Re: [Postgres-xc-developers] Potential bug in copy command

[Nikhil S. <ni...@st...>]

+1

I had diagnosed this same issue quite a while ago. We should wait for the
buffer to drain out before adding more into it. The buffer size was going
beyond 1GB in size pretty quickly!

Regards,
Nikhils


On Wed, Oct 23, 2013 at 10:35 AM, Koichi Suzuki <koi...@gm...>wrote:

> I've found that in copy command, we have a risk to overflow the buffer in
> coordinator if datanode is very slow (for various reasons).
>
> When we issue copy command against tens of gigabytes of data, coordinator
> send all of then without synch.   When some of the data fails to send, it
> adds next data and tries to send all of them.   When a datanode is very
> slow (for any reason), the data will continue to be cashed at the
> coordinator and finally overflows.
>
> The patch avoids this issue.   When amount of unsent data exceeds the
> criteria, coordinator will keep retry until this amount is below the second
> criteria.
>
> This can be applied to all the releases, as well as the master.
>
> Regards;
> ---
> Koichi Suzuki
>
>
> ------------------------------------------------------------------------------
> October Webinars: Code for Performance
> Free Intel webinars can help you accelerate application performance.
> Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most
> from
> the latest Intel processors and coprocessors. See abstracts and register >
> http://pubads.g.doubleclick.net/gampad/clk?id=60135991&iu=/4140/ostg.clktrk
> _______________________________________________
> Postgres-xc-developers mailing list
> Pos...@li...
> https://lists.sourceforge.net/lists/listinfo/postgres-xc-developers
>
>


-- 
StormDB - http://www.stormdb.com
The Database Cloud