[Sqlgrey-users] Memory leak in 1.5.x

[Lionel B. <lio...@bo...>]

Hi, here's a bounce I got as list admin (I doubt it ever reached the
list as I've no trace of a delivery attempt from sourceforge in my own
server logs).


> Dear Friends,
>
> SQLgrey works fine for me except one thing. The memory usage of the
> process
> keep increasing and never stops. I doubt if there is some memory leak
> problem
> within the program or even the perl program.
>
> The situation is once the process begins, the memory usage which can
> be monitored
> by ps or top keep increasing and never stops until it reachs an OS
> limit and the
> process will be terminated.
>
> I would like to know if there exist some garbage collection machenism
> in the sqlgrey or perl code?
>
> The OS is freebsd 4.11
>    perl is made from /usr/ports of freebsd and the version is 5.8.6
>    sqlgrey is 1.5.6
>    the config of sqlgrey is almost the default.
>    the backend database used is postgresql 7.4.7
>
> sqlgrey=# SELECT count(*) from connect ;
> count -------
> 95284
> (1 row)
>
> ps axuww | grep sqlgrey
> sqlgrey    33263  0.0  4.5 248452 246964  pa  S+    3:17PM   0:12.56
> /usr/bin/perl -w /usr/local/sbin/sqlgrey (perl5.8.6)
>
> Any suggestion is welcome.
>
> David Wang


After careful examination I believe there is indeed a leak in SQLgrey.
I've not much mail coming on my server so I didn't spot it right away
(and my employer only uses SQLgrey since yesterday when I upgraded to
Postfix 2.1...).

The leak is quite hard to spot: I use DBI "prepare_cached" to help
performance in most cases. When I changed the timestamp related
computations during 1.5.x I didn't spot an obvious problem: many queries
now can't reuse the prepared statements since the timestamps are now
statics instead of dynamically computed in the SQL queries so they
change on each new message.

I believe that DBI is simply leaking prepared statements. Expect a 1.5.7
update with a fix shortly today.

Lionel