Abhishek created KUDU-3322:
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             Summary: Handle to situation of last seen event ID in Kudu master 
being more than the latest event ID from HMS
                 Key: KUDU-3322
                 URL: https://issues.apache.org/jira/browse/KUDU-3322
             Project: Kudu
          Issue Type: Improvement
            Reporter: Abhishek


Came across a scenario where HMS database was lost and restored from an old 
backup which reset the latest event ID (monotonically increasing integer) in 
HMS to a lower value than what it should be.

Since Kudu master has a last seen event ID greater than the one in HMS 
currently, it could not process any new events generated. For example, Kudu 
table deletion was not happening as the Kudu master expects an event ID which 
is higher than the one it has last seen but the event ID in HMS for the table 
deletion is less than the one in the Kudu master.

This also causes discrepancy between the metadata in HMS and Kudu masters. It 
would be better if the Kudu master upon startup does the comparison of the last 
seen event ID and latest event ID in HMS and crash if the one in HMS is lower 
with a helpful message/clarifying question like:
{code:java}
Found the last seen event ID in the local Kudu master to be greater than the 
latest event ID in HMS. Was there any backup or restore done on HMS 
recently?{code}



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