Bbetween 1.1.6 and 1.1.7 compression was changed so that each compression task runs in the per-context executor.

Also between 1.1.6 and 1.1.7 a ScheduledExecutorService was added to the context. But the per-context ExecutorService is now deprecated (and calling getExecutorService() actually gives you the ScheduledExecutorService).

In 1.1.6 the ExecutorService was set up like this:

static public ExecutorService newExecutorService() {
    return new ThreadPoolExecutor(CoreConstants.CORE_POOL_SIZE, CoreConstants.MAX_POOL_SIZE, 0L, TimeUnit.MILLISECONDS, new SynchronousQueue<Runnable>(),
                    THREAD_FACTORY);
}

where CoreConstants.MAX_POOL_SIZE is 32. But in 1.1.7 the executor is set up like this:

    static public ScheduledExecutorService newScheduledExecutorService() {
        return new ScheduledThreadPoolExecutor(CoreConstants.SCHEDULED_EXECUTOR_POOL_SIZE, THREAD_FACTORY);
    }

where CoreConstants.SCHEDULED_EXECUTOR_POOL_SIZE is 2. So the number of tasks than can run concurrently has reduced quite significantly.