Oracle Enterprise Manager 13c – KILL SESSION for Application Administrators – Part 1

Basically to execute a ALTER SYSTEM KILL SESSION command you have to be a) a DBA or b) you need the ALTER SYSTEM privilege. Granting the ALTER SYSTEM privilege to a Non-DBA has big risks. This user is now able to change a lot of parameters like memory parameters, NLS settings etc.

In one of my projects, a small team of well known application administrators is having a read-only account in Enterprise Manager 12c to verify the performance, see the user sessions and many more of their subset of databases. And sometimes, they have to kill a hanging Oracle session. Until now they called the DBA: “Please do it for me”. Sure, we can build a small PL/SQL procedure on every database and give them the executions rights so they can kill a session in their terminal theirself. But this is not very user friendly.

Here is an approach to manage the small path between security and manageability. I am aware that this is – like we say in Switzerland – a “Kompromiss”. But in fact we have implemented this solution in a production environment two months ago without any negative impacts.

Note: All the steps which are show below in Enterprise Manager 13c can be executed in 12c too.

The Concept

  • we create a new database user in the target databases
  • we create a new role with ALTER SYSTEM privilege in the target databases
  • we enable auditing for ALTER SYSTEM commands in the target databases
  • we create a new Enterprise Manager role for the application administrators
  • we create a new named credential with the new user and grant it to the application administrators
  • we build an Enterprise Manager report which shows us the ALTER SYSTEM actions based on a metric extension

The New Database User

This user has to be created in every target database.

The New Database Role

This role has to be created in every target database.

Grant role to the user:

Enable Auditing for ALTER SYSTEM Commands

For ALTER SESSION and ALTER SYSTEM:

Verify the enabled audit settings:

Verify the audit parameterin the target database. If audit_trail is not set to EXTENDED, the SQL command which was executed is not recorded. How it works with Unified Auditing will be verified in a later blog post.

In the example below you can see the difference in the column SQL_TEXT.

Enterprise Manager Role

Setup – Security – Role – Create

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Set name and description – Next

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Next

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Activate the checkbox for the privilige Connect to any viewable target and scroll down

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Add database targets and set the Manage Targets Privilege Grants

  • For EM12c use: View
  • For EM13c use: Manage Database Sessions

Next

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Next

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Select the user to grant the role – Next

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Finish

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The role is now created and be granted to a user.

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Enterprise Manager Named Credential

The application adninistrators don’t have to know the password for the created user with the ALTER privileges. We create a named credential and give the admins the permission to use it.

Setup – Security – Named Credentials – Create

Set Credential Name, Authenticated Target Type, Credential Type and set Scope to Global. The Credential Properties are according to our new created user APPL_ADMIN.

Scroll down to set Access Control

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Add Grant

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Search for the user, in my case it is APPL_BERGER

Select

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Feel free to test ist against a target which contains the APPL_ADMIN user.

Save

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Test

Now we test the configuration. The role APPL_ADMIN was granted to my user APPL_BERGER. On the target database TVD12 user SCOTT has locked some data.

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On the target site we go to the Blocking Sessions page

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The Named Credential is already filled in.

Login

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Select the session – Kill Session

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Confirm the action to kill the selected session immediate – Yes

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Session has been killed.

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Verification

On the target database, an audit record was generated. Login as user SYS and execute this query. You can see the TIME, the USERNAME, the EM13c USERNAME in column CLIENT_ID and the SQL statement which was executed in background.

Summary – Part 1

As I said in the introduction, giving some other users than DBAs the ALTER SYSTEM privilege is risky. But when the DBAs and application adminstrators are working as a team, then this can be a possible solution to make their daily business easier.

In the next blog post I will show how you can create a Enterprise Manager report based on a Metric Extension to produce daily reports of the ALTER SYSTEM actions.