[geeks] Virtual Hosting, with a twist

[James Fogg]

> On 7/3/07, James Fogg <James at jdfogg.com> wrote:
> > It would work, except VMWare (incl. ESX) falls on its face when you
> > open a ton of network sockets. I've learned this from
> expensive experience.
>
> Care to elaborate?


I work for a company that has, among other products, a network device
management tool. It "talks" to network devices on the usual ports,
telnet, ssh, snmp, tftp etc. When we've had clients try to run our
product on a VMWare instance the performance goes in the toilet.

Our application is pretty light weight (as light weight as a Java app
can be anyways). After some experimentation we've found that it's when
we reach out to the network devices (up to 200 at a time) we kill VMWare
performance. It appears to be something related to how VMWare handles
its network stack. Dropping the connection limit down to 20 doesn't
bring back a whole lot of performance.