Re: Centos 6.9 and centos 7 - Mailing list pgsql-general

From Nicola Contu
Subject Re: Centos 6.9 and centos 7
Date
Msg-id CAMTZZh3M_wOeBZmUG8GweEr0zztSyc=pGT3GYFbQqsF1A_t=Ww@mail.gmail.com
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In response to Re: Centos 6.9 and centos 7  (Chris Mair <chris@1006.org>)
Responses Re: Centos 6.9 and centos 7
List pgsql-general
These are the timings in centos 7 : Time: 4.248 ms Time: 2.983 ms Time: 3.027 ms Time: 3.298 ms Time: 4.420 ms Time: 2.599 ms Time: 2.555 ms Time: 3.008 ms Time: 6.220 ms Time: 4.275 ms Time: 2.841 ms Time: 3.699 ms Time: 3.387 ms These are the timings in centos 6: Time: 1.722 ms Time: 1.670 ms Time: 1.843 ms Time: 1.823 ms Time: 1.723 ms Time: 1.724 ms Time: 1.747 ms Time: 1.734 ms Time: 1.764 ms Time: 1.622 ms This is top on centos 6 : [root@****]# top top - 14:33:32 up 577 days, 23:08, 1 user, load average: 0.16, 0.11, 0.15 Tasks: 1119 total, 1 running, 1118 sleeping, 0 stopped, 0 zombie Cpu(s): 0.0%us, 0.1%sy, 0.0%ni, 99.9%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 132040132k total, 129530504k used, 2509628k free, 108084k buffers Swap: 11665404k total, 331404k used, 11334000k free, 124508916k cached This is top on centos 7: top - 14:35:38 up 73 days, 19:00, 6 users, load average: 22.46, 20.89, 20.54 Tasks: 821 total, 13 running, 807 sleeping, 0 stopped, 1 zombie %Cpu(s): 14.2 us, 5.0 sy, 0.0 ni, 77.5 id, 3.1 wa, 0.0 hi, 0.2 si, 0.0 st KiB Mem : 26383592+total, 4301464 free, 6250384 used, 25328406+buff/cache KiB Swap: 16777212 total, 11798876 free, 4978336 used. 24497036+avail Mem The production machine is obviously more accessed. But that does not seem to be the problem as running the same query on the replica of the production machine (same config of the master but not accessed by anyone) gives the same bad result: Time: 6.366 ms 2017-12-04 15:19 GMT+01:00 Chris Mair : > centos 7 : >> Time: 3.884 ms >> >> centos 6.9 >> > Time: 1.620 ms > >> >> >> Is there anything you can advice to solve or identify the problem? >> > > Can you run this query 10 times on each server and note the timings? > > I'd like to see the reproducability of this. > > Also: both machines are otherwise idle (check with top or uptime)? > > Bye, > Chris. > > >

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