[Axis2] Architecture Question (Concurrency)

[Marc Lefebvre <ml...@akimeka.com>]

I am deploying a POJO webservice using Axis2 and Java2Wsdl, etc...   Its
all working nicely, but in developing the java code of my webservice I
had some questions about HOW internally Axis works so that I can be sure
of some possible issues that may arise.
 
Does Axis create a separate thread for each webservice call?  I am
assuming yes at this point.
 
If so, then, in the webservice any data structure that is accessed by
these threads must be thread safe.  Right?
 
So, for example, if I had a HashMap that gets populated, read, and
deleted by webservice calls, I need to use the concurrent libraries
version of this HashMap.  Right?   Otherwise there could be contention
issues.
 
I am assuming the Axis framework does not provide ANY kind of protection
against concurrency issues.
 
Are there any other issues I should keep in mind in developing the
webservice due to the architecture of Axis?
 
Thanks...
 

Re: [Axis2] Architecture Question (Concurrency)

[Deepal jayasinghe <de...@gmail.com>]

Marc Lefebvre wrote:
> I am deploying a POJO webservice using Axis2 and Java2Wsdl, etc...  
> Its all working nicely, but in developing the java code of my
> webservice I had some questions about HOW internally Axis works so
> that I can be sure of some possible issues that may arise.
>  
> Does Axis create a separate thread for each webservice call?  I am
> assuming yes at this point.
Yes, each request is handle by a separate thread. In the case of
SimpleHTTP Server we use Thread pool, and in the case of App server, we
use the thread given by the app server.
>  
> If so, then, in the webservice any data structure that is accessed by
> these threads must be thread safe.  Right?
As long as you have written the code not to have class variables, then
it would. Depending on the service scope we create different number of
service class instances.  For example, for request scope we create new
service instance for each service scope, whereas for Application scope
we have single instance of the service class.

>  
> So, for example, if I had a HashMap that gets populated, read, and
> deleted by webservice calls, I need to use the concurrent libraries
> version of this HashMap.  Right?   Otherwise there could be contention
> issues.
I think that would be a good idea.
>  
> I am assuming the Axis framework does not provide ANY kind of
> protection against concurrency issues.
>  
> Are there any other issues I should keep in mind in developing the
> webservice due to the architecture of Axis?
I think stateless nature is something you need to keep in mind, do not
try to store values in your service class, instead use different
contexts provided by Axis2.

Thanks,
Deepal
>  
> Thanks...
>  


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