Thread: Backups

Hello all

Very simple question -  does pg_dump/dumpall hit the server in terms of database performance? We currently do nightly backups and I want to move to hourly backups but not at the expense of hogging all the resources for 5 mins.

Pg_dumpall is currently producing a 1GB file - that's the combined size of around 30 databases and it takes around 5 mins to run.

Thanks
Rich

Hi Richard,


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If Pac-Man had affected us as kids, we'd all be running around in a darkened room munching pills and listening to repetitive music.

Thanks for a quick reply. The server has 6 cores, 6GB ram and top gets to 2.3-2.5 load average when running the dumpall. So I assume we are nowhere near this causing performance issues for users?
Thanks
Rich




On 15/03/12 12:21, Bèrto ëd Sèra wrote:

Hi Richard,

it's no easy answer. If your server has plenty of free resources there won't be trouble, but I do have customers who cannot even imagine of launching a dump in normal traffic hours. How loaded is your box, currently?

Cheerio

Bèrto

On 15 March 2012 12:15, Richard Harley <richard@scholarpack.com> wrote:

Hello all

Very simple question -  does pg_dump/dumpall hit the server in terms of database performance? We currently do nightly backups and I want to move to hourly backups but not at the expense of hogging all the resources for 5 mins.

Pg_dumpall is currently producing a 1GB file - that's the combined size of around 30 databases and it takes around 5 mins to run.

Thanks
Rich

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If Pac-Man had affected us as kids, we'd all be running around in a darkened room munching pills and listening to repetitive music.

Hi

On Thu, Mar 15, 2012 at 6:15 AM, Richard Harley <richard@scholarpack.com> wrote:
> Hello all
>
> Very simple question -  does pg_dump/dumpall hit the server in terms of
> database performance? We currently do nightly backups and I want to move to
> hourly backups but not at the expense of hogging all the resources for 5
> mins.
>
> Pg_dumpall is currently producing a 1GB file - that's the combined size of
> around 30 databases and it takes around 5 mins to run.

I'd suggest you look at using PITR backups.

Richard Harley wrote:
> Very simple question -  does pg_dump/dumpall hit the server in terms
of database performance? We
> currently do nightly backups and I want to move to hourly backups but
not at the expense of hogging
> all the resources for 5 mins.
>
> Pg_dumpall is currently producing a 1GB file - that's the combined
size of around 30 databases and it
> takes around 5 mins to run.

pg_dump will be a performance hit, because it consumes disk I/O
capacity.
You could measure how the system is affected by your current backup.

On the other hand, instead of doing an hourly pg_dump, it might be
preferable to do a filesystem backup and PITR. That way you have to
do a backup only once a day (or week, depends how much traffic you have
and how fast you have to restore) and can still recover to an
arbitrary point in time.

Yours,
Laurenz Albe

Perhaps a RAM DISK could be considered in the equation



On Thu, 2012-03-15 at 16:30 +0100, Albe Laurenz wrote:
> Richard Harley wrote:
> > Very simple question -  does pg_dump/dumpall hit the server in terms
> of database performance? We
> > currently do nightly backups and I want to move to hourly backups but
> not at the expense of hogging
> > all the resources for 5 mins.
> >
> > Pg_dumpall is currently producing a 1GB file - that's the combined
> size of around 30 databases and it
> > takes around 5 mins to run.
>
> pg_dump will be a performance hit, because it consumes disk I/O
> capacity.
> You could measure how the system is affected by your current backup.
>
> On the other hand, instead of doing an hourly pg_dump, it might be
> preferable to do a filesystem backup and PITR. That way you have to
> do a backup only once a day (or week, depends how much traffic you have
> and how fast you have to restore) and can still recover to an
> arbitrary point in time.
>
> Yours,
> Laurenz Albe
>