예제 #1
0
// Makes a request to the server. If the responseStream chan is not nil it will expect a response from the server
// with a matching request.Id. The REQUEST_RETRY_ATTEMPTS constant of 3 and the RECONNECT_RETRY_WAIT of 100ms means
// that an attempt to make a request to a downed server will take 300ms to time out.
func (self *ProtobufClient) MakeRequest(request *protocol.Request, r cluster.ResponseChannel) error {
	if request.Id == nil {
		id := atomic.AddUint32(&self.lastRequestId, uint32(1))
		request.Id = &id
	}
	if r != nil {
		self.requestBufferLock.Lock()

		// this should actually never happen. The sweeper should clear out dead requests
		// before the uint32 ids roll over.
		if oldReq, alreadyHasRequestById := self.requestBuffer[*request.Id]; alreadyHasRequestById {
			message := "already has a request with this id, must have timed out"
			log.Error(message)
			oldReq.r.Yield(&protocol.Response{
				Type:         protocol.Response_ERROR.Enum(),
				ErrorMessage: &message,
			})
		}
		self.requestBuffer[*request.Id] = &runningRequest{timeMade: time.Now(), r: r, request: request}
		self.requestBufferLock.Unlock()
	}

	data, err := request.Encode()
	if err != nil {
		return err
	}

	conn := self.getConnection()
	if conn == nil {
		conn = self.reconnect()
		if conn == nil {
			return fmt.Errorf("Failed to connect to server %s", self.hostAndPort)
		}
	}

	if self.writeTimeout > 0 {
		conn.SetWriteDeadline(time.Now().Add(self.writeTimeout))
	}
	buff := bytes.NewBuffer(make([]byte, 0, len(data)+8))
	binary.Write(buff, binary.LittleEndian, uint32(len(data)))
	buff.Write(data)
	_, err = conn.Write(buff.Bytes())

	if err == nil {
		return nil
	}

	// if we got here it errored out, clear out the request
	self.requestBufferLock.Lock()
	delete(self.requestBuffer, *request.Id)
	self.requestBufferLock.Unlock()
	self.reconnect()
	return err
}
예제 #2
0
파일: shard.go 프로젝트: vovkasm/facette
func (self *ShardData) forwardRequest(request *p.Request) ([]<-chan *p.Response, []uint32, error) {
	ids := []uint32{}
	responses := []<-chan *p.Response{}
	for _, server := range self.clusterServers {
		responseChan := make(chan *p.Response, 1)
		// do this so that a new id will get assigned
		request.Id = nil
		log.Debug("Forwarding request %s to %d", request.GetDescription(), server.Id)
		server.MakeRequest(request, responseChan)
		responses = append(responses, responseChan)
		ids = append(ids, server.Id)
	}
	return responses, ids, nil
}