[FX.php List] Server is busy...please try again

[Tim 'Webko' Booth]

Dear Jonathan;

> Hi folks.
>
> "Server is busy...please try again".
>
> You might see this message on a sophisticated airlines reservation  
> web site, but not if a Filemaker web server is too busy or has a  
> problem. The browser just times out.  This can be a real problem if  
> a multi-step operation fails to finish before the time out.
>
> I need to install a fix for this eventuality for one client. My plan  
> is to set a flag in an existing customer record before starting the  
> operation and then resetting the flag upon completion.  Any flags  
> that remain set indicate a potential problem. This is possible when  
> you are editing an existing record.  I am going to do that straight  
> away.
>
> NOTE: We have learned (the hard way) that the answer is *not* to  
> increase the browser expiration time. When there is a web server  
> problem, the last thing you want to do is stack up queries that  
> don't expire.  This *will* crash the web server if it hasn't already  
> done so.
>
> But back to the "Server is busy...please try again" option....
>
> Would this involve having one server talking to a second server  
> where the first server can return the friendly message before the  
> browser times out?  Or, is this a job for javascript?  Has anyone  
> done this before? I'm sure that it is commonplace in many  
> industries, but is not in my bag of tricks yet.

The problem is that XML engine is single-threaded, as far as I know.

On a multi-connection database (like mySQL) you can check how many  
connections, and then redirect to a Busy page if it's over a certain  
number [1]...

When there is only one connection, then a long request will clog it  
for all the requests after as well.

I can't think of a way to test easily without being part of the issue,  
as it would then be another request, stuck behind the long-running  
one... Happy to see if anyone else has an idea about accomplishing this.

Cheers

Webko

[1] the main reason our heaviest use systems are hybrid FM/mySQL, so  
we can do something with excess requests - and mySQL can handle a  
*lot* more requests in a given time period.