aerospike device overload error

cf_queue.c

int
cf_queue_pop(cf_queue *q, void *buf, int ms_wait)
{
	struct timespec tp;

	if (ms_wait > 0) {
		cf_set_wait_timespec(ms_wait, &tp);
	}

	cf_queue_lock(q);

	if (q->threadsafe) {

		// Note that we have to use a while() loop. The pthread_cond_signal()
		// documentation says that AT LEAST ONE waiting thread will be awakened.
		// If more than one are awakened, the first will get the popped element,
		// others will find the queue empty and go back to waiting.

		while (CF_Q_EMPTY(q)) {
			if (CF_QUEUE_FOREVER == ms_wait) {
				pthread_cond_wait(&q->CV, &q->LOCK);
			}
			else if (CF_QUEUE_NOWAIT == ms_wait) {
				pthread_mutex_unlock(&q->LOCK);
				return CF_QUEUE_EMPTY;
			}
			else {
				pthread_cond_timedwait(&q->CV, &q->LOCK, &tp);

				if (CF_Q_EMPTY(q)) {
					pthread_mutex_unlock(&q->LOCK);
					return CF_QUEUE_EMPTY;
				}
			}
		}
	}
	else if (CF_Q_EMPTY(q)) {
		return CF_QUEUE_EMPTY;
	}

	memcpy(buf, CF_Q_ELEM_PTR(q, q->read_offset), q->element_sz);
	q->read_offset++;

	// This probably keeps the cache fresher because the queue is fully empty.
	if (q->read_offset == q->write_offset) {
		q->read_offset = q->write_offset = 0;
	}

	cf_queue_unlock(q);
	return CF_QUEUE_OK;
}

drv_ssd-section-1.c

// Thread "run" function that flushes write buffers to device.
void *
run_write(void *arg)
{
	drv_ssd *ssd = (drv_ssd*)arg;

	while (ssd->running) {
		ssd_write_buf *swb;

		if (CF_QUEUE_OK != cf_queue_pop(ssd->swb_write_q, &swb, 100)) {
			continue;
		}

		// Sanity checks (optional).
		ssd_write_sanity_checks(ssd, swb);

		// Flush to the device.
		ssd_flush_swb(ssd, swb);

		if (ssd->shadow_name) {
			// Queue for shadow device write.
			cf_queue_push(ssd->swb_shadow_q, &swb);
		}
		else {
			// If this swb was a defrag destination, release the sources.
			swb_release_all_vacated_wblocks(swb);

			// Transfer to post-write queue, or release swb, as appropriate.
			ssd_post_write(ssd, swb);
		}
	} // infinite event loop waiting for block to write

	return NULL;
}

drv_ssd-section-2.c

void
ssd_flush_swb(drv_ssd *ssd, ssd_write_buf *swb)
{
	// Wait for all writers to finish.
	while (cf_atomic32_get(swb->n_writers) != 0) {
		;
	}