Re: [HACKERS] More thoughts about FE/BE protocol

On 11 Apr 2003, Bruce Badger wrote:

> On Fri, 2003-04-11 at 04:15, Tom Lane wrote:
> 
> > Well, as far as network roundtrips go, it's always been true that you
> > don't really have to wait for the backend's response before sending the
> > next command.  The proposal to decouple SYNC from individual commands
> > should make this easier: you fire off N commands "blind", then a SYNC.
> > When the sync response comes back, it's done.  If any of the commands
> > fail, all else up to the SYNC will be ignored, so you don't have the
> > problem of commands executing against an unexpected state.
> 
> Is SYNC going to be a new kind of message?  Is the SYNC response yet
> another?
> 
> Either way, could this be used as a keep-alive for long-lived
> connections?  (some users of the current Smalltalk drivers report that
> long lived connections over the Internet sometimes just die)

If there's talk of keep-alive messages, what of keep-alive from server to
client.

There's been a few reports of backends been left hanging around because clients
have dropped the connection or network issues have blocked connections in such
a manner that the server hasn't seen the connection close. I believe this is
only going to be an issue on systems configured to not use keep-alive packets.
So it may be deemed nothing to do with postgresql and if it's an issue the
sys/net admin has to get involved.


-- 
Nigel J. Andrews