[TriLUG] ldirectord.cf

[Jon Carnes]

On Mon, 2003-12-08 at 15:37, Ryan Wheaton wrote:
> Ok.  that makes sense, and it's what i figured..  but...
> 
> how does this work if we set a [php session file] cookie that is 
> resident until the client closes the browser?

If the cookie is client based (of course!) then you don't need to worry
about persistent connections as the cookie contains all the information
and it should work with any of the virtual servers.

>   Is the persistent 
> connection then non-needed?  what happens when the server that the 
> client was directed to dies mid-session?

The client will have to reconnect, but UltraMonkey should turn off the
redirect to that server if it is down, and then all the redirect records
for that server will be deleted from the reverse-NAT tables. The clients
will then be sent to new servers in the cluster, once they make their
next request.

>   does it automatically fail 
> over to another realserver?  Or will the client just get "connection 
> timed out" and then when they hit 'reload' the director will fwd their 
> request on to the 'good' server? 

If the server dies in mid-load, then the client will have to reattach.
That's fairly minor and in most cases un-noticeable.

Jon
> 
> -rtw
> 
> On Monday, Dec 8, 2003, at 12:30 America/Denver, Jon Carnes wrote:
> 
> > On Mon, 2003-12-08 at 11:39, Ryan Wheaton wrote:
> >> I'm using UltraMonkey to load balance two http and https servers and I
> >> have a question about the load balancer conf file.  What exactly does
> >> the 'persistent = n' option do??  The man page isn't too 
> >> informative....
> >>
> >> 'persistent = n
> >>
> >>         Number of seconds for persistent client connections.'
> >>
> >>
> >> thanks,
> >>
> >> -r
> >
> > I generally set this equal to the length of time that you cache a
> > persistent state on the web-server.  The value is how long the 
> > Connector
> > for LVS should remember which server it sent a person to.  If another
> > request comes from that same source then the Connector will forward 
> > them
> > on to the same virtual server.
> >
> > In that way, you can have persistent states that exist on a single
> > webserver for each user, and each request always goes back to the same
> > server in your cluster.
> >
> > If that doesn't shed any light on it for you, then let me know and I'll
> > be happy to go into more (or less) detail.
> >
> > Jon
> >
> > -- 
> > TriLUG mailing list        : 
> > http://www.trilug.org/mailman/listinfo/trilug
> > TriLUG Organizational FAQ  : http://trilug.org/faq/
> > TriLUG Member Services FAQ : http://members.trilug.org/services_faq/
> > TriLUG PGP Keyring         : http://trilug.org/~chrish/trilug.asc
> >
>