David Parker wrote:
> 1.1.5-RC2
>  
> We have a fairly high transaction rate on database in which we have
> slony installed. In some of our load-testing we are ending up with
> ~400K records in the sl_log_1 table within the default
> SLON_CLEANUP_SLEEP. Since we have to limit disk usage as much as
> possible for this particular database, we would like to reduce the
> cleanup interval to limit the growth of that table, but I don't see
> any way to configure this.
>  
> My current plan is just to use an environment variable, and hack our
> copy of the code to be aware of it. Is there an already-supported,
> easier way to configure this that I have just missed?
>  
> Also, I'd like to hear any caveats/warnings about lower bound limits
> for this value, e.g. in which situations the possibility of deadlock
> somewhere arises, etc.
>  
> Thanks in advance.
Rather than using an environment variable, I'd suggest turning this into
one of the internal slon options.

That would involve:

1.  setting up a variable name, probably defined in either slon.c or
maybe directly in cleanup-thread.c

2.  adding an entry to ConfigureNamesInt in conf-options.h

3.  Using the variable in cleanup-thread.c

4.  Documentation changes :-)

That way this would be easy to put into CVS HEAD and add in for others'
use.  (And you could configure it in slon .conf files, and such...)

As far as lower bound goes, I don't see too much problem there.  The
value is used to determine how long the cleanup thread sleeps between
invocations.  The shortest that could *possibly* fall to is zero, in
which case it would run continually.