re-adding roles of cloudera management service

[#1]

Hi,

We have a Cloudera Express 5.7.0 Cluster with 8 nodes. my problem is that for a test, I deleted all of instance roles of Cloudera management service and add again all of them successfully except Activity Monitor. and when I want to restore it again using Add Instance Roles, in Activity Monitor Databse setup it cannot connect to amon DB because of following Error:

'

ERROR 1524316542@scm-web-43508:com.cloudera.cmon.NozzleIPCWrapper: Error getting HDFS summary for hdfs: org.apache.avro.AvroRemoteException: java.net.ConnectException: Connection refused

'

now I have 2 question: 1.what is the problem with adding role again?

and 2.if I add role again successfully, will these role's previous configurations remove?

[#2 · Accepted solution]

for others' use I write my solution.

just restart amon database (in my case, mysql database) solved the problem!

and all of roles were added with no corruption in their previous configurations 🙂