Re: [Firebird-devel] Max transaction duration

[Pavel C. <pc...@us...>]

David,

On 13 Dec 2002 at 21:48, David Jencks wrote:

> I am to some extent still learning, but  I think it is total time since
> transaction started.

Interesting, so server should kill requests in progress when time ticket 
expire ? I'd worry to introduce that. 
 
> Right now, since I am working on the jboss tm, I'm thinking more about
> transaction timeouts.
> 
> Thinking about it I think connection timeouts are useful too.  How about
> considering the JINI renewable lease model for them: a client requests a
> lease for a particular length of time, and the server can grant a lease for
> that length or less.  If the client decides it needs the resource for
> longer, it has to renew the lease periodically with the server, the server
> can again decide if and for how long it will grant the lease.  

What I still don't fully understand is the reason why one needs a timeout 
on trn. Only one reason I can imagine is to prevent blocking of server 
resources from dead clients, so some sort of keep-alive protocol is more 
suitable than pure timeout. But we just can think about the same thing in 
different terms ? Well, if this is the case, then I agree with you, even 
on trn "timeout" (one can have live connection but dead thread with trn). 
So, optional keep-alive protocol controlled by client (not by server as 
it is now on connections) at transaction level is a valuable feature.

> BTW as I recall JINI also has leases on transactions for their timeout
> model.  This would be fine with me also since it is even more flexible
> than the simple timeout model.  It does seem to involve some
> asynchronous communication (sending lease renewals while you are
> waiting for a query to complete). 

Interesting. Can you design an API concept for FB ?

Best regards
Pavel Cisar
http://www.ibphoenix.com
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