ourdelta-developers team mailing list archive

[Arjen Lentz <arjen@xxxxxxxxxxxxx>]

Hi Weldon

On 30/09/2009, at 9:39 AM, Weldon Whipple wrote:
> I'll leave valgrind running all night on my development box.

Excellent.

> It's altogether possible that the leak isn't a leak in the  
> traditional sense.
>
> With the CLIENT_STATISTICS bug, what was actually happening is that  
> a flood of queries were received with 3rd-level domains as  
> hostnames--all longer than 16 characters long.
>
> MySQL tried to match the long hostname with an already exiting one.  
> We ended up getting a new entry in the CLIENT_STATISTICS table for  
> every query. When we issued a SELECT on that table, all the columns  
> were 0 (IIRC) except for the second one displayed. That one  
> displayed a truncated hostname.
>
> ... So that wasn't really forgetting to free some malloc'ed memory.  
> It was just that the longer mysqld ran, the larger the  
> CLIENT_STATISTICS table grew ... and it just kept growing (and  
> growing and growing).
>
> It's possible that what our admins are reporting isn't really a  
> leak, but some internal table growing. It might be that a "fix"  
> would be to just have a switch (global variable/my.cnf cirective) to  
> disable the tables we aren't using, then see if the bloat stops ...

What you can also try is disabling the statistics on one slave, and  
see if it still grows/leaks.
MySQL will always grow in mem over time as it grabs allocated mem and  
keeps it in its internal memory pool.
But that's not leakage.

> I'll DoS my box all night and see what valgrind says tomorrow  
> morning. (Thus far, the only errors I've seen are three "Conditional  
> jump of move depends on uninitialised value(s)" in strmake  
> (strmake.c:44), on initialization.)


Do report that at bugs.mysql.com
Or at bugs.launchpad.net/mysql-server

Valgrind errors should not linger around, and Sun/MySQL should not  
send out releases where Valgrind is not clean.


Cheers,
Arjen.
--
Arjen Lentz, Exec.Director @ Open Query (http://openquery.com)
Exceptional Services for MySQL at a fixed budget.

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