Re: [Postgres-xc-general] pgbench suggestion

[Michael P. <mic...@gm...>]

On Fri, Nov 16, 2012 at 1:59 PM, Tatsuo Ishii <is...@po...> wrote:

> > (ccing XC general ML)
> >
> > On Fri, Nov 16, 2012 at 12:40 PM, Tatsuo Ishii <is...@po...>
> wrote:
> >
> >> We have up to 8 servers, where each server has data
> >> node/coorrdinator/GTM proxy. We have GTM on a seprate server. Then we
> >> execute multiple pgbench -k -S against the servers(each pgbench
> >> connect to different server).
> >>
> > OK, this should not happen...
> > How many max connections are you using per Coordinator
>
> 100.
>
> > and how many
> > Coordinators do you have?
>
> Up to 4.
> The number of coordinators are same as data nodes. So when we test 4
> data nodes(suppose they are d1 to d4), we are doing something like
> this:
>
> on host c1: pgbench -c 100 -S -h d1
> on host c2: pgbench -c 100 -S -h d2
> on host c3: pgbench -c 100 -S -h d3
> on host c4: pgbench -c 100 -S -h d4
>
That looks OK. I was wondering if the maximum active transactions possible
on GTM (1024) was reached, leading to your error.
The warning "Cannot connect to GTM..." "Xid is invalid." only happens when
a node tries to get a connection from GTM but it cannot, making me think
that GTM is not online or you have some firewall/network problems between
the node and GTM.
-- 
Michael Paquier
http://michael.otacoo.com