I was trying to login into Ambari, But it shows invalid user name and password combination.and i was trying admin for username and password also.it is not working. Could you please help me on this issue.
By default the ambari credentials are Username: admin and Password: admin. If it is changed somehow then you can reset the Ambari admin credentials directly from the DB:
1. Log on to ambari server host shell
2. Run 'psql -U ambari-server ambari'
3. Enter password 'bigdata'
4. In psql: (following will reset ambari user "admin" password to "admin"
update ambari.users set user_password='538916f8943ec225d97a9a86a2c6ec0818c1cd400e09e03b660fdaaec4af29ddbb6f2b1033b81b00' where user_name='admin'
5. Quit psql
6. Run 'ambari-server restart'
However if you are using HDP Sandbox then you might have to reset the admin credentials for the first time.