java - reading lots of messages from amazon sqs -

i trying read sqs queue bunch of messages on (~2mil) running in trouble how setup threading model decent performance.

i tried this:

            executorservice es = executors.newfixedthreadpool(16);             //getapproximatenumberofmessages() - uses sqs regular (not async) client call getqueueattributes, etc             final atomicinteger approximatenumberofmessages = new atomicinteger(getapproximatenumberofmessages());             while(approximatenumberofmessages.get() > 0) {                 es.execute(new runnable() {                     @override                     public void run() {                         //getmessages uses sqs regular (not async) client call receivemessage()                         list<message> messages = getmessages();                         (message message : messages) {                             handlesinglemessage(message);                         }                         approximatenumberofmessages.decrementandget();                     }                 });             } 

however, out of memory exceptions. tried switching threadpoolexecutor suggested here, when process seems lock up.

is there way process messages asynchronously without running out of memory?