My cluster has three buckets,and 8 nodes. In one bucket, one node has a strange phenomenon：
1. The ops of the key not exists in bucket is very high, and it up to 1.1k/s, see also in
2. Only one node has the exception, other nodes is ok, see also in
3. The exception node's status see in
4. The exception node VBUCKET RESOURCES see in
5. When I set the exception key in the bucket by manual, the ops is also up to 1.1k/s, and then delete it from bucket, the ops also not down;
I had investigated the situation before the question posted that.
1. The application has no such reading or writing log about the key, while other keys can be found.
2. I logined to the exception node(192.168.250.174) and got the network connection of the port 11209~11213, there is no other application connect to the port except my application.
As what I said in the last comment, I failed over the node(192.168.250.174) , and the execption node changed to another node(192.168.250.154), while the exception key also changed to another.