code: private void startEvictor() {
          cancelEvictor();
          if (evictorCheckPeriodSeconds > 0) {
              logger.info("Start redis client evictor...");
              evictor = new Evictor(getClientList(), evictorFailedTimesToBeTickOut);
              EvictionTimer.schedule(evictor, evictorDelayCheckSeconds, evictorCheckPeriodSeconds);
          }
      }
docs: 开启失效剔除/恢复策略监听线程