Shahim, That reference shows user code implementing the multithreaded wrapper around core uima. Given that it would be [your] application code, you could stop after instantiating one analysis engine, inspect the typesystem and update the database schema before instantiating more AE. In this case it is all under the control of the application code.
Note that UIMA-AS and the CPE do not synchronize access to an annotator from different threads; they run multiple instances of an annotator in different threads, assuming that the user specifies that the annotator is thread safe by declaring in the annotator's descriptor "MultipleInstancesAllowed=true". Eddie On Tue, May 1, 2012 at 3:03 PM, Shahim Essaid <[email protected]> wrote: > Hi Eddie, > > I am new to UIMA so I might have to reread the documentation. I was > under the impression that I can use multiple threads as long as I use > a cas pool and a multi threaded AE. This is described here: > > http://uima.apache.org/d/uimaj-2.4.0/tutorials_and_users_guides.html#ugr.tug.applications.multi_threaded > > Did I misunderstand this part of the documentation? In my case I am > running Core UIMA and I would benefit from multitasking. (many of my > annotators have a lot of idle time waiting for responses from remote > servers) > > This is my first time using UIMA and I have spent too much time trying > to persist the annotations in a database because I am frequently > changing my type system and experimenting with various analysis > approaches. Keeping the schema and INSERT statements in synch with the > type system was time consuming and error prone. I would like to > automate the persistence of the annotations based on the current type > system if possible. I was looking at Liquibase as an API that could be > used during the initialization of my pipelines to update the database > schema and then write a generic JDBC based annotator to write/insert > the cas to the database. Any thoughts? > > Best, > Shahim > > > > On Tue, May 1, 2012 at 10:54 AM, Eddie Epstein <[email protected]> wrote: >> Core UIMA is a single-threaded framework. There are two multi-threaded >> deployment wrappers, UIMA-AS and the older CPE. Are you using one of >> these wrappers? >> >> Eddie >> >> >> >> On Mon, Apr 30, 2012 at 2:01 PM, Shahim Essaid <[email protected]> wrote: >>> Hi All, >>> >>> I am trying to write a primitive analysis engine that checks, and >>> creates or updates a database schema based on the type system. I need >>> to synchronize the initialization of this component so that only one >>> instance of the component will do this task when there are multiple >>> instances being instantiated. >>> >>> What is the correct object to synchronize on? Is the type system >>> object the correct one and does it maintain its identity throughout a >>> JVM run? Is it a different object in the other aggregates even though >>> they use the same type system description? >>> >>> I need to block all other threads in the other instances of the >>> current component until the database is updated. I also need this >>> object to be specific to the current aggregate so that other >>> aggregates running in the same JVM can have their own synchronization >>> objects and database updates independent of each other. In other >>> words, I can't use a JVM wide object. >>> >>> Thank you, >>> Shahim
