Golang Broker.Connected方法代码示例

func withRetry(
	b *sarama.Broker,
	cfg *sarama.Config,
	f func() error,
) error {
	var err error
	for max := 0; max < cfg.Metadata.Retry.Max; max++ {
		if ok, _ := b.Connected(); !ok {
			if err = b.Open(cfg); err == nil {
				err = f()
			}
		} else {
			err = f()
		}

		if err == nil {
			return nil
		}

		retry, reconnect := checkRetryQuery(err)
		if !retry {
			return err
		}

		time.Sleep(cfg.Metadata.Retry.Backoff)
		if reconnect {
			closeBroker(b)
		}
	}
	return err
}

// Connects to the broker that handles all produce and consume
// requests for the given chain (Partition Leader Replica)
func newBroker(brokers []string, cp ChainPartition) (Broker, error) {
	var candidateBroker, connectedBroker, leaderBroker *sarama.Broker

	// Connect to one of the given brokers
	for _, hostPort := range brokers {
		candidateBroker = sarama.NewBroker(hostPort)
		if err := candidateBroker.Open(nil); err != nil {
			logger.Warningf("Failed to connect to broker %s: %s", hostPort, err)
			continue
		}
		if connected, err := candidateBroker.Connected(); !connected {
			logger.Warningf("Failed to connect to broker %s: %s", hostPort, err)
			continue
		}
		connectedBroker = candidateBroker
		break
	}

	if connectedBroker == nil {
		return nil, fmt.Errorf("Failed to connect to any of the given brokers (%v) for metadata request", brokers)
	}
	logger.Debugf("Connected to broker %s", connectedBroker.Addr())

	// Get metadata for the topic that corresponds to this chain
	metadata, err := connectedBroker.GetMetadata(&sarama.MetadataRequest{Topics: []string{cp.Topic()}})
	if err != nil {
		return nil, fmt.Errorf("Failed to get metadata for topic %s: %s", cp, err)
	}

	// Get the leader broker for this chain partition
	if (cp.Partition() >= 0) && (cp.Partition() < int32(len(metadata.Topics[0].Partitions))) {
		leaderBrokerID := metadata.Topics[0].Partitions[cp.Partition()].Leader
		logger.Debugf("Leading broker for chain %s is broker ID %d", cp, leaderBrokerID)
		for _, availableBroker := range metadata.Brokers {
			if availableBroker.ID() == leaderBrokerID {
				leaderBroker = availableBroker
				break
			}
		}
	}

	if leaderBroker == nil {
		return nil, fmt.Errorf("Can't find leader for chain %s", cp)
	}

	// Connect to broker
	if err := leaderBroker.Open(nil); err != nil {
		return nil, fmt.Errorf("Failed to connect ho Kafka broker: %s", err)
	}
	if connected, err := leaderBroker.Connected(); !connected {
		return nil, fmt.Errorf("Failed to connect to Kafka broker: %s", err)
	}

	return &brokerImpl{broker: leaderBroker}, nil
}

func closeBroker(b *sarama.Broker) {
	if ok, _ := b.Connected(); ok {
		b.Close()
	}
}