrUnexpectedEOF
if retryErr, ok := err.(retry.Retryable); disconnected || (ok && retryErr.CanRetry()) {
retryableErrors++
}
if remainingNonErrorRPCs := len(replicas) - errors; remainingNonErrorRPCs < 1 {
return nil, roachpb.NewSendError(
fmt.Sprintf("too many errors encountered (%d of %d total): %v",
errors, len(clients), err), remainingNonErrorRPCs+retryableErrors >= 1)
}
// Send to additional replicas if available.
if len(orderedClients) > 0 {
log.Trace(opts.Context, "error, trying next peer")
sendOneFn(opts, rpcContext, orderedClients[0], done)
orderedClients = orderedClients[1:]
}
}
}
}
// 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.ctx)
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()
peerID := c.peerID
g.mu.Unlock()
if peerID != 0 {
log.Infof(ctx, "node %d: closing client to node %d (%s): %s", nodeID, peerID, c.addr, err)
} else {
log.Infof(ctx, "node %d: closing client to %s: %s", nodeID, c.addr, err)
}
}
}
})
}