Beep… beep… beep… It’s PagerDuty telling you that a node has gone down, or a rack has gone down, or your whole cluster has just rebooted. Either way, your cluster is RED: some shards are not assigned, which means that your data is not fully available.bepp... bepp... bepp... 호출기가 울린다. node 혹은 rack에 장애가 발생했다. 또는 전체 cluster가 reboot 되었다. 어느 쪽이든 cluster가 RED(일부 shard가 할당되지 않았다. 즉, data를 완전히 사용할 수 없다...