hyperledger/fabric · error

failed connecting to %s: %v

Error message

failed connecting to %s: %v

What it means

The discovery client stub wraps the low-level gRPC failure of discovery.Service.Send into a single contextual error. The underlying %v contains the real cause (TLS handshake failure, connection refused, authentication rejection, deadline exceeded). It surfaces whenever the signed discovery request could not be delivered or processed by the peer.

Source

Thrown at discovery/cmd/stub.go:82

	comm, err := comm.NewClient(conf.TLSConfig)
	if err != nil {
		return nil, err
	}
	signer, err := signer.NewSigner(conf.SignerConfig)
	if err != nil {
		return nil, err
	}
	timeout, cancel := context.WithTimeout(context.Background(), defaultTimeout)
	defer cancel()

	disc := discoveryclient.NewClient(comm.NewDialer(server), signer.Sign, 0)

	resp, err := disc.Send(timeout, req, &discovery.AuthInfo{
		ClientIdentity:    signer.Creator,
		ClientTlsCertHash: comm.TLSCertHash,
	})
	if err != nil {
		return nil, errors.Errorf("failed connecting to %s: %v", server, err)
	}
	return &response{
		Response: resp,
	}, nil
}

// RawStub is a stub that communicates with the discovery service
// without any intermediary.
type RawStub struct{}

// Send sends the request, and receives a response
func (stub *RawStub) Send(server string, conf common.Config, req *discoveryclient.Request) (ServiceResponse, error) {
	comm, err := comm.NewClient(conf.TLSConfig)
	if err != nil {
		return nil, err
	}
	signer, err := signer.NewSigner(conf.SignerConfig)
	if err != nil {

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Verify the peer address/port and that discovery service is enabled (CORE_PEER_DISCOVERY_ENABLED... / peer.discovery.enabled=true in network config)
2. Check TLS: ensure tlsCertHash matches and CA certs are trusted by the client context
3. Re-enroll or refresh the client identity if the peer rejected the signature/auth info
4. Increase the timeout and confirm network connectivity (nc/curl to the peer port)

Example fix

// before
resp, err := disc.Send(0, req, authInfo) // zero timeout fails fast

// after
resp, err := disc.Send(5*time.Second, req, &discovery.AuthInfo{
    ClientIdentity:    signer.Creator,
    ClientTlsCertHash: comm.TLSCertHash,
})
if err != nil {
    return fmt.Errorf("failed connecting to %s: %w", server, err)
}

// pre-check connectivity before Send
conn, err := grpc.Dial(server, grpc.WithTransportCredentials(creds))
if err != nil {
    return fmt.Errorf("peer %s unreachable before discovery: %w", server, err)
}
conn.Close()

resp, err := stub.Send(timeout, req, authInfo)
if err != nil {
    var wrapped string = err.Error()
    if strings.Contains(wrapped, "deadline exceeded") {
        // retry with backoff
    } else if strings.Contains(wrapped, "certificate") || strings.Contains(wrapped, "tls") {
        // fix TLS config, do not retry
    }
    return fmt.Errorf("discovery to %s failed: %w", server, err)
}

When it happens

Trigger: Peer unreachable or wrong port; TLS certificate hash mismatch (ClientTlsCertHash does not match peer TLS config); peer's discovery service rejects the auth info (stale enrollment cert); timeout elapsing before response.

Common situations: Discovery service not enabled on the target peer; connecting through a proxy that strips TLS; expired or rotated MSP certificates in the local context; firewall blocking the peer port in Docker/Kubernetes environments.

Related errors

• failed connecting to discovery service
• client didn't send a TLS certificate
• client claimed TLS hash doesn't match computed TLS hash from
• Error getting broadcast client: %s
• client didn't include its TLS cert hash

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/5944d43826baae46. Report an issue: GitHub.