Thank you so much for your time guys. I'm digging into the LongRequest example 
to see how I can implement WOLongResponsePage.

On 2011-04-04, at 8:53 PM, Chuck Hill wrote:

> 
> On Apr 4, 2011, at 5:37 PM, Kevin Hinkson wrote:
> 
>> Hi all,
>> I am a bit puzzled about how WO handles concurrent requests.
>> 
>> I have a request that can run for a very long time, let's say 30 minutes.
> 
> That sounds more like a periodic task than a real request.
> 
> 
>> After looking around at other posts, the options for allowing this to run 
>> without the adaptor and apache complaining after a minute or so are:
>> 
>> * implement WOLongResponsePage
>> * Adjust the adaptor timeout settings
>> * make it run faster
> 
> * Do what Mike said.  Which in this case is The Right Answer.
> 
> 
>> Since I could not make the data crunching any faster and I'm lazy, I opted 
>> to adjust the adaptor timeout settings. This worked fine I thought. 
> 
> That is not doing yourself any favors.  That is just going to hide the 
> problem with your app gets overloaded and seriously annoy your users.
> 
> 
>> I am also running my app with the argument 
>> -WOAllowsConcurrentRequestHandling=YES (among others settings) which I 
>> thought would mean that one instance can handle multiple incoming requests.
> 
> Yes, but it does not make EOF multi-threaded.  If your long request was 
> sending email instead of doing database access, then things would be 
> different.
> 
> 
>> But that does not seem to be the case. My app is running with one local 
>> instance that should allow concurrent request handling but that one request 
>> (the long running one) blocks, preventing others from running (they just 
>> timeout). My solution has been to just add another instance and then 
>> schedule them to restart 12 hours apart.
> 
> The preference is to run more than a single instance for load balancing, 
> fault tolerance, and scheduling.
> 
> 
>> So, my questions.
>> 
>> 1. Is changing the adaptor timeout setting the best option or is 
>> WOLongResponse inherently better in some way?
> 
> See above.
> 
> 
>> 2. What does WOAllowsConcurrentRequestHandling do or not do? Did I 
>> misunderstand this argument?
> 
> It affects how HTTP requests are dispatched.  It does not prevent bottlenecks 
> downstream in your code.
> 
>> 3. Why do we have to schedule restarts of instances? I suspect it has to do 
>> with memory usage but I've never seen a clear answer on this.
> 
> The main reason is to allow the JVM to return memory to the OS.  It can also 
> help to coverup bugs in your code.
> 
> 
> 
>> 4. How many instances should I really be running per app? Maybe some 
>> examples of how you guys handle deciding how many to run would be great.
> 
> 
> I'd say a minimum of two and a maximum of how many are needed.  If two 
> provides the response time you are looking for, then that is enough.  Too 
> many wastes system resources.  It is a balancing act.
> 
> 
> Chuck
> 
> -- 
> Chuck Hill             Senior Consultant / VP Development
> 
> Practical WebObjects - for developers who want to increase their overall 
> knowledge of WebObjects or who are trying to solve specific problems.    
> http://www.global-village.net/products/practical_webobjects
> 
> 
> 
> 
> 
> 
> 

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