[Bug 1802487] Re: Fix performance regression in v1.57

[Launchpad Bug Tracker]

This bug was fixed in the package python-memcache -
1.57-2ubuntu0.18.04.1

---------------
python-memcache (1.57-2ubuntu0.18.04.1) bionic; urgency=medium

  * d/p/py2-perf.patch: Cherry pick fix to use native C implementation
    for pickle under Python 2, resolving issues with performance
    degradation (LP: #1802487).

 -- James Page <james.page at ubuntu.com>  Thu, 22 Nov 2018 11:50:53 +0000

** Changed in: python-memcache (Ubuntu Bionic)
       Status: Fix Committed => Fix Released

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https://bugs.launchpad.net/bugs/1802487

Title:
  Fix performance regression in v1.57

Status in python-memcache package in Ubuntu:
  Fix Released
Status in python-memcache source package in Bionic:
  Fix Released
Status in python-memcache source package in Cosmic:
  Fix Released
Status in python-memcache source package in Disco:
  Fix Released

Bug description:
  [Impact]
  Performance under Python 2 with this package since 1.54 is poor due to the lack of use of the native C implementation of pickle.

  [Test Case]
  run attached memcache-test.py under python 2.
  with proposed fixes, should be approximately 2/3 of the execution time of the unpatched version.

  [Regression Potential]
  The picked fix is relatively minor and simply adjusts the import under Py2 to use the native C implementation so regression potential will be low.

  [Original Bug Report]
  Just migrated a python 2 application from 14.04 LTS to 18.04 LTS and got a serious performance degradation. Like 1000 times slower. After some profiling it was concluded that the problem was the transition from cPickle back to pickle for data serialization.

  This is a problem fixed in version 1.58.
  https://github.com/linsomniac/python-memcached/releases/tag/1.58

  Please upgrade python-memcache to a more recent version or patch the
  current version.

  Versions affected: Ubuntu 16.04 LTS and Ubuntu 18.04 LTS

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