umustafi opened a new pull request, #3982:
URL: https://github.com/apache/gobblin/pull/3982

   Dear Gobblin maintainers,
   
   Please accept this PR. I understand that it will not be reviewed until I 
have checked off all the steps below!
   
   
   ### JIRA
   - [ ] My PR addresses the following [Gobblin 
JIRA](https://issues.apache.org/jira/browse/GOBBLIN/) issues and references 
them in the PR title. For example, "[GOBBLIN-XXX] My Gobblin PR"
       - https://issues.apache.org/jira/browse/GOBBLIN-XXX
   
   
   ### Description
   - [ ] Here are some details about my PR, including screenshots (if 
applicable):
   We're seeing a MySQLTransactionRollbackException: Deadlock found when trying 
to get lock when calling MysqlMultiActiveLeaseArbiter. attemptLeaseIfNewRow() 
in the rare case when two hosts check the lease arbiter table at the same time, 
see there's no entry matching the current primary key and try to insert it at 
the exact same time (both wait for lock on the same row). Normally, there's 
slight discrepancy that results in an IntegrityConstraintViolationException if 
one insert succeeds before the other OR  one finishes the write early and the 
other sees the entry when reading the getResult of the arbiter table. This PR 
adds retries with exponential backoff for transient SQL exceptions to the 
insert statement. Note, it's not needed for other cases when the INSERT/UPDATE 
statements are conditional on a read value. 
   
   ### Tests
   - [X] My PR adds the following unit tests __OR__ does not need testing for 
this extremely good reason:
   Exponential backoff is tested by other functions, no other major updates 
here 
   
   ### Commits
   - [ ] My commits all reference JIRA issues in their subject lines, and I 
have squashed multiple commits if they address the same issue. In addition, my 
commits follow the guidelines from "[How to write a good git commit 
message](http://chris.beams.io/posts/git-commit/)":
       1. Subject is separated from body by a blank line
       2. Subject is limited to 50 characters
       3. Subject does not end with a period
       4. Subject uses the imperative mood ("add", not "adding")
       5. Body wraps at 72 characters
       6. Body explains "what" and "why", not "how"
   
   


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