[DCC] Re: dccd issues

On Wed, Oct 25, 2006 at 09:20:29PM -0600, Vernon Schryver wrote:
> > From: Kelsey Cummings 
> 
> > I run 4 dcc servers and have run into something confusing.  On 2 out of the
> > four servers that run dccd the RSS of the dccd process is 1.6g with a
> > vmsize of ~2g.  On the other 2, the RSS is only a couple hundred mb where
> > the vmsize is also ~2g.  It appears that on these two servers dccd is also
> > trashing the disks pretty hard whereas on the other two, little or no disk
> > activity is shown.  The only difference that I've been able to figure out
> > so far is that the two servers that with the lower RSS are public servers.
> > The other two are not but are configured identically.  
> >
> > Any ideas here?
> 
> Since the 4 boxes are similar, and the 4 dccd process have similar
> virtual sizes, the reason that their resident sets differ can only be
> (a) one pair of servers is hardly working and so their residents are
> small or (b) other work is fighting for RAM and squeezing the pages out
> memory.  Lots of disk activity is consistent with thrashing, so
> my guess is (b).  I find `top` for seeing what's going on.
> And sometimes `vmstat 1`  Or the local UNIX flavor's equivalents.

The only problem with that Vernon is that the two servers which are hardly
working have the larger resident size.  The public servers only a
170-250mb.  Of course, this morning, all of the servers are using about
1.5gb -- yesterday the unusual memory usage was persistent even after
restarts of dccd.

I'll keep an eye on it.

-- 
Kelsey Cummings - kgc@corp.sonic.net      sonic.net, inc.
System Architect                          2260 Apollo Way
707.522.1000                              Santa Rosa, CA 95407