how to resolve Can't establish db connection.. Exiting.. when ranger service add on my machin

[#1]

Traceback (most recent call last):
  File "/var/lib/ambari-agent/cache/common-services/RANGER/0.4.0/package/scripts/ranger_admin.py", line 225, in <module>
    RangerAdmin().execute()
  File "/usr/lib/python2.6/site-packages/resource_management/libraries/script/script.py", line 329, in execute
    method(env)
  File "/var/lib/ambari-agent/cache/common-services/RANGER/0.4.0/package/scripts/ranger_admin.py", line 97, in start
    self.configure(env, upgrade_type=upgrade_type, setup_db=params.stack_supports_ranger_setup_db_on_start)
  File "/usr/lib/python2.6/site-packages/resource_management/libraries/script/script.py", line 119, in locking_configure
    original_configure(obj, *args, **kw)
  File "/var/lib/ambari-agent/cache/common-services/RANGER/0.4.0/package/scripts/ranger_admin.py", line 139, in configure
    setup_ranger_db()
  File "/var/lib/ambari-agent/cache/common-services/RANGER/0.4.0/package/scripts/setup_ranger_xml.py", line 258, in setup_ranger_db
    user=params.unix_user,
  File "/usr/lib/python2.6/site-packages/resource_management/core/base.py", line 166, in __init__
    self.env.run()
  File "/usr/lib/python2.6/site-packages/resource_management/core/environment.py", line 160, in run
    self.run_action(resource, action)
  File "/usr/lib/python2.6/site-packages/resource_management/core/environment.py", line 124, in run_action
    provider_action()
  File "/usr/lib/python2.6/site-packages/resource_management/core/providers/system.py", line 262, in action_run
    tries=self.resource.tries, try_sleep=self.resource.try_sleep)
  File "/usr/lib/python2.6/site-packages/resource_management/core/shell.py", line 72, in inner
    result = function(command, **kwargs)
  File "/usr/lib/python2.6/site-packages/resource_management/core/shell.py", line 102, in checked_call
    tries=tries, try_sleep=try_sleep, timeout_kill_strategy=timeout_kill_strategy)
  File "/usr/lib/python2.6/site-packages/resource_management/core/shell.py", line 150, in _call_wrapper
    result = _call(command, **kwargs_copy)
  File "/usr/lib/python2.6/site-packages/resource_management/core/shell.py", line 303, in _call
    raise ExecutionFailed(err_msg, code, out, err)
resource_management.core.exceptions.ExecutionFailed: Execution of 'ambari-python-wrap /usr/hdp/current/ranger-admin/dba_script.py -q' returned 1. 2020-02-12 12:05:38,812  [I] Running DBA setup script. QuiteMode:True
2020-02-12 12:05:38,812  [I] Using Java:/usr/jdk64/jdk1.8.0_112/bin/java
2020-02-12 12:05:38,812  [I] DB FLAVOR:MYSQL
2020-02-12 12:05:38,812  [I] DB Host:ip-172-31-27-99.ec2.internal
2020-02-12 12:05:38,813  [I] ---------- Verifying DB root password ---------- 
2020-02-12 12:05:38,813  [I] DBA root user password validated
2020-02-12 12:05:38,813  [I] ---------- Verifying Ranger Admin db user password ---------- 
2020-02-12 12:05:38,813  [I] admin user password validated
2020-02-12 12:05:38,813  [I] ---------- Creating Ranger Admin db user ---------- 
2020-02-12 12:05:38,813  [JISQL] /usr/jdk64/jdk1.8.0_112/bin/java  -cp /usr/hdp/2.6.1.0-129/ranger-admin/ews/lib/mysql-connector-java.jar:/usr/hdp/current/ranger-admin/jisql/lib/* org.apache.util.sql.Jisql -driver mysqlconj -cstring jdbc:mysql://ip-xxx-xx-xx-xx.ec2.internal/mysql -u ranger -p '********' -noheader -trim -c \; -query "SELECT version();"
SQLException : SQL state: 42000 com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Access denied for user 'ranger'@'ip-xxx-xx-xx-xx.ec2.internal' to database 'mysql' ErrorCode: 1044
2020-02-12 12:05:39,132  [E] Can't establish db connection.. Exiting..

[#2 · Accepted solution]

@AarifAkhter 

You need to create permissions within mysql for your ranger user.

An example of this is:

CREATE DATABASE ranger;
CREATE USER 'ranger'@'hdp.cloudera.com' IDENTIFIED BY 'ranger';
GRANT ALL PRIVILEGES ON *.* TO 'ranger'@'hdp.cloudera.com' WITH GRANT OPTION;
FLUSH PRIVILEGES;

where you replace in your hostname for ranger in place of hdp.cloudera.com above:  

ip-xxx-xx-xx-xx.ec2.internal

I would also recommend to install using FQDNs (Fully Qualified Domain Names).

Please accept this answer as the solution to close the topic.