Hi devs,
I would like to propose a discussion thread about abstraction of Cache LookupFunction with metrics for cache in connectors to make cache out of box for connector developers. There are multiple LookupFunction implementations in individual connectors [1][2][3][4] so far. At the same time, users can monitor cache in LookupFunction by adding uniform cache metrics to optimize tasks or troubleshoot. I have posted an issue about this, see <https://issues.apache.org/jira/browse/FLINK-25409>, and made a brief design <https://docs.google.com/document/d/1L2eo7VABZBdRxoRP_wPvVwuvTZOV9qrN9gEQxjhSJOc/edit?usp=sharing>. Looking forward to your feedback, thanks. Best regards, Yuan [1] https://github.com/apache/flink/blob/master/flink-connectors/flink-connector-jdbc/src/main/java/org/apache/flink/connector/jdbc/table/JdbcRowDataLookupFunction.java [2] https://github.com/apache/flink/blob/master/flink-connectors/flink-connector-hive/src/main/java/org/apache/flink/connectors/hive/FileSystemLookupFunction.java [3] https://github.com/apache/flink/blob/master/flink-connectors/flink-connector-hbase-base/src/main/java/org/apache/flink/connector/hbase/source/HBaseRowDataLookupFunction.java [4] https://github.com/apache/flink/blob/master/flink-connectors/flink-connector-hbase-2.2/src/main/java/org/apache/flink/connector/hbase2/source/HBaseRowDataAsyncLookupFunction.java
