Re: after postgres upgrade - ERROR: current transaction

my guess is that the query causing the error in 7.3 actually was valid
syntax in 7.1, so the query never errored out and the transaction never
had to be rolled back. quickest way to find out which query is to make
the mods to postgresql.conf i mentioned below and get it from your
server logs.

Robert Treat

On Tue, 2003-09-16 at 12:23, Abdul-Wahid Paterson wrote:
> I have kinda put my finger on the problem. It seems that a transaction
> was crashing out somewhere in my code and a rollback was not being done
> (I have not found the line of code yet) and the next PHP script to take
> on the connection was therefore getting a message saying that the
> current transaction was aborted.
>
> I changed my PHP connection setting to not use persistent connections
> and the problem was fixed. Although, that was not a good solution for me
> as I have high sever load.
>
> I then wrote a php shutdown function to always do a rollback at the end
> of the script. I switched on the persistent connections again, and
> everything was fine. Thus concluding that the problem was indeed a
> failed transaction that had not been rollback. (At least this will be
> good enough until I can sift through the thousands of lines of code
> looking for transaction code that has a missing rollback).
>
> The thing that still puzzles me is this: If you remember from my earlier
> post, the only thing I have changed here is the database server (from
> postgres 7.1.3 to 7.3.4). What I don't understand is why did 7.1.3 never
> cause a problem with the failed transactions not being rolledback?
> Postgres surely doesn't know that it is a new PHP script using the
> connection as all Postgres knows about is the Apache HTTP process
> holding the connection open. Can anyone shed some light on the
> difference between version? Or perhaps there is something else in
> Postgres configuration that would change the above behaviour.
>
> Best regards,
>
> Abdul-Wahid
>
> On Mon, 2003-09-15 at 19:48, Robert Treat wrote:
> > While I would recommend you upgrade your php to be built against 7.3,
> > before that you can use one of the new 7.3 error messages to find out
> > where things are going awry. in your postgresql.conf set
> > log_min_error_statement = error. this will cause the offending sql
> > statement to be written to your logs, with this you can narrow down
> > where in your web code your problems are being created, and better
> > attack the problem at that point.
> >
> > Robert Treat
> >
> > On Mon, 2003-09-15 at 14:18, Abdul-Wahid Paterson wrote:
> > > Hi,
> > >
> > > I have had a site working for the last 2 years and have had no
> problems
> > > until at the weekend I replace my database server with a newer one.
> The
> > > database migration went like a dream and I had the whole db changed
> over
> > > in 1 hour.
> > >
> > > Since the upgrade I have been getting the following error message
> > > sporadically.
> > >
> > > ERROR: current transaction is aborted, queries ignored until end of
> > > transaction block
> > >
> > >
> > > I have the following setup
> > >
> > > Webserver:
> > > Apache 1.3.27 (Redhat 7.2)
> > > PHP 4.1.2
> > >
> > > Database server (old): Postgres 7.1.3
> > > Database server (new): Postgres 7.3.4
> > >
> > > The PHP scripts have not changed. I am using PEAR::DB for database
> > > access. I think it is the PEAR::DB that is actually making the
> > > transactions because some times the error message some times gets
> > > generated when I don't even have a transaction. Not too sure about
> that
> > > though.
> > >
> > > The funny thing is, when I first start up the web-server I don't get
> any
> > > error messages and the site carries on working fine just as it did
> when
> > > using the old database server.
> > >
> > > However, after about an hour. I suddenly get 10 errors a minute from
> my
> > > site (average of course) with the majority of pages still accessing
> > > fine. After a bit more time, this doubles to 20 errors a minute. If
> I
> > > carry on leaving the site, I eventually get error messages every
> second.
> > > The error message seem to be generated from completely unrelated
> bits of
> > > my code.
> > >
> > > When I restart Apache the error messages go away and the site
> functions
> > > as normal.
> > >
> > > My theory is, since I am using persistent connections in PHP, a
> > > connection is some how becoming...unstable...for the want of a
> better
> > > word. That connection then returns an error on every single request.
> > >
> > > To put my theory to test, I have turned off the persistent
> connections
> > > on my site and everything appears to be working fine now. I now need
> to
> > > work out where to go from here as my server load is high and I would
> > > prefer to use persistent connections.
> > >
> > > Has anyone experienced any similar problems with changing Postgres
> > > versions? Do I need to upgrade my PHP on the web-server as the
> RedHat
> > > postgres the PHP was built against was Postgres 7.1.3? Anyone have
> any
> > > suggestions on how I can fix this?
> > >
--
Build A Brighter Lamp :: Linux Apache {middleware} PostgreSQL