This bug was fixed in the package simplestreams - 0.1.0~bzr430-0ubuntu1 --------------- simplestreams (0.1.0~bzr430-0ubuntu1) yakkety; urgency=medium
* New upstream snapshot. - set a default user agent (LP: #1578622) - glance mirror: do not require that hypervisor_config be present (LP: #1578624) - Optimise read_signed method for better performance (LP: #1580534) -- Scott Moser <smo...@ubuntu.com> Thu, 12 May 2016 12:55:30 -0400 ** Changed in: simplestreams (Ubuntu) Status: Confirmed => Fix Released -- You received this bug notification because you are a member of नेपाली भाषा समायोजकहरुको समूह, which is subscribed to Xenial. Matching subscriptions: Ubuntu 16.04 Bugs https://bugs.launchpad.net/bugs/1580534 Title: Signature verification is too slow Status in simplestreams: Fix Committed Status in simplestreams package in Ubuntu: Fix Released Status in simplestreams source package in Xenial: Confirmed Bug description: [Impact] When running against http://cloud- images.ubuntu.com/releases/streams/v1/com.ubuntu.cloud:released:download.sjson, read_signed() in simplestreams/utils.py seems to take minutes (402 seconds in my instrumented timing) running 100% CPU. At the time of my test, download.sjson is 451737 bytes in 1870 lines. This makes a uvtool sync virtually unusable on Xenial. [Development Fix] The culprit is the constant += of a string as it is read in. This is inefficient in Python as each += results in a new string that has to be allocated. Keeping the lines in a list and joining them at the end reduces the time to 0.127 seconds. [Stable Fix] No change cherry-pick of fix committed upstream. [Test Case] On a machine with reasonable connectivity, run: uvt-simplestreams- libvirt sync release=xenial arch=amd64 Expected result: takes a few seconds with minimal CPU use. Actual result: takes more than five minutes with CPU pegged at 100%. Scott also has a more direct test case here: http://paste.ubuntu.com/16377613/ [Original Notes] Merge proposal to follow. I'm filing this bug to track a Xenial SRU. To manage notifications about this bug go to: https://bugs.launchpad.net/simplestreams/+bug/1580534/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~group.of.nepali.translators Post to : group.of.nepali.translators@lists.launchpad.net Unsubscribe : https://launchpad.net/~group.of.nepali.translators More help : https://help.launchpad.net/ListHelp