Ambari cluster expansion node + expansion service operation

1. Prepare before capacity expansion

   a. Turn off firewall 
   systemctl stop firewalld.service
   systemctl disable firewalld.service
   
   b. To configure /etc/hosts,  Configure mutual trust 
   ssh-keygen -t rsa : Three consecutive times , When it's done, it'll be /root/.ssh/id_rsa.pub  Inside public key ,cp To authorized_keys
    Put the original cluster node /root/.ssh/authorized_keys cp To the expansion node , And add the public key of the expansion node 
   c. install JDK
    Will the master node JDK,  And  /etc/proflie  scp To the expansion node .
   d. install Ntp
   

2. Add host - Page operation
   Enter host name ;
   Enter the private key of the master node : If it is filled in incorrectly, the following error will be reported
   ERROR MESSAGE: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password) Don't fill in the wrong key here !!
   After completion, go to the next step , Select installation services
   3. Add service
   
   Installation error :

stderr: 
Traceback (most recent call last):
  File "/usr/lib/ambari-agent/lib/resource_management/core/providers/system.py", line 51, in _ensure_metadata
    _user_entity = pwd.getpwnam(user)
KeyError: 'getpwnam(): name not found: hbase'

.......
KeyError: 'getgrnam(): name not found: hadoop'

resolvent :
Because the expansion will not automatically create users , So you need to create it manually , The following users need to create ,
groupadd hbase
useradd -d /home/hbase -g hbase hbase
groupadd hdfs
useradd -d /home/hdfs -g hdfs hdfs
groupadd hadoop
useradd -d /home/hadoop -g hadoop hadoop
yarn-ats
groupadd yarn-ats
useradd -d /home/yarn-ats -g yarn-ats yarn-ats
ams
groupadd ams
useradd -d /home/ams -g ams ams
tez
groupadd tez
useradd -d /home/tez -g tez tez
groupadd logsearch
useradd -d /home/logsearch -g logsearch logsearch

5. After the expansion is completed , Some components need to start the instance manually