The REST service will be called by multiple clients, concurrently (I have a web application that calls this service). On the web server, for each request a new thread is created that will use the service instance to call the functionality and have the results returned back. If I create only one instance of the UimaAsynchronousEngine and call the sendAndReceive() method on it, that is also synchornized and blocking, wouldn't this mean that the requests from the client will be treated in a serial manner not in parallel? Because my understanding is that because the client blocks until the reply and because that method is synchronized, it won't be able to send further CASes to the pipeline (from other threads) and have them processed in parallel. Please correct me if I'm wrong.
Thanks, Mihaela On Wednesday, February 26, 2014 4:48 PM, Jaroslaw Cwiklik <[email protected]> wrote: Mihaela, does your REST service provide threading to handle client requests? If so, you can consider using a shared instance of UimaAsynchronousEngine client. Each thread would call sendAndReceive() and block until reply comes. This would be the most efficient way of doing this I think. Jerry C On Tue, Feb 25, 2014 at 2:15 PM, Mihaela M <[email protected]> wrote: > Hello, > > I have an Uima As pipeline that has more annotators running in parallel. > On top of this I want to build a REST service that would invoke the > pipeline for a given text and return the annotations found back to the > client. The REST service should support a high number of concurrent > requests. > > > Because of the need of having a synchronous call to the pipeline I thought > I should use UimaAsynchronousEngine's sendAndReceive(CAS) method, but > because this method is synchronized and blocks until the pipeline returns > the reply, if I have only one instance of UimaAsynchronousEngine and the > processing time is not that good all the calls of the web service will be > handled synchronously, not in parallel. > > In this case , is it feasible to create a pool of UimaAsynchronousEngine > clients (the pool size will match the CAS pool size of the uima as > pipeline, which will add also more running instances of each annotator) and > in the web service have one of the available clients in the pool reused to > call the uima as pipeline synchronously? I know that each such client opens > some connections to the ActiveMQ broker (at least two) so I expect to add > some overhead to the message broker and my web server but I don't know how > bad could it be. > > > If I tune the pipeline so that is supports high throughput, what would be > the best approach for adding this REST client with high throughput as well? > > I'm looking forward for any feedback or suggestions. > > Thanks, > Mihaela
