实践数据湖iceberg 第三课 在sqlclient中，以sql方式从kafka读数据到iceberg

 

环境说明

从实践中了解hive catalog 的特点
环境说明：
flink1.11.6
iceberg 0.11
kafka2.12_2.4.1

---

1. 启动带hive和kafka功能的flink-sql

[root@hadoop101 software]# bin/sql-client.sh embedded -j /opt/software/iceberg-flink-runtime-0.11.1.jar  -j /opt/software/flink-sql-connector-hive-2.3.6_2.11-1.11.0.jar  -j /opt/software/flink-sql-connector-kafka_2.11-1.11.6.jar shell

2. 创建一个hive datalog，来存放iceberg文件

CREATE CATALOG hive_catalog WITH (
  'type'='iceberg',
  'catalog-type'='hive',
  'uri'='thrift://hadoop101:9083',
  'clients'='5',
  'property-version'='1',
  'hive-conf-dir'='/opt/module/hive/conf'
);

Flink SQL> show catalogs;
default_catalog
hive_catalog

创建hadoop catalog

CREATE CATALOG hadoop_catalog WITH (
  'type'='iceberg',
  'catalog-type'='hadoop',
  'warehouse'='hdfs://ns/user/hive/warehouse/iceberg_hadoop_catalog',
  'property-version'='1'
);

3 .catalog下创建数据库和表

代码如下（示例）：
创建数据库

use  catalog hive_catalog
create database iceberg_db;

创建表：

create table `hive_catalog`.`iceberg_db`.`ib_test_log`(
 data String
);

4. 创建生产者，消费者

[root@hadoop102 kafka]# kafka-console-consumer.sh --topic test_log --bootstrap-server hadoop101:9092,hadoop102:9092,hadoop103:9092

生产者随意生产数据
[root@hadoop101 ~]# kafka-console-producer.sh --topic test_log  --broker-list hadoop101:9092,hadoop102:9092

#5. 检查生产者的数据是否能读取到

Flink SQL>  select data from default_catalog.source.kafka_test_log;
[INFO] Result retrieval cancelled.

很确定能读取到

5. 把数据写入到iceberg表

insert into hive_catalog.iceberg_db.ib_test_log select data from default_catalog.source.kafka_test_log;

发现hdfs上的表，数据目录大小一直都是0，但生产者在不断写入数据，topic名称也检查了。

6.写入失败分析

一开始，觉得是catalog不对，重新定义catalog，（kafka表没有加catalog和database前缀，如下图）

重新定义kafka的catalog后，还是读取不到。

给kafka表定义一个catalog和database, 发现还是读不到数据，bytes received还是0

taskManager日志

TaskManager的stack信息，的确有在select数据，难道没有select到？

"Kafka Fetcher for Source: TableSourceScan(table=[[default_catalog, source, kafka_test_log]], fields=[data]) -> IcebergStreamWriter (1/1)" Id=2405 RUNNABLE
	at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)
	at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)
	at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93)
	at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)
	-  locked sun.nio.ch.Util$3@19f5e8f7
	-  locked java.util.Collections$UnmodifiableSet@744f2387
	-  locked sun.nio.ch.EPollSelectorImpl@2180e63e
	at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)
	at org.apache.flink.kafka.shaded.org.apache.kafka.common.network.Selector.select(Selector.java:794)
	at org.apache.flink.kafka.shaded.org.apache.kafka.common.network.Selector.poll(Selector.java:467)
	at org.apache.flink.kafka.shaded.org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:547)
	...

	Number of locked synchronizers = 1
	- java.util.concurrent.locks.ReentrantLock$FairSync@2402c423

"Legacy Source Thread - Source: TableSourceScan(table=[[default_catalog, source, kafka_test_log]], fields=[data]) -> IcebergStreamWriter (1/1)" Id=2401 WAITING on java.lang.Object@12863204
	at java.lang.Object.wait(Native Method)
	-  waiting on java.lang.Object@12863204
	at java.lang.Object.wait(Object.java:502)
	at org.apache.flink.streaming.connectors.kafka.internal.Handover.pollNext(Handover.java:73)
	at org.apache.flink.streaming.connectors.kafka.internal.KafkaFetcher.runFetchLoop(KafkaFetcher.java:137)
	at org.apache.flink.streaming.connectors.kafka.FlinkKafkaConsumerBase.run(FlinkKafkaConsumerBase.java:823)
	at org.apache.flink.streaming.api.operators.StreamSource.run(StreamSource.java:110)
	at org.apache.flink.streaming.api.operators.StreamSource.run(StreamSource.java:66)
	at org.apache.flink.streaming.runtime.tasks.SourceStreamTask$LegacySourceFunctionThread.run(SourceStreamTask.java:266)

"Thread-2084" Id=2404 TIMED_WAITING on java.util.LinkedList@1fd868c8
	at java.lang.Object.wait(Native Method)
	-  waiting on java.util.LinkedList@1fd868c8
	at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:418)

"OutputFlusher for Source: TableSourceScan(table=[[default_catalog, source, kafka_test_log]], fields=[data]) -> IcebergStreamWriter" Id=2400 TIMED_WAITING
	at java.lang.Thread.sleep(Native Method)
	at org.apache.flink.runtime.io.network.api.writer.RecordWriter$OutputFlusher.run(RecordWriter.java:328)

"IcebergFilesCommitter -> Sink: IcebergSink hive_catalog.iceberg_db.ib_test_log (1/1)" Id=2399 WAITING on java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject@394fdc1b
	at sun.misc.Unsafe.park(Native Method)
	-  waiting on java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject@394fdc1b
	at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
	at org.apache.flink.streaming.runtime.tasks.mailbox.TaskMailboxImpl.take(TaskMailboxImpl.java:136)
	at org.apache.flink.streaming.runtime.tasks.mailbox.MailboxProcessor.processMail(MailboxProcessor.java:313)
	at org.apache.flink.streaming.runtime.tasks.mailbox.MailboxProcessor.runMailboxLoop(MailboxProcessor.java:188)
	at org.apache.flink.streaming.runtime.tasks.StreamTask.runMailboxLoop(StreamTask.java:608)
	at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:574)
	...

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总结(问题排查思路)

什么原因造成呢？看官网是这么做的，看网上其他博客，都能正常获取到数据（他们为什么这么顺利完成这个写入 demo?）。
其实以为是自己的kafka,flink版本不一致，kafka是2.11的scala,flink,iceberg是2.12的，但也没有代码报错，我还是统一更改为2.12的scala版本，还是不行 （排除了版本不一致问题）。
还是说明原因呢？

把hive catalog改为hadoop catalog也不行（排除是hive的问题）。

是否是flink对应的kafka版本不一致呢？ 换个kafka版本，校验看看