[FLINK-29887] Lookup cache in JDBC table connector is not each process (i.e. TaskManager) will hold a cache

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Not A Bug
• Component/s: Connectors / JDBC
• Assignee: Unassigned
• Reporter: linweijiang
• Created: 04/Nov/22 09:41
• Updated: 07/Nov/22 01:58
• Resolved: 07/Nov/22 01:58

Description

hi~ I saw the description of "When lookup cache is enabled, each process (i.e. TaskManager) will hold a cache" on the website. When I print out the hashCode of cache in each slot’s thread, I find that they are inconsistent. But according to the above website‘s instructions, cache's hashCode should be the same.

The context for verification is local IDEA.

Can you help me explain? thks~

 

//org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunction # eval()  add a line of code: 
LOG.info("cache hashCode is: {}", cache);


//log
2022-11-04 17:22:53,118 INFO  org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunction [Source: daily[1] -> Calc[2] -> LookupJoin[3] -> Calc[4] -> ConstraintEnforcer[5] (8/8)#0] [] - cache hashCode is: org.apache.flink.shaded.guava30.com.google.common.cache.LocalCache$LocalManualCache@656ae7d9
2022-11-04 17:22:53,118 INFO  org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunction [Source: daily[1] -> Calc[2] -> LookupJoin[3] -> Calc[4] -> ConstraintEnforcer[5] (6/8)#0] [] - cache hashCode is: org.apache.flink.shaded.guava30.com.google.common.cache.LocalCache$LocalManualCache@5c3a31c2
2022-11-04 17:22:53,118 INFO  org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunction [Source: daily[1] -> Calc[2] -> LookupJoin[3] -> Calc[4] -> ConstraintEnforcer[5] (5/8)#0] [] - cache hashCode is: org.apache.flink.shaded.guava30.com.google.common.cache.LocalCache$LocalManualCache@598a856e
2022-11-04 17:22:53,118 INFO  org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunction [Source: daily[1] -> Calc[2] -> LookupJoin[3] -> Calc[4] -> ConstraintEnforcer[5] (7/8)#0] [] - cache hashCode is: org.apache.flink.shaded.guava30.com.google.common.cache.LocalCache$LocalManualCache@765328ef
2022-11-04 17:22:53,118 INFO  org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunction [Source: daily[1] -> Calc[2] -> LookupJoin[3] -> Calc[4] -> ConstraintEnforcer[5] (3/8)#0] [] - cache hashCode is: org.apache.flink.shaded.guava30.com.google.common.cache.LocalCache$LocalManualCache@47f36967
2022-11-04 17:22:53,118 INFO  org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunction [Source: daily[1] -> Calc[2] -> LookupJoin[3] -> Calc[4] -> ConstraintEnforcer[5] (1/8)#0] [] - cache hashCode is: org.apache.flink.shaded.guava30.com.google.common.cache.LocalCache$LocalManualCache@2b2ea2f
2022-11-04 17:22:53,118 INFO  org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunction [Source: daily[1] -> Calc[2] -> LookupJoin[3] -> Calc[4] -> ConstraintEnforcer[5] (4/8)#0] [] - cache hashCode is: org.apache.flink.shaded.guava30.com.google.common.cache.LocalCache$LocalManualCache@1901ad34
2022-11-04 17:22:53,118 INFO  org.apache.flink.connector.jdbc.table.JdbcRowDataLookupFunction [Source: daily[1] -> Calc[2] -> LookupJoin[3] -> Calc[4] -> ConstraintEnforcer[5] (2/8)#0] [] - cache hashCode is: org.apache.flink.shaded.guava30.com.google.common.cache.LocalCache$LocalManualCache@6c441f09