Re: [PoC] load balancing in libpq

On 23 September 2012 05:50, Satoshi Nagayasu <snaga(at)uptime(dot)jp> wrote:

> I have just written the first PoC code to enable load balancing
> in the libpq library.
>
> This libpq enhancement is intended to allow PostgreSQL users to
> take advantage of the replication in easier way.
>
> With using this patch, PQconnectdb() function accepts multiple
> connection info strings, and pick one of them by round-robin basis
> to connect.

It's certainly worth thinking about. New ideas are good, if they have
some justification.

A load balancing solution that only works at connection level isn't
much of a solution, IMHO.

If you have multiple connection strings in the client program, its
trivial to put them in an array and pick one randomly, then use that.
So this is already available as a solution in user space.

Also, any client based solution presumes we can ship lists of cluster
metadata to clients, which we have no solution for, so it places a
much greater burden on the administrator. Load balancing config needs
to be held more centrally.

--
Simon Riggs http://www.2ndQuadrant.com/
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