On Fri, Oct 28, 2011 at 9:53 AM, Mike Orr <sluggos...@gmail.com> wrote:
> I have a few Pylons applications that share a SQL access log routine.
> Yesterday I migrated it from MySQL to PostgreSQL, and I'm getting a
> bunch of errors like this:
>
>>> connection = self.contextual_connect(close_with_result=True)
> Module sqlalchemy.engine.base:1229 in contextual_connect
>>> return self.Connection(self, self.pool.connect(),
>>> close_with_result=close_with_result, **kwargs)
> Module sqlalchemy.pool:142 in connect
>>> return _ConnectionFairy(self).checkout()
> Module sqlalchemy.pool:304 in __init__
>>> rec = self._connection_record = pool.get()
> Module sqlalchemy.pool:161 in get
>>> return self.do_get()
> Module sqlalchemy.pool:631 in do_get
>>> raise exc.TimeoutError("QueuePool limit of size %d overflow %d reached,
>>> connection timed out, timeout %d" % (self.size(), self.overflow(),
>>> self._timeout))
> TimeoutError: QueuePool limit of size 5 overflow 10 reached,
> connection timed out, timeout 30
>
> I assume this means I should set ``create_engine(pool_size=,
> max_overflow=)`` to some large number. But what would be a good
> starting point if it's currently at the default? 25? 50? The sites
> are like this:
>
>
> Site #1: Highest traffic. Failing at 6 requests/minute according to
> the error reports in my inbox. Using Postgres only for the stats, but
> soon will be using it for site stuff too (which is working fine with
> SQLite).
>
> Site #2: Second-highest traffic. Using Postgres both for the stats and
> the site. No problems seen yet.
>
> Site #3: The most critical site, but moderate traffic. Using
> PostgreSQL for both the stats and the site. One user complaint.
>
> Site #4: Small site, little used. Using PostgreSQL only for stats.
I checked the requests per hour since yesterday afternoon.
Site #1 stopped working at 6pm and has no requests logged until I
restarted it. Still, I got six of these exceptions every minute this
morning. And I could connect to the db via psql fine. On what occasion
does SQLA raise this error? Is it opening a new connection? Does it
try once, or try multiple times before it times out? Should I set
'pool_recycle'?
Site #2 has between 590 - 1255 requests per hour in that time.
Site #3 has max 17 requests per hour. And I clarified that the user
may not have gotten an error on this site, I may have misunderstood
his report.
Site #4 has 0 requests per hour, which is typical.
--
Mike Orr <sluggos...@gmail.com>
--
You received this message because you are subscribed to the Google Groups
"sqlalchemy" group.
To post to this group, send email to sqlalchemy@googlegroups.com.
To unsubscribe from this group, send email to
sqlalchemy+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/sqlalchemy?hl=en.
