On Thu, 27 Apr 2000, Dan McCormick wrote:
> If you split things between a proxy and a mod_perl server, the first hit
> would have to go through to the mod_perl server to initiate the session,
> but subsequent requests which may not need the session info could be
> sent to the proxy. Is that possible?
Anything that actually uses the session data to do something specific to
this user will have to go through to the backend mod_perl server. Generic
pages without user customization could be served from the proxy cache
though.
> Further, what are the standard ways to load balance a session-tracking
> app across multiple servers when the sessions are stored in memory and a
> given user has to be consistently sent back to the same machine?
Most of the commercial load-balancing tools support the concept of
"sticky" load-balancing, which routes people back to the same box each
time. If you can't do that, you have to share the sessions across all app
servers, probably by putting them into a database.
> Can round-robin DNS be counted on to send people back to the same
> server over the life of a given session?
It should work, but round-robin DNS has its own shortcomings (no failover
support) that usually send people to NAT-based approaches for high-traffic
commercial sites.
- Perrin
