I don't have a small enough test case to submit yet, but my code looks something like this:

executorService.submit(new Runnable() {
    @Override public void run() {
        while (!Thread.currentThread().isInterrupted()) {
            doWork();
        }
    }
});

Sometimes, when I call Future.cancel(true), the while loop does not terminate. I'm not sure if this bug is with the AWS SDK 1.3.30 or the Apache HttpClient (I've tried the latest stable version 4.2.3 with no luck either)

I've mentioned this on the Apache HttpClient mailing list too: http://mail-archives.apache.org/mod_mbox/hc-httpclient-users/201301.mbox/%3CCAA7ZWuUPb_7ztCw1-5pyJ2%2BByWVk7McsvtGewa9ahKjXRtOzMA%40mail.gmail.com%3E