.Net 5 CanalSharp Mysql CDC (增量同步，捕获变更数据)Docker 系列之 Canal (CDC 增量同步,捕获变更数据)

CanalSharp 阿里云的解决方案，需要两部分

Canal  服务端要和Mysql 连在一起（目前我是用docker部署的服务）

另外一部分就是 CanalSharp 单独的客户端服务(.Net 5 服务)

CanalSharp文档 可以参考：https://canalsharp.azurewebsites.net/zh/

安装服务，可以点击下边的连接。

Docker 系列之 Canal (CDC 增量同步,捕获变更数据)

而CanalSharp 就可以直接 Nuget 安装

另外一个包是日志，不需要的话，可以不需要，但是，我这个Demo还是需要的

Install-Package CanalSharp.AspNetCore -Version 0.0.7
Install-Package Microsoft.Extensions.Logging.Console -Version 6.0.0-preview.6.21352.12

以下是代码，也是从github上抄下来的。

github 地址 ：https://github.com/dotnetcore/CanalSharp

class Program
    {
        private static ILogger _logger;
        static async Task Main(string[] args)
        {
            await SimpleConn();
            //await ClusterConn();
        }

        static async Task ClusterConn()
        {
            using var loggerFactory = LoggerFactory.Create(builder =>
            {
                builder
                    .AddFilter("Microsoft", LogLevel.Debug)
                    .AddFilter("System", LogLevel.Information)
                    .AddConsole();
            });
            _logger = loggerFactory.CreateLogger<Program>();
            var conn = new ClusterCanalConnection(new ClusterCanalOptions("localhost:2181", "12350") { UserName = "canal", Password = "canal" },
                loggerFactory);
            await conn.ConnectAsync();
            await conn.SubscribeAsync();
            await conn.RollbackAsync(0);
            while (true)
            {
                try
                {
                    var msg = await conn.GetAsync(1024);
                    PrintEntry(msg.Entries);
                }
                catch (Exception e)
                {
                    _logger.LogError(e, "Error.");
                    await conn.ReConnectAsync();
                }

            }
        }

        static async Task SimpleConn()
        {
            using var loggerFactory = LoggerFactory.Create(builder =>
            {
                builder
                    .AddFilter("Microsoft", LogLevel.Debug)
                    .AddFilter("System", LogLevel.Information)
                    .AddConsole();
            });
            _logger = loggerFactory.CreateLogger<Program>();
            var conn = new SimpleCanalConnection(new SimpleCanalOptions("127.0.0.1", 11111, "12349"), loggerFactory.CreateLogger<SimpleCanalConnection>());
            await conn.ConnectAsync();
            await conn.SubscribeAsync();
            await conn.RollbackAsync(0);
            while (true)
            {
                var msg = await conn.GetAsync(1024);
                PrintEntry(msg.Entries);
                await Task.Delay(300);
            }
        }

        private static void PrintEntry(List<Entry> entries)
        {
            foreach (var entry in entries)
            {
                if (entry.EntryType == EntryType.Transactionbegin || entry.EntryType == EntryType.Transactionend)
                {
                    continue;
                }

                RowChange rowChange = null;

                try
                {
                    rowChange = RowChange.Parser.ParseFrom(entry.StoreValue);
                }
                catch (Exception e)
                {
                    _logger.LogError(e.ToString());
                }

                if (rowChange != null)
                {
                    EventType eventType = rowChange.EventType;

                    _logger.LogInformation(
                        $"================> binlog[{entry.Header.LogfileName}:{entry.Header.LogfileOffset}] , name[{entry.Header.SchemaName},{entry.Header.TableName}] , eventType :{eventType}");

                    foreach (var rowData in rowChange.RowDatas)
                    {
                        if (eventType == EventType.Delete)
                        {
                            PrintColumn(rowData.BeforeColumns.ToList());
                        }
                        else if (eventType == EventType.Insert)
                        {
                            PrintColumn(rowData.AfterColumns.ToList());
                        }
                        else
                        {
                            _logger.LogInformation("-------> before");
                            PrintColumn(rowData.BeforeColumns.ToList());
                            _logger.LogInformation("-------> after");
                            PrintColumn(rowData.AfterColumns.ToList());
                        }
                    }
                }
            }
        }

        private static void PrintColumn(List<Column> columns)
        {
            foreach (var column in columns)
            {
                Console.WriteLine($"{column.Name} ： {column.Value}  update=  {column.Updated}");
            }
        }
    }

运行后，结果如下：

数据库和表结构如下:

 其他的 业务扩展，还得仔细琢磨逻辑。