canal 环境搭建 canal 与kafka通信（三）

canal 占用了生产者

.net core端 使用消费者获取canal 消息

安装 Confluent.Kafka  demo使用 1.3.0

 public static void Consumer()
        {
            var conf = new ConsumerConfig
            {
                GroupId = "canal-group",
                BootstrapServers = "192.168.1.26:9092",
                // Note: The AutoOffsetReset property determines the start offset in the event
                // there are not yet any committed offsets for the consumer group for the
                // topic/partitions of interest. By default, offsets are committed
                // automatically, so in this example, consumption will only start from the
                // earliest message in the topic 'my-topic' the first time you run the program.
                AutoOffsetReset = AutoOffsetReset.Earliest,
                EnableAutoCommit = true //是否自动提交  默认为true

            };

            using (var c = new ConsumerBuilder<Ignore, string>(conf).Build())
            {
                //指定 消费那个分区
                //c.Assign(new TopicPartition ("flexmall13",new Partition ()))
                c.Subscribe("flexmall13");

                CancellationTokenSource cts = new CancellationTokenSource();
                Console.CancelKeyPress += (_, e) =>
                {
                    e.Cancel = true; // prevent the process from terminating.
                    cts.Cancel();
                };

                try
                {
                    while (true)
                    {
                        try
                        {
                            var cr = c.Consume(cts.Token);
                            Console.WriteLine($"Consumed message '{cr.Value}' at: '{cr.TopicPartitionOffset}'.");

                            //如果配置 自动提交为 否 需要手动提交

                            //c.Commit();
                            //c.Commit(new List<TopicPartitionOffset>() { cr.TopicPartitionOffset });
                        }
                        catch (ConsumeException e)
                        {
                            Console.WriteLine($"Error occured: {e.Error.Reason}");
                        }
                    }
                }
                catch (OperationCanceledException e)
                {
                    // Ensure the consumer leaves the group cleanly and final offsets are committed.

                    Console.WriteLine($"OperationCanceledException occured: {e.StackTrace}");
                    c.Close();
                }
            }
        }
    }

注意：

1. 在config项 中 有 EnableAutoCommit 设置是否自动应答提交，默认是 true，如果设置为否，需要在消费后，手动 commit。

2.消费者指定订阅 分区，如果不指定使用Subscribe，指定需要使用Assign