Re: Anyone know whats going on with PostgreSQL async_exec errors?

Hunter Hillegas
2006-11-26T09:29:37Z

So, I''m not entirely clear on this... From what you''ve written
and
the source code, it sounds like in a production app (Mongrel), we
would be crazy to have allow_concurrency on false. Does turning it
off kill performance entirely, assuming we are using the C process
bindings?

Or do I just not understand how this stuff works"

On Nov 25, 2006, at 5:39 PM, Jeremy Kemper wrote:

> On 11/24/06, zdennis <zdennis@mktec.com> wrote:
> Anyone know what''s going on with ActiveRecord Edge and 1.2RC1 unit
> tests. I get 13 failures from the "async_exec" method call.  ie:
>
>   test_callback_rollback_in_save(ConcurrentTransactionTest):
>   ActiveRecord::StatementInvalid: NoMethodError: undefined method
>   `async_exec'' for #<PGconn:0xb75a8754>: SET
client_min_messages TO
>   ''warning''
>
>
> Is this a known failure that someone in core is working on or is this
> functionality that needs to be fixed/implemented?
>
> The C bindings emulate nonblocking API calls using async_exec; the
> postgres-pr driver does not. This is used for multithreaded Active
> Record by setting AR::Base.allow_concurrency = true. The
> pessimistic locking tests would deadlock without it.
>
> This is not a regression, but it should be fixed.
>
> jeremy
>
> >