是时候改变你数仓的增量同步方案了
< 返回列表时间: 2019-11-28来源:OSCHINA
经过一段时间的演化,spark-binlog,delta-plus慢慢进入正轨。spark-binlog可以将MySQL binlog作为标准的Spark数据源来使用,目前支持insert/update/delete 三种事件的捕捉。 delta-plus则是对Delta Lake的一个增强库,譬如在Delta Plus里实现了将binlog replay进Detla表,从而保证Delta表和数据库表接近实时同步。除此之外,detla-plus还集成了譬如布隆过滤器等来尽快数据更新更新速度。更多特性可参考我写的专栏。
数据湖Delta Lake 深入解析 ​ zhuanlan.zhihu.com 图标 有了这两个库,加上Spark,我们就能通过两行代码完成库表的同步。
以前如果要做数据增量同步,大概需要这么个流程:
问题很明显,Pipeline长,涉及到技术多,中间转存其实也挺麻烦的,难做到实时。我们希望可以更简单些,比如最好是这样:
然后我可能只要写如下代码就可以搞定:
val spark: SparkSession = ???
val df = spark.readStream. format("org.apache.spark.sql.mlsql.sources.MLSQLBinLogDataSource"). option("host","127.0.0.1"). option("port","3306"). option("userName","xxxxx"). option("password","xxxxx"). option("databaseNamePattern","mlsql_console"). option("tableNamePattern","script_file"). optioin("binlogIndex","4"). optioin("binlogFileOffset","4"). load()
df.writeStream. format("org.apache.spark.sql.delta.sources.MLSQLDeltaDataSource").
option(" path ","/tmp/sync/tables"). option("mode","Append"). option("idCols","id"). option("duration","5"). option("syncType","binlog"). checkpointLocation("/tmp/cpl-binlog2") .mode(OutputMode.Append).save("{db}/{table}") 读和写,非常简单。读你需要提供MySQL binlog信息,写的时候指定主键,以及表的存储路径。
如果使用MLSQL则更简单,下面是一个完整的流式同步脚本:
set streamName="binlog";
load binlog.`` where host="127.0.0.1" and port="3306" and userName="xxxx" and password="xxxxxx" and bingLogNamePrefix="mysql-bin" and binlogIndex="4" and binlogFileOffset="4" and databaseNamePattern="mlsql_console" and tableNamePattern="script_file" as table1;
save append table1
as rate. mysql_{db}.{table} options mode="Append" and idCols="id" and duration="5" and syncType="binlog" and checkpointLocation="/tmp/cpl-binlog2";
因为是增量同步,所以第一次需要先全量同步一次,用MLSQL也很简单:
connect jdbc where url="jdbc: mysql://127.0.0.1:3306/mlsql_console?characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&tinyInt1isBit=false " and driver="com.mysql.jdbc.Driver" and user="xxxxx" and password="xxxx" as db_cool;
load jdbc. db_cool.script_file as script_file; save overwrite script_file as delta. mysql_mlsql_console.script_file ;
load delta. mysql_mlsql_console.script_file as output; 如果你使用了Console则可在编辑器里直接运行:

如果你安装了binlog2delta插件, 则可享受向导便利:
热门排行