What's the problem on having dfs.namenode.handler.count configured too high?

[#1]

I am following Smartsense recommendation to make my cluster operationally more efficient, however there is a lot of documentation on how to set mentioned feature within ambari an why handlers are important for RPC, no one is mentioning why having this feature set "too high" affects a cluster.

Can anyone share some thought here?

Regards!"

[#2 · Accepted solution]

Below the answer in case someone need it:

"Each handler (worker) thread consume resources/memory on the NN. We can not set this value too high because it will consume unnecessary resources and cause extra burden on the NN."

[#3]

It is recommended that the RPC handler count is set to 20 * log2(Cluster Size) with an upper limit of 200. Refer more details here : https://community.hortonworks.com/articles/43839/scaling-the-hdfs-namenode-part-2.html