IBM QRadar SIEM V7.5 provides several types of resource restriction mechanisms to manage access control and data visibility. The three main types are:

Role-based restrictions: These restrictions limit what actions users can perform based on their assigned roles. Each role has specific permissions that dictate access to different functionalities and data within QRadar.

Tenant-based restrictions: This type of restriction is used in multi-tenant environments, where different tenants (organizational units) need to have isolated views and access to their data. Tenant-based restrictions ensure that users from one tenant cannot access data from another tenant.

Domain-based restrictions: Domains in QRadar are used to segment data logically. Domain-based restrictions control which data is visible to users based on the domains they have been granted access to.

These restriction types ensure that access control is granular and adheres to organizational security policies.

Reference IBM QRadar SIEM documentation outlines the use of role-based, tenant-based, and domain-based restrictions for managing access control and data visibility.

In IBM QRadar SIEM V7.5, the default value for the maximum number of active offenses is set to 2500. This limit is in place to manage system performance and ensure efficient processing of security incidents. Here's the detailed information:

Default Setting: The default setting for the maximum number of active offenses is 2500.

Impact: If this limit is reached, QRadar will not generate new offenses until some of the existing offenses are closed or archived.

Configuration: Administrators can adjust this setting based on their organizational needs, but the default value is 2500.

Reference This information is detailed in the QRadar SIEM configuration and tuning guides, which specify default settings and provide instructions for modifying the maximum number of active offenses if necessary.

To optimize event and flow payload searches for log data stored for up to a month, an administrator should configure the retention period for payload indexes. Here's the process:

Retention Period Configuration: Set the retention period for payload indexes to match the desired data storage duration (e.g., one month).

Improved Search Efficiency: By configuring the retention period appropriately, QRadar ensures that the indexed data is efficiently searchable, improving performance during searches.

Index Management: Regularly manage and clean up indexes to maintain optimal system performance and storage utilization.

Reference The IBM QRadar SIEM administration guides provide instructions on configuring retention periods for various types of indexes, including payload indexes, to optimize search performance.

QRadar event data is stored in the Ariel database on the Event Processor and any attached Data Nodes. The Event Processor is responsible for processing incoming events, performing correlation, and storing the event data. The attached Data Nodes provide additional storage capacity and can be used to extend the storage available to the Event Processor.

Reference IBM QRadar SIEM V7.5 Administration documentation.

When using the DSM (Device Support Module) Editor in IBM QRadar to map an event to an OID (Object Identifier), the Event ID field is mandatory. The Event ID uniquely identifies the event within QRadar and is essential for ensuring that the correct event data is associated with the appropriate OID. This mapping process allows QRadar to properly categorize and handle events based on their unique identifiers.

Reference QRadar SIEM V7.5 Administration Guide - Chapter on DSM Editor and Event Mapping