Question: How to monitor the QPS in Cassandra local node or cluster

Hi, everyone, I want to monitor the Cassandra cluster using Zabbix, but I have no idea about hot monitor the QPS on local Cassandra node ? I search the internet but haven't any result about how to get the QPS. anyone had any idea? Thanks!

Exception at Tried to hard link to file that does not exist

Hi, I'm new to cassandra and told to write a script to backup the cassandra cluster every day, but it throws an exception at one node as below: Exception in thread "main" java.lang.RuntimeException: Tried to hard link to file that does not exist /var/cassandra/data/forseti/activity/forseti-activ