postgres-xc-general Mailing List for Postgres-XC

On Fri, Sep 30, 2011 at 8:18 PM, Michael Paquier
<mic...@gm...> wrote:
>
> This may be a problem, but I'm not sure.
> Have you tried to set LD_LIBRARY_PATH to connect refer to the path where you
> installed postgres-xc libs?
> Regarding your settings, it should be in /usr/local/pgsql/lib.

An interesting point. I'll check it on Monday when I get back to the office.

ChrisA

On Fri, Sep 30, 2011 at 4:51 PM, Chris Angelico <ro...@gm...> wrote:

> On Fri, Sep 30, 2011 at 4:48 PM, Michael Paquier
> <mic...@gm...> wrote:
> > Retry to start GTM with with command, it may make a difference:
> > gtm -x 1000 -D /usr/local/pgsql/data/gtm/ -p 6667 -l gtm.log &
> > ...
> > This was perhaps autovacuum transactions that were committing on nodes
> with
> > the same transaction ID as a past transaction. A transaction ID being
> > committed twice on a node makes it crash with a FATAL error.
> >
>
> Made that change, thanks. Doesn't appear to have changed anything from
> the state as at my second post; Unix socket isn't working but TCP
> socket is. It's worth being correct, anyhow.
>
> Is it a consideration that I'm using libpqxx?
>
This may be a problem, but I'm not sure.
Have you tried to set LD_LIBRARY_PATH to connect refer to the path where you
installed postgres-xc libs?
Regarding your settings, it should be in /usr/local/pgsql/lib.
-- 
Michael Paquier
http://michael.otacoo.com

On Fri, Sep 30, 2011 at 4:48 PM, Michael Paquier
<mic...@gm...> wrote:
> Retry to start GTM with with command, it may make a difference:
> gtm -x 1000 -D /usr/local/pgsql/data/gtm/ -p 6667 -l gtm.log &
> ...
> This was perhaps autovacuum transactions that were committing on nodes with
> the same transaction ID as a past transaction. A transaction ID being
> committed twice on a node makes it crash with a FATAL error.
>

Made that change, thanks. Doesn't appear to have changed anything from
the state as at my second post; Unix socket isn't working but TCP
socket is. It's worth being correct, anyhow.

Is it a consideration that I'm using libpqxx?

Chris Angelico

Hi,

On Fri, Sep 30, 2011 at 2:49 PM, Chris Angelico <ro...@gm...> wrote:

> $ gtm -D /usr/local/pgsql/data/gtm/ -p 6667 -l gtm.log &
>
You should start gtm with a minimum transaction ID value sufficient to avoid
conflicts by what has been created with initdb, which creates all the
default objects of a database in a data folder. initdb itself uses
transaction IDs up to 708 if I recall, so you need to start GTM with a value
superior than that.

Retry to start GTM with with command, it may make a difference:
gtm* -x 1000* -D /usr/local/pgsql/data/gtm/ -p 6667 -l gtm.log &

x option on GTM specifies from which transaction ID value GTM should begin
to feed all the cluster nodes.

$ tail -F /usr/local/pgsql/data/gtm/gtm.log
> $ postgres -D /usr/local/pgsql/data -p 15432 -i -X
> $ postgres -D /usr/local/pgsql/data1 -i -C
>
This looks correct.

>
> The command lines were partly derived from
> http://sourceforge.net/mailarchive/message.php?msg_id=26377904 but I
> don't really know what port numbers I should use. In
> /usr/local/pgsql/data/postgresql.conf are a number of references to
> 'port', most of them commented; the only one that's active is:
> gtm_port 6667
>
> When I tried to fire up gtm on port 6666, it immediately terminated
> without message. I assume this means that it couldn't bind to the
> port, but I have no way to confirm this.
>
It think 6666 is the default port value is by pooler on Coordinator,
therefore it may not work.

>
> There's a similar conf file in .../data1/ which I have now also edited
> to put gtm_port to 6667. Without this change, I was getting total
> inability to connect; now, I still get a lack of pooled commections.
>
> $ sudo su postgres
> $ psql
> psql (9.1beta2)
> Type "help" for help.
> postgres=# create user chris with password 'chris';
> ERROR:  Failed to get pooled connections
> PANIC:  cannot abort transaction 45, it was already committed
> server closed the connection unexpectedly
>        This probably means the server terminated abnormally
>        before or while processing the request.
> The connection to the server was lost. Attempting reset: Failed.
> !>
>
> Meanwhile, the other logs show odd messages; mainly, complaining that
> the database was improperly shut down.
>
This was perhaps autovacuum transactions that were committing on nodes with
the same transaction ID as a past transaction. A transaction ID being
committed twice on a node makes it crash with a FATAL error.

Regards,
-- 
Michael Paquier
http://michael.otacoo.com

Update! It's now almost all working - I'd mucked up the config files
(and then in subsequent editing, didn't realise the errors as I
mentally assumed that commented-out entries were just restating the
defaults). There's just one small issue: Unix sockets support. If I
use "host=::1" in the connection string, my program can connect no
trouble; leaving it off throws an error "No such file or directory"
attempting to connect to "/var/run/postgresql/.s.PGSQL.5432".
Unfortunately I haven't found where that's configured... it's probably
something really obvious that I've missed!

Sorry to bother you over nothing. :)

Chris Angelico

Greetings!

I'm attempting to set up a test "cluster" on a single computer, for
testing purposes. It's the first experience I have with PostgreSQL-XC,
and I know I've mucked stuff up, but I'm hoping someone can help me
sort out the mess I've got myself into.

So far, I've cloned the source tree and configured it --prefix=/usr
(this may very well have been an unwise choice). I then created two
data directories at /usr/local/pgsql/data and /usr/local/pgsql/data1,
and attempted to launch the three parts of the server, in separate
windows. All three sessions are running on the same computer (a Dell
laptop running 64-bit Ubuntu 10.10), and are invoked from 'sudo su
postgres' to get to the expected user.

$ gtm -D /usr/local/pgsql/data/gtm/ -p 6667 -l gtm.log &
$ tail -F /usr/local/pgsql/data/gtm/gtm.log

$ postgres -D /usr/local/pgsql/data -p 15432 -i -X

$ postgres -D /usr/local/pgsql/data1 -i -C

The command lines were partly derived from
http://sourceforge.net/mailarchive/message.php?msg_id=26377904 but I
don't really know what port numbers I should use. In
/usr/local/pgsql/data/postgresql.conf are a number of references to
'port', most of them commented; the only one that's active is:
gtm_port 6667

When I tried to fire up gtm on port 6666, it immediately terminated
without message. I assume this means that it couldn't bind to the
port, but I have no way to confirm this.

There's a similar conf file in .../data1/ which I have now also edited
to put gtm_port to 6667. Without this change, I was getting total
inability to connect; now, I still get a lack of pooled commections.

$ sudo su postgres
$ psql
psql (9.1beta2)
Type "help" for help.
postgres=# create user chris with password 'chris';
ERROR:  Failed to get pooled connections
PANIC:  cannot abort transaction 45, it was already committed
server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!>

Meanwhile, the other logs show odd messages; mainly, complaining that
the database was improperly shut down.

Any assistance would be much appreciated!

Chris Angelico