[Commits] Rev 4507: MDEV-6680: Performance of domain_parallel replication is disappointing in http://bazaar.launchpad.net/~maria-captains/maria/10.0

knielsen at knielsen-hq.org knielsen at knielsen-hq.org
Thu Nov 13 16:10:54 EET 2014


At http://bazaar.launchpad.net/~maria-captains/maria/10.0

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revno: 4507
revision-id: knielsen at knielsen-hq.org-20141003094323-tfnmwzxnoxemmram
parent: knielsen at knielsen-hq.org-20140930141843-28knfm96vc15grdk
committer: Kristian Nielsen <knielsen at knielsen-hq.org>
branch nick: work-10.0-mdev6676
timestamp: Fri 2014-10-03 11:43:23 +0200
message:
  MDEV-6680: Performance of domain_parallel replication is disappointing
  
  Marked-for: 10.0
  
  The code that handles free lists of various objects passed to worker threads
  in parallel replication handles freeing in batches, to avoid taking and
  releasing LOCK_rpl_thread too often. However, it was possible for freeing to
  be delayed to the point where one thread could stall the SQL driver thread due
  to full queue, while other worker threads might be idle. This could
  significantly degrade possible parallelism and thus performance.
  
  Clean up the batch freeing code so that it is more robust and now able to
  regularly free batches of object, so that normally the queue will not run full
  unless the SQL driver thread is really far ahead of the worker threads.


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