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1.主键字段为空问题

• 错误信息

org.apache.flink.table.api.TableException: Column 'bus_no' is NOT NULL, however, a null value is being written into it. You can set job configuration 'table.exec.sink.not-null-enforcer'='DROP' to suppress this exception and drop such records silently.

• 问题原因

  	sink 表定义了主键，flink-sql在使用jdbc 插入时，定义的主键中的属性存在空值
  PRIMARY  KEY (col,col2,col3,col4,col5,col6,col7) NOT ENFORCED
  

• 解决
  确定主键属性是否有空值，若为空则确定是否可作为主键属性（若正确则将其置为默认值）；若不符合业务情况，则重新定义主属性集合，确保不出现空值
  ​

2.flink-sql jdbc 并发写入Mysql出现死锁

• 错误信息

 org.apache.flink.connector.jdbc.internal.JdbcOutputFormat.flush(JdbcOutputFormat.java:240)
java.sql.BatchUpdateException: Batch entry 0 INSERT INTO dm_hljy.dm_hljy_sims_day_payment_info(sign_year_type, pay_source, campus_name, school_name, depart_name, pay_time, pay_channel_name, day_fee_amounts) VALUES ('2033', '3', '教育 ', ' 初级中学', ' 初级中学', '2022-02-18 00:00:00+08'::timestamp, '微信', '61310.00'::numeric) ON DUPLICATE KEY UPDATE day_fee_amounts=VALUES(day_fee_amounts) was aborted: ERROR: dn_6003_6004: deadlock detected
  Detail: Process 139972369676032 waits for ShareLock on transaction 1091179704; blocked by process 139976955991808.
Process 139976955991808 waits for ShareLock on transaction 1091179703; blocked by process 139972369676032.
  Hint: See server log for query details.  Call getNextException to see other errors in the batch.
	at com.huawei.gauss200.jdbc.jdbc.BatchResultHandler.handleCompletion(BatchResultHandler.java:171) ~[huaweicloud-dws-jdbc-8.1.1.1-200.jar:?]
	at com.huawei.gauss200.jdbc.core.v3.QueryExecutorImpl.executeBatch(QueryExecutorImpl.java:586) ~[huaweicloud-dws-jdbc-8.1.1.1-200.jar:?]
	at com.huawei.gauss200.jdbc.jdbc.PgStatement.executeBatch(PgStatement.java:883) ~[huaweicloud-dws-jdbc-8.1.1.1-200.jar:?]
	at com.huawei.gauss200.jdbc.jdbc.PgPreparedStatement.executeBatch(PgPreparedStatement.java:1580) ~[huaweicloud-dws-jdbc-8.1.1.1-200.jar:?]
	at org.apache.flink.connector.jdbc.statement.FieldNamedPreparedStatementImpl.executeBatch(FieldNamedPreparedStatementImpl.java:65) ~[flink-connector-jdbc-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.connector.jdbc.internal.executor.TableSimpleStatementExecutor.executeBatch(TableSimpleStatementExecutor.java:64) ~[flink-connector-jdbc-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.connector.jdbc.internal.executor.TableBufferReducedStatementExecutor.executeBatch(TableBufferReducedStatementExecutor.java:101) ~[flink-connector-jdbc-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.connector.jdbc.internal.JdbcOutputFormat.attemptFlush(JdbcOutputFormat.java:266) ~[flink-connector-jdbc-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.connector.jdbc.internal.JdbcOutputFormat.flush(JdbcOutputFormat.java:236) ~[flink-connector-jdbc-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.connector.jdbc.internal.JdbcOutputFormat.writeRecord(JdbcOutputFormat.java:215) ~[flink-connector-jdbc-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.connector.jdbc.internal.GenericJdbcSinkFunction.invoke(GenericJdbcSinkFunction.java:57) ~[flink-connector-jdbc-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.table.runtime.operators.sink.SinkOperator.processElement(SinkOperator.java:65) ~[flink-table-runtime-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.runtime.tasks.CopyingChainingOutput.pushToOperator(CopyingChainingOutput.java:82) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.runtime.tasks.CopyingChainingOutput.collect(CopyingChainingOutput.java:57) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.runtime.tasks.CopyingChainingOutput.collect(CopyingChainingOutput.java:29) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.api.operators.CountingOutput.collect(CountingOutput.java:56) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.api.operators.CountingOutput.collect(CountingOutput.java:29) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.api.operators.TimestampedCollector.collect(TimestampedCollector.java:51) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.table.runtime.operators.sink.SinkUpsertMaterializer.processElement(SinkUpsertMaterializer.java:128) ~[flink-table-runtime-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.runtime.tasks.OneInputStreamTask$StreamTaskNetworkOutput.emitRecord(OneInputStreamTask.java:233) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.runtime.io.AbstractStreamTaskNetworkInput.processElement(AbstractStreamTaskNetworkInput.java:134) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.runtime.io.AbstractStreamTaskNetworkInput.emitNext(AbstractStreamTaskNetworkInput.java:105) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.runtime.io.StreamOneInputProcessor.processInput(StreamOneInputProcessor.java:65) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.runtime.tasks.StreamTask.processInput(StreamTask.java:524) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.runtime.tasks.mailbox.MailboxProcessor.runMailboxLoop(MailboxProcessor.java:216) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.runtime.tasks.StreamTask.runMailboxLoop(StreamTask.java:812) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:761) ~[flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.runtime.taskmanager.Task.runWithSystemExitMonitoring(Task.java:958) [flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.runtime.taskmanager.Task.restoreAndInvoke(Task.java:937) [flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:751) [flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at org.apache.flink.runtime.taskmanager.Task.run(Task.java:573) [flink-dist-1.15.0-h0.cbu.mrs.320.r33.jar:1.15.0-h0.cbu.mrs.320.r33]
	at java.lang.Thread.run(Thread.java:750) [?:1.8.0_332]
Caused by: com.huawei.gauss200.jdbc.util.PSQLException: ERROR: dn_6003_6004: deadlock detected
  Detail: Process 139972369676032 waits for ShareLock on transaction 1091179704; blocked by process 139976955991808.
Process 139976955991808 waits for ShareLock on transaction 1091179703; blocked by process 139972369676032.
  Hint: See server log for query details.
	at com.huawei.gauss200.jdbc.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2856) ~[huaweicloud-dws-jdbc-8.1.1.1-200.jar:?]
	at com.huawei.gauss200.jdbc.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2587) ~[huaweicloud-dws-jdbc-8.1.1.1-200.jar:?]
	at com.huawei.gauss200.jdbc.core.v3.QueryExecutorImpl.executeBatch(QueryExecutorImpl.java:575) ~[huaweicloud-dws-jdbc-8.1.1.1-200.jar:?]
	... 30 more

• 错误原因

flink-sql在写入sql时定义了主键，flink-sql进行upser 操作（主键记录不存在则进行insert，存在则进行update）
flink-sql 插入时，会根据主键对sink表进行查询，若并发度大于1,则可能存在两个及以上线程查询同一条记录，出现死锁情况

• 解决

 设置flink-sql jdbc 并发度为1，（flink jdbc 并发度跟随flink 作业并发度；也可以单独设置）
设置flink-sql 并发度 ： parallelism.default: 1
也可以单独设置jdbc 并发度： （不跟随flink作业并发度） 
WITH (
  'connector' = 'jdbc',
  'url' = 'jdbc:gaussdb://dws-hl-datalake.dws.myhuaweiclouds.com:8000/hl_datamart',
  'table-name' = 'dm_hljy.dm_hljy_sims_security_send_back_student_info',
   'connection.max-retry-timeout' = '600s',
  'sink.max-retries' = '6',
   'sink.parallelism'= '1',
   'username' = '用户名',
   'password' = ‘密码'
 );