Thread: Drop down in connect time between 9.3.6 and 9.3.9 ?

Drop down in connect time between 9.3.6 and 9.3.9 ?

From
Marc Mamin
Date:
Hello,
We've just upgraded some productive servers from 9.3.6 to 9.3.9, and it seems that the time to get a connection (or
possiblyto disconnect) has become much slower. 
These tests are consistent when run against different servers.

tests with 9.4.1 show fast times, but we don't have a later version to test yet.

Is this a known issue ?

    9.3.6:
    time { i=0; while [ $i -lt 1000 ]; do let i++; psql -c 'select 1' ; done; } >/dev/null

    real    0m4.994s
    user    0m0.088s
    sys     0m0.272s

    9.3.9:
    time { i=0; while [ $i -lt 1000 ]; do let i++; psql -c 'select 1' ; done; } >/dev/null

    real    0m11.081s
    user    0m0.140s
    sys     0m0.208s

regards,

Marc Mamin


Re: Drop down in connect time between 9.3.6 and 9.3.9 ?

From
Albe Laurenz
Date:
Marc Mamin wrote:
> We've just upgraded some productive servers from 9.3.6 to 9.3.9, and it seems that the time to get a
> connection (or possibly to disconnect) has become much slower.
> These tests are consistent when run against different servers.
> 
> tests with 9.4.1 show fast times, but we don't have a later version to test yet.
> 
> Is this a known issue ?
> 
>     9.3.6:
>     time { i=0; while [ $i -lt 1000 ]; do let i++; psql -c 'select 1' ; done; } >/dev/null
> 
>     real    0m4.994s
>     user    0m0.088s
>     sys     0m0.272s
> 
>     9.3.9:
>     time { i=0; while [ $i -lt 1000 ]; do let i++; psql -c 'select 1' ; done; } >/dev/null
> 
>     real    0m11.081s
>     user    0m0.140s
>     sys     0m0.208s

I guess you are hitting this bug:
http://www.postgresql.org/message-id/15290.1435103076@sss.pgh.pa.us

Fixed in this commit:
http://www.postgresql.org/message-id/E1Z8C3Z-0004Ko-1h@gemulon.postgresql.org

You could apply the patch on your system if necessary.

Yours,
Laurenz Albe