JDBC源连接器错误：事务中止。由于范围内键的冲突，它被一个更高优先级的事务伤害

Question

当我启动连接器时，有时会出现以下错误，但最终还是可以获得数据。

ERROR Failed to run query for table TimestampIncrementingTableQuerier{table="order_item", query='null', 
topicPrefix='test_', incrementingColumn='order_item_id', timestampColumns=[updated_time]}: {} 
(io.confluent.connect.jdbc.source.JdbcSourceTask:404)
com.google.cloud.spanner.jdbc.JdbcSqlExceptionFactory$JdbcAbortedDueToConcurrentModificationException: 
The transaction was aborted and could not be retried due to a concurrent modification
...
Caused by: com.google.cloud.spanner.AbortedDueToConcurrentModificationException: 
The transaction was aborted and could not be retried due to a concurrent modification
...
Suppressed: com.google.cloud.spanner.connection.AbstractBaseUnitOfWork$SpannerAsyncExecutionException: 
Execution failed for statement: 
SELECT * FROM `order_item` WHERE `order_item`.`updated_time` < @p1 AND ((`order_item`.`updated_time` = @p2 AND `order_item`.`order_item_id` > @p3) OR `order_item`.`updated_time` > @p4) ORDER BY `order_item`.`updated_time`,`order_item`.`order_item_id` ASC
...
Caused by: com.google.cloud.spanner.AbortedException: ABORTED: io.grpc.StatusRuntimeException: 
ABORTED: Transaction was aborted. It was wounded by a higher priority transaction due to conflict on keys in range [[5587892845991837697,5587892845991837702], [5587892845991837697,5587892845991837702]), column adjust in table order_item.
retry_delay {
  nanos: 12974238
}
 - Statement: 'SELECT * FROM `order_item` WHERE `order_item`.`updated_time` < @p1 AND ((`order_item`.`updated_time` = @p2 AND `order_item`.`order_item_id` > @p3) OR `order_item`.`updated_time` > @p4) ORDER BY `order_item`.`updated_time`,`order_item`.`order_item_id` ASC'
...

我想知道这个错误是怎么发生在我的情况下的。顺便说一句，即使有错误，连接器仍然可以在最后收集数据。有人能帮忙吗？太感谢你们了！

Answer 1

我不确定整个管道是如何设置的，但错误表明您正在读/写事务中执行查询。Cloud Spanner上的任何读/写事务都可能被Cloud Spanner中止，并可能导致您所看到的错误。

如果您的管道只从Cloud Spanner读取数据，最好的做法是将JDBC连接设置为只读和自动提交模式。通过将readonly=true和autocommit=true属性添加到URL中，可以直接在JDBC连接URL中执行此操作。

示例：