geektutu/7days-golang · error

h.Error

Error message

h.Error

What it means

Same mechanism as error 81 in day7-registry: when receive() reads a response whose header Error field is non-empty, the server reported a failure and the client converts h.Error into call.Error. The registry day adds heart-beat and registry features but the error path is unchanged.

Source

Thrown at gee-rpc/day7-registry/client.go:151

		}
	}
}

func (client *Client) receive() {
	var err error
	for err == nil {
		var h codec.Header
		if err = client.cc.ReadHeader(&h); err != nil {
			break
		}
		call := client.removeCall(h.Seq)
		switch {
		case call == nil:
			// it usually means that Write partially failed
			// and call was already removed.
			err = client.cc.ReadBody(nil)
		case h.Error != "":
			call.Error = fmt.Errorf(h.Error)
			err = client.cc.ReadBody(nil)
			call.done()
		default:
			err = client.cc.ReadBody(call.Reply)
			if err != nil {
				call.Error = errors.New("reading body " + err.Error())
			}
			call.done()
		}
	}
	// error occurs, so terminateCalls pending calls
	client.terminateCalls(err)
}

// Go invokes the function asynchronously.
// It returns the Call structure representing the invocation.
func (client *Client) Go(serviceMethod string, args, reply interface{}, done chan *Call) *Call {
	if done == nil {

View on GitHub (pinned to cf36443821)

Solutions

1. Read the actual message in call.Error from Call() and fix the server-side cause.
2. Confirm the service method name string matches the registered service exactly.
3. Verify args and reply types are gob-compatible and identical on both sides.

Example fix

// before
client.Call("WrongSvc.Div", args, reply)
// after
client.Call("Arith.Div", args, reply)

// Ensure server registered the service before dialing:
// var _ = gee.Register(new(Arith))

err := client.Call("Arith.Div", args, reply)
var rpcErr error
if err != nil {
    log.Printf("call %s failed: %v", "Arith.Div", err) // contains server h.Error
    rpcErr = err
}

When it happens

Trigger: Server handler for the requested service/method returned an error; method not found; server failed to decode args or encode reply; call observed in the receive goroutine.

Common situations: Method name mismatch between client Call and server registration; wrong arg/reply types causing gob decode errors server-side; server panics converted to error responses.

Related errors

• h.Error
• connection is shut down
• reading body
• rpc client: call failed:
• number of options is more than 1

AI-assisted analysis of geektutu/7days-golang@cf36443821 (2026-09-03). Data as JSON: /api/errors/e77ff748a0a2a42c. Report an issue: GitHub.