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[Launchpad Bug Tracker <1007038@xxxxxxxxxxxxxxxxxx>]

[Expired for oslo.db because there has been no activity for 60 days.]

** Changed in: oslo.db
       Status: Incomplete => Expired

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https://bugs.launchpad.net/bugs/1007038

Title:
  Nova is issuing unnecessary ROLLBACK statements to MySQL

Status in Cinder:
  Invalid
Status in OpenStack Compute (nova):
  Invalid
Status in oslo.db:
  Expired

Bug description:
  I'm not sure exactly where this is coming from yet, but Nova is
  issuing a "ROLLBACK" to MySQL after nearly every SELECT statement,
  even though I think the connection should be autocommit mode. This is
  unnecessary and wastes time (network roundtrip) and resources
  (database CPU cycles).

  I suspect this is getting generated by sqlalchemy when ever a
  connection is handed back to the pool, since the number of rollbacks
  roughly coincides with the number of "select 1" statements that I see
  in the logs. Those are issued by the MySQLPingListener when a
  connection is taken out of the pool.

  I opened a bug already for the unnecessary "select 1" statements, but
  I'm opening this as a separate bug. If someone finds a way to fix both
  at once, that'd be great.

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