问题一：Flink报错remaining connection slots are reserved for non-replication superuser connections
Flink报错remaining connection slots are reserved for non-replication superuser connections
参考答案：
这个报错一般为连接数超了。
【解决方案】
● 指引用户看每个接入节点（Frontend，FE）连接的app_name，查看flink-connector使用的holo client连接数。
● 查看是不是有其他作业在连接holo。
● 建议参考连接数管理，杀一下连接数。
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问题二：Flink报错java.lang.IllegalArgumentException: Illegal Capacity: -1
Flink报错java.lang.IllegalArgumentException: Illegal Capacity: -1
参考答案：
在作业使用Map State的遍历操作时，出现java.lang.IllegalArgumentException: Illegal Capacity: -1异常，报错原因及解决方案参考文档。
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https://developer.aliyun.com/ask/476373?spm=a2c6h.13066369.question.14.6f064d5c8JIqqA
问题三：实时计算Flink报错INFOorg.apache.flink.fs.osshadoop.shaded.com.aliyun.oss
实时计算Flink报错INFOorg.apache.flink.fs.osshadoop.shaded.com.aliyun.oss
参考答案：
可参考QA：INFO：org.apache.flink.fs.osshadoop.shaded.com.aliyun.oss
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https://developer.aliyun.com/ask/475321?spm=a2c6h.13066369.question.15.6f064d5c8I2tum
问题四：实时计算Flink报错Waiting for a cluster to become ready
实时计算Flink报错Waiting for a cluster to become ready
参考答案：
该报错可能是集群没有资源导致的，可以排查下集群是否还有资源。
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https://developer.aliyun.com/ask/475539?spm=a2c6h.13066369.question.16.6f064d5ch6eAe5
问题五：Flink报错Encountered change event for table yhtplus.organization whose schema isn't known to this connector
Flink报错Encountered change event for table yhtplus.organization whose schema isn't known to this connector
参考答案：
报错详情：
ERROR io.debezium.connector.mysql.BinlogReader [] - Encountered change event 'Event{header=EventHeaderV4{timestamp=xxx, eventType=TABLE_MAP, serverId=xxx, headerLength=xxx, dataLength=xxx, nextPosition=xxx, flags=xxx}, data=TableMapEventData{tableId=xxx, database='xxx', table='xxx', columnTypes=xxx, xxx..., columnMetadata=xxx,xxx..., columnNullability={xxx,xxx...}, eventMetadata=null}}' at offset {ts_sec=xxx, file=mysql-bin.xxx, pos=xxx, gtids=xxx, server_id=xxx, event=xxx} for table xxx.xxx whose schema isn't known to this connector. One possible cause is an incomplete database history topic. Take a new snapshot in this case. Use the mysqlbinlog tool to view the problematic event: mysqlbinlog --start-position=30946 --stop-position=31028 --verbose mysql-bin.004419 202x-xx-xx xx:xx:xx,xxx ERROR io.debezium.connector.mysql.BinlogReader [] - Error during binlog processing. Last offset stored = null, binlog reader near position = mysql-bin.xxx/xxx 202x-xx-xx xx:xx:xx,xxx ERROR io.debezium.connector.mysql.BinlogReader [] - Failed due to error: Error processing binlog event org.apache.kafka.connect.errors.ConnectException: Encountered change event for table statistic.apk_info whose schema isn't known to this connector at io.debezium.connector.mysql.AbstractReader.wrap(AbstractReader.java:241) ~[ververica-connector-mysql-1.12-vvr-3.0.0-SNAPSHOT-jar-with-dependencies.jar:1.12-vvr-3.0.0-SNAPSHOT] at io.debezium.connector.mysql.AbstractReader.failed(AbstractReader.java:218) ~[ververica-connector-mysql-1.12-vvr-3.0.0-SNAPSHOT-jar-with-dependencies.jar:1.12-vvr-3.0.0-SNAPSHOT]。
报错原因：
使用了debezium.snapshot.mode=never导致可能出现该错误。
解决方案：
不建议使用debezium.snapshot.mode=never，因为never会从binlog开头读取数据， 但是binlog开头的binlog事件对应的table schema和当前表的schema可能不匹配，所以会报该错误。 可以通过'debezium.inconsistent.schema.handling.mode'='warn'参数绕过。
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https://developer.aliyun.com/ask/476370?spm=a2c6h.13066369.question.17.6f064d5cS8G9lb
