[geeks] the "pen" TCP load balancer

[Greg A. Woods]

[ On Wednesday, November 6, 2002 at 14:59:53 (-0500), Kurt Huhn wrote: ]
> Subject: Re: [geeks] Misuse of Java
>
> woods at weird.com (Greg A. Woods) wrote:
> 
> > spikes on Sat. AM.  It's currently fed by a pair of Mac OS X boxes
> > fronted by a "pen"(*) load balancer running on a measly little
> > single-CPU Pentium-II 300MHz machine with a single 100baseT/FDX
> 
> I tried pen a few years ago and found it didn't work quite right - for some
> reason packets were getting dropped.

It has improved enormously in the last little while.  Earlier this year
we found and fixed a file descriptor leak and one of those once-in-a-
million corrupted stream bugs and fed the patches back to the developer.

It was pretty bad C code originally and it mis-used the unix system
interface in several ways, which ultimately was the cause of the data
corruption we saw.  The most recent release does better error checking
all around and has a lot more features.

>  Would you mind giving some insight
> into configuration, Greg.

I can't say too much beyond what I've already said.  It's pretty simple,
after all:  the HTTP connections hit "pen" and it passes them on to the
web servers.

It works equally well for most TCP-based services that can be shared
(including SMTP, but perhaps not FTP), and is smart enough that it can
be configured to keep the same client connecting to the same back-end
server for multiple requests.

>  Any pointers to info
> appreciated.

The "pen" web site should have all you need.

	http://siag.nu/pen/

-- 
								Greg A. Woods

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