我们收到“java.lang.OutOfMemory错误：在大约1024个线程后，无法在jboss上创建新的本地线程””，因为应用程序占用了所有最大用户进程

ulimit -a
core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 14866
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 10240
cpu time               (seconds, -t) unlimited

**max user processes              (-u) 1024**

virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

发生这一切的代码如下：

ExecutorService service = Executors.newFixedThreadPool(2);  
Collection<Callable<String>> tasks = new ArrayList<Callable<String>>();  
tasks.add(ctgService);**--> THIS IS THE LINE OF OOM**
try{
    List<Future<String>> taskFutures = service.invokeAll(tasks, 60L, TimeUnit.SECONDS);  
    for (Future<String> future : taskFutures) {  
        ctgMsgOut = future.get();
    }  
} catch (InterruptedException ie){
     throw new TimeoutException("The response from GEC-CTG has exceeded the timeout");
} catch (CancellationException ce){
    throw new TimeoutException("The response from GEC-CTG has exceeded the timeout");           
} catch (ExecutionException ee){
    if (ee.getCause() instanceof TimeoutException){
        throw new TimeoutException("The response from GEC-CTG has exceeded the timeout");
    }else{
        throw new ConnectException("Connect exception");
    }
} catch (Exception e){  
        e.printStackTrace();
}finally {
    service.shutdown();
}
ctgMsgOut = "<MessageOutGEC>" + ctgMsgOut +  "</MessageOutGEC>";

exchange.getOut().setBody(ctgMsgOut, String.class);

exchange.getOut().setHeaders(exchange.getIn().getHeaders());

请你能帮我弄明白代码哪里不对吗？在service.shutdown（）之后我应该添加tasks.clear（）还是tasks.remove（ctgService）？
谢谢你