Can not start cloudera-scm-server-db because of "The CM is using external DB" - postgresql

Question

I've updated jdk from 1.8_131 to 1.8_151 for CDH5. So i need to restart the cluster to make it take affect. In the begining i use cloudrea manager web page to restart, but it failed when zookeeper started which is the first step. Then I made a bad choice which is close cloudrea manager in terminal including kill -9 postgresql process. After that, i could't open the cloudrea manager web page.
I use following instructions to start the cluster.
service cloudera-scm-server-db start
service cloudera-scm-server start
service cloudera-scm-agent start
All of them are failed, because /var/log/cloudera-scm-server and /var/log/cloudera-scm-agent disappear.
So I creat these two files manually also include dg.log and cloudera-scm-agent.log
At this time, the server and agent could start. But server-db still can not. The next is some details.
Starting cloudera-scm-server-db (via systemctl): Job for
cloudera-scm-server-db.service failed because the control process
exited with error code. See "systemctl status
cloudera-scm-server-db.service" and "journalctl -xe" for details
journalctl -xe
The CM is using external DB. Failed to start embedded DB service, giving up
service --status-all
What i've done:
So, what should i do now? thank you thank you very much!!!

Answer 1

The above problem had been sovled.
If you open this /etc/cloudera-scm-server/db.properties file, which shown as below.
# cat /etc/cloudera-scm-server/db.properties
Auto-generated by scm_prepare_database.sh
#
Sat Oct 1 12:19:15 PDT 201
#
com.cloudera.cmf.db.type=postgresql
com.cloudera.cmf.db.host=localhost
com.cloudera.cmf.db.name=scm
com.cloudera.cmf.db.user=scm
com.cloudera.cmf.db.password=TXqEESuhj5
com.cloudera.cmf.db.setupType=EXTERNAL
EXTERNAL is the crux.
In my CDH service, I use embedded postgresql as my server database. But it's not recommended to use by cloudera offical. I'm a new man on Cloudera, so I made a mistake.
I wrongly use a command which only prepared for Cloudera Manager Server external database.
/usr/share/cmf/schema/scm_prepare_database.sh postgresql scm scm scm_password
The above command can config db.properties
As long as you run above command, com.cloudera.cmf.db.setupType will be set to EXTERNAL(For more details about this, you can find in Cloudera docs)
The most direct and effective way is to reset password of scm.
Then
update the password
set Type as EMBEDDED
make port 7432 listening(you can use netstat -nltp to check)
in db.properties.
#vim cat /etc/cloudera-scm-server/db.properties
Auto-generated by scm_prepare_database.sh
Sat Oct 1 12:19:15 PDT 201
com.cloudera.cmf.db.type=postgresql
com.cloudera.cmf.db.host=localhost:7432
com.cloudera.cmf.db.name=scm
com.cloudera.cmf.db.user=scm
com.cloudera.cmf.db.password=new_password
com.cloudera.cmf.db.setupType=EMBEDDED
Now close all cloudera-scm service and restart in order server-db,server,agent.
If /var/log was cleared wrongly.
You can creat these files such as /var/log/cloudera-scm-server and /var/log/cloudera-scm-agent manually.
It is noteworthy that you should creat these file by user cloudera-scm, otherwise the log can not be written, and you won't find what error happened from log file.