Flink动态更新维表

1.Lookup join

概念:Lookup join是针对于由作业流表触发,关联右侧维表来补全数据的场景 。

默认情况下,在流表有数据变更,都会触发维表查询(可以通过设置维表是否缓存,来减轻查询压力),由于不保存状态,因此对内存占用较小。(以上来自网络)

具体配置如下:

SET execution.checkpointing.interval=5000;

SET state.checkpoints.dir=hdfs://hadoop01:9000/flink/checkpoints/2023090510549999;

SET execution.runtime-mode=streaming;

// 定义维表,维表 可以有主键,不能有水位线字段

CREATE TEMPORARY TABLE source_dim_dept (

`id` BIGINT,

`dept` STRING,

PRIMARY KEY(id) NOT ENFORCED

) WITH (

'connector'='jdbc',

'url'='jdbc:mysql://1.1.1.1:3306/data_storage?autoReconnect=true&useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true&serverTimezone=Asia/Shanghai',

'username'='data_manage',

'password'='xxxxxx',

'table-name'='source_dim_dept ',

'lookup.cache'='PARTIAL',

'lookup.partial-cache.expire-after-write'='30s',

'lookup.cache.ttl' = '30s',

'lookup.cache.max-rows'='5',

'lookup.partial-cache.max-rows'='5'

);

// 流表 -流表必须要有 PROCTIME(),和 水位线字段

CREATE TABLE source_kafka_stream_data(

`id` BIGINT,

`ts` BIGINT,

`price` FLOAT,

proc_time AS PROCTIME(),

`auto_row_time` AS cast(CURRENT_TIMESTAMP as timestamp(3)),

WATERMARK FOR `auto_row_time` AS `auto_row_time` - INTERVAL '0' SECONDS

) WITH (

'connector'='kafka',

'properties.group.id'='data_processing_producer',

'scan.startup.mode'='group-offsets',

'properties.auto.offset.reset'='latest',

'topic'='data-paimon-test',

'properties.bootstrap.servers'='1.1.1.1:9192',

'format'='json'

);

CREATE VIEW transform_tableJoin_XeH7VK1o2U AS

select `status`,`id`,`ts`,`price`, PROCTIME() as auto_row_time from (

select c.`dept` as `status`,c.`id` as `id`,O.`ts` as `ts`,O.`price` as `price`

from source_kafka_stream_data AS O

JOIN source_dim_dept FOR SYSTEM_TIME AS OF O.proc_time AS c

on O.id=c.id ) ;


*注意坑在这里:上述的 连接中流表的时间字段一定要用 PROCTIME() 类型的 AS OF O.proc_time,如果 用水位线字段则Flink 会转为TemperalJoin

而不是Lookup join


// 以下是输出,无特殊配置

CREATE CATALOG paimon WITH (

'type' = 'paimon',

'warehouse' = 'hdfs://hadoop01:9000/painmon/data-processing/paimon_ods'

);

USE CATALOG paimon;

create database if not exists paimon.paimon_ods_db;

drop table if exists paimon_ods_db.paimon_test_stream_join;

CREATE TABLE if not exists paimon_ods_db.paimon_test_stream_join(

`uuid` STRING,

`status` STRING,

`id` BIGINT,

`ts` BIGINT,

`price` DOUBLE

) WITH (

'sink.parallelism'='8',

'bucket'='8',

'bucket-key'='uuid',

'write-mode'='append-only',

'sink.use-managed-memory-allocator'='true',

'sink.managed.writer-buffer-memory'='512MB',

'num-sorted-run.compaction-trigger'='20',

'write-buffer-size'='1024MB',

'write-buffer-spillable'='true'

);

INSERT INTO paimon_ods_db.paimon_test_stream_join select uuid(),`status`,`id`,`ts`,`price` from default_catalog.default_database.transform_tableJoin_XeH7VK1o2U;



2.Temporal join 时态表连接

时态表是一个随时间演变的表,在Flink中也称为动态表。

时态表中的行与一个或多个时态周期相关联,并且所有Flink表都是时态的(动态的)。时态表包含一个或多个版本化的表快照,它可以是跟踪更改的更改历史表(例如数据库更改日志,包含所有快照),也可以是具体化更改的维表(例如包含最新快照的数据库表)。

时态表可以分为版本表和普通表。

版本表:如果时态表中的记录可以追踪和并访问它的历史版本,这种表我们称之为版本表,来自数据库的 changelog (如mysql binlog)可以定义成版本表,版本表内的数据始终不会自动清理,只能通过upsert触发。

普通表:如果时态表中的记录仅仅可以追踪并和它的最新版本,这种表我们称之为普通表,来自数据库 或 HBase 、redis的表可以定义成普通表。

(以上来自网络)

SET execution.checkpointing.interval=5000;

SET state.checkpoints.dir=hdfs://hadoop01:9000/flink/checkpoints/2023090510549999;

SET execution.runtime-mode=streaming;

// 定义维表,维表一定要有主键和水位线字段

CREATE TEMPORARY TABLE source_dim_dept (

`id` BIGINT,

`dept` STRING,

`auto_row_time` AS cast(CURRENT_TIMESTAMP as timestamp(3)),

WATERMARK FOR `auto_row_time` AS `auto_row_time` - INTERVAL '0' SECONDS

PRIMARY KEY(id) NOT ENFORCED

) WITH (

'connector'='jdbc',

'url'='jdbc:mysql://1.1.1.1:3306/data_storage?autoReconnect=true&useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true&serverTimezone=Asia/Shanghai',

'username'='data_manage',

'password'='xxxxx',

'table-name'='source_dim_dept ',

'lookup.cache'='PARTIAL',

'lookup.partial-cache.expire-after-write'='30s',

'lookup.cache.ttl' = '30s',

'lookup.cache.max-rows'='5',

'lookup.partial-cache.max-rows'='5'

);

// 流表 -流表要有 水位线字段

CREATE TABLE source_kafka_stream_data(

`id` BIGINT,

`ts` BIGINT,

`price` FLOAT,

proc_time AS PROCTIME(),

`auto_row_time` AS cast(CURRENT_TIMESTAMP as timestamp(3)),

WATERMARK FOR `auto_row_time` AS `auto_row_time` - INTERVAL '0' SECONDS

) WITH (

'connector'='kafka',

'properties.group.id'='data_processing_producer',

'scan.startup.mode'='group-offsets',

'properties.auto.offset.reset'='latest',

'topic'='data-paimon-test',

'properties.bootstrap.servers'='1.1.1.1:9192',

'format'='json'

);

CREATE VIEW transform_tableJoin_XeH7VK1o2U AS

select `status`,`id`,`ts`,`price`, PROCTIME() as auto_row_time from (

select c.`dept` as `status`,c.`id` as `id`,O.`ts` as `ts`,O.`price` as `price`

from source_kafka_stream_data AS O

JOIN source_dim_dept FOR SYSTEM_TIME AS OF O.auto_row_timeAS c

on O.id=c.id ) ;


*注意坑在这里:上面的Lookup Join 区别也在这里,连接中流表的时间字段一定要用 水位线字段 类型的 AS OF O.auto_row_time


// 以下是输出,无特殊配置

CREATE CATALOG paimon WITH (

'type' = 'paimon',

'warehouse' = 'hdfs://hadoop01:9000/painmon/data-processing/paimon_ods'

);

USE CATALOG paimon;

create database if not exists paimon.paimon_ods_db;

drop table if exists paimon_ods_db.paimon_test_stream_join;

CREATE TABLE if not exists paimon_ods_db.paimon_test_stream_join(

`uuid` STRING,

`status` STRING,

`id` BIGINT,

`ts` BIGINT,

`price` DOUBLE

) WITH (

'sink.parallelism'='8',

'bucket'='8',

'bucket-key'='uuid',

'write-mode'='append-only',

'sink.use-managed-memory-allocator'='true',

'sink.managed.writer-buffer-memory'='512MB',

'num-sorted-run.compaction-trigger'='20',

'write-buffer-size'='1024MB',

'write-buffer-spillable'='true'

);

INSERT INTO paimon_ods_db.paimon_test_stream_join select uuid(),`status`,`id`,`ts`,`price` from default_catalog.default_database.transform_tableJoin_XeH7VK1o2U;

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