private static synchronized void doSet() {
		String key = RandomUtils.random(36, true, true);
		String val = RandomUtils.random(12, true, true);
		try {
			 long startTime = System.nanoTime(); // ... the code being measured ... 
			 redis.set(key, val);
			 long estimatedTime = System.nanoTime() - startTime; 
			 setRunTimes.add(estimatedTime);
			 System.out.println("SET " + key + "=>" + val + " in " + estimatedTime + " ns");
		} catch (RedisConnectionException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (RedisIOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (RedisTimeoutException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (RedisException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		keys.add(key);
		/*synchronized (lock) {
			tasks --;
			if (tasks <= 0) {
					lock.notifyAll();
			}
		}*/
	}